D Waves User Manual Waves_User_Manual

User Manual: Pdf D-Waves_User_Manual

Open the PDF directly: View PDF .
Page Count: 136

Download
Open PDF In Browser	View PDF

1D/2D/3D Modelling suite for integral water solutions

DR
AF

Delft3D Flexible Mesh Suite

D-Waves

User Manual

DR
AF
T

DR
AF

D-Waves

Simulation of short-crested waves with SWAN

User Manual

Released for:
Delft3D FM Suite 2018
D-HYDRO Suite 2018

Version: 1.1
SVN Revision: 54363
April 18, 2018

DR
AF

D-Waves, User Manual

Published and printed by:
Deltares
Boussinesqweg 1
2629 HV Delft
P.O. 177
2600 MH Delft
The Netherlands

For sales contact:
telephone: +31 88 335 81 88
fax:
+31 88 335 81 11
e-mail:
software@deltares.nl
www:
https://www.deltares.nl/software

telephone:
fax:
e-mail:
www:

+31 88 335 82 73
+31 88 335 85 82
info@deltares.nl
https://www.deltares.nl

For support contact:
telephone: +31 88 335 81 00
fax:
+31 88 335 81 11
e-mail:
software.support@deltares.nl
www:
https://www.deltares.nl/software

Copyright © 2018 Deltares
All rights reserved. No part of this document may be reproduced in any form by print, photo
print, photo copy, microfilm or any other means, without written permission from the publisher:
Deltares.

Contents

Contents
List of Figures

vii

List of Tables

1 A guide to this manual
1.1 Introduction . . . . . . . . . . . . . . . .
1.2 Overview . . . . . . . . . . . . . . . . .
1.3 Manual version and revisions . . . . . . .
1.4 Typographical conventions . . . . . . . .
1.5 Changes with respect to previous versions

.
.
.
.
.

1
1
1
2
2
2

2 Introduction to D-Waves
2.1 SWAN wave model . . . . . . . . . . . . . . . . . .
2.1.1 Introduction . . . . . . . . . . . . . . . . . .
2.1.2 Conceptual design of SWAN: an introduction .
2.1.3 Coupling of SWAN with D-Flow Flexible Mesh
2.2 Areas of application . . . . . . . . . . . . . . . . . .
2.3 Standard features . . . . . . . . . . . . . . . . . . .
2.4 Special features . . . . . . . . . . . . . . . . . . . .
2.5 Utilities . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.
.
.
.

3
3
3
3
3
4
4
4
4

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

5
5
5
6
7
7
8
8
8
8
8
9
11
11
11
11
13
13

.
.
.
.
.
.
.
.
.

13
13
14
14
14
15
15
16
16

.
.
.
.
.

DR
AF

.
.
.
.
.

3 Getting started
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Overview of D-Waves plug-in . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1 Project tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.2 Central (map) window . . . . . . . . . . . . . . . . . . . . . . .
3.2.3 Map tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.4 Message window . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.5 Time navigator . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Setting up a D-Waves model (basic steps) . . . . . . . . . . . . . . . . .
3.3.1 Add a D-Waves model . . . . . . . . . . . . . . . . . . . . . . .
3.3.2 Set up a D-Waves model . . . . . . . . . . . . . . . . . . . . . .
3.3.3 Validate D-Waves model . . . . . . . . . . . . . . . . . . . . . .
3.3.4 File tree (to be implemented) . . . . . . . . . . . . . . . . . . . .
3.3.5 Run D-Waves model . . . . . . . . . . . . . . . . . . . . . . . .
3.3.6 Inspect model output . . . . . . . . . . . . . . . . . . . . . . . .
3.3.7 Import/export or delete a D-Waves model . . . . . . . . . . . . . .
3.3.8 Save project . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.9 Exit Delta Shell . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Important differences and new features compared to the former GUI (Delft3DWaves) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.1 Project vs model . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.2 Load/save vs import/export . . . . . . . . . . . . . . . . . . . . .
3.4.3 Working from the map . . . . . . . . . . . . . . . . . . . . . . .
3.4.4 Coordinate conversion . . . . . . . . . . . . . . . . . . . . . . .
3.4.5 Model area . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.6 Ribbons (hot keys) . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.7 Context menus (RMB) . . . . . . . . . . . . . . . . . . . . . . .
3.4.8 Scripting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 Graphical User Interface
17
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2 MDW file, attribute files and file formats . . . . . . . . . . . . . . . . . . . . 17

Deltares

iii

D-Waves, User Manual

Filenames and coventions . . . . . . . . . . . . . . . . . . . . . . .
Setting up a D-Waves model . . . . . . . . . . . . . . . . . . . . . .
4.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.2 Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.2.1 Obstacles . . . . . . . . . . . . . . . . . . . . . .
4.4.2.2 Observation Points . . . . . . . . . . . . . . . . . .
4.4.2.3 Observation Curves . . . . . . . . . . . . . . . . .
4.4.3 Hydrodynamics from flow - currently default tab . . . . . . . . .
4.4.4 Spectral resolution (deafult) - currently default tab . . . . . . . .
4.4.5 Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.5.1 Import and export grids and bathymetries . . . . . . .
4.4.5.2 Create and/or edit grids in RGFGRID . . . . . . . . .
4.4.5.3 Create and/or edit bathymetries using the spatial editor
4.4.5.4 Nest domains . . . . . . . . . . . . . . . . . . . .
4.4.5.5 Spectral resolution and wind (per domain) . . . . . .
4.4.6 Time Frame, Hydrodynamics and Wind . . . . . . . . . . . . .
4.4.7 Boundary Conditions . . . . . . . . . . . . . . . . . . . . . .
4.4.8 Physical parameters . . . . . . . . . . . . . . . . . . . . . .
4.4.8.1 Constants . . . . . . . . . . . . . . . . . . . . . .
4.4.9 Physical processes . . . . . . . . . . . . . . . . . . . . . . .
4.4.10 Numerical parameters . . . . . . . . . . . . . . . . . . . . .
4.4.11 Output parameters . . . . . . . . . . . . . . . . . . . . . . .
4.4.12 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DR
AF

4.3
4.4

5 Conceptual description
5.1 Introduction . . . . . . . . . . . . . . . . . . .
5.2 General background . . . . . . . . . . . . . .
5.2.1 Units and co-ordinate systems . . . . .
5.2.2 Choice of grids and boundary conditions
5.2.3 Output grids . . . . . . . . . . . . . .
5.3 Physical background of SWAN . . . . . . . . .
5.3.1 Action balance equation . . . . . . . .
5.3.2 Propagation through obstacles . . . . .
5.3.3 Wave-induced set-up . . . . . . . . . .
5.3.4 Diffraction . . . . . . . . . . . . . . .
5.4 Full expressions for source terms . . . . . . . .
5.4.1 Input by wind . . . . . . . . . . . . . .
5.4.2 Dissipation of wave energy . . . . . . .
5.4.3 Nonlinear wave-wave interactions . . . .
5.5 Numerical implementation . . . . . . . . . . .
5.5.1 Propagation . . . . . . . . . . . . . .

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

18
19
19
21
22
24
24
25
25
27
27
28
28
28
30
30
34
39
39
40
44
45
48

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

49
49
49
49
50
52
52
52
56
57
57
57
57
58
60
63
64

References

A Files of Delft3D-WAVE
A.1 MDW-file . . . . . . . . . . . . . . . . . . . . .
A.1.1 General description . . . . . . . . . . . .
A.1.2 Offline calculation . . . . . . . . . . . . .
A.2 Attribute files of Delft3D-WAVE . . . . . . . . . .
A.2.1 Introduction . . . . . . . . . . . . . . . .
A.2.2 Orthogonal curvilinear grid . . . . . . . .
A.2.3 Time-series for wave boundary conditions
A.2.4 Obstacle file . . . . . . . . . . . . . . .
A.2.5 Segment file . . . . . . . . . . . . . . .

.
.
.
.
.
.
.
.
.

73
73
73
77
77
77
77
79
79
81

Deltares

Contents

Depth file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Space-varying bottom friction (not yet implemented for Delft3D-WAVE) 83
Wave boundary conditions . . . . . . . . . . . . . . . . . . . . . . 84
A.2.8.1 Time-varying and uniform wave conditions in
file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
A.2.8.2 Time-varying and space-varying wave boundary conditions
using BCW files . . . . . . . . . . . . . . . . . . . . . . 85
A.2.8.3 Space-varying wave boudnary conditions using for UNIBEST
coupling (-file) . . . . . . . . . . . . . . . . . 92
A.2.8.4 Time- and space-varying wave boundary conditions: TPAR
file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
A.2.9 Spectral input and output files . . . . . . . . . . . . . . . . . . . . . 93
A.2.10 Space-varying wind field . . . . . . . . . . . . . . . . . . . . . . . 98
A.2.10.1 Space-varying wind on the computational (SWAN) grid . . . 100
A.2.10.2 Space-varying wind on an equistant grid . . . . . . . . . . 104
A.2.10.3 Space-varying wind on a curvilinear grid . . . . . . . . . . 108
A.2.10.4 Space-varying wind on a Spiderweb grid . . . . . . . . . . 111

DR
AF

B Definition of SWAN wave variables

A.2.6
A.2.7
A.2.8

C Example of MDW-file Siu-Lam

Deltares

117
121

DR
AF

D-Waves, User Manual

Deltares

List of Figures

DR
AF

3.9
3.10
3.11
3.12
3.13
3.14
3.15
3.16
3.17
3.18

Start-up lay-out Delta Shell framework . . . . . . . . . . . . . . . . . . .
Project tree of D-Waves plugin . . . . . . . . . . . . . . . . . . . . . . .
Central map with contents of the D-Waves plug-in . . . . . . . . . . . . . .
Map tree controlling map contents . . . . . . . . . . . . . . . . . . . . .
Log of messages, warnings and errors in message window . . . . . . . . .
Time navigator in Delta Shell . . . . . . . . . . . . . . . . . . . . . . . .
Adding a new model from the ribbon . . . . . . . . . . . . . . . . . . . .
Adding a new model using the Right Mouse Button on "project1" in the project
tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Select "Wave model" . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Validate model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Validation report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Run model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output of wave model in project tree . . . . . . . . . . . . . . . . . . . .
Import wave model from project tree . . . . . . . . . . . . . . . . . . . .
Import wave model from file ribbon . . . . . . . . . . . . . . . . . . . . .
Set map coordinate system using RMB . . . . . . . . . . . . . . . . . . .
Select a coordinate system using the quick search bar . . . . . . . . . . .
Perform operations using the hot keys . . . . . . . . . . . . . . . . . . . .

3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8

4.1
4.2
4.3

4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
4.15
4.16
4.17
4.18
4.19

4.20
4.21
4.22
4.23
4.24
4.25
4.26
4.27
4.30
4.28
4.29

Deltares

Overview of the general tab . . . . . . . . . . . . . . . . . . . . . . . . .
Set the model coordinate system . . . . . . . . . . . . . . . . . . . . . .
Nautical convention (left panel) and Cartesian convention (right panel) for direction of winds and (incident) waves . . . . . . . . . . . . . . . . . . . .
Add Area features using the Region ribbon . . . . . . . . . . . . . . . . .
Area features added to map . . . . . . . . . . . . . . . . . . . . . . . . .
Edit Area features using the Edit section of the Map ribbon . . . . . . . . .
Attribute table with properties of obstacles . . . . . . . . . . . . . . . . .
Select which quantities should be used from FLOW computation . . . . . .
Import a RGFGRID file from the project tree . . . . . . . . . . . . . . . . .
Visualize the D-Waves grid on the central map . . . . . . . . . . . . . . .
Create and/or edit the grid using RGFGRID . . . . . . . . . . . . . . . .
Create and/or edit the grid using the spatial editor . . . . . . . . . . . . . .
Create or edit the grid using RGFGRID . . . . . . . . . . . . . . . . . . .
Create or edit the grid using RGFGRID . . . . . . . . . . . . . . . . . . .
Create or edit the grid using RGFGRID . . . . . . . . . . . . . . . . . . .
Specify spectral resolution and wind per domain . . . . . . . . . . . . . .
Adding time points using the table . . . . . . . . . . . . . . . . . . . . . .
Pasting time points from another series or program, for example Excel . . .
Synchronizing the time points with the time points specified for the boundary
conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specification of constant hydrodynamics . . . . . . . . . . . . . . . . . .
Specification of hydrodynamics per time point . . . . . . . . . . . . . . . .
Specification of constant wind . . . . . . . . . . . . . . . . . . . . . . . .
Specification of wind per time point . . . . . . . . . . . . . . . . . . . . .
Specification of wind (field) from file . . . . . . . . . . . . . . . . . . . . .
Add a spiderweb wind field . . . . . . . . . . . . . . . . . . . . . . . . .
Select Add Boundary from Region ribbon . . . . . . . . . . . . . . . . . .
Draw the boundary support points on the map . . . . . . . . . . . . . . .
Overview of the boundary conditions editor . . . . . . . . . . . . . . . . .
Boundaries are added to the project tree under Boundary Conditions . . . .
Edit the spatial definition in the attribute table . . . . . . . . . . . . . . . .

.
.
.
.
.
.
.

5
6
7
7
8
8
8

.
.
.
.
.
.
.
.
.
.
.

9
9
10
10
11
12
12
13
14
15
15

. 19
. 20
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

21
22
22
22
23
25
27
27
28
29
29
29
30
30
31
31

.
.
.
.
.
.
.
.
.
.
.
.

31
32
32
33
33
33
33
34
35
35
36
36

vii

D-Waves, User Manual

4.31 Activate a support point in the boundary condition editor and inspect the location of the selected support point in the Geomtery view . . . . . . . . . . .
4.32 Select spectrum shape and set corresponding properties . . . . . . . . . .
4.33 Specify parameterized wave boundary conditions and inspect in graph . . .
4.34 Overview of physical Constants . . . . . . . . . . . . . . . . . . . . . . .
4.35 Overview of physical Processes . . . . . . . . . . . . . . . . . . . . . . .
4.36 Overview of Numerical parameters . . . . . . . . . . . . . . . . . . . . .
4.37 Overview of Output parameters . . . . . . . . . . . . . . . . . . . . . . .

5.2
5.3
A.1
A.2
A.3

Definition wind components for space varying wind . . . . . . . . . .
Definition sketch of wind direction according to Nautical convention . .
Illustration of the data to grid conversion for meteo input on a separate
linear grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wind definition according to Nautical convention . . . . . . . . . . .
Spiderweb grid definition . . . . . . . . . . . . . . . . . . . . . . .

. . .
. . .
curvi. . .
. . .
. . .

. 103
. 104
. 110
. 112
. 113

DR
AF

A.4
A.5

36
37
38
39
40
44
46

Nautical convention (left panel) and Cartesian convention (right panel) for direction of winds and (incident) waves . . . . . . . . . . . . . . . . . . . . . 49
Definition of grids (input, computational and output grids) in Delft3D-WAVE . . 50
Disturbed regions in the computational grid . . . . . . . . . . . . . . . . . . 51

5.1

.
.
.
.
.
.
.

viii

Deltares

List of Tables

DR
AF

List of Tables

Deltares

DR
AF

D-Waves, User Manual

Deltares

1 A guide to this manual
1.1

Introduction
This User Manual concerns the module D-Waves.
This module is part of several Modelling suites, released by Deltares as Deltares Systems
or Dutch Delta Systems. These modelling suites are based on the Delta Shell framework.
The framework enables to develop a range of modeling suites, each distinguished by the
components and — most significantly — the (numerical) modules, which are plugged in. The
modules which are compliant with the Delta Shell framework are released as D-Name of the
module, for example: D-Flow Flexible Mesh, D-Waves, D-Water Quality, D-Real Time Control,
D-Rainfall Run-off.

1.2

DR
AF

Therefore, this user manual is shipped with several modelling suites. In the start-up screen
links are provided to all relevant User Manuals (and Technical Reference Manuals) for that
modelling suite. It will be clear that the Delta Shell User Manual is shipped with all these
modelling suites. Other user manuals can be referenced. In that case, you need to open the
specific user manual from the start-up screen in the central window. Some texts are shared
in different user manuals, in order to improve the readability.
Overview

In this manual advice is given on how to get started with the SWAN wave model. Furthermore,
the manual gives a description on how to use the SWAN model within D-Waves.
Generally, the following items with respect to the use of the D-Waves module will be described
in this manual.
Chapter 2: Introduction to D-Waves, provides specifications of D-Waves such as required
computer configuration, how to install the software, as well as its main features.
Chapter 3: Getting started, introduces the D-Waves Graphical User Interface (GUI), used to
define the input required for a wave simulation.
Chapter 4: Graphical User Interface, provides practical information on the selection of all
parameters and the tuning of the model.
Chapter 5: Conceptual description, discusses the unit and co-ordinate system, the various
grids, grid-numbering etc. In addition, a brief description is given on the physics and numerics
that have been implemented in D-Waves.
References, provides a list of publications and related material on the D-Waves module.
Appendix A: Files of Delft3D-WAVE, gives a description of all the attribute files that can be
used in the D-Waves input. This information is required for generating certain attribute files
either manually or by means of other utility programs. For other attribute files this description
is just for your information.
Appendix B: Definition of SWAN wave variables, the definition of the integral wave parameters is given.
Appendix C: Example of MDW-file Siu-Lam, an example of a Master Definition file for the
Wave <∗.mdw> input file for the WAVE module is given.

Deltares

1 of 124

D-Waves, User Manual

1.3

Manual version and revisions
This manual applies to:

the D-HYDRO Suite, version 2016
the Delft3D Flexible Mesh Suite, version 2016
1.4

Typographical conventions
Throughout this manual, the following conventions help you to distinguish between different
elements of text.
Description

Module
Project

Title of a window or a sub-window are in given in bold.
Sub-windows are displayed in the Module window and
cannot be moved.
Windows can be moved independently from the Module window, such as the Visualisation Area window.

Save

Item from a menu, title of a push button or the name of
a user interface input field.
Upon selecting this item (click or in some cases double
click with the left mouse button on it) a related action
will be executed; in most cases it will result in displaying
some other (sub-)window.
In case of an input field you are supposed to enter input
data of the required format and in the required domain.

DR
AF

Example

<\tutorial\wave\swan-curvi>

Directory names, filenames, and path names are expressed between angle brackets, <>. For the Linux
and UNIX environment a forward slash (/) is used instead of the backward slash (\) for PCs.

“27 08 1999”

Data to be typed by you into the input fields are displayed between double quotes.
Selections of menu items, option boxes etc. are described as such: for instance ‘select Save and go to
the next window’.

delft3d-menu

Commands to be typed by you are given in the font
Courier New, 10 points.
In this User manual, user actions are indicated with this
arrow.

[m s−1 ] [−]

1.5

Units are given between square brackets when used
next to the formulae. Leaving them out might result in
misinterpretation.

Changes with respect to previous versions
This is the first edition which is published.

2 of 124

Deltares

2 Introduction to D-Waves
2.1
2.1.1

SWAN wave model
Introduction
To simulate the evolution of random, short-crested wind-generated waves in estuaries, barrier
islands with tidal inlets, tidal flats, lakes, channels etc., the D-Waves module can be used. DWaves is based on the third-generation SWAN model - SWAN is an acronym for Simulating
WAves Nearshore (see e.g. Holthuijsen et al. (1993); Booij et al. (1999); Ris et al. (1999)).

http://www.swan.tudelft.nl/

The SWAN model was developed at Delft University of Technology (The Netherlands). It is
specified as the new standard for nearshore wave modelling and coastal protection studies.
The SWAN model has been released under public domain. For more information about SWAN
reference is made to the SWAN home page:

2.1.2

DR
AF

D-Waves computes wave propagation, wave generation by wind, non-linear wave-wave interactions and dissipation, for a given bottom topography, wind field, water level and current field
in waters of deep, intermediate and finite depth.
Conceptual design of SWAN: an introduction

The SWAN model is based on the discrete spectral action balance equation and is fully spectral (in all directions and frequencies). The latter implies that short-crested random wave fields
propagating simultaneously from widely different directions can be accommodated (e.g. a
wind sea with super-imposed swell). SWAN computes the evolution of random, short-crested
waves in coastal regions with deep, intermediate and shallow water and ambient currents. The
SWAN model accounts for (refractive) propagation due to current and depth and represents
the processes of wave generation by wind, dissipation due to whitecapping, bottom friction
and depth-induced wave breaking and non-linear wave-wave interactions (both quadruplets
and triads) explicitly with state-of-the-art formulations. Wave blocking by currents is also explicitly represented in the model.
To avoid excessive computing time and to achieve a robust model in practical applications,
fully implicit propagation schemes have been applied. The SWAN model has successfully
been validated and verified in several laboratory and (complex) field cases (see Ris et al.
(1999); WL | Delft Hydraulics (1999, 2000)).
2.1.3

Coupling of SWAN with D-Flow Flexible Mesh

This is discussed in the D-Flow Flexible Mesh User Manual.

Deltares

3 of 124

D-Waves, User Manual

2.2

Areas of application
The D-Waves model can be used for coastal development and management related projects
and for harbour and offshore installation design. It can also be used as a wave hindcast
model. Typical areas for the application of the SWAN model may vary of up to more than 50
km × 50 km. Generally, the model can be applied in the following areas:

2.3

estuaries
tidal inlets
lakes
barrier islands with tidal flats
channels
coastal regions

Standard features
The SWAN model accounts for the following physics:

wave refraction over a bottom of variable depth and/or a spatially varying ambient current
depth and current-induced shoaling
wave generation by wind
dissipation by whitecapping
dissipation by depth-induced breaking
dissipation due to bottom friction (three different formulations)
nonlinear wave-wave interactions (both quadruplets and triads)
wave blocking by flow
transmission through, blockage by or reflection against obstacles
diffraction

DR
AF

Note that diffraction and reflections are now available in the present SWAN version under
D-Waves.
2.4

Special features

A special feature is the dynamic interaction with D-Flow Flexible Mesh (i.e. two way wavecurrent interaction). By this the effect of waves on current (via forcing, enhanced turbulence
and enhanced bed shear stress) and the effect of flow on waves (via set-up, current refraction
and enhanced bottom friction) are accounted for.
2.5

Utilities

In using D-Waves, the following utilities are important:
module

description

RGFGRID
Delft3D-QUICKPLOT

for generating grids.
for visualising simulation results.

For details on using these utility programs you are referred to the respective User Manuals.

4 of 124

Deltares

3 Getting started
3.1

Introduction
The D-Waves plugin is part of the Delta Shell framework. For an introduction to the general
look-and-feel and functionalities of the DeltaShell framework you are referred to the Delta Shell
framework manual. This Chapter gives an overview of the basic features of the D-Waves
plugin and will guide you through the main steps to set up a D-Waves model. For a more
detailed description of the GUI features you are referred to 4. For technical documentation
you are referred to the D-Waves manual.
Overview of D-Waves plug-in

Delta Shell is only available for Windows operating systems. You can either install the msiversion or copy the zip-version. For the msi-version first follow the steps in the installatio
guide. Consequently, open Delta Shell by double-clicking the Delta Shell icon in programs
or the short-cut on your desktop. For the zip-version you don’t have to install anything. First
unpack the zip, consequently go to bin and double-click DeltaShell.Gui.exe to open Delta
Shell.

DR
AF

3.2

When you open Delta Shell for the first time the lay-out will look like Figure 3.1. The basic
lay-out consists of the following items:

project tree - upper left
map tree and data window - lower left
central (map) window - upper centre
message window and time navigator - lower centre
region and chart window - upper right
properties and undo/redo window - lower right

Figure 3.1: Start-up lay-out Delta Shell framework

All the windows can be customized/hidden according to your own preferences. These settings will be automatically saved for the next time you open Delta Shell. The most important
windows for the D-Waves plugin are the project tree, central (map) window, map tree, the

Deltares

5 of 124

D-Waves, User Manual

message window and time navigator. The contents of these windows are briefly discussed in
the subsections below.
Project tree
After adding or importing a Delft3D-WAVE model (see section . . . ), the project tree will be
extended with wave model specific features (see Figure 3.2). The project tree provides you
with the basic steps to set up a Delft3D-WAVE model.
The project tree consists of the following features:

Area
Domain (outer)
Hydrodynamics
Spectral resolution
Time Frame
Boundary conditions
Physical parameters

general model information such as description, model coordinate
system, simulation mode, directional convention, etc.
geographical (GIS based) features, such as observation points and
curves and obstacles
model grid and bathymetry (multiple in case of nested model)
variables to be copied from FLOW model in case of a coupled model
default spectral settings
time points and (time-varying) hydrodynamic and wind conditions
wave boundary conditions and spectrum specification
physical settings for processes such as setup, wave breaking, refraction, triads, etc.
numerical simulation settings
output specification
output after running the simulation

General

DR
AF

3.2.1

Numerical parameters
Output parameters
Output

Upon clicking the items in the project tree the corresponding tab (in case of GIS/map-independent
model settings), attribute table (in case of GIS/map-dependent model settings) or editor view
(in case of advanced editing options) will open. Using the right mouse button (RMB) gives
options such as importing/exporting model data.

Figure 3.2: Project tree of D-Waves plugin

6 of 124

Deltares

Getting started

3.2.2

Central (map) window

DR
AF

The central window shows the contents of the main editor you are working with. In most cases
this will be the central map with tabulated input fields (see Figure 3.3). The map is used to edit
GIS dependent model data, the tabulated input fields to edit overall model settings. Moreover,
the contents of the central window can also be a specific editor such as the time point editor
or the boundary condition editor. Each of these editors will open as a separate view.

Figure 3.3: Central map with contents of the D-Waves plug-in

3.2.3

Map tree

The map tree allows the user to control the visibility of the contents of the central map using
checkboxes. Furthermore, the user can add (wms) layers, such as satellite imagery (see
Figure 3.4).
Note: : Please note that the map usually has a different coordinate system than the model. In
rendering the model attributes they are transformed to the map coordinate system (for visual
inspection on the map), but the model will be saved in the model coordinate system.

Figure 3.4: Map tree controlling map contents

Deltares

7 of 124

D-Waves, User Manual

3.2.4

Message window
The message window (Figure 3.5) provides a log of information on the recent activities in
Delta Shell. It also provides warning and error messages.

Figure 3.5: Log of messages, warnings and errors in message window

3.2.5

Time navigator

DR
AF

The time navigator (Figure 3.6) can be used to step through time dependent model output
and other time dependent GIS features on the map.

Figure 3.6: Time navigator in Delta Shell

3.3

Setting up a D-Waves model (basic steps)

This section shows the basic steps to set up a D-Waves model. For a more detailed description of the steps and GUI features you are referred to chapter 4.
3.3.1

Add a D-Waves model

After starting up Delta Shell, the start page will open with a default project (i.e. ”project1”, see
Figure 3.1). To add a D-Waves model to the project you have the following options:

click ”New Model” in the ”Home”-ribbon (Figure 3.7)
use the Right Mouse Button (RMB) on ”project1” in the project tree, go to ”Add” and ”New
Model’ (Figure 3.8)

From the list of available models (which can vary depending on your installation), select ”Wave
model” (Figure 3.9).

Figure 3.7: Adding a new model from the ribbon

3.3.2

Set up a D-Waves model
To set up the wave model follow the steps in the project tree. For a more detailed description,
see chapter 4.

8 of 124

Deltares

DR
AF

Getting started

Figure 3.8: Adding a new model using the Right Mouse Button on "project1" in the project
tree

Figure 3.9: Select "Wave model"

3.3.3

Validate D-Waves model
You can check whether your model setup is valid by using the RMB in the project tree and

Deltares

9 of 124

D-Waves, User Manual

DR
AF

select "Validate" (Figure 3.10). This will produce a validation report (Figure 3.11). Red exclamation marks indicate the parts of the model that are still invalid. By clicking the hyperlink you
will be automatically redirected to the invalid step in the model setup, so that you can correct
it.

Figure 3.10: Validate model

Figure 3.11: Validation report

10 of 124

Deltares

Getting started

3.3.4

File tree (to be implemented)
To check the file paths and names of the attribute files which are linked to your model, you
can select "File tree" using the RMB on your model in the project tree.

3.3.5

Run D-Waves model
If you are satisfied with the model setup, you can run it from Delta Shell using the RMB on
model and select ”Run model” (Figure 3.12).

DR
AF

Note: it is also possible to run Delft3D-WAVE outside Delta Shell using the command line.

Figure 3.12: Run model

3.3.6

Inspect model output

The simulation will start and the output will be stored in the output folder in the project tree
(Figure 3.13). Delta Shell provides some basic tools to inspect the model output. For more
extensive and advanced options you are referred to Quickplot and Muppet.
3.3.7

Import/export or delete a D-Waves model
To import an existing Delft3D-WAVE model either use the RMB on the project level in the
project tree (Figure 3.14) or go to the ”File”-ribbon and press the "Import" (Figure 3.15). Likewise you can export a model or delete a model.
For the steps in the project tree that are linked to attribute files (observation points, grid,
bathymetry, etc.) you can use the RMB to import or export these attribute files.

Deltares

11 of 124

DR
AF

D-Waves, User Manual

Figure 3.13: Output of wave model in project tree

Figure 3.14: Import wave model from project tree

12 of 124

Deltares

DR
AF

Getting started

Figure 3.15: Import wave model from file ribbon

3.3.8

Save project

To save the project (and, hence, the model) use the disk-icon on the Quick Access Toolbar
or the "File"-ribbon (Figure 3.15). If you would like to save the project under a different name
use "Save as".
3.3.9

Exit Delta Shell

If you are finished you can exit Delta Shell using the red cross or pressing the "Exit" button in
the "File"-ribbon (Figure 3.15).
3.4

Important differences and new features compared to the former GUI (Delft3D-Waves)
The differences between the former D-Waves GUI and the D-Waves plugin in Delta Shell in
lay-out and functionality are numerous. Here, we address only the most important differences
in the workflow.

3.4.1

Project vs model

The entity "project" is new in the Delta Shell GUI. In the hierarchy the entity "project" is on a
higher level than the entity "model". A project can contain multiple models, which can either
run standalone or coupled. The user can run all models in the project at once (on project
level) or each model separately (on model level). When the user saves the project, the project
settings will be saved in a *.dsproj configuration file and the project data in a *.dsproj_data
folder. The *.dsproj_data folder contains folders with all input and output files for the models
within the project. There is no model intelligence in the *.dsproj configuration file, meaning
that the models can also be run outside the GUI from the *.dsproj_data folder.

Deltares

13 of 124

D-Waves, User Manual

3.4.2

Load/save vs import/export
The user can load an existing Delta Shell project, make changes in the GUI and, consequently,
save all the project data. Loading and saving means working on the original project data, i.e.
the changes made by the user overwrite the original project data. Alternatively, use "save as"
to keep the original project data and save the changes project data at another location (or with
another name).
Import/export functionality can be used to copy data from another location into the project
(import) or, vice versa, to copy data from the project to another location (export). Import/export
is literally copying, e.g.:

import: changes on the imported data will only affect the data in the project and not the
source data (upon saving the project)

export: the model data is copied to another location ”as is”, changes made afterwards will

3.4.3

Working from the map

only affect the data in the project not the exported data (upon saving the project)

3.4.4

DR
AF

One of the most important differences with the former GUI is the central map. The central
map is comparable with the former ”visualization area”, but with much more functionality and
flexibility. The map helps you to see what you’re doing and inspect the model at all times. You
can use the ”Region” and ”Map” ribbons to add/edit model features in the map.
Coordinate conversion

With the map as a central feature, functionality to convert model and map coordinates is an
indispensable feature. In the ”General” tab you can set the model coordinate system. In the
map tree you can set the map coordinate system using the RMB (Figure 3.16). The coordinate
systems are subdivided in geographic and projected systems. Use the quick search bar to
find the coordinate system you need either by name or EPSG code (Figure 3.17).

Figure 3.16: Set map coordinate system using RMB

14 of 124

Deltares

Getting started

3.4.5

DR
AF

Figure 3.17: Select a coordinate system using the quick search bar

Model area

The model area contains geographical (GIS based) features, such as observation points &
curves and obstacles. In contrast to the former GUI, these features can even exist without a
grid or outside the grid and they are not based on grid coordinates, implying that their location
remains the same when the grid is changed (for example by (de-)refining).
Finally, for the computations, the SWAN computational core interpolates the features to the
grid. In the future we would like to show to which grid points the features are snapped before
running the computation. However, this requires some updates in the SWAN computational
core.
3.4.6

Ribbons (hot keys)

Delta Shell makes use of ribbons, just like Microsoft Office. You can use these ribbons for
most of the operations. With the ribbons comes hot key functionality, providing shortcuts to
perform operations. If you press ”ALT”, you will see the letters and numbers to access the
ribbons and the ribbon contents (i.e. operations). For example, ”ALT” + ”H” will lead you to the
”Home”-ribbon (Figure 3.18).
Note: : Implementation of the hot key functionality is still work in progress.

Figure 3.18: Perform operations using the hot keys

Deltares

15 of 124

D-Waves, User Manual

3.4.7

Context menus (RMB)
Context menus are the menus that pop up using the right mouse button (RMB). These context
menus provide you with some handy functionality and shortcuts specific for the selected item.
The functionality is available in all Delta Shell windows and context dependent. You can best
try it yourself to explore the possibilities.
Scripting

Delta Shell has a direct link with scripting in Iron Python (NB: this is not the same as C-Python).
This means that you can get and set data, views and model files by means of scripting instead
of having to do all manually. Scripting can be a very powerful tool to automate certain steps of
your model setup or to add new functionality to the GUI. You can add a new script by adding
a new item, either in the ”Home”-ribbon or through the RMB.

DR
AF

3.4.8

16 of 124

Deltares

4 Graphical User Interface
4.1

Introduction
In order to set up a wave model you must prepare an input file. The input file stores all the
parameters used for a wave computation with D-Waves. The parameters can be divided into
three categories:
1 parameters that define the physical processes being modelled,
2 parameters that define the numerical techniques used to solve the equations that describe
the physical processes,
3 parameters that control the wave computation and store its results.

Within the range of realistic values, it is likely that the solution is sensitive to the selected
parameter values, so a concise description of all parameters is required. The input data
(defined by you) is stored into an input file which is called the Master Definition file for Wave
or MDW-file.

4.2

DR
AF

In section 4.2 we discuss some general aspects of the MDW-file and its attribute files. section 4.3 discusses shortly the filenames and their extension. In section 4.4 we explain how
to work with the WAVE Graphical User Interface in Delta Shell, including is input parameters,
their restrictions and their valid ranges or domain.
MDW file, attribute files and file formats

The Master Definition Wave file (MDW-file) is the input file for the wave program. It contains all
the necessary data that is required to define a wave model and run a wave computation. Some
of the parameter values are given directly in the MDW-file. Other parameters are defined in
attribute files, referred to by specific statements in de MDW-file. The latter is particularly the
case when parameters contain a large number of data (e.g. spatially varying data such as
a variable wind or friction field). The user-defined attribute files are listed and described in
Appendix A.
The D-Waves plugin in Delta Shell is a tool that is used to assign values to all the necessary
parameters or to import the names of the attribute files into the MDW-file. When the data
you entered is saved, an mdw-file, containing all the specified data, is created in the selected
working directory.
Although you are not supposed to work directly on the mdw-file (with a text editor) it is useful
to have some idea of what its structure is, as it reflects the idea of the designer on how to
handle large amounts of input data. For an example of an MDW-file, see Appendix C.
The basic characteristics of an MDW-file are:
- It is an ASCII file.
- The file is divided in datagroups.
- It is keyword based.
The mdw-file is an intermediate file between the D-Waves plugin and the D-Waves module
(e.g. the computational core). As it is an ASCII-file, it can be transported to an arbitrary
hardware platform. Consequently, the wave module and the WAVE Graphical User Interface
program do not necessarily have to reside in the same hardware platform.

Deltares

17 of 124

D-Waves, User Manual

As explained before, input parameters that contain a lot of data are defined in attribute files.
How to set up these attribute files is explained elsewhere in this chapter. The mdw-file only
contains permanent input parameters and references to these attribute files. The formats of
all attribute files (and of the mdw-file itself) are described in detail in Appendix A.
The mdw-file and its attribute files form a complete set, defining a simulation. When storing
your simulation input, always make sure you include the complete set of MDW-file and attribute
files.
Filenames and coventions
The names of the mdw-file and its attribute files have a specific structure, some aspects are
obliged while others are only advised or preferred.

The name of an mdw-file must have the following structure: . The
consists of an arbitrary combination of (maximum 252) letters and numbers. This
will be part of the result files to safeguard the link between an mdw-file and the result files.
Restriction:
The maximum length of the is 252 characters!

DR
AF

4.3

The names of the attribute files follow the general file naming conventions, i.e. they have the
following structures: .. Where:
- is any combination of characters allowed for filenames, except spaces.
- There is no limitation other than the platform dependent limitations; you are referred to
your platform manual for details. We suggest to add some continuation character, for
instance <-number> to the to distinguish between various updates or modifications of the file.
- The is mandatory as indicated below.

Quantity

Filename and mandatory extension

Bathymetry or water depth
Curvilinear grid
Grid enclosure
Wind field
Spiderweb wind field
Spectral wave boundary
Wave boundary conditions
1D wave spectrum
2D wave spectrum
Curves
Output locations
Obstacles
Obstacles locations

.dep
.grd
.enc
.wnd
.spw
.bnd
.bcw
.sp1
.sp2
.pol
.loc
.obs
.pol

18 of 124

Deltares

Graphical User Interface

4.4

Setting up a D-Waves model
In this section, all input parameters in the data groups of the mdw-file will be described in the
order in which they appear in the project tree of D-Waves. We will describe all data groups in
consecutive order. For each input quantity we give:

A short description of its meaning. In many cases we add a more comprehensive discussion to put the quantity and its use in perspective.

The restrictions on its use.
The range of allowed values, called its domain, and its default value.
General

In the general tab (Figure 4.1) you can set the basic settings of your model, i.e.:

DR
AF

4.4.1

Figure 4.1: Overview of the general tab

Model coordinate system (default: )

By clicking the earth icon, you can select the coordinate system (CS) for your model. Use
the quick search bar to find your CS either by name or EPSG code (Figure 4.2). The list of
CS that you select is limited to those that are supported by SWAN (the computational core of
D-Waves), i.e. only the WGS84 geographic CS and most projected CS.
Note: Please note that the CS is not (yet) a property in the D-Waves import files. At the
moment it is only used to convert geographical model information to the map CS.
Project name (default: )
The name of the project may not be longer than 16 characters (restriction of the SWAN computational core).
Project number (default: (default: )
The project number may not be longer than 4 characters (restriction of the SWAN computational core).
Verify input (default: no)

Deltares

19 of 124

D-Waves, User Manual

DR
AF

Figure 4.2: Set the model coordinate system

During pre-processing SWAN checks the input data. Depending on the severity of the errors
encountered during this pre-processing, SWAN does not start a computation.
Reference date (default: 01-Jan-00 12:00 AM)

This is the reference date relative to which the time points are defined. For accuracy reasons
choose the reference date not too far away from your time points.
Simulation mode (default: stationary)

You can choose between stationary, quasi-stationary and non-stationary. The stationary mode
is considered to be justified when the residence time of the simulated waves – the time that
waves require to travel through the model domain – is small relative to the time scale of
changes in the wave boundary conditions and forcing (e.g. wind and currents). As the model
domain increases or time scale of changes in boundary conditions and forcing decreases,
non-stationary simulations become more appropriate. In case of non-stationary simulations
you have to provide the time step and time interval of the non-stationary simulations.
Note: To do quasi-stationary

Time step (default: 5 minutes)

The time step for non-stationary simulations
Time interval (default: 0 minutes)
The time interval for non-stationary simulations
Time scale (default: 60 minutes)
Unit of time
Directional convention (default: nautical)

20 of 124

Deltares

Graphical User Interface

In the input and output of SWAN the direction of wind and waves are defined according to
either the Cartesian convention or the Nautical convention (see Figure 5.1 for definitions).

Cartesian
This option indicates that the Cartesian convention for wind and wave direction (SWAN
input and output) will be used. The direction is the angle between the vector and the
positive x-axis, measured counter-clockwise (the direction where the waves are going to
or where the wind is blowing to).
Nautical
This option indicates that the nautical convention for wind and wave direction will be used.
The direction of the vector from the geographic North measured clockwise + 180◦ . This is
the direction where the waves are coming from or where the wind is blowing from.
North

East

West

East

DR
AF

West

North

South

Figure 4.3: Nautical convention (left panel) and Cartesian convention (right panel) for direction of winds and (incident) waves

Couple to Delft3D-FM (default: no)

You can specify a FLOW computation from which the results are to be used as input for the
wave computation (so-called offline coupling). If you want to do this, this is the place to define
the FLOW computation to be used.
All needed results are stored in the communication file (com-file) produced by the FLOW
computation Therefore, the FLOW com-file has to be present in your working directory.
Remarks:
When using a FLOW model, make sure that the selected mdf-file and its associated
com-file are located in your working directory, since the two modules will communicate
with each other by this com-file.
During the computations, D-Waves determines the water depth from the bottom level,
the water level and the water level correction. Bottom levels are defined as the level
of the bottom relative to some horizontal datum level (e.g. a still water level), positive
downward. Water levels are defined with respect to the same datum as the bottom; the
water level is positive upward.
4.4.2

Area
The model area contains geographical (GIS based) features, such as observation points &
curves and obstacles. These features can be added using the "Region"-ribbon (see FrefFig:RegionRibbon and FrefFig:MapAreaFeatures). You can also import and export the attribute files using the RMB in the project tree (Note: NB: still to be implemented). If you
would like to change the locations of the features use the "Edit" section of the "Map"-ribbon
(see FrefFig:EditMapFeatures). You can delete features by selecting them and simply using

Deltares

21 of 124

D-Waves, User Manual

the button. By selecting a feature from the map and double clicking it, the attribute
table will open with feature specific properties (see Figure 4.7 for obstacles).
All the features defined in Area can exist without a grid and they are not based on grid coordinates, implying that their location remains the same when the grid is changed (for example
by (de-)refining).

DR
AF

Figure 4.4: Add Area features using the Region ribbon

Figure 4.5: Area features added to map

Figure 4.6: Edit Area features using the Edit section of the Map ribbon

4.4.2.1

Obstacles
Obstacles are sub-grid features through which waves are transmitted or against which waves
are reflected or both at the same time (see FrefFig:ObstaclesProperties). The location of the
obstacle is defined by a sequence of corner points of a polyline. The obstacles interrupt the
propagation of the waves from one grid point to the next wherever this obstacle line is located
between two neighbouring grid points of the computational grid (the resolution of transmission
or blockage is therefore equal to the computational grid spacing).
With respect to the type of the obstacle, the following options are available:

22 of 124

Deltares

DR
AF

Graphical User Interface

Figure 4.7: Attribute table with properties of obstacles

Sheet: With this option you indicate that the transmission coefficient is a constant along
the obstacle.

Dam: With this option you indicate that the transmission coefficient depends on the in

cident wave conditions at the obstacle and on the obstacle height (which may be submerged).
Reflections: With this option you can specify if the obstacle is reflective (specular or diffusive; possibly in combination with transmission) and the constant reflection coefficient.
Reflection coefficient (default = 0)
The reflection coefficient is formulated in terms of ratio of reflected significant wave height
over incoming significant wave height.
Transmission coefficient (default = 1.0)
is the transmission coefficient for the significant wave height (coefficient = 0.0: no transmission = complete blockage).
Height (default = 0.0)
The elevation of the top of the obstacle above the reference level (same reference level
as for bottom etc.); use a negative value if the top is below that reference level (possibly
in case of submerged obstacles).
Alpha (default = 2.6)
Coefficient determining the transmission coefficient depending on the shape of the dam.
Beta (default = 0.15)
Coefficient determining the transmission coefficient depending on the shape of the dam.

Remark:
When Reflections at obstacles are activated, then for each computational grid the directional space should be Circle or Sector covering the full circle of 360◦ .
When a lot of obstacles have to be defined, the procedure described above can be quite cumbersome. Therefore, it also possible to define a number of obstacles by importing a polyline
file in which you defined the corner points of the obstacles. Note: Still to be implemented.

Deltares

23 of 124

D-Waves, User Manual

Remarks:
Reflections will only be computed if the spectral directions cover the full 360◦ .
In case of specular reflection the angle of reflection equals the angle of incidence.
In case of diffuse and scattered reflection in which the angle of reflection does not equal
the equal the angle of incidence.
Domain:
Lower limit

Upper limit

Reflection
Reflection coefficient

1.0

Transmission coefficient

Dam (max number = 250):

Height

-100.

+100.

1.8
0.1

Sheet (max number = 250):

4.4.2.2

0.0

1.0

2.6

0.15

DR
AF

Beta

Unit

No
0.0

Alpha

Default

Parameter

Observation Points

With Observation Points you can specify (monitoring) locations at which wave output should
be generated by D-Waves, similar to the observation points in Delft3D FM. The values of
the output quantities at the observation points are interpolated from the computational grid
and written to a Table file. You can add, edit and delete these curves using the ribbons.
Alternatively, you can import the locations from a <∗.loc> file. The format of the <∗.loc> file
should be:

4.4.2.3

x1
x2

y1
y2

..
.

Observation Curves

With Observation Curves you can specify a (curved) output curve at which wave output should
be generated by D-Waves. Actually this curve is a broken line, defined by you in terms of
segments. The values of the output quantities along the curve are interpolated from the
computational grid. You can add, edit and delete these curves using the ribbons.
Remark:
The names of output curves and/or curve segments as displayed in the attribute table,
are not input for SWAN. The names are only displayed for your convenience. Moreover,
the number in the names does not determine the sequence. The first curve in the list
is the first curve specified, the second curve in the list is the second curve specified,
though the name may suggest differently. Reloading this scenario will renumber the
names of curves and segments but not the order.

24 of 124

Deltares

Graphical User Interface

4.4.3

Hydrodynamics from flow - currently default tab
In case FLOW results have been selected to be coupled to D-Waves, the results are read from
the com-file and interpolated from the computational FLOW grid to the computational WAVE
grid. Usually the FLOW grid is chosen smaller than the WAVE grid. Therefore an option is
available to extend the values at the boundary of the FLOW grid to the boundary of the WAVE
grid. Furthermore, you specify which hydrodynamic results should be extended.
When the FLOW computation is performed in 2DH mode, for each of the options Water level,
Current, Bathymetry and Wind the following three options can be chosen, see Figure 4.8:

DR
AF

Don’t use Don’t use the quantity for the wave simulation
Use but don’t extend Use this quantity in the wave simulation but don’t extend
Use and extend Use this quantity in the wave simulation but don’t extend

Figure 4.8: Select which quantities should be used from FLOW computation

If the the FLOW computation is performed in 3D mode then an additional Current type needs
to be specified. This current type can have the following values:

depth averaged Use the depth averaged flow-velocity for the wave simulation.
surface layer Use the flow-velocity in the surface layer for the wave simulation.
wave dependent A weighted flow-velocity will be used, the velocity is dependent on the
orbital velocity of the wave and is especially of interest for stratified flows, see Kirby and
Chen (1989).
4.4.4

Spectral resolution (deafult) - currently default tab

For each computational grid the spectral resolution in both directional and frequency space
needs to be specified. SWAN only assigns wave energy to the wave directions and wave
frequencies specified in the spectral resolution. In this tab you can set the default setting
for the spectral resolution (see Figure 4.8). By default these settings will be assigned to all
computational grids. However, the spectral resolution can be made domain dependent (see
section 4.4.5.5).

Deltares

25 of 124

D-Waves, User Manual

DR
AF

Directional space
Circle
This option indicates that the spectral directions cover the full circle. This option is default.
Sector
This option means that only spectral wave directions in a limited directional sector are
considered. The range of this sector is given by Start direction and End direction.
Start direction
This is the first direction (in degrees) of the directional sector. It can be defined either in
the Cartesian or the Nautical convention (see Figure 5.1), but this has to be consistent
with the convention adopted for the computation, to be defined in the Data Group Physical
parameters.
End direction
It is the last direction of the sector (required for option Sector; Cartesian or Nautical convention, but in consistency with the convention adopted for the computation).
Remarks:
The Start direction should be smaller than the End direction.
When Reflections at obstacles are activated, then the spectral directions must cover
the full circle of 360◦ .
Number of directions
This is the number of bins in the directional space. For Circle this is the number of subdivisions of a full circle, so the spectral directional resolution is

∆θ = 360◦ /(Number of directions)

In the case a directional sector is used, the spectral directional resolution is

∆θ = (End direction - Start direction)/(Number of directions)

Frequency space
Lowest frequency
This is the lowest discrete frequency that is used in the calculation (in Hz).
Highest frequency
This is the highest discrete frequency that is used in the calculation (in Hz).
Number of frequency bins
The number of bins in frequency space is one less than the number of frequencies. It
defines the resolution in frequency space between the lowest discrete frequency and the
highest discrete frequency. This resolution is not constant, since the frequencies are logarithmically distributed. The number of frequency bins depends on the frequency resolution
∆f that you require (see SWAN UM (2000), pages 39 and 49).

Domain:

Parameter

Lower limit

Upper limit

Default

Unit

Start direction

-360

360

degree

End direction

-360

360

degree

Number of directions

500

Lowest frequency

0.0

0.05

Highest frequency

0.0

Number of frequency bins

26 of 124

Deltares

Graphical User Interface

4.4.5

Domain
Under in the project tree you define the geographic location, size and orientation of the computational grids by creating or importing one or more attribute grid files,
which are curvilinear grids generated with RGFGRID (grd-file). The grids can be defined in a
common Cartesian co-ordinate system or in a spherical co-ordinate system.

Import and export grids and bathymetries

You can import and export a (previously generated) grid using the RMB on the
(see Figure 4.9). Likewise, import and export a bathymetry for the domain. The imported
grid/bathymetery can be viewed and inspected in the central map (see Figure 4.10).

DR
AF

4.4.5.1

Remarks:
The computational grid must be much larger than the domain where wave results are
needed, because of the ‘shadow’ zone on both sides of the wave incident direction.
A grid that is created in RGFGRID always has an associated enclosure file (∗.enc). This
file is not imported in the WAVE-GUI, but it will be used in case computational grids are
nested, so it has to be present in the working directory.

Figure 4.9: Import a RGFGRID file from the project tree

Figure 4.10: Visualize the D-Waves grid on the central map

Deltares

27 of 124

D-Waves, User Manual

4.4.5.2

Create and/or edit grids in RGFGRID
To generate a grid from scratch or edit an imported grid, double click on "Grid" under
in the project tree and RGFGRID will open (see Figure 4.11). You can use RGFGRID to create
and edit the grid. See the RGFGRID manual for more information.
Note: Do not forget to save the RGFGRID project before closing RGFGRID to save the
changes and transfer them to Delta Shell.

DR
AF

Remark:
The formats of the grid files are defined in Appendix A.

Figure 4.11: Create and/or edit the grid using RGFGRID

4.4.5.3

Create and/or edit bathymetries using the spatial editor

To generate a bathymetry from scratch or edit an imported bathymetry, double click on "Bathymetry" under in the project tree and the spatial editor will open (see Figure 4.12). You can use the spatial editor to create and edit the bathymetry. See the Appendix
.... for more information.
Remark:
The formats of the depth files are defined in Appendix A.
4.4.5.4

Nest domains
D-Waves supports the use of nested computational grids in one wave computation. The idea
of nesting is to have a coarse grid for a large area and one or more finer grids for smaller areas.
The coarse grid computation is executed first and the finer grid computations use these results
to determine their boundary conditions. Nesting can be repeated on ever decreasing scales.
When you want to use the nesting option, you have to create multiple domains. This can be
done using the RMB on the in the project tree (see Figure 4.13). You can add
either an interior or exterior domain. A popup will show up in which you can enter the name
of the new domain (Figure 4.14). Consequently, the with the corresponding
grid and bathymetry features will show up in the project tree (see Figure 4.15). The grids and

28 of 124

Deltares

Graphical User Interface

DR
AF

Figure 4.12: Create and/or edit the grid using the spatial editor

bathymetries can be added, edited and imported in the same way as described before for one
domain.
Remarks:
The first grid cannot be nested in another one. For this grid, boundary conditions must
be specified in the Data Group Boundaries.
A grid cannot be nested in itself. An error message will pop up if you try this.

Figure 4.13: Create or edit the grid using RGFGRID

Figure 4.14: Create or edit the grid using RGFGRID

Deltares

29 of 124

D-Waves, User Manual

Figure 4.15: Create or edit the grid using RGFGRID

4.4.5.5

Spectral resolution and wind (per domain)

DR
AF

By double clicking the in the project tree the domain tab will open. In the
domain tab you can specify whether you would like to use the default settings for the spectral
resolution (section 4.4.4) and wind (section 4.4.6) or set these properties specific for the
domain.

Figure 4.16: Specify spectral resolution and wind per domain

4.4.6

Time Frame, Hydrodynamics and Wind

In the Time frame tab you can specify the time points on which wave computations have to be
carried out, hydrodynamic conditions (water level and currents) and wind conditions.
Time points

There are three options: you want to perform a standalone wave computation, you want to
perform an offline coupling with Delft3D-FM, or you want to perform an online coupling with
Delft3D-FM (in the latter two cases, you specified a FLOW computation in the tab General).
Time steps must be specified for a standalone wave computation. For a coupled flow-wave
(online or offline) computation the time steps (and corresponding hydrodynamics and wind)
are usually copied from the flow computation.
In the time point editor you can add time points in the following ways:

Using the table
Here you can add time points step by step (Figure 4.17)

Pasting copied time series
Using the RMB you can paste copied time series (Figure 4.18)

Using the time series generator

30 of 124

Deltares

Graphical User Interface

Note: Still to be implemented
Synchronizing with the boundary conditions
Using the synchronizing button (Figure 4.19) you can use the time points that are specified
for the boundary conditions.

DR
AF

Figure 4.17: Adding time points using the table

Figure 4.18: Pasting time points from another series or program, for example Excel

Figure 4.19: Synchronizing the time points with the time points specified for the boundary
conditions

Hydrodynamics

If the hydrodynamics are not copied from a Flow computation, they have to specified here.
You have two options:

Constant

Specify constant hydrodynamics for all time points (Figure 4.20)

Per time point

Specify time point specific hydrodynamics (Figure 4.21)
Note: These are the hydrodynamics for all domains.

Deltares

31 of 124

D-Waves, User Manual

DR
AF

Figure 4.20: Specification of constant hydrodynamics

Figure 4.21: Specification of hydrodynamics per time point

Wind

If the wind conditions are not copied from a Flow computation, they have to specified here.
You have three options:

Constant

Specify constant wind for all time points (Figure 4.22)

Per time point

Specify time point specific wind conditions which are uniform in space (Figure 4.23)

From file

Include wind conditions from a file (Figure 4.24). The wind conditions can be variable
in space and time. Optionally, you can add a spiderweb wind field (usually used for the
specification of cyclone winds) on top of the (background) wind field (Figure 4.25).
Note: These are the default settings for all (nested) domains. Alternatively, these settings
can be made domain dependent (see section 4.4.5.5)
The ranges for the (uniform) wind conditions are as follows:
Domain:
Parameter

Lower limit

Upper limit

Default

Unit

Wind speed

0.0

50.0

0.0

m/s

Wind direction

-360.0

360.0

0.0

deg

Remark:

32 of 124

Deltares

Graphical User Interface

If the wind speed is larger than zero, and in Physical Parameters the third generation
mode is selected, then the Quadruplets will be activated.

DR
AF

Figure 4.22: Specification of constant wind

Figure 4.23: Specification of wind per time point

Figure 4.24: Specification of wind (field) from file

Figure 4.25: Add a spiderweb wind field

Deltares

33 of 124

D-Waves, User Manual

Boundary Conditions
Under Boundary Conditions in the project tree the incident wave conditions at the boundary
of the first, and only the first, computational grid are prescribed. All other computational grids
(i.e. the nested grids) obtain their boundary information from other grids.
In the D-Waves computations, wave boundary conditions may be specified at different sides.
The general procedure to specify boundary conditions is the following. For each of the boundaries:

1 Draw the boundary location(s) in the central map (can be multiple support points).
2 Specify whether the values of the incident wave conditions are Uniform or Spatially varying
along the boundary.
3 Specify whether the values of the incident wave conditions are Parameterized (Constant
in time), Parameterized (Timeseries) or Spectrum based (from file).
4 Activate the support point(s) that you want to put conditions on.
5 Set the spectrum settings (if not loaded from file).
6 Specify the condtions (which may be time series)
Below, each of the six steps described above is explained further.

DR
AF

4.4.7

Remark:
Alternatively, you can select a (pre-processed) 2-dimensional spectrum file that is providing the spectral data along the boundary directly (optionally varying in time).
Boundary location(s)

You can specify the boundary locations by selecting Add Boundary from the Region ribbon
(see Figure 4.26) and cosequently drawing the boundary or boundaries on the central map
(see Figure 4.27). In contrast to the previous D-Waves GUI boundaries can only be specified
in terms of xy coordinates, not in grid coordinates or by orientation. After drawing the boundaries they will be automatically snapped to the grid. The boundaries are added to the project
tree under Boundary Conditions (Figure 4.28).

Figure 4.26: Select Add Boundary from Region ribbon

Spatial definition
The spatial definition can be set in the attribute table (see Figure 4.29) of the boundary, which
you can open by double clicking Boundary Conditions in the project tree. Alternatively, you can
set the spatial definition in the boundary condition editor (see Figure 4.30), which is opened
by double clicking the Boundary in the project tree or double clicking the boundary in the
map view. The boundary condition may be Uniform along a boundary, but it may also be
Space-varying:

Uniform
With this option the wave conditions are uniform along a boundary.

Space-varying
34 of 124

Deltares

Graphical User Interface

Figure 4.27: Draw the boundary support points on the map

DR
AF

With this option the wave spectra can vary along the boundary. The incident wave field is
prescribed at a number of support points along the boundary. These points are characterised by their distance from the begin point of the boundary (inidcated by the numbers).
The wave spectra for grid points on the boundary of the computational grid are calculated
by SWAN by spectral interpolation.

Figure 4.30: Overview of the boundary conditions editor

Spectral specification

The boundary conditions in SWAN can be specified in terms of integral wave parameters
(Parameterized (Constant in time or time series)) or they can be read from an external file
(Spectrum based (from file)). You can select this in the boundary condition editor.

Parametric
With this option you define the boundary condition as parametric spectral input.
From file
With this option the boundary condition are read from an external file (bnd-file).

Deltares

35 of 124

DR
AF

D-Waves, User Manual

Figure 4.28: Boundaries are added to the project tree under Boundary Conditions

Figure 4.29: Edit the spatial definition in the attribute table

Activate support points

In order to put conditions on the boundaries you first have to activate one (or multiple) support
point(s) from the list by clicking the green "+"-button (see Figure 4.31). In the geometry panel
next to it you can see which of the points along the boundary is selected (Figure 4.31).

Figure 4.31: Activate a support point in the boundary condition editor and inspect the
location of the selected support point in the Geomtery view

36 of 124

Deltares

Graphical User Interface

Spectrum settings
In the spectrum panel the spectrum shape and settings can be selected and set (see Figure 4.32):
Shape: With this option you can define the shape of the input spectra.

JONSWAP (default)

DR
AF

This option indicates that a JONSWAP type spectrum is assumed.
Peak enh. Fact.
This is the peak enhancement parameter of the JONSWAP spectrum. The default value
is 3.3.
Pierson-Moskowitz
This option means that a Pierson-Moskowitz type spectrum will be used.
Gauss
This option indicates that a Gaussian-shaped frequency spectrum will be used. If this
option is used, the width of the spectrum in frequency space has to be specified. Selecting
this option the Spreading box will be enabled.
Spreading
Width of the Gaussian frequency spectrum expressed as a standard deviation in [Hz].
Period: With this input you can specify which wave period parameter (i.e. Peak or Mean
period) will be used as input.

Peak (default)

The peak period Tp is used as characteristic wave period.

Mean

The mean wave period Tm01 is used as characteristic wave period. For the definition see
Appendix B.
Directional spreading: With this input you can specify the width of the directional distribution.
The distribution function itself is: cos(θ − θpeak ).

Cosine power (default)

The directional width is expressed with the power m itself.

Degrees (standard deviation)

The directional spreading is expressed in terms of the directional standard deviation of the
[cos(θ − θpeak )] distribution (for a definition see Appendix B).

Figure 4.32: Select spectrum shape and set corresponding properties

Deltares

37 of 124

D-Waves, User Manual

Edit conditions
In case of a parameterized wave spectrum, the (time-dependent) conditions can be set in the
conditions table and inspected in the corresponding graph (Figure 4.33).
The wave conditions are specified in terms of:

Significant wave height
The significant wave height specified in m.

Wave period

DR
AF

The characteristic period of the energy spectrum. It is the value of the peak period (in s)
if option Peak is chosen in the Spectral space sub-window or it is the value of the mean
period if option Mean is chosen in the above same sub-window.
Direction
Mean wave direction (direction of wave vector in degree) according to the Nautical or
Cartesian convention.
Directional spreading
This is the directional standard deviation in degrees if the option Degrees is chosen in the
SWAN Spectral Space window; or it is the power m if the option Cosine power is chosen
in the same window.

Figure 4.33: Specify parameterized wave boundary conditions and inspect in graph

Defaults and ranges
Domain:

Parameter

Lower limit

Upper limit

Default

Unit

Number of points to specify
boundary

300

Spectral peak factor

10.

3.3.

Distance from corner point

Y-length

Significant wave height

25.

Spectral peak period

0.1

20.

Wave direction

-360

360.

◦

Directional width (m)

100.

38 of 124

Deltares

Graphical User Interface

Figure 4.34: Overview of physical Constants

Physical parameters

DR
AF

4.4.8

In the tab Physical parameters you can specify a number of physical parameters. These are:

Constants: Here you can specify constants such as the gravitational constant and the
water density
Processes: With these parameters you can influence some of the physical processes of
SWAN (i.e.type of formulation, dissipation processes, non-linear wave-wave interactions).
4.4.8.1

Constants

In the tab Constants you can specify the following parameters (see Figure 4.34):
Gravity
The gravitational acceleration in m/s2 . The default value is 9.81 m/s2 .
Water density
The water density ρ in kg/m3 . The default value is 1025 kg/m3 .

North
The direction of North with respect to the x-axis (Cartesian convention). The default value is
90◦ i.e. x-axis pointing East.
Minimum depth
The threshold depth in [m]; in the computation any positive depth smaller than this threshold
depth is set to the threshold depth. The default 0.05 m.

Deltares

39 of 124

DR
AF

D-Waves, User Manual

Figure 4.35: Overview of physical Processes

Domain:

Parameter

Lower limit

Upper limit

Default

Unit

Acceleration of gravity

9.8

10.

9.81

m/s2

Density of water

950.

1050.

1025.

kg/m3

North

-360.

360.

90.

deg

0.05

Minimum depth

4.4.9

Physical processes

SWAN contains a number of physical processes (see Figure 4.35) that add or withdraw wave
energy to or from the wave field. The processes included are: wave growth by wind, whitecapping, bottom friction, depth induced wave breaking, non-linear wave-wave interactions
(quadruplets and triads). SWAN can run in several modes, indicating the level of parameterisation. For initial SWAN runs, it is strongly advised to use the default values as shown
in Figure 4.35. First it should be determined whether or not a certain physical process is
relevant to the result. If this cannot be decided by means of a simple hand computation,
you can perform a SWAN computation without and with the physical process included in the
computations, in the latter case using the standard values chosen in SWAN.

Generation mode for physical formulations:
1st generation
With this option you indicate that SWAN should run in first-generation mode.
2nd generation
With this option you indicate that SWAN should run in second-generation mode (for more
information, reference is made to the SWAN manual).

40 of 124

Deltares

Graphical User Interface

DR
AF

3rd generation
With this option you indicate that SWAN should run in third-generation mode. Activated
are wind input, quadruplet interactions and white-capping. Triads, bottom friction and
depth-induced breaking are not activated by this option.
Remark:
If SWAN runs in third generation mode and the wind speed is larger than zero, then
the Quadruplets in Sub-data Group Various will be activated.
None
With this option you indicate that no deep water physical processes (i.e. wind, whitecapping and quadruplets) are activated.
Wave set-up
If this option is activated, the wave induced set-up is computed and accounted for in the
wave computations (during the computation it is added to the depth that is obtained from
the bottom and the water level). This option should only be used if SWAN is applied as
standalone model or if wave-induced set-up is not accounted for in the flow computations.
Depth-induced breaking
With this option you can influence depth-induced wave breaking in shallow water in the
SWAN model (see section 5.3.1). Ticking off this depth-induced term is usually unwise,
since this leads to unacceptably high wave heights near beaches (the compute wave
heights ‘explode’ due to shoaling effects).
B&J model
This option means that to model the energy dissipation in random waves due to depthinduced breaking, the bore-based model of Battjes and Janssen (1978) is used. In this
option a constant breaker parameter is to be used.
Alpha
The coefficient for determining the rate of dissipation. Default = 1.0.
Gamma
The value of the breaker parameter defined as Hm /d. Default = 0.73.
Non-linear triad interactions (LTA)
With this option you can activate the triad wave-wave interactions in the SWAN model
(see section 5.3.1). Ticking off this feature means that the non-linear wave-wave interactions due to the triads are not taken into account. LTA means that the Lumped Triad
Approximation (LTA) of Eldeberky and Battjes (1996) is used.
Alpha
The value of the proportionality coefficient αEB . The default value is equal to 0.1.
Beta
This controls the maximum frequency that is considered in the computations. The value
determines the ratio of the maximum frequency over the mean frequency, for which the
interactions are computed. The default value is 2.2.
Bed friction
With this option you can activate bed friction (see section 5.3.1). If this option is not used,
SWAN will not account for bed friction. In SWAN three different formulations are available,
i.e. that of Hasselmann et al. (1973) (JONSWAP), Collins (1972); Madsen et al. (1988)).
The default option is de-activated.
JONSWAP
This indicates that the semi-empirical expression derived from the JONSWAP results for
bottom friction dissipation (Hasselmann et al., 1973) will be activated.
- Coefficient
The coefficient of the JONSWAP formulation. It is equal to 0.067 m2 s−3 for wind sea
conditions (default value) and equal to 0.038 m2 s−3 for swell conditions.
Collins
This indicates that the expression of Collins (1972) will be activated.

Deltares

41 of 124

D-Waves, User Manual

- Coefficient
The Collins bottom friction coefficient, default = 0.015.
Madsen et al.
This indicates that the expression of Madsen et al. (1988) is activated.
- Coefficient
The equivalent roughness length scale of the bottom. Default = 0.05 m.

Diffraction

DR
AF

With this option you can activate diffraction in the wave computation. The default option
is de-activated. The diffraction implemented in SWAN is based on a phase-decoupled
refraction-diffraction approximation (Holthuijsen et al., 1993). It is expressed in terms of
the directional turning rate of the individual wave components in the 2D wave spectrum.
The approximation is based on the mild-slope equation for refraction and diffraction, omitting phase information.
Smoothing coefficient
During every smoothing step all grid points exchange [smoothing coefficient] times the
energy with their neighbours. Default = 0.2.
Smoothing steps
Number of smoothing steps. The default value is equal to 5.
Adapt propagation
Switch to turn on or off the adaption of propagation of velocities in geographic space due
to diffraction. The default value is activated (when diffraction is activated).
Remark:
The process diffraction can only be solved accurately when a detailed grid is applied.
Several studies (e.g. Ilic (1994)) have shown that the grid size should be about 1/10
of the wave length; so, dx = L/10. In case of much coarser grids, the SWAN
computation can become unstable and results are not reliable. So, use diffraction
with care!
Wind growth
If this option is activated, wind growth is included in the computation. Note: Only if wind
is included in the computation.
White-capping
For the white capping two model descriptions are possible:
buttonoff (default)
button(Komen et al., 1984)
button(Van der Westhuysen, 2007)
Quadruplets
If this option is activated, quadruplets are included in the computation. Note: Only if wind
is included in the computation.
Refraction
If this option is activated, refraction is included in the computation.
Frequency shifting
If this option is activated, frequency shifting is included in the computation
Wave force computation
With the integration of the fully spectral SWAN model under the Delft3D model it is possible to compute the wave forces on the basis of the energy wave dissipation rate or on the
gradient of the radiation stress tensor (SWAN UM, 2000).

42 of 124

Deltares

Graphical User Interface

Domain:
Parameter

Lower limit

Upper limit

Default

Generation mode

3rd
tion

Wave set-up

inactive

Depth-induced breaking:

B&J model

Unit

genera-

Alfa

0.1

1.0

Gamma

0.55

1.2

0.73

inactive

Alfa

0.001

Beta

0.001

0.10

2.2

JONSWAP

DR
AF

Bottom friction

Non-linear triad interactions

Bottom friction coefficient

0.067

Diffraction

inactive

m2 /s3

Smoothing coefficient

1.0

0.2

Smoothing steps

999

Adapt propation

active

Wind growth

inactive

White capping

Komen et al

Quadruplets

inactive

Refraction

active

Frequency shift

active

Wave forces

Radiation
stress

Deltares

43 of 124

D-Waves, User Manual

4.4.10

DR
AF

Figure 4.36: Overview of Numerical parameters

Numerical parameters

In the Numerical parameters tab you can modify parameters that affect the stability and accuracy of the numerical computation (see Figure 4.36). To obtain robust results with acceptable
accuracy, apply the default diffusion parameters.

Spectral space

In this sub-window you can control the amount of diffusion of the implicit scheme in the
directional space through the Directional space (CDD) parameter and frequency space
through the Frequency space (CSS).
Directional space
A value of CDD = 0 corresponds to a central scheme and has the largest accuracy (diffusion ≈ 0) but the computation may more easily generate spurious fluctuations. A value of
CDD = 1 corresponds to an upwind scheme and it is more diffusive and therefore preferable if (strong) gradients in depth or current are present. The default value is CDD =
0.5.
Frequency space
A value of CSS = 0 corresponds to a central scheme and has the largest accuracy (diffusion ≈ 0) but the computation may more easily generate spurious fluctuations. A value of
CSS = 1 corresponds to an upwind scheme and it is more diffusive and therefore preferable if (strong) gradients in current are present. The default value is CSS = 0.5.
Accuracy criteria (to terminate the iterative computations)
With these options you can influence the criteria for terminating the iterative procedure
in the SWAN computation (for convergence criteria of SWAN see section 5.5.1). SWAN
stops the iteration if:
a) The change in the local significant wave height (Hs) from one iteration to the next is
less than:

◦ fraction Relative change of that wave height or
◦ fraction Relative change w.r.t. mean value of the average significant wave height
(averaged over all wet grid points)
b) and if the change in the local mean wave period from one iteration to the next is less
than:

44 of 124

Deltares

Graphical User Interface

◦ fraction Relative change of that period or
◦ fraction Relative change w.r.t. mean value of the average mean wave period (averaged over all wet grid points)
c) and if the conditions a) and b) are fulfilled in more than fraction Percentage of wet grid
points % of all wet grid points.

Relative change
The default value is 0.02.
Relative change w.r.t. mean value
The default value is 0.02, for both Hs and Tm01 .
Percentage of wet grid points
The default value is 98%.
You can also control the terminating procedure by giving the maximum number of iterations Max. number of iterations after which the computation stops.
Max. number of iterations
The default value is 15.

DR
AF

Domain:
Parameter

Lower limit

Upper limit

Default

Unit

Diffusion θ -space (directional)

0.5

Diffusion σ -space (frequency)

0.5

Relative change

0.02

Percentage of wet grid points

100%

98%

Max. number of iterations

Relative change w.r.t.
value (Hs and Tm01 )

4.4.11

mean

Output parameters

In the tab Output parameters (see Figure 4.37) you can determine to which grid (i.e. WAVE
or FLOW grid) output is written and to which extent the computations should be monitored.
The latter option can be used to specify that D-Waves should produce intermediate (model)
results during a SWAN run (test output) if the program produces unexpected results.
There are a couple of options available to monitor the SWAN computation:
Level of test output (Default: 0)
For values up to 50 test output is made that can be interpreted by you. For values above
50, information for the programmer is produced. For values under 100 the amount is usually
reasonable, for values above 200 it can be huge.
Trace subroutine calls (Default: off)
In case an error occurs, the name of the subroutine where the error occurred is written.
Write and use hotstart file (Default: no)
This option can be used to write the entire wave field at the end of a computation to an
initialisation file and use this field as initial condition in a subsequent SWAN run. In many

Deltares

45 of 124

D-Waves, User Manual

Figure 4.37: Overview of Output parameters

DR
AF

cases with a series of wave runs, this option can save significantly amount of computational
time. In case of a FLOW-WAVE coupling with a frequent update, the hydrodynamic conditions
have not changed a lot since a previous wave computation. Therefore SWAN can use the
results of a previous SWAN run as the initial condition for the wave field.
The format of the hotstart file is identical to the format of the files written by the 2D-spectrum
output in the pre-defined locations.
Remarks:
It is recommended to gradually vary the wave directions in the file. When
computing a wave condition using an existing HOT-file, which is generated during a
wave computation with a large different wave direction, the use of a HOT-file can lead
to unrealistic wave fields. Check the wave results carefully.
When applying only one wave condition (e.g. during a flow-wave coupling) it can be wise
to increase the required accuracy (in % of wet points) initially. The subsequent wave
computations may be completed faster in this way, although the first wave computation
will probably need more computational time.
Only verify input files (Default: no)
During pre-processing SWAN checks the input data. Depending on the severity of the errors
encountered during this pre-processing, SWAN does not start a computation. You can influence the error level above which SWAN will not start computations. The error level is coded
as follows:

Warnings
Errors (possibly automatically repaired or repairable by SWAN)
Severe Errors

D-Waves offers two options to save the results of the calculation: on the communication file
(if available) and on an output file.

Output for FLOW grid (Default: off)
Click in the check box to turn this option on or off. If you select Output for FLOW grid, a
communication file is available and will be updated. The FLOW model (and other modules)
can read and use the wave data directly, since the information is automatically converted
to the curvilinear grid definition by the wave module. In ?? a description of the output
parameters on the communication file is given.

46 of 124

Deltares

Graphical User Interface

DR
AF

co-ordinates of output location (with respect to the problem coordinates)
DEPT
water depth [m]
HSIG
significant wave height [m]
DIR
mean wave direction [◦ ]
Tpeak
peak wave period [s]
TM01
mean wave period (Tm01 ) [s]
DSPR
directional spreading of the waves [◦ ]
UBOT
root-mean-square value of the maximum of the orbital motion
near the bottom [m/s]
XWindv, YWindv
wind components [m/s]
Xvel, Yvel
current velocity components [m/s]
The parameters written in the 1D spectra file are:

XP, YP

A curvilinear grid file (FLOW grid) is required to enable this conversion. In case hydrodynamic results from a FLOW simulation are used, the flow input file has been selected.
The grid definition is read from this file. If no hydrodynamic results are used, a Select
grid file button is displayed and a grid file can be selected. If a grid file is selected, still a
communication file is needed. The WAVE simulation will expect that the communication
file is available. The communication file can be generated by running a
stand-alone FLOW simulation or a online FLOW/WAVE simulation.
Output for computational grids (Default: off)
If this option is chosen, detailed output is generated on one or more computational grids.
This output is written to a NEFIS file with basename WAVM (waves map file). In ?? a
description of the output parameters on the file is given.
Output for specific locations
For the locations defined as observation points you can have three types of output: Table,
1D spectra or 2D spectra.
The parameters written to the Table file are:

absolute frequencies [Hz]
energy densities [J m−2 Hz−1 ]
average nautical direction [degrees]
directional spreading [degrees]

The parameters written in the 2D spectra file are:
absolute frequencies [Hz]
spectral nautical directions [degrees]
energy densities [J m−2 Hz−1 deg−1 ]

Remarks:
The Table output for specific locations is stored in files .tab in case of
multiple grids and multiple time points. For the overall computational grid i = 1, for
the first nested grid i = 2, etc. For the first time point j = 1, for the second j = 2,
etc.
The 1D spectra output for specific locations is stored in files .
Similar for the 2D spectra output in files.
In case of only one grid and multiple time points the files are , and .
In case of multiple grids and only one time points the files are , and .
In case of only one grid and only one time points the files are , and .
Output curves

Deltares

47 of 124

D-Waves, User Manual

The following output quantities will be generated by D-Waves at the output locations along
a curve.

Output
Note: Yet to be specified

DR
AF

4.4.12

XP, YP
co-ordinates of output location (with respect to the problem co-ordinates)
DIST
distance along the output curve in [m]
DEPT
depth in [m]
HSIG
significant wave height [m]
PER
mean wave period (Tm01 , [s])
DIR
mean wave direction [degrees]
DSPR
directional spreading of the waves [degrees]
DISS
dissipation rate [J m−2 s−1 ]
WLEN
mean wave length [m]
U,V
current velocity [m/s]
All the data of each output curve is presented in a table and will be saved in only one file,
named: .

48 of 124

Deltares

5 Conceptual description
5.1

Introduction
The purpose of this chapter is to give some general background with respect to the unit and
co-ordinate system, the grids (resolution, orientation etc.) and the boundary conditions of the
SWAN model. Advice will be given how to choose the basic input for Delft3D-WAVE for the
SWAN computations.

5.2.1

General background
Units and co-ordinate systems

DR
AF

5.2

A brief description is given with respect to the physics (see section 5.3) and numerics (section 5.4) that have been implemented in the SWAN model. This description has been copied with permission of Delft University of Technology, The Netherlands (personal communication
with dr N. Booij and dr L.H. Holthuijsen, 1999) - from the SWAN manual for SWAN version
40.41. The description given here is indicative only. For a full and proper description reference
is made to SWAN UM (2000).

Delft3D-WAVE expects all quantities that are input by the user, to be expressed by means of
the S.I. system of units: m, kg, s and composites of these with accepted compounds, such
as Newton [N] and Watt [W]. Consequently the wave height and water depth are in [m], wave
period in [s] etc. Directions and spherical co-ordinates are in degrees [◦ ] and not in radians.
Delft3D-WAVE can operate in a flat plane and on a spherical earth.
North

North

West

East

South

West

East

South

Figure 5.1: Nautical convention (left panel) and Cartesian convention (right panel) for direction of winds and (incident) waves

In the input for Delft3D-WAVE the directions of winds and (incident) waves are defined relative
to the co-ordinate system according to a Nautical convention or Cartesian convention, see
Figure 5.1 (for definitions reference is made to Appendix B).
In the Cartesian system, all geographic locations and orientations in SWAN, e.g. for the computational grid or for output points, are defined in one common Cartesian co-ordinate system
with origin (0,0) by definition. This geographical origin may be chosen totally arbitrarily by you.
In the spherical system, all geographic locations and orientations in Delft3D-WAVE are defined in geographic longitude and latitude. Both co-ordinate systems are designated in this
manual as the problem co-ordinate system. Figure 5.2 shows how the locations of the various
grids are determined with respect to the problem co-ordinates.

Deltares

49 of 124

D-Waves, User Manual

Y
MX * DX
MY * DY

α P0

Y P0

X P0

Figure 5.2: Definition of grids (input, computational and output grids) in Delft3D-WAVE

Choice of grids and boundary conditions

For your convenience Delft3D-WAVE accepts input and provides output on different grids.

DR
AF

5.2.2

It is not uncommon that a bottom grid is available as an existing data set without any relation
whatsoever to Delft3D-WAVE. You may want output on an entirely different grid (but in the
same region of course), whereas the computations in Delft3D-WAVE may require a different
grid altogether.
For these reasons Delft3D-WAVE operates with different grids (each may have a different
origin, orientation and resolution).
Input grids on which the bathymetry, current field and wind field (if present) are given by
you; one computational grid on which Delft3D-WAVE performs the computations, and one (or
more) output grid(s) on which you require output of Delft3D-WAVE.
During the computations (on the computational grid) Delft3D-WAVE obtains bathymetry and
current information by bilinear interpolation from the input grid. The output on the output
grid is in turn obtained in Delft3D-WAVE by interpolation from the computational grid. These
interpolations will cause some loss of accuracy.
Input grids

Bathymetry and current input need to be provided to Delft3D-WAVE on so-called input grids
(they need not be identical with the computational, the output grids or other input grids). It is
best to make an input grid larger than the computational grid, in fact, so large that it completely
covers the computational grid for every expected situation. In the region outside the input grid
Delft3D-WAVE assumes that the bottom level and friction coefficient are identical to those at
the nearest boundary of the input grid (lateral shift from that boundary). In the regions not
covered by this lateral shift (i.e. in the outside corner quadrants of the input grid), a constant
field equal to the value at the nearest corner point of the input grid is taken.
You should choose the resolution for the input grid such that relevant spatial details in the
bathymetry and in the current pattern are well resolved. Special care is required in cases with
sharp and shallow ridges in the sea bottom. In such cases the shallowest parts are of vital
importance to obtain good Delft3D-WAVE results (during propagation the waves are ‘clipped’
by surf breaking at some maximum value determined by the minimum depth). To represent

50 of 124

Deltares

Conceptual description

these shallowest parts in the bottom grid, you may want to have one grid line coincide with
the ridge top (even if this means ”moving” the ridge to the nearest line in the bathymetry grid).
If this is not done, the computed wave height behind the shoal may well be computed higher
than it is in reality, because the ridge is seen deeper in Delft3D-WAVE than it actually is (too
coarse resolution to see shallow peak of the ridge).
Computational grid and boundary conditions

The computational grid is a grid in four dimensions: x-, y - and θ -, σ - space. The computational grid in x-, y -space must be chosen by you with care. You should choose the location
of the up-wave boundary in water so deep that refraction effects have not (yet) influenced the
wave field. However, a deep water up-wave boundary is not a strict requirement for Delft3DWAVE. This advice is not applicable if the incoming waves are provided by a model which
takes refraction into account, for instance Delft3D-WAVE itself (in a nested mode).

DR
AF

The computational grid must be larger than the area where you want to know the wave parameters. The length (in x-direction) needs not be longer than from the up-wave boundary to
the most down-wave point of interest. The width (in y -direction) must be larger than that of
the area of interest, because along each lateral side of the grid (if there is an open boundary along that side) a region exists where the wave field is disturbed (in Delft3D-WAVE) by
an import of zero energy from the lateral boundaries (see Figure 5.3). This is not the case
if the wave conditions along the lateral boundaries are specified by you or obtained from a
previous Delft3D-WAVE run or if that boundary is closed (e.g. by land). The angle of the line
dividing the disturbed area from the undisturbed area from the up-wave corner points (of the
computational grid) is approximately equal to the half-power width of the directional energy
distribution of the waves (this half-power width is typically 20◦ to 40◦ for waves generated by
the local wind or 5◦ to 10◦ for swell).

Figure 5.3: Disturbed regions in the computational grid

The spatial resolution of the computational grid should be sufficient to resolve relevant details
of the wave field. Usually a good choice is to take the resolution of the computational grid
approximately equal to that of the input (bathymetry/current) grid.
The computational spectral grid needs also to be provided by you. In frequency space it is
simply defined by a minimum and maximum frequency and the frequency resolution which
is proportional to the frequency itself (e.g. ∆f = 0.1f ). In the frequency domain this lowest frequency and highest frequency and the number of frequencies must be chosen. The
value of lowest frequency must be slightly smaller than 0.6 times the value of the lowest peak
frequency expected. The value of the highest frequency must be at least 2.5 to 3 times the
highest peak frequency expected; usually it is chosen less than or equal to 1 Hz.

Deltares

51 of 124

D-Waves, User Manual

In directional space the directional range is the full 360◦ unless you specify a limited directional range. This may be convenient (less computer time and/or space) when waves travel
towards a coast within a limited sector of 180◦ , say. The directional resolution is determined
by the number of discrete directions that is provided by you. For wind seas with a directional spreading of typically 30◦ on either side of the mean wave direction, a resolution of 10◦
seems enough whereas for swell with a directional spreading of less than 10◦ , a resolution of
2◦ or less may be required. If you are confident that no energy will occur outside a certain
directional sector (or is willing to ignore this energy), then the computations by SWAN can be
limited to the directional sector that does contain energy. This may often be the case of waves
propagating to shore within a sector of 180◦ around some mean wave direction.

Output grids

DR
AF

5.2.3

Nonstationary situations are simulated with the SWAN model as quasi-stationary with repeated model runs. This implies that as e.g. the flow computations progress in time, a (stationary) wave computation is performed at specified, intermediate time levels. Such stationary
wave computations are usually considered to be acceptable since the travel time of the waves
from the seaward boundary to the coast is mostly relatively small compared to the time scale
of variations in incoming wave field, the wind or tidal induced variations in depth and currents.

Delft3D-WAVE can provide output on the computational grids or on grids that are independent from the computational grid like the Delft3D-FLOW grid. It must be pointed out that the
information on a flow grid is obtained from the computational grid by spatial interpolation.
Therefore it is wise to choose a resolution that is fine enough to show relevant spatial details.
The spatial interpolation implies that some inaccuracies are introduced. It also implies that
bathymetry or current information on an (output) plot has been obtained by interpolating twice:
once from the input grid to the computational grid and once from the computational grid to the
output grid. If the input, computational and output grids are identical, then no interpolation
errors occur.
In the regions where the output grid does not cover the computational grid Delft3D-WAVE
assumes output values equal to zero.
5.3
5.3.1

Physical background of SWAN
Action balance equation

In SWAN the waves are described with the two-dimensional wave action density spectrum,
even when non-linear phenomena dominate (e.g., in the surf zone). The rational for using the
spectrum in such highly non-linear conditions is that, even in such conditions it seems possible
to predict with reasonable accuracy this spectral distribution of the second order moment of
the waves (although it may not be sufficient to fully describe the waves statistically). The
spectrum that is considered in SWAN is the action density spectrum N (σ, θ) rather than
the energy density spectrum E(σ, θ) since in the presence of currents, action density is
conserved whereas energy density is not (Whitham, 1974). The independent variables are
the relative frequency σ (as observed in a frame of reference moving with the current velocity)
and the wave direction θ (the direction normal to the wave crest of each spectral component).
The action density is equal to the energy density divided by the relative frequency: N (σ, θ) =
E(σ, θ)/σ . In SWAN this spectrum may vary in time and space.
In SWAN the evolution of the wave spectrum is described by the spectral action balance

52 of 124

Deltares

Conceptual description

equation which for Cartesian co-ordinates is (e.g., Hasselmann et al. (1973)):

∂
∂
∂
∂
∂
S
N+
cx N +
cy N +
cσ N + cθ N =
∂t
∂x
∂y
∂σ
∂θ
σ

(5.1)

The first term in the left-hand side of this equation represents the local rate of change of action density in time, the second and third term represent propagation of action in geographical
space (with propagation velocities cx and cy in x- and y -space, respectively). The fourth term
represents shifting of the relative frequency due to variations in depths and currents (with
propagation velocity cσ in σ -space). The fifth term represents depth-induced and currentinduced refraction (with propagation velocity cθ in θ -space). The expressions for these propagation speeds are taken from linear wave theory (Whitham, 1974; Mei, 1983; Dingemans,
1997). The term S (= S(σ, θ)) at the right-hand side of the action balance equation is the
source term in terms of energy density representing the effects of generation, dissipation and
non-linear wave-wave interactions. A brief summary of the formulations that are used for the
various source terms in SWAN is given next.
The following processes are accounted for in SWAN:

DR
AF

generation by wind,
dissipation by whitecapping, bottom friction and depth-induced breaking,
non-linear wave-wave interaction (quadruplets and triads).

In addition wave propagation through obstacles and wave-induced set-up of the mean sea
surface can be computed in SWAN. These phenomena are addressed separately below (see
Sections 5.3.2 and 5.3.3).
Wind input

Transfer of wind energy to the waves is described in SWAN with a resonance mechanism
(Phillips, 1957) and a feed-back mechanism (Miles, 1957). The corresponding source term
for these mechanisms is commonly described as the sum of linear and exponential growth:

Sin (σ, θ) = A + BE(σ, θ)

(5.2)

in which A and B depend on wave frequency and direction, and wind speed and direction.
The effects of currents are accounted for in SWAN by using the apparent local wind speed and
direction. The expression for the term A is due to Cavaleri and Malanotte-Rizzoli (1981) with
a filter to avoid growth at frequencies lower than the Pierson-Moskowitz frequency (Tolman,
1992a). Two optional expressions for the coefficient B are used in the model. The first is
taken from an early version of the WAM model (known as WAM Cycle 3, the WAMDI group
(1988)). It is due to Snyder et al. (1981), rescaled in terms of friction velocity U∗ by Komen
et al. (1984). The drag coefficient to relate U∗ to the driving wind speed at 10 m elevation
U10 is taken from Wu (1982). The second expression for B in SWAN is taken from the most
recent version of the WAM model (known as WAM Cycle 4, Komen et al. (1994)). It is due
to Janssen (1991a) and it accounts explicitly for the interaction between the wind and the
waves by considering atmospheric boundary layer effects and the roughness length of the
sea surface. The corresponding set of equations is solved (as in the WAM model) with the
iterative procedure of Mastenbroek et al. (1993).

Deltares

53 of 124

D-Waves, User Manual

Dissipation
The dissipation term of wave energy is represented by the summation of three different contributions: whitecapping Sds,w (σ, θ), bottom friction Sds,b (σ, θ) and depth-induced breaking
Sds,br (σ, θ).
Whitecapping is primarily controlled by the steepness of the waves. In presently operating
third-generation wave models (including SWAN) the whitecapping formulations are based on
a pulse-based model (Hasselmann, 1974), as adapted by the WAMDI group (1988):

k
Sds,w (σ, θ) = −Γσ̃ E(σ, θ)
k̃

(5.3)

˜ and k̃
where Γ is a steepness dependent coefficient, k is the wave number and sigma
denote a mean frequency and a mean wave number, respectively (cf. the WAMDI group
(1988)). Komen et al. (1984) estimated the value of Γ by closing the energy balance of the
waves in fully developed conditions. This implies that this value depends on the wind input
formulation that is used.

DR
AF

An alternative description for whitecapping in SWAN is given by Van der Westhuysen et al.
(2007) and Van der Westhuysen (2007), which is an adapted form of the expression of Alves
and Banner (2003). The latter is based on the apparent relationship between wave groups and
whitecapping dissipation. This adaption is due to the fact that it can also be applied to mixed
sea-swell conditions and in shallow water. This was done by removing the dependencies on
mean spectral steepness and wavenumber in the original expression, and by applying source
term scaling arguments for its calibration (see below). This led to the following expression for
whitecapping dissipation:

Sds,w (σ, θ) =

0
−Cds

B(k)
Br

p/2

(tanh(kh))(2−p0 )/4

p
gkE(σ, θ)

(5.4)

in which the density function B(k) is the azimuthal-integrated spectral saturation, which is
positively correlated with the probability of wave group-induced breaking. It is calculated from
frequency space variables as follows:

Z2π

B(k) =

cg k 3 E(σ, θ)dθ

(5.5)

and Br = 1.75 × 10−3 is a threshold saturation level. The proportionality coefficient is set
0
to Cds
= 5.0 × 10−5 . When B(k) > Br , waves break and the exponent p is set equal to a
calibration parameter p0 . For B(k) ≤ Br there is no breaking, but some residual dissipation
proved necessary. This is obtained by setting p = 0.
Depth-induced dissipation may be caused by bottom friction, by bottom motion, by percolation
or by back-scattering on bottom irregularities (Shemdin et al., 1978). For continental shelf
seas with sandy bottoms, the dominant mechanism appears to be bottom friction (e.g., Bertotti
and Cavaleri (1994)) which can generally represented as:

Sds,b (σ, θ) = −Cbottom

σ2
E(σ, θ)
g 2 sinh2 (kd)

(5.6)

in which Cbottom is a bottom friction coefficient. A large number of models have been proposed since the pioneering paper of Putnam and Johnson (1949). Hasselmann et al. (1973)

54 of 124

Deltares

Conceptual description

suggested to use an empirically obtained constant. It seems to perform well in many different conditions as long as a suitable value is chosen (typically different for swell and wind
sea; Bouws and Komen (1983)). A non-linear formulation based on drag has been proposed
by Hasselmann and Collins (1968) which was later simplified by Collins (1972). More complicated, eddy viscosity models have been developed by Madsen et al. (1988) (see Weber
(1991a)) and by Weber (1989, 1991a,b). Considering the large variations in bottom conditions in coastal areas (bottom material, bottom roughness length, ripple height etc.), there
is no field data evidence to give preference to a particular friction model (Luo and Monbaliu,
1994). For this reason, the simplest of each of these types of friction models has been implemented in SWAN: the empirical JONSWAP model of Hasselmann et al. (1973), the drag law
model of Collins (1972) and the eddy-viscosity model of Madsen et al. (1988). The effect of a
mean current on the wave energy dissipation due to bottom friction is not taken into account
in SWAN. The reasons for this are given by Tolman (1992b) who argues that state-of-the-art
expressions vary too widely in their effects to be acceptable. He found that the error in finding
a correct estimate of the bottom roughness length scale has a much larger impact on the
energy dissipation rate than the effect of a mean current.

DR
AF

The process of depth-induced wave-breaking is still poorly understood and little is known
about its spectral modelling. In contrast to this, the total dissipation (i.e., integrated over the
spectrum) due to this type of wave breaking can be well modelled with the dissipation of a
bore applied to the breaking waves in a random field (Battjes and Janssen, 1978; Thornton
and Guza, 1983). Laboratory observations (e.g., Battjes and Beji (1992), Vincent et al. (1994);
Arcilla et al. (1994) and Eldeberky and Battjes (1996)) show that the shape of initially unimodal spectra propagating across simple (barred) beach profiles, is fairly insensitive to depthinduced breaking. This has led Eldeberky and Battjes (1995) to formulate a spectral version of
the bore model of Battjes and Janssen (1978) which conserves the spectral shape. Expanding
their expression to include directions, the expression that is used in SWAN is:

Sds,br (σ, θ) = −

Dtot
E(σ, θ)
Etot

(5.7)

in which Etot and Dtot is the rate of dissipation of the total energy due to wave breaking
according to Battjes and Janssen (1978). Adding a quadratic dependency on frequency as
suggested by Mase and Kirby (1992) (supported by Elgar et al. (1997)) seems to have no
noticeable effect on the SWAN results. Chen and Guza (1997) inferred from observations and
simulations with a Boussinesq model that the high-frequency levels are insensitive to such
frequency dependency because an increased dissipation at high frequencies is compensated
approximately by increased non-linear energy transfer (but they did find the frequency dependency to be relevant in time domain). The value of Dtot depends critically on the breaking
parameter γ = Hmax /d (in which Hmax is the maximum possible individual wave height in
the local water depth d). In Delft3D-WAVE a constant value is available equal to γ = 0.73
(the mean value of the data set of Battjes and Stive (1985).
Non-linear wave-wave interactions
In deep water, quadruplet wave-wave interactions dominate the evolution of the spectrum.
They transfer wave energy from the spectral peak to lower frequencies (thus moving the peak
frequency to lower values) and to higher frequencies (where the energy is dissipated by whitecapping). In very shallow water, triad wave-wave interactions transfer energy from lower frequencies to higher frequencies often resulting in higher harmonics (Beji and Battjes, 1993)
(low-frequency energy generation by triad wave-wave interactions is not considered here).
A full computation of the quadruplet wave-wave interactions is extremely time consuming and
not convenient in any operational wave model. A number of techniques, based on parametric
methods or other types of approximations have been proposed to improve computational

Deltares

55 of 124

D-Waves, User Manual

speed (see Young and Van Vledder (1993) for a review). In SWAN the computations are
carried out with the Discrete Interaction Approximation (DIA) of Hasselmann et al. (1985).
This DIA has been found quite successful in describing the essential features of a developing
wave spectrum (Komen et al., 1994). For uni-directional waves, this approximation is not valid.
In fact, the quadruplet interaction coefficient for these waves is nearly zero (G.Ph. van Vledder,
personal communication, 1996). For finite-depth applications, Hasselmann and Hasselmann
(1981) have shown that for a JONSWAP-type spectrum the quadruplet wave-wave interactions
can be scaled with a simple expression (it is used in SWAN).

5.3.2

DR
AF

A first attempt to describe triad wave-wave interactions in terms of a spectral energy source
term was made by Abreu et al. (1992). However, their expression is restricted to non-dispersive
shallow water waves and is therefore not suitable in many practical applications of wind waves.
The breakthrough in the development came with the work of Eldeberky and Battjes (1995) who
transformed the amplitude part of the Boussinesq model of Madsen and Sørensen (1993) into
an energy density formulation and who parameterised the biphase of the waves on the basis
of laboratory observations (Battjes and Beji, 1992; Arcilla, Roelvink, O’Connor, Reniers and
Jimenez, 1994). A discrete triad approximation (DTA) for co-linear waves was subsequently
obtained by considering only the dominant self-self interactions. Their model has been verified with flume observations of long-crested, random waves breaking over a submerged bar
(Beji and Battjes, 1993) and over a barred beach (Arcilla et al., 1994). The model appeared to
be fairly successful in describing the essential features of the energy transfer from the primary
peak of the spectrum to the super harmonics. A slightly different version, the Lumped Triad
Approximation (LTA) was later derived by Eldeberky and Battjes (1996). This LTA is used in
SWAN.
Propagation through obstacles

SWAN can estimate wave transmission through a (line-)structure such as a breakwater (dam).
Such an obstacle will affect the wave field in two ways, first it will reduce the wave height locally
all along its length, and second it will cause diffraction around its end(s). The model is not able
to account for diffraction. In irregular, short-crested wave fields, however, it seems that the
effect of diffraction is small, except in a region less than one or two wavelengths away from the
tip of the obstacle (Booij et al., 1992). Therefore the model can reasonably account for waves
around an obstacle if the directional spectrum of incoming waves is not too narrow. Since
obstacles usually have a transversal area that is too small to be resolved by the bathymetry
grid in SWAN, an obstacle is modelled as a line. If the crest of the breakwater is at a level
where (at least part of the) waves can pass over, the transmission coefficient Kt (defined as
the ratio of the (significant) wave height at the down-wave side of the dam over the (significant)
wave height at the up-wave side) is a function of wave height and the difference in crest level
and water level. The expression is taken from Goda et al. (1967):

F
π
+β
Kt = 0.5 1 − sin
2α Hi

for

−β−α<

F
<α−β
Hi

(5.8)

where F = h − d is the freeboard of the dam and where Hi is the incident (significant) wave
height at the up-wave side of the obstacle (dam), h is the crest level of the dam above the
reference level (same as reference level of the bottom), d the mean water level relative to the
reference level, and the coefficients α, β depend on the shape of the dam (Seelig, 1979):
Case
Vertical thin wall
Caisson
Dam with slope 1:3/2

56 of 124

1.8
2.2
2.6

0.1
0.4
0.15

Deltares

Conceptual description

The above expression is based on experiments in a wave flume, so strictly speaking it is only
valid for normal incidence waves. Since there is no data available on oblique waves it is assumed that the transmission coefficient does not depend on direction. Another phenomenon
that is to be expected is a change in wave frequency since often the process above the dam is
highly non-linear. Again there is little information available, so in the model it is assumed that
the frequencies remain unchanged over an obstacle (only the energy scale of the spectrum is
affected and not the spectral shape).
5.3.3

Wave-induced set-up

Fx + gd

In a (geographic) 1D case the computation of the wave induced set-up is based on the vertically integrated momentum balance equation which is a balance between the wave force
(gradient of the wave radiation stress) and the hydrodynamic pressure gradient (no waveinduced currents exist).

∂ η̄
=0
∂x

(5.9)

DR
AF

where d is the total water depth (including the wave-induced set-up) and η̄ is the mean surface
elevation (including the wave-induced set-up).
In a 2D case, computations are also based on the vertically integrated momentum balance
equation (in two geographic dimensions), supplemented with the observation of Dingemans
et al. (1987) that the wave-induced currents are mainly driven by the divergence-free part of
the wave forces whereas the set-up is mainly due to the rotation-free part of these forces. To
compute the set-up, it would then be sufficient to compute the set-up as if the currents are
zero, which implies that the divergence of all forces considered would be zero:

∂Fx ∂Fy
∂
+
+
∂x
∂y
∂x

∂η
∂
∂η
gd
+
gd
=0
∂x
∂y
∂y

(5.10)

Note that divergence = 0 is only an approximation of the true divergence. These two equations
have been implemented in SWAN. The 2D set-up module can be activated within Delft3DWAVE.
5.3.4

Diffraction

To accommodate diffraction in SWAN simulations, a phase-decoupled refraction-diffraction
approximation is suggested (Holthuijsen et al., 1993). It is expressed in terms of the directional
turning rate of the individual wave components in the 2D wave spectrum. The approximation
is based on the mild-slope equation for refraction and diffraction, omitting phase information.
It does therefore not permit coherent wave fields in the computational domain.
5.4

Full expressions for source terms
The complete expressions for the physical processes of generation, dissipation and non-linear
wave-wave interactions that are available in the SWAN model are given here.

5.4.1

Input by wind
Wave growth by wind is described by:

Sin (σ, θ) = A + BE(σ, θ)

Deltares

(5.11)

57 of 124

D-Waves, User Manual

in which A describes linear growth and BE exponential growth. It should be noted that the
SWAN model is driven by the wind speed at 10 m elevation U10 whereas the computations
use the friction velocity U∗ . For the WAM Cycle 3 formulation the transformation from U10 to
U∗ is obtained with:
2
U∗2 = CD U10

(5.12)

in which CD is the drag coefficient from Wu (1982) ? :

CD (U10 ) =

1.2875 × 10−3
for U10 < 7.5 m/s
(0.8 + 0.065 [s/m] × U10 ) × 10−3 for U10 ≥ 7.5 m/s

(5.13)

The expression for B is due to Komen et al. (1984). Their expression is a function of U∗ /cph :

U∗
ρa
28
cos(θ − θw ) − 1
σ
(5.14)
B = max 0, 0.25
ρw
cph
in which cph is the phase speed and ρa and ρw are the density of air and water, respectively.

This expression is also used in WAM Cycle 3 (cf. the WAMDI group (1988)).
Dissipation of wave energy

DR
AF

5.4.2

Whitecapping

The processes of whitecapping in the SWAN model are represented by the pulse-based model
of Hasselmann (1974). Reformulated in terms of wave number (rather than frequency) so as
to be applicable in finite water depth (cf. the WAMDI group (1988)), this expression is:

k
Sds,w (σ, θ) = −Γσ̃ E(σ, θ)
(5.15)
k̃
where σ̃ and k̃ denote the mean frequency and the mean wave number (for expressions
see below) respectively and the coefficient Γ depends on the overall wave steepness. This
steepness dependent coefficient, as given by the WAMDI group (1988), has been adapted by
Günther et al. (1992) based on Janssen (1991a,b):

Γ = ΓKJ

p
s̃
k
= Cds (1 − δ) + δ
s̃P M
k̃

(5.16)

For δ = 0 the expression of Γ reduces to the expression as used by the WAMDI group
(1988). The coefficients Cds , δ and m are tunable coefficients, s̃ is the overall wave steepness
(defined below), s̃P M is the value of s̃ for the Pierson-Moskowitz spectrum (1964; s̃P M =
(3.02 × 10−3 )1/2 ). This overall wave steepness s̃ is defined as:

s̃ = k̃

p
Etot

(5.17)

The mean frequency σ̃ , the mean wave number k̃ and the total wave energy Etot is defined
as (cf. the WAMDI group (1988)):

Z
−1
σ̃ = Etot
0

2π

Z
0

∞

1
E(σ, θ)dσdθ
σ

−1

−2
Z 2π Z ∞
1
−1
√ E(σ, θ)dσdθ
k̃ = Etot
k
0
0
Z 2π Z ∞
Etot =
E(σ, θ)dσdθ
0

58 of 124

(5.18)

Deltares

Conceptual description

The values of the tunable coefficients Cds and δ and exponent p in this model have been
obtained by Komen et al. (1984) by closing the energy balance of the waves in idealised
wave growth conditions (both for growing and fully developed wind seas) for deep water. This
implies that coefficients in the steepness dependent coefficient Γ depend on the wind input
formulation that is used. For the wind input of Komen et al. (1984) (corresponding to WAM
Cycle 3; the WAMDI group (1988)):

Cds = 2.36 × 10−5 ,
δ = 0 and
p = 4.

(5.19)
(5.20)
(5.21)

Bottom friction

DR
AF

σ2
Sds,b (σ, θ) = −Cbottom 2
E(σ, θ)
g sinh2 (kd)

The bottom friction models that have been selected for SWAN are the empirical model of
JONSWAP (Hasselmann et al., 1973), the drag law model of Collins (1972) and the eddyviscosity model of Madsen et al. (1988). The formulations for these bottom friction models
can all be expressed in the following form:
(5.22)

in which Cbottom is a bottom friction coefficient that generally depends on the bottom orbital
motion represented by Urms :
2
Urms

2π

∞

σ2
E(σ, θ)dσdθ
sinh2 (kd)

(5.23)

Hasselmann et al. (1973) found from the results of the JONSWAP experiment Cbottom =
CJON = 0.038 m2 s−3 for swell conditions. Bouws and Komen (1983) selected a bottom
friction coefficient of CJON = 0.067 m2 s−3 for fully developed wave conditions in shallow
water. Both values are available in SWAN.
The expression of Collins (1972) is based on a conventional formulation for periodic waves
with the appropriate parameters adapted to suit a random wave field. The dissipation rate is
calculated with the conventional bottom friction formulation of Eq. (5.22) in which the bottom
friction coefficient is Cbottom = Cf gUrms with Cf = 0.015 (Collins, 1972). (Note that Collins
(1972) contains an error in the expression due to an erroneous Jacobean transformation; see
page A-16 of Tolman (1990).)
Madsen et al. (1988) derived a formulation similar to that of Hasselmann and Collins (1968)
but in their model the bottom friction factor is a function of the bottom roughness height and
the actual wave conditions. Their bottom friction coefficient is given by:

g
Cbottom = fw √ Urms
2

(5.24)

in which fw is a non-dimensional friction factor estimated by using the formulation of Jonsson
(1966) (cf. Madsen et al. (1988)):

1
√ +
4 fw

log

1
√
4 fw

= mf +

log

ab
KN

(5.25)

in which mf = −0.08 (Jonsson and Carlsen, 1976) and ab is a representative near-bottom
excursion amplitude:

a2b

=2
0

Deltares

2π

∞

1
E(σ, θ)dσdθ
sinh2 (kd)

(5.26)

59 of 124

D-Waves, User Manual

and KN is the bottom roughness length scale. For values of ab /KN smaller than 1.57 the
friction factor fw is 0.30 (Jonsson, 1980).
Depth-induced wave breaking
To model the energy dissipation in random waves due to depth-induced breaking, the borebased model of Battjes and Janssen (1978) is used in SWAN. The mean rate of energy
dissipation per unit horizontal area due to wave breaking Dtot is expressed as:

σ
1
2
Dtot = − αBJ Qb
Hm
4
2π

(5.27)

in which αBJ = 1 in SWAN, Qb [-] is the fraction of breaking waves determined by:

1 − Qb
Etot
= −8 2
ln Qb
Hm

(5.28)

DR
AF

in which Hm is the maximum wave height that can exist at the given depth and σ̄ is a mean
frequency defined as:

σ̄ =

−1
Etot

2π

∞

σE(σ, θ)dσdθ

(5.29)

Extending the expression of Eldeberky and Battjes (1995) to include the spectral directions,
the dissipation for a spectral component per unit time is calculated in SWAN with:

Sds,br (σ, θ) = Dtot

E(σ, θ)
Etot

(5.30)

The maximum wave height Hm is determined in SWAN with Hm = γd, in which γ is the
breaker parameter and d is the total water depth (including the wave-induced set-up if computed by SWAN). In literature, this breaker parameter γ is often a constant or it is expressed
as a function of bottom slope or incident wave steepness (Galvin, 1972; Battjes and Janssen,
1978; Battjes and Stive, 1985; Arcilla and Lemos, 1990; Kaminsky and Kraus, 1993; Nelson,
1987, 1994). Since SWAN is locally defined, the dependency on incident wave steepness
cannot be used.
In the publication of Battjes and Janssen (1978) in which the dissipation model is described,
a constant breaker parameter, based on Miche’s criterion, of γ = 0.8 was used. Battjes
and Stive (1985) re-analysed wave data of a number of laboratory and field experiments and
found values for the breaker parameter varying between 0.6 and 0.83 for different types of
bathymetry (plane, bar-trough and bar) with an average of 0.73. From a compilation of a large
number of experiments Kaminsky and Kraus (1993) have found breaker parameters in the
range of 0.6 to 1.59 with an average of 0.79.
5.4.3

Nonlinear wave-wave interactions
Quadruplet wave-wave interactions
The quadruplet wave-wave interactions are computed with the Discrete Interaction Approximation (DIA) as proposed by Hasselmann et al. (1985). Their source code (slightly adapted
by Tolman, personal communication, 1993) has been used in the SWAN model. In the Discrete Interaction Approximation two quadruplets of wave numbers are considered, both with

60 of 124

Deltares

Conceptual description

frequencies:

σ1 = σ2 = σ
σ3 = σ(1 + λ) = σ +
σ4 = σ(1 − λ) = σ −

(5.31)

where λ is a constant coefficient set equal to 0.25. To satisfy the resonance conditions for
the first quadruplet, the wave number vectors with frequency σ3 and σ4 lie at an angle of
θ1 = −11.5◦ and θ2 = 33.6◦ to the two identical wave number vectors with frequencies σ1
and σ2 . The second quadruplet is the mirror of this first quadruplet (the wave number vectors
with frequency σ3 and σ4 lie at mirror angles of θ3 = 11.5◦ and θ4 = −33.6◦ .

∗
∗∗
Snl4 (σ, θ) = Snl4
(σ, θ) + Snl4
(σ, θ)

Within this discrete interaction approximation, the source term Snl4 (σ, θ) is given by:
(5.32)

∗
∗∗
where Snl4
(σ, θ) refers to the first quadruplet and Snl4
(σ, θ) to the second quadruplet (the
∗∗
∗
expressions for Snl4 (σ, θ) are identical to those for Snl4
(σ, θ) for the mirror directions) and:

DR
AF

∗
∗
∗
∗
Snl4
(σ, θ) = 2δSnl4
(α1 , σ, θ) − δSnl4
(α2 , σ, θ) − δSnl4
(α3 , σ, θ)

(5.33)

in which α1 = 1, α2 = (1 + λ) and α3 = (1 − λ). Each of the contributions (i = 1, 2, 3) is:

σ 11
δSnl4 (αi σ, θ) = Cnl4 (2π)2 g −4
2π

2
+
E 2 (αi σ, θ)E 2 (αi σ + , θ)E 2 (αi σ − , θ)
E (αi σ , θ) E 2 (αi σ − , θ)
2
+
−2
E (αi σ, θ)
(1 + λ)4
(1 − λ)4
(1 − λ2 )4
(5.34)

The constant Cnl4 = 3×107 . Following Hasselmann and Hasselmann (1981), the quadruplet
interaction in finite water depth is taken identical to the quadruplet transfer in deep water
multiplied with a scaling factor R:

Snl4,finite depth = R(kp d)Snl4,infinite depth

(5.35)

where R is given by:

R(kp d) = 1 +

Csh1
(1 − Csh2 kp d) exp(Csh3 kp d)
kp d

(5.36)

in which kp is the peak wave number of the JONSWAP spectrum for which the original computations were carried out. The values of the coefficients are: Csh1 = 5.5, Csh2 = 6/7
and Csh3 = −1.25. In the shallow water limit, i.e., kp d → 0 the non-linear transfer tends to
infinity. Therefore a lower limit of kp d = 0.5 is applied (cf. WAM Cycle 4; Komen et al. (1994),
resulting in a maximum value of R(kp d) = 4.43. To increase the model robustness in case
of arbitrarily shaped spectra, the peak wave number kp is replaced by kp = 0.75k̄ (Komen
et al., 1994).

Deltares

61 of 124

D-Waves, User Manual

Triad wave-wave interactions
The Lumped Triad Approximation (LTA) of Eldeberky and Battjes (1996), which is a slightly
adapted version of the Discrete Triad Approximation of Eldeberky and Battjes (1995) is used
in SWAN in each spectral direction:
−
+
Snl3 (σ, θ) = Snl3
(σ, θ) + Snl3
(σ, θ)

(5.37)

with
+
Snl3
(σ, θ) = max{0, αEB 2πccg J 2 | sin(β)|{E 2 (σ/2, θ)−2E(σ/2, θ)E(σ, θ)}} (5.38)

and
−
+
Snl3
(σ, θ) = −2Snl3
(2σ, θ)

(5.39)

in which αEB is a tunable proportionality coefficient. The bi-phase β is approximated with

0.2
Ur

π π
β = − + tanh
2
2
with Ursell number U r :

DR
AF

g Hs T̄ 2
Ur = √
8 2π 2 d2

(5.40)

(5.41)

with T̄ = 2π/σ̄ . Usually, the triad wave-wave interactions are calculated only for 0.1 ≤
U r ≤ 10. But for stability reasons, it is calculated for the whole range 0 ≤ U r ≤ 10.
This means that both quadruplets and triads are computed at the same time. The interaction
coefficient J is taken from Madsen and Sørensen (1993):

2
(gd + 2c2σ/2 )
kσ/2

kσ d gd +

2
gd3 kσ2
15

− 52 σ 2 d2

(5.42)

Wave-induced set-up

In a geographic 1D case the computation of the wave induced set-up is based on the vertically
integrated momentum balance equation which is a balance between the wave force (gradient
of the wave radiation stress normal to the coast) and the hydrostatic pressure gradient (note
that the component parallel to the coast causes wave-induced currents but no set-up):

dSxx
dη̄
+ ρgH
=0
(5.43)
dx
dx
where H = d+ η̄ is the total water depth (including the wave-induced set-up), d is the bottom
level, η̄ is the mean surface elevation (including the wave-induced set-up) and

Z
n−1
2
Sxx = ρg
n cos θ +
E dσdθ
(5.44)
2
is the radiation stress tensor.
Observation and computations based on the vertically integrated momentum balance equation of Dingemans et al. (1987) show that the wave-induced currents are mainly driven by
the divergence-free part of the wave forces whereas the set-up is mainly due to the rotationfree part of these forces. To compute the set-up, it would then be sufficient to consider the
divergence of the momentum balance equation. If the divergence of the acceleration in the
resulting equation is ignored, the result is:

∂Fx ∂Fy
∂
∂ η̄
∂
∂ η̄
+
+
(ρgH ) +
(ρgH ) = 0
∂x
∂y
∂x
∂x
∂y
∂y

62 of 124

(5.45)

Deltares

Conceptual description

Diffraction
In a simplest case, we assume there are no currents. This means that cσ = 0. Let denotes the
propagation velocities in geographic and spectral spaces for the situation without diffraction
as: cx,0 , cy,0 and cθ,0 . These are given by:

cx,0 =

∂ω
cos(θ),
∂k

cy,0 =

∂ω
sin(θ),
∂k

cθ,0 = −

1 ∂ω ∂h
k ∂h ∂n

(5.46)

where k is the wave number and n is perpendicular to the wave ray. We consider the following
eikonal equation:

K 2 = k 2 (1 + δ)

(5.47)

with δ denoting the diffraction parameter as given by:

∇(ccg ∇Hs )
ccg Hs

(5.48)

δ=

Due to diffraction, the propagation velocities are given by:

where δ̄ =
5.5

cy = cy,0 δ,

cθ = cθ,0 δ̄ −

∂ δ̄
∂ δ̄
cy,0 +
cx,0
∂x
∂y

(5.49)

DR
AF

cx = cx,0 δ̄,
√

1 + δ.

Numerical implementation

The integration of the action balance equation has been implemented in SWAN with finite
difference schemes in all five dimensions (time, geographic space and spectral space). In
Delft3D-WAVE, SWAN is applied in a stationary mode so that time has been omitted from
the equations. Below the propagation schemes in geographical and spectral space are briefly
described.
The geographic space is discretised with a rectangular grid with constant resolutions ∆x
and ∆y in x- and y -direction respectively (in fact, this rectangular grid is a special case
of the curvi-linear grid that has been programmed in SWAN. The spectrum in the model
is discretised with a constant directional resolution ∆θ and a constant relative frequency
resolution ∆σ/σ (logarithmic frequency distribution). For reasons of economy, an option
is available to compute only wave components travelling in a pre-defined directional sector
(θmin < θ < θmax ; e.g., those components that travel shorewards within a limited directional
sector). The discrete frequencies are defined between a fixed low-frequency cut-off and a
fixed high-frequency cut-off (the prognostic part of the spectrum). For these frequencies the
spectral density is unconstrained. Below the low-frequency cut-off (typically fmin = 0.04 Hz
for field conditions) the spectral densities are assumed to be zero. Above the high-frequency
cut-off (typically 1 Hz for field conditions) a diagnostic f −m tail is added (this tail is used to
compute non-linear wave-wave interactions at the high frequencies and to compute integral
wave parameters). The reason for using a fixed high-frequency cut-off rather than a dynamic
cut-off frequency that depends on the wind speed or on the mean frequency, as in the WAM
and WAVEWATCH III model, is that in coastal regions mixed sea states with rather different
characteristic frequencies may occur. For instance, a local wind may generate a very young
sea behind an island, totally unrelated to (but superimposed on) a simultaneously occurring
swell. In such cases a dynamic cut-off frequency may be too low to properly account for the
locally generated sea state. Based on physical arguments the value of m (the power in the
above expression of the spectral tail) should be between 4 and 5 (Phillips, 1985). In SWAN
m = 4 if the wind input formulation of Komen et al. (1984) is used (cf. WAM Cycle 3) and
m = 5 if the wind input formulation of Janssen (1991a) is used (cf. WAM Cycle 4).

Deltares

63 of 124

D-Waves, User Manual

Propagation

The numerical schemes in SWAN have been chosen on the basis of robustness, accuracy
and economy. Since the nature of the basic equation is such that the state in a grid point
is determined by the state in the up-wave grid points, the most robust scheme would be an
implicit upwind scheme (in both geographic and spectral space). The adjective ”implicit” is
used here to indicate that all derivatives of action density (x or y ) are formulated at one computational level, ix or iy , except the derivative in the integration dimension for which also the
previous or up-wave level is used (x or y in stationary mode). For such a scheme the values
of space steps, ∆x and ∆y would be mutually independent. An implicit scheme would also
be economical in the sense that such a scheme is unconditionally stable. It permits relatively
large time steps in the computations (much larger than for explicit schemes in shallow water). Several years of experience in using the second-generation HISWA shallow water wave
model (Holthuijsen et al., 1989) has shown that for coastal regions a first-order upwind difference scheme in geographic space is usually accurate enough. This experience, together with
test computations with SWAN has also shown that in spectral space a higher accuracy than
that of a first-order upwind scheme is required. This can be achieved by supplementing such a
scheme with a second-order central approximation (more economic than a second-order upwind scheme). For SWAN therefore, implicit upwind schemes in both geographic and spectral
space have been chosen, supplemented with a central approximation in spectral space.

DR
AF

5.5.1

The fact that in geographic space, the state in a grid point is determined by the state in the upwave grid points (as defined by the direction of propagation), permits a decomposition of the
spectral space into four quadrants. In each of the quadrants the computations can be carried
out independently from the other quadrants except for the interactions between them due
to refraction and non-linear wave-wave interactions (formulated in corresponding boundary
conditions between the quadrants). The wave components in SWAN are correspondingly
propagated in geographic space with the first-order upwind scheme in a sequence of four
forward-marching sweeps (one per quadrant). To properly account for the boundary conditions
between the four quadrants, the computations are carried out iteratively at each time step. The
discretization of the action balance equation is (for positive propagation speeds; including the
computation of the source terms but ignoring their discretisation):

[cy N ]iy − [cy N ]iy −1 n
[cx N ]ix − [cx N ]ix −1
+
∆x
∆y
iy ,iσ ,iθ
ix ,iσ ,iθ
n

(1 − ν)[cσ N ]iσ +1 + 2ν[cσ N ]iσ − (1 + ν)[cσ N ]iσ −1
+
2∆σ
ix ,iy ,iθ
n∗

n
(1 − η)[cθ N ]iθ +1 + 2η[cθ N ]iθ − (1 + η)[cθ N ]iθ −1
S
+
=
2∆θ
σ ix ,iy ,iσ ,iθ
ix ,iy ,iσ

(5.50)
where ix , iy , iσ and iθ are grid counters and ∆x, ∆y , ∆σ and ∆θ are the increments in
geographic space and spectral space respectively. The iterative nature of the computation
is indicated with the iteration index n (the iteration index for the source terms n∗ is equal to
n or n − 1, depending on the source term, see below). Because of these iterations, the
scheme is also approximately implicit for the source terms. For negative propagation speeds,
appropriate + and - signs are required in Eq. (5.50).
The coefficients ν and η determine the degree to which the scheme in spectral space is upwind or central. They thus control the numerical diffusion in frequency and directional space,

64 of 124

Deltares

Conceptual description

respectively. A value of ν = 0 or η = 0 corresponds to central schemes which have the
largest accuracy (numerical diffusion 0). Value of ν = 1 or η = 1 correspond to upwind
schemes which are somewhat more diffusive and therefore less accurate but more robust.
If large gradients of the action density in frequency space or directional space are present,
numerical oscillations can arise (especially with the central difference schemes) resulting in
negative values of the action density. In each sweep such negative values are removed from
the two-dimensional spectrum by setting these values equal to zero and re-scaling the remaining positive values such that the frequency-integrated action density per spectral direction is
conserved. The depth derivatives and current derivatives in the expressions of cσ and cθ
are calculated with a first-order upwind scheme. For very strong refraction the value of cθ is
reduced in each grid point and for each wave component individually with the square of the
fraction of the grid spacing over which kd < 3.0.

The propagation scheme is implicit as the derivatives of action density (in x or y ) at the
computational level (ix or iy , respectively) are formulated at that level except in the integration
dimension (x or y ; depending on the direction of propagation) where also the up-wave level
is used. The values of ∆x and ∆y are therefore still mutually independent.

DR
AF

The boundary conditions in SWAN, both in geographic space and spectral space are fully
absorbing for wave energy that is leaving the computational domain or crossing a coast line.
The incoming wave energy along open geographic boundaries needs to be prescribed by
you. For coastal regions such incoming energy is usually provided only along the deepwater boundary and not along the lateral geographic boundaries (i.e., the spectral densities
are assumed to be zero). This implies that such erroneous lateral boundary conditions are
propagated into the computational area. The affected areas are typically triangular regions
with the apex at the corners between the deep-water boundary and the lateral boundaries,
spreading towards shore at an angle of 30◦ to 45◦ (for wind sea conditions) on either side of
the deep-water mean wave direction (less for swell conditions; this angle is essentially equal
to the one-sided width of the directional distribution of the incoming wave spectrum). For this
reason the lateral boundaries should be sufficiently far away from the area of interest to avoid
the propagation of this error into the area.

Deltares

65 of 124

DR
AF

D-Waves, User Manual

66 of 124

Deltares

References
Abreu, M., A. Larraza and E. Thornton, 1992. “Nonlinear transformation of directional wave
spectra in shallow water.” Journal of Geophysical Research 97: 15579–15589.
Alves, J. and M. Banner, 2003. “Performance of a saturation-based dissipation-rate source
term in modelling the fetch-limited evolution of wind waves.” J. Phys. Oceanogr. 33: 1274–
1298.
Arcilla, A. and C. Lemos, 1990. Surf-Zone Hydrodynamics. Centro Internacional de Métodos
Numéricos en Ingenieria, Barcelona.
Arcilla, A., B. Roelvink, B. O’Connor, A. Reniers and J. Jimenez, 1994. “The Delta flume ’93
experiment.” In Proceedings Coastal Dynamics Conference ’94, pages 488–502.

Battjes, J. and S. Beji, 1992. “Breaking waves propagating over a shoal.” In Proceedings 23rd
International Conference Coastal Engineering, ASCE, pages 42–50.
Battjes, J. and J. Janssen, 1978. “Energy loss and set-up due to breaking of random waves,.”
In Proceedings 16th International Conference Coastal Engineering, ASCE, pages 569–587.

DR
AF

Battjes, J. and M. Stive, 1985. “Calibration and verification of a dissipation model for random
breaking waves.” Journal of Geophysical Research 90 (C5): 9159–9167.
Beji, S. and J. Battjes, 1993. “Experimental investigation of wave propagation over a bar.”
Coastal Engineering 19: 151–162.
Bertotti, L. and L. Cavaleri, 1994. “Accuracy of wind and wave evaluation in coastal regions.”
In Proceedings 24th International Conference Coastal Engineering, ASCE, pages 57–67.
Booij, N., L. H. Holthuijsen and P. H. M. de Lange, 1992. “The penetration of short-crested
waves through a gap.” In Proceedings 23rd International Conference Coastal Engineering,
Venice 4-9 Oct., 1992, New York, 1993, pages 1044–1052.
Booij, N., R. Ris and L. Holthuijsen, 1999. “A third-generation wave model for coastal regions,
Part I, Model description and validation.” Journal of Geophysical Research 104 (C4): 7649–
7666.
Bouws, E. and G. Komen, 1983. “On the balance between growth and dissipation in an
extreme, depth-limited wind-sea in the southern North Sea.” Journal of Physical Oceanography 13: 1653–1658.
Cavaleri, L. and P. Malanotte-Rizzoli, 1981. “Wind wave prediction in shallow water: Theory
and applications.” Journal of Geophysical Research 86 (C11): 10 961–10 973.
Chen, Y. and R. Guza, 1997. “Modelling of breaking surface waves in shallow water.” Journal
of Geophysical Research 102 (C11): 25 035–25 046.
Collins, J., 1972. “Prediction of shallow water spectra.” Journal of Geophysical Research
77 (15): 2693–2707.
Delft3D-FLOW UM, 2013. Delft3D-FLOW User Manual. Deltares, 3.14 ed.
Dingemans, M. W., 1997. Water Wave Propagation over Uneven Bottoms, Vol. 1 and 2.
Advanced Series on Ocean Engineering, Vol. 13. World Scientific, London.
Dingemans, M. W., A. C. Radder and H. J. de Vriend, 1987. “Computation of the driving forces
of wave-induced currents.” Coastal Engineering 11: 539–563.

Deltares

67 of 124

D-Waves, User Manual

Eldeberky, Y. and J. Battjes, 1995. “Parameterization of triad interactions in wave energy
models, Gdansk, Poland.” In Proceedings Coastal Dynamics Conference ’95, pages 140–
148.
Eldeberky, Y. and J. A. Battjes, 1996. “Spectral modelling of wave breaking: Application to
Boussinesq equations.” Journal of Geophysical Research 101 (C1): 1253–1264.
Elgar, S., R. Guza, B. Raubenheimer, T. Herbers and E. Gallagher, 1997. “Spectral evolution
of shoaling and breaking waves on a barred beach.” Journal of Geophysical Research
102 (C7): 15797–15805.
Galvin, C., 1972. “Waves on beaches and resulting sediment transport.” In Wave breaking in
shallow water, pages 413–455. Academic Press Inc.

Goda, Y., H. Takeda and Y. Moriya, 1967. Laboratory investigation of wave transmission over
breakwaters. Tech. Rep. 13, Rep. port and Harbour Res. Institution. (from Seelig, 1979).
Günther, H., S. Hasselmann and P. A. E. M. Janssen, 1992. The WAM model Cycle 4 (revised
version). Tech. Rep. 4, Deutsch. Klim. Rechenzentrum, Hamburg, Germany.

DR
AF

Hasselmann, K., 1974. “On the spectral dissipation of ocean waves due to whitecapping.”
Boundary-Layer Meteorology 6 (1-2): 107–127.
Hasselmann, K., T. P. Barnett, E. Bouws, H. Carlson, D. E. Cartwright, K. Enke, J. Ewing, H. Gienapp, D. E. Hasselmann, P. Kruseman, A. Meerburg, P. Müller, D. J. Olbers,
K. Richter, W. Sell and H. Walden, 1973. “Measurements of wind wave growth and swell
decay during the Joint North Sea Wave Project (JONSWAP).” Deutsche Hydrographische
Zeitschrift 8 (12).
Hasselmann, K. and J. Collins, 1968. “Spectral dissipation of finite-depth gravity waves due
to turbulent bottom friction.” Journal of Marine Research 26: 1–12.
Hasselmann, S. and K. Hasselmann, 1981. “A symmetrical method of computing the nonlinear transfer in a gravity-wave spectrum.” Hamburger Geophysikalische Einzelschriften
52 (8): 138p. Serie A.
Hasselmann, S., K. Hasselmann, J. Allender and T. Barnett, 1985. “Computations and parameterizations of the nonlinear energy transfer in a gravity wave spectrum. Part II: Parameterizations of the nonlinear transfer for application in wave models.” Journal of Physical
Oceanography 15 (11): 1378–1391.
Holthuijsen, L., N. Booij and T. Herbers, 1989. “A prediction model for stationary, short-crested
waves in shallow water with ambient currents.” Coastal Engineering 13: 23–54.
Holthuijsen, L., N. Booij and R. Ris, 1993. “A spectral wave model for the coastal zone.” In
Proceedings of 2nd International Symposium on Ocean Wave Measurement and Analysis,
New Orleans, pages 630–641.
Ilic, S., 1994. The role of offshore breakwaters in the coastal defence: comparison of two
measurement systems. Tech. rep., University of Plymouth School of Civil and Structural
Engineering.
Janssen, P., 1991a. “Quasi-linear theory of wind-wave generation applied to wave forecasting.”
Journal of Physical Oceanography 21: 1631–1642.
Janssen, P. A. E. M., 1991b. Consequences of the effect of surface gravity waves on the
mean air flow. Tech. rep., International Union of Theor. and Appl. Mech. (IUTAM), Sydney,
Australia. 193-198.

68 of 124

Deltares

References

Jonsson, I., 1966. “Wave boundary layers and friction factors.” In Proceedings 10th International Conference Coastal Engineering, ASCE, pages 127–148.
Jonsson, I. and N. Carlsen, 1976. “Experimental and theoretical investigations in an oscillatory
turbulent boundary layer.” Journal of Hydraulic Research 14: 45–60.
Jonsson, I. G., 1980. “A new approach to rough turbulent boundary layers.” Ocean Engineering 7: 109–152.
Kaminsky, G. and N. Kraus, 1993. “Evaluation of depth-limited wave breaking criteria.” In
Proceedings of 2nd International Symposium on Ocean Wave Measurement and Analysis,
pages 180–193. New Orleans.

Kirby, J. T. and T.-M. Chen, 1989. “Surface waves on vertically sheared flows: approximate
dispersion relations.” Journal of Geophysical Research 94: 1013–1027.
Komen, G., L. Cavaleri, M. Donelan, K. Hasselmann, S. Hasselmann and P. Janssen, 1994.
Dynamics and Modelling of Ocean Waves. Camebridge University Press.

DR
AF

Komen, G., S. Hasselmann and K. Hasselmann, 1984. “On the existence of a fully developed
wind-sea spectrum.” Journal of Physical Oceanography 14: 1271–1285.
Kuik, A., G. van Vledder and L. Holthuijsen, 1988. “A method for the routine analysis of
pitch-and-roll buoy wave data.” Journal of Physical Oceanography 18: 1020–1034.
Luo, W. and J. Monbaliu, 1994. “Effects of the bottom friction formulation on the energy
balance for gravity waves in shallow water.” Journal of Geophysical Research 99 (C9):
18501–18511.
Madsen, O., Y.-K. Poon and H. Graber, 1988. “Spectral wave attenuation by bottom friction:
Theory.” In Proceedings 21th International Conference Coastal Engineering, ASCE, pages
492–504.
Madsen, P. and O. Sørensen, 1993. “Bound waves and triad interactions in shallow water.”
Ocean Engineering 20 (4): 359–388.
Mase, H. and J. Kirby, 1992. “Hybrid frequency-domain KdV equation for random wave transformation.” In Proceedings 23th International Conference Coastal Engineering, ASCE,
pages 474–487.
Mastenbroek, C., G. Burger and P. Janssen, 1993. “The dynamical coupling of a wave model
in a storm surge model through the atmospheric boundary layer.” Journal of Physical
Oceanography 23: 1856–1866.
Mei, C., 1983. The applied dynamics of ocean surface waves. Wiley, New York.
Miles, J., 1957. “On the generation of surface waves by shear flows.” Journal of Fluid Mechanics 3: 185–204.
Nelson, R., 1987. “Design wave heights on very mild slopes: An experimental study.” Transactions of the Institution of Engineers, Australia, Civil Engineering 29: 157–161.
Nelson, R. C., 1994. “Depth limited wave heights in very flat regions.” Coastal Engineering
23: 43–59.
Phillips, N. A., 1957. “A co-ordinate system having some special advantages for numerical
forecasting.” Journal of Meteorology 14: 184–185.
Phillips, O., 1985. “Spectral and statistical properties of the equilibrium range in windgenerated gravity waves.” Journal of Fluid Mechanics 156: 505–531.

Deltares

69 of 124

D-Waves, User Manual

Putnam, J. and J. Johnson, 1949. “The dissipation of wave energy by bottom friction.” Transactions - American Geophysical Union 30: 67–74.
Ris, R., N. Booij and L. Holthuijsen, 1999. “A third-generation wave model for coastal regions,
Part II: Verification.” Journal of Geophysical Research 104 (C4): 7649–7666.
Seelig, W., 1979. “Effects of breakwaters on waves: laboratory tests of wave transmission by
overtopping.” In Proceedings Conference Coastal Structures, vol. 79:2, pages 941–961.
Shemdin, P., K. Hasselmann, S. Hsiao and K. Herterich, 1978. “Non linear and linear bottom
interaction effects in shallow water.” In Turbulent Fluxes through the Sea Surface Wave
Dynamics and Prediction, NATO Conference Series, no. 1 in V, pages 347–372.

Snyder, R., F. Dobson, J. Elliot and R. Long, 1981. “Array measurement of atmospheric
pressure fluctuations above surface gravity waves.” Journal of Fluid Mechanics 102: 1–59.
SWAN UM, 2000. SWAN Cycle III version 40.11 User Manual (not the short version). Delft
University of Technology, Delft, The Netherlands, 0.00 ed.

DR
AF

Thornton, E. and R. Guza, 1983. “Transformation of wave height distribution.” Journal of
Geophysical Research 88 (C10): 5925–5938.
Tolman, H., 1990. Wind wave propagation in tidal seas. Ph.D. thesis, Delft University of
Technology, Department of Civil Engineering, The Netherlands.
Tolman, H. L., 1992a. “Effects of numerics on the physics in a third-generation windwave
model.” Journal of Physical Oceanography 22: 1095–1111.
Tolman, H. L., 1992b. “An evaluation of expressions for the wave energy dissipation due to
bottom friction in the presence of currents.” Coastal Engineering 16: 165–179.
Vincent, C., J. Smith and J. Davis, 1994. “Parameterization of wave breaking in models.” In
M. Isaacson and M. Quick, eds., Proceedings of International Symp.: Waves - Physical and
Numerical Modelling, vol. II, pages 753–762. University of British Columbia, Vancouver,
Canada.
WAMDI group, 1988. “The WAM model a third generation ocean wave prediction model.”
Journal of Physical Oceanography 18: 1775–1810.
Weber, S., 1989. Surface gravity waves and turbulent bottom friction. Ph.D. thesis, University
of Utrecht, The Netherlands.
Weber, S. L., 1991a. “Bottom friction for wind sea and swell in extreme depth-limited situations.” Journal of Physical Oceanography 21: 149–172.
Weber, S. L., 1991b. “Eddy-viscosity and drag-law models for random ocean wave dissipation.” Journal of Fluid Mechanics 232: 73–98.
Westhuysen, A. J. Van der, 2007. Advances in the spectral modelling of wind waves in the
nearshore. Ph.D. thesis, Delft University of Technology. Fac. of Civil Engineering.
Westhuysen, A. Van der, M. Zijlema and J. Battjes, 2007. Nonlinear saturation-based whitecapping dissipation in SWAN for deep and shallow water. Ph.D. thesis, Delft University of
Technology.
Whitham, G., 1974. Linear and nonlinear waves. Wiley, New York.
WL | Delft Hydraulics, 1999. Modification first-guess SWAN and bench mark tests for SWAN.
Tech. Rep. H3515, WL | Delft Hydraulics, Delft, The Netherlands, Delft.

70 of 124

Deltares

References

WL | Delft Hydraulics, 2000. Physical formulations SWAN and data for validation. Tech. Rep.
H3528, WL | Delft Hydraulics, Delft, The Netherlands, Delft.
Wu, J., 1982. “Wind-stress coefficients over sea surface from breeze to hurricane.” Journal of
Geophysical Research 87 (C12): 9704–9706.

DR
AF

Young, I. R. and G. van Vledder, 1993. “A review of the central role of nonlinear interactions
in wind-wave.” Philosophical transaction of the Royal Society London A 342: 505–524.

Deltares

71 of 124

DR
AF

D-Waves, User Manual

72 of 124

Deltares

A Files of Delft3D-WAVE

General description
File contents
Filetype
File format
Filename
Generated

The Master Definition WAVE file (MDW-file) is the input file for the
wave simulation program.
ASCII
Free formatted

WAVE-GUI or manually offline

The Master Definition WAVE file (MDW-file) is the input file for the wave simulation program.
It contains all the necessary data required for defining a model and running the simulation
program. In the MDW-file you can define attribute files in which relevant data (for some parameters) are stored. This is especially useful when parameters contain a large number of
data (e.g. time-dependent or space varying data). The user-definable attribute files are listed
and described in Appendix A.

A.1.1

MDW-file

DR
AF

A.1

The MDW-file has the following general characteristics:

Each line contains a maximum of 300 characters.
Each set of input parameter(s) is preceded by a chapter name enclosed in square brackets
(e.g. [WaveFileInformation]).
Each input parameter is preceded by a Keyword.
A Keyword is a combination of numerical and alpha-numerical characters, but starting
with an alpha-numeric character, followed by an equal sign “=”.
The MDW-file is an intermediate file between the WAVE-GUI and the WAVE simulation program. As it is an ASCII-file, it can be transported to an arbitrary hardware platform. Consequently, the WAVE simulation program and the WAVE-GUI do not necessarily have to reside
on the same hardware platform.
Generally, you need not to bother about the internal layout or content of the MDW-file. It is,
however, sometimes useful to be able to inspect the file and/or make small changes manually.
Therefore the MDW-file is an ordinary ASCII-file which you can inspect and change with your
favourite ASCII-editor.
The MDW-file is self contained, i.e. it contains all the necessary information about the model
concerned. It can therefore be used as model archive by storing/printing the file.
Here we list all the possible chapters and keywords of the MDW-file:
Record description:
Keyword

Format

Description

string

should be 02.00

C∗16

project name

WaveFileInformation

FileVersion
General

ProjectName

continued on next page
∗

May be specified multiple times
+
Not supported by WAVE-GUI
R = Real; I = Integer; L = Logical; C = Character

Deltares

73 of 124

D-Waves, User Manual

continued from previous page
Format

Description

ProjectNr

C∗4

project number

Description∗

C∗72

description line

OnlyInputVerify

switch for input validation or simulation run: false = simulation run, or true = input validation only

SimMode

key-value

simulation mode: stationary, quasi-stationary, non-stationary

TimeStep

time step in case of non-stationary simulation

TScale+

1 R, optional

unit of time, default is 60.0)

string

name of mdf-file containing FLOW input. If FlowFile is empty, FLOW is not running online. If FlowFile is
non-empty, FLOW is running online.

FlowMudFile+

string

name of mdf-file containing FLOW input for the mud phase of a two phased FLOW model. If FlowMudFile is
empty, MUD is not running online. If FlowMudFile is non-empty, MUD is running online.

FlowBedLevel

default usage of bed level from hydrodynamic computation by all domains: 0 = “don’t use”, 1 = “use but don’t
extend”, 2 = “use and extend” if necessary. May be overruled by same keyword in group "domain". Not relevant
when FlowFile is empty; default: 0

FlowWaterLevel

See description of FlowBedLevel above.

FlowVelocity

See description of FlowBedLevel above.

FlowVelocityType

key-value

method of velocity computation (depth-averaged, surface-layer, wave-dependent; default: depth-averaged)

FlowWind

See description of FlowBedLevel above.

DirConvention

key-value

direction specification convention: nautical, cartesian

ReferenceDate

C∗10

reference date (string format: YYYY-MM-DD)

DR
AF

FlowFile

Keyword

ObstacleFile

string

name of file containing obstacles

TSeriesFile

string

name of file containing time-dependent quantities

TimePntBlock

1 I, optional

number of table in TSeriesFile containing time points; only if TSeriesFile has been specified

MeteoFile∗+

characters

Name of file containing meteo input

DirSpace

1 R, optional

default directional space: circle, sector

1 R, optional

default number of directional bins

1 R, optional

default start direction in case of sector directional space

1 R, optional

default end direction in case of sector directional space

1 R, optional

default number of frequencies

1 R, optional

default minimum frequency

1 R, optional

default maximum frequency

WaterLevel

default water level

XVeloc

default velocity in x-direction

default velocity in y -direction

default wind speed

default wind direction

NDir
StartDir
EndDir
NFreq
FreqMin
FreqMax

YVeloc
WindSpeed
WindDir
∗

TimePoint

TimePoint should be specified if TimePntBlock is not included and not Online with FLOW.
1R

time in minutes since refdate 0:00 hours

WaterLevel

water level at specified time point

XVeloc

velocity in x direction at specified time point

velocity in y direction at specified time point

wind speed at specified time point

wind direction at specified time point

Time

YVeloc
WindSpeed
WindDir
Constants

WaterLevelCorrection1 R

Overall water level correction

Gravity

gravitational acceleration (default: 9.81 m/s2 )

WaterDensity

density of water (default: 1025 kg/m3 )

NorthDir

direction of north relative to x axis (default: 90◦ )

MinimumDepth

minimum water depth below which points are excluded from the computation (default: 0.05 m)

generation mode of physics: 1 for first-generation, 2 for second-generation, 3 for third-generation

Processes

GenModePhys

continued on next page
∗

May be specified multiple times
+
Not supported by WAVE-GUI
R = Real; I = Integer; L = Logical; C = Character

74 of 124

Deltares

Files of Delft3D-WAVE

continued from previous page
Format

Description

WaveSetup

include wave setup (default: false)

Breaking

include wave breaking (default: true)

BreakAlpha

alpha coefficient for wave breaking (default: 1.0)

BreakGamma

gamma coefficient for wave breaking (default: 0.73)

Triads

include triads (default: false)

TriadsAlpha

alpha coefficient for triads (default: 0.1)

TriadsBeta

beta coefficient for triads (default: 2.2)

BedFriction

string

bed friction type (none, jonswap, collins, madsen et al., default: jonswap)

BedFricCoef

bed friction coefficient (default: 0.067 for jonswap, 0.015 for collins, 0.05 for madsen et al.)

Diffraction

include diffraction (default: true)

DiffracCoef

diffraction coefficient (default: 0.2)

DiffracSteps

number of diffraction smoothing steps (default: 5)

DiffracProp

include adaption of propagation velocities due to diffraction (default: true)

WindGrowth

include wind growth (default: true)

WhiteCapping

key-value

white capping: (Off, Komen, Westhuysen, default: Komen)

Quadruplets

include quadruplets (default: false)

Refraction

include refraction (default: true)

FreqShift

include frequency shifting in frequency space (default: true)

WaveForces

key-value

method of wave force computation (dissipation 3d, dissipation, radiation stresses <2013; default: dissipation 3d)

DirSpaceCDD

discretisation in directional space: 0 for central, 1 for upwind (default: 0.5)

FreqSpaceCSS

discretisation in frequency space: 0 for central, 1 for upwind (default: 0.5)

RChHsTm01

relative change of wave height or mean wave period with respect to local value (default: 0.02)

RChMeanHs

relative change of wave height with respect to model-wide average wave height (default: 0.02)

RChMeanTm01

relative change of mean wave period with respect to model-wide average mean wave period (default: 0.02)

PercWet

percentage of points included in simulation at which convergence criteria must be satisfied (default: 98%)

MaxIter

maximum number of iterations for convergence (default: 15)

TestOutputLevel

test output level (default: 0)

TraceCalls

trace subroutine calls (default: false)

UseHotFile

write and read hotstart files (default: false)

MapWriteInterval

interval for writing data to map file(s) in minutes

WriteCOM

write results to communication file(s) (default: false)

COMWriteInterval

interval for writing data to communication file(s) in minutes

AppendCOM

upon writing to communication file(s) overwrite the previous data (false) or append to the data series (true) (default:
false)

MassFluxToCOM+

1 L, optional

write mass fluxes due to wave to communication file(s) (default: true)

LocationFile

string, optional

file name of output locations

CurveFile

string, optional

file name of output curves

WriteTable

write tables for output locations (default: false)

WriteSpec1D

write 1D spectra for output locations (default: false)

WriteSpec2D

write 2D spectra for output locations (default: false)

Grid

string

file name of computational grid

BedLevelGrid

string

file name of bed level grid (default: equal to computational grid)

BedLevel

string

file name of bed level data

DirSpace

directional space: circle, sector

NDir

number of directional bins

DR
AF

Keyword

Numerics

Output

∗

Domain

continued on next page
∗

May be specified multiple times
Not supported by WAVE-GUI
R = Real; I = Integer; L = Logical; C = Character
+

Deltares

75 of 124

D-Waves, User Manual

continued from previous page
Keyword

Format

Description

StartDir

start direction in case of sector directional space

EndDir

end direction in case of sector directional space

NFreq

number of frequencies

FreqMin

minimum frequency

FreqMax

maximum frequency

NestedInDomain

number of domain in which current domain is nested (required for domains 2 and following)

FlowBedLevel

See description of FlowBedLevel in group [General]

FlowWaterLevel

See description of FlowBedLevel in group [General]

FlowVelocity

See description of FlowBedLevel in group [General]

FlowVelocityType

See description of FlowBedLevel in group [General]

FlowWind

See description of FlowBedLevel in group [General]
∗

Name of file containing meteo input

MeteoFile

write map file for current domain (default: true)

Name

string

boundary name

Definition

key-value

definition type (orientation, grid-coordinates, xy-coordinates)

Orientation

key-value

boundary orientation in case of boundary definition by means of orientation (north, northwest, west,
southwest, south, southeast, east, northeast)

DR
AF

Boundary∗

Output

DistanceDir

key-value

direction of distance measurements for boundary segments in case of boundary definition by means of orientation
(clockwise, counter-clockwise; default: counter-clockwise)

StartCoordM

start m-coordinate of boundary in case of boundary definition by means of grid-coordinates

EndCoordM

end m-coordinate of boundary in case of boundary definition by means of grid-coordinates

StartCoordN

start n-coordinate of boundary in case of boundary definition by means of grid-coordinates

EndCoordN

end n-coordinate of boundary in case of boundary definition by means of grid-coordinates

StartCoordX

start x-coordinate of boundary in case of boundary definition by means of xy-coordinates

EndCoordX

end x-coordinate of boundary in case of boundary definition by means of xy-coordinates

StartCoordY

start y-coordinate of boundary in case of boundary definition by means of xy-coordinates

EndCoordY

end y-coordinate of boundary in case of boundary definition by means of xy-coordinates

SpectrumSpec

key-value

spectrum specification type (from file, parametric)

SpShapeType

key-value

spectrum shape type in case of parametric spectrum specification (jonswap, pierson-moskowitz, gauss)

PeriodType

key-value

wave period type in case of parametric spectrum specification (peak, mean)

DirSpreadType

key-value

directional spreading type in case of parametric spectrum specification (power, degrees)

PeakEnhancFac

peak enhancement factor in case of jonswap spectrum

GaussSpread

width of spectral distribution in case of gaussian spectrum

CondSpecAtDist∗

distance along boundary at which boundary condition is specified, uniform boundary condition if not specified

WaveHeight∗

wave height at specified distance or uniform value in case of parametric spectrum specification

Period∗

wave period at specified distance or uniform valuein case of parametric spectrum specification

∗

wave direction at specified distance or uniform value in case of parametric spectrum specification

DirSpreading∗

directional spreading at specified distance or uniform value in case of parametric spectrum specification

Spectrum∗

string

file name containing spectrum (string) in case of spectrum specification from file

Direction

∗

May be specified multiple times
+
Not supported by WAVE-GUI
R = Real; I = Integer; L = Logical; C = Character

76 of 124

Deltares

Files of Delft3D-WAVE

A.1.2

Offline calculation
Running WAVE offline using FLOW output is currently not supported by the WAVE-GUI. To
setup such a simulation please create an input file for an online WAVE-FLOW simulation first,
and subsequently adjust the following items in the mdw-file with a text editor:

The keyword FlowFile must be removed from the group [General].
By default WAVE will look for the FLOW output on a pair of files
where the name part matches the WAVE runid: . If the FLOW output

Example:

DR
AF

[Timepoint]
Time = 1440
[Timepoint]
Time = 1680

should be read from another com-file or from multiple com-files (such as in the case of
a domain decomposition or parallel FLOW simultion) the name of all the runids need to
be specified using the keyword ComFile in the group [General], e.g. ComFile =
rif-001 rif-002 rif-003 for a three partition FLOW simulation.
A time point must be specified for each time for which a calculation must be performed

The specified time points must correspond with times written on the com-file.
A.2
A.2.1

Attribute files of Delft3D-WAVE
Introduction

In the following sections we describe the attribute files used in the input MDW-file of Delft3DWAVE. Most of these files contain the quantities that describe one specific item, such as the
bathymetry or the grid.
Most of the attribute files can be generated by the WAVE-GUI after defining an input scenario.
Some files can only be generated by utility programs such as the curvilinear grid generated
by RGFGRID . Still, we describe both types of files as it might be useful to know how the input
data is structured to be able to generate (large) files.
For each file we give the following information (if relevant):

File content.
File type (free formatted, fix formatted or unformatted).
Filename and extension.
Generated by (i.e. how to generate the file).
Restrictions on the file content.
Example(s).

Remarks:
The access mode of all attribute files is sequential.
In the examples the file contents is printed in font Courier New 10 and comment (not
included in the file) in font Times New Roman 9, unless stated explicitly differently.
A.2.2

Orthogonal curvilinear grid
File contents
The co-ordinates of the orthogonal curvilinear grid at the depth points.
Filetype
ASCII

Deltares

77 of 124

D-Waves , User Manual

File format
Filename
Generated

Free formatted

RGFGRID

Record description:
Record

Record description
Preceding description records, starting with an asterisk (∗), will be
ignored.

Record with Co-ordinate System = Cartesian or value

Record with

Spherical

Missing Value = -9.99999000000000024E+02.
If this record is not given 0.0 will be assumed as missing value.

The number of grid points in m- and n-direction (2 integers).

DR
AF

Three real values (not used).

5 to K+5

A label and record number, the x-component of the world coordinates of all points in m-direction, starting with row 1 to row
nmax, with as many continuation records as required by mmax
and the number of co-ordinates per record. The label and record
number are suppressed on the continuation lines. This set of records
is repeated for each row until n = nmax.

K+5 to 2K+4

A similar set of records for the y -component of the world coordinates.

K is the number of records to specify for all grid points a set of x- and y -co-ordinates.
Restrictions:
The grid must be orthogonal.
Input items in a record are separated by one or more blanks.
Example:

*
* Deltares, Delft3D-RGFGRID Version 4.16.01.4531, Sep 30 2008, 23:32:27
* File creation date: 2008-10-01, 23:19:22
*
Coordinate System = Cartesian
9
7
0 0 0
Eta=
1
0.00000000000000000E+00
1.00000000000000000E+02
2.000000...
5.00000000000000000E+02
6.00000000000000000E+02
7.000000...
Eta=
2
0.00000000000000000E+00
1.00000000000000000E+02
2.000000...
5.00000000000000000E+02
6.00000000000000000E+02
7.000000...
Eta=
3
0.00000000000000000E+00
1.00000000000000000E+02
2.000000...
5.00000000000000000E+02
6.00000000000000000E+02
7.000000...
Eta=
4
0.00000000000000000E+00
1.00000000000000000E+02
2.000000...
5.00000000000000000E+02
6.00000000000000000E+02
7.000000...
Eta=
5
0.00000000000000000E+00
1.00000000000000000E+02
2.000000...

78 of 124

Deltares

Files of Delft3D-WAVE

Eta=

5.00000000000000000E+02
0.00000000000000000E+00
5.00000000000000000E+02
0.00000000000000000E+00
5.00000000000000000E+02
1.00000000000000000E+02
1.00000000000000000E+02
2.00000000000000000E+02
2.00000000000000000E+02
3.00000000000000000E+02
3.00000000000000000E+02
4.00000000000000000E+02
4.00000000000000000E+02
5.00000000000000000E+02
5.00000000000000000E+02
6.00000000000000000E+02
6.00000000000000000E+02
7.00000000000000000E+02
7.00000000000000000E+02

6.00000000000000000E+02
1.00000000000000000E+02
6.00000000000000000E+02
1.00000000000000000E+02
6.00000000000000000E+02
1.00000000000000000E+02
1.00000000000000000E+02
2.00000000000000000E+02
2.00000000000000000E+02
3.00000000000000000E+02
3.00000000000000000E+02
4.00000000000000000E+02
4.00000000000000000E+02
5.00000000000000000E+02
5.00000000000000000E+02
6.00000000000000000E+02
6.00000000000000000E+02
7.00000000000000000E+02
7.00000000000000000E+02

7.000000...
2.000000...
7.000000...
2.000000...
7.000000...
1.000000...
1.000000...
2.000000...
2.000000...
3.000000...
3.000000...
4.000000...
4.000000...
5.000000...
5.000000...
6.000000...
6.000000...
7.000000...
7.000000...

Time-series for wave boundary conditions
File contents
Time-series for wave boundary conditions.
Filetype
ASCII
File format
Fix format for header information; free format for time-series data.
Filename

Generated
FLOW-GUI, program Delft3D-NESTHD or manually offline

DR
AF

A.2.3

Eta=

Record description:

Keyword

Description

location
time-function
reference-time
time-unit

location name (quoted string)
time function type (quoted string: "non-equidistant")
reference time (yyyymmdd integer or quoted string: "from model")
time unit (quoted string: "decades", "years", "days", "hours", "minutes", "seconds", "ddhhmmss", "absolute")
interpolation type (quoted string: "linear" or "block")
parameter name & unit

interpolation
parameter &
unit
A.2.4

Obstacle file
File contents
Filetype
File format
Filename
Generated

Name of the polyline with obstacles.
ASCII
Fix formatted for text variables, free formatted for real and integer
values.

QUICKIN as land boundary, or manually offline

Record description:
A header block containing information about versions, and the name of the polyline file.
For each observation area the details.

Deltares

79 of 124

D-Waves , User Manual

Keyword

Format

Description

ObstacleFileInformation

FileVersion string
PolylineFilestring

version number of <∗.obs> file
name of polyline file with polylines defining obstacles

Obstacle∗

May be specified multiple times

DR
AF

∗

name of obstacle in polyline file
type of obstacle (sheet, dam)
transmission coefficient in case of sheet obstacle
dam height in case of dam obstacle
alpha in case of dam obstacle
beta in case of dam obstacle
type of reflections (no, specular, diffuse)
reflection coefficient if reflections are activated

Name
string
Type
key-value
TransmCoef 1 real
Height
1 real
Alpha
1 real
Beta
1 real
Reflections key-value
ReflecCoef 1 real

Restriction:
The maximum record length in the file is 132.
Example:

The number of obstacles is 2. They are called ‘Breakwater West’, ’Breakwater East 2’ and
’Breakwater East 1’
[ObstacleFileInformation]
FileVersion = 02.00
PolylineFile = breakwater.pol
[Obstacle]
Name
= Breakwater West
Type
= dam
Height
= 0.0000000e+000
Alpha
= 2.5999999e+000
Beta
= 1.5000001e-001
Reflections = no
[Obstacle]
Name
= Breakwater East 1
Type
= dam
Height
= 0.0000000e+000
Alpha
= 2.5999999e+000
Beta
= 1.5000001e-001
Reflections = no
[Obstacle]
Name
= Breakwater East 2
Type
= dam
Height
= 0.0000000e+000
Alpha
= 2.5999999e+000
Beta
= 1.5000001e-001
Reflections = no

Example polyline file:
Breakwater West
7
2

80 of 124

Deltares

Files of Delft3D-WAVE

1.9174138E+05
6.0961231E+05
1.9190197E+05
6.1048831E+05
1.9242755E+05
6.1140806E+05
1.9321591E+05
6.1228400E+05
1.9422327E+05
6.1301400E+05
1.9536202E+05
6.1358338E+05
1.9655916E+05
6.1394831E+05
Breakwater East 1
2
2
2.0846027E+05
6.0775812E+05
2.0838540E+05
6.0968968E+05
Breakwater East 2
2
2
2.1022712E+05
6.0998915E+05
2.1031696E+05
6.0765331E+05

Segment file
File contents

The coordinates of one or more polylines. Each polyline (piecewise
linear) is written in a single block of data.
ASCII
Free formatted

RGFGRID, QUICKIN, Delta Shell, etc

Filetype
File format
Filename
Generated

DR
AF

A.2.5

Record description:
Record

Record description

Preceding description records, starting with an asterisk (∗), and will
be ignored.

1
2

A non blank character string, starting in column one.
Two integers Nr , Nc representing the numbers of rows and number
of columns for this block of data.

Two reals representing the x, y or λ, φ-coordinate, followed by remaining data values at that location (if Nc > 2).

Example:

*
* Polyline L007
*
L007
6 2
132400.0
132345.0
132165.0
131940.0
131820.0
131585.0
*
* Polyline L008
*
L008
4 2
131595.0

Deltares

549045.0
549030.0
549285.0
549550.0
549670.0
549520.0

549685.0

81 of 124

D-Waves , User Manual

549865.0
550025.0
550175.0

*
* Polyline L009
*
L009
6 2
131595.0
148975.0
150000.0
152105.0
153150.0
154565.0

549655.0
564595.0
564935.0
565500.0
566375.0
567735.0

Depth file
File contents

The bathymetry in the model area, represented by depth values (in
metres) for all grid points.
ASCII
Free formatted or unformatted

FLOW-GUI (only for uniform depth values).
Offline with QUICKIN and data from digitised charts or GIS-database.

Filetype
File format
Filename
Generated

DR
AF

A.2.6

131750.0
131595.0
131415.0

Record description:
Filetype

Record description

Free formatted

Depth values per row, starting at N = 1 to N = Nmax, separated
by one or more blanks. The number of continuation lines is determined by the number of grid points per row (Mmax) and the maximum record size of 132.

Unformatted

Mmax depth values per row for N = 1 to N = Nmax.

Restrictions:
The file contains one M and N line more than the grid dimension.
The maximum record length in the free formatted file is 132.
Depth values from the file will not be checked against their domain.
The input items are separated by one or more blanks (free formatted file only).
The default missing value is: −999.0
Example:

File containing 16 ∗ 8 data values for a model area with 15 ∗ 7 grid points (free formatted file).
1.0
12.0
3.0
14.0
5.0
16.0
7.0
18.0
9.0
20.0

82 of 124

2.0
13.0
4.0
15.0
6.0
17.0
8.0
19.0
10.0
19.0

3.0
14.0
5.0
16.0
7.0
18.0
9.0
-7.0
11.0
18.0

4.0
-5.0
6.0
17.0
8.0
19.0
10.0
19.0
12.0
17.0

-5.0
-999.0
7.0
-999.0
9.0
-999.0
11.0
-999.0
13.0
-999.0

-5.0

8.0

9.0

10.0

11.0

-6.0

10.0

11.0

12.0

13.0

10.0

-7.0

12.0

13.0

14.0

15.0

12.0

13.0

14.0

15.0

16.0

17.0

14.0

15.0

16.0

17.0

18.0

19.0

Deltares

Files of Delft3D-WAVE

-7.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
19.0
18.0
17.0
16.0
15.0 -999.0
-8.0
-8.0
15.0
16.0
17.0
18.0
19.0
20.0
19.0
18.0
17.0
16.0
15.0
14.0
13.0 -999.0
-999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
-999.0 -999.0 -999.0 -999.0 -999.0

The resulting 2D-matrix for the depth values is then (for simplicity all values are here transformed into integers, in reality this does not occur):
N-direction

A.2.7

-9
-8
-7
9
7
5
3
1

-9
-8
12
10
8
6
4
2

-9
15
13
11
9
7
5
3

18
16
14
12
10
8
6
4

19
17
15
13
11
9
7
-5

20
18
16
14
12
10
-6
-5

19
19
17
15
13
-7
-6
-5

18
20
18
16
14
12
10
8

17
19
19
17
15
13
11
9

16
18
20
18
16
14
12
10

15
17
19
19
17
15
13
11

14
16
18
20
18
16
14
12

13
15
17
19
19
17
15
13

12
14
16
18
-7
18
16
14

13 14 15 16
→ M-direction

8
7
6
5
4
3
2
1

-9
13
15
17
19
19
17
-5

-9
-8
14
16
18
20
-6
-5

DR
AF

↑

Space-varying bottom friction (not yet implemented for Delft3D-WAVE)
File contents:
Bottom friction coefficients values (induced by waves) for all grid
points, starting from row number (y-direction) 1 for all points in the xdirection (1 to MMAX), until the last row number (NMAX). Note that
for the bottom friction values also a constant value over the entire
computational area can be applied (see ??).
File type:
free formatted / unformatted.
Restrictions:
maximum record length in the (free) formatted file is 132. Bottom
friction coefficients values from the file will not be checked against
the ranges specified in ?? (domain of input parameters).
Example:
(formatted file)
0.01
0.01
0.012
0.013
0.014

0.01
0.01
0.012
0.013
0.014

0.02
0.02
0.011
0.013
0.013

0.03
0.03
0.03
0.03
0.03

The resulting 2D-matrix for the bottom friction coefficients values:
N-direction
↑

8
7
6
5
4
3
2
1

Deltares

0.014
0.013
0.012
0.011
0.01
0.01

0.013
0.013
0.011
0.01
0.02
0.02

0.03
0.03
0.03
0.03
0.03
0.03

13 14 15 16
→ M-direction

83 of 124

D-Waves, User Manual

A.2.8

Wave boundary conditions
In Delft3D-WAVE the users could choose different sets of wave boundary conditions and wind
conditions. However not all the features could be specified by the GUI. The functionalities
could be used by adding keywords in -file.
In the following subsections, 4 options are described:
1
2
3
4

Time-varying and uniform wave conditions in file

In some cases where e.g. the morphology is event-driven or design conditions for a structure
are needed, a set of different wave conditions are to be calculated. These wave conditions
can be specified in an additional file, called (rid=runid of the -file).
This file can only be used when constant parametric boundary conditions are prescribed
in the wave model. If other boundary conditions are specified, these will be adjusted into
constant parametric boundary conditions. To use this Wavecon option, just simply add the
file to the working directory and the system will use the file automatically.

DR
AF

A.2.8.1

Time-varying and uniform wave conditions in .
Time-varying and space-varying wave boundary conditions using -files
Space-varying wave boundary conditions using for UNIBEST coupling ( file)
Space-varying wave boundary conditions: Spectral input and output files

A WAVE computation is always performed on a certain time point (based on the reference
date). If a file exists in the working directory, it will get its wave boundary
conditions (including wind and water level) from that file. The boundary condition values in the
default file will not be used then. When the time point of the wave computation
lies between two prescribed time points in the file, it will interpolate the wave,
wind and water level conditions between these two time points.
Remarks:
If the wind speed is prescribed as 0 m/s, wind will not be taken into account in the wave
computation.
If the time point of the wave computation lies before the first prescribed time field in the
file, it will use the conditions of this first field.
If a mean period is chosen in the default file, this period will be modified
into the peak period (the value of the period will remain the same).
If a variable boundary condition is chosen in the default file, this condition
will be modified into a constant condition along the whole boundary.
The defined wave boundary conditions are overruled by the prescribed wave conditions
in the file.
File contents:
File type:
Restrictions:
Example:

* Itdate Hs
BL01
3 8 * number of
0
0.01
60
1.00
240
0.01

List of wave and wind conditions
free formatted/unformatted.
maximum record length in the (free) formatted file is 132.
formatted file of a

Dir(◦ )

rows
1.0
7.0
10.0

number of columns
270
10 0
0.0
270
4
1.26 10.0
270
10 0.70 5.0

windspeed

wind dir.(◦ )

270
270
270

Description of parameters:

84 of 124

Deltares

Files of Delft3D-WAVE

Hs [m]
Tp [s]
Dir [◦ ]

ms [-] or [◦ ]

Water level [m]

DR
AF

Wind speed [m/s]
Wind direction [◦ ]

Time point after reference date in minutes; should be given in minutes after the reference date (ITDATE), specified in the
file.
Significant wave height in metres; this value will be prescribed on all
specified wave boundaries.
Peak period of the energy spectrum. This value will be prescribed
on all specified wave boundaries.
Mean wave direction according to the Nautical or Cartesian convention (in degrees). This value will be prescribed on all specified wave
boundaries.
Width energy distribution. This is the directional standard deviation
in power or in degrees. If the option Degrees is chosen in the subwindow Spectral space, it is in degree. If the option Cosine power is
chosen in the same above sub-window, it is in the power m.
The additional water level over the entire wave model. The water
level is measured positively upward from the same datum from which
the bottom levels are taken.
Wind velocity at 10 m elevation.
Wind direction at 10 m elevation according to the convention, specified in the sub-window Constants.

Itdate [min]

Remarks:
The defined wave boundary conditions in the mdw file are overruled by the prescribed
wave conditions in the file.
If wavecon or file is used as wave boundary condition, the width energy
distribution ms is set (overwritten) to be power.
A.2.8.2

Time-varying and space-varying wave boundary conditions using BCW files
In Delft3D-WAVE, time series of wave boundary conditions have been implemented which
are not able to be set in GUI yet. The users can include the keywords TSeriesFile in Datagroup General in MDW-file. The format of BCW-file refer to the section A.2.3. The segments
of boundary conditions could be set using the keywords CondSpecAtDist in Datagroup
Boundary in MDW-file. If the wave computations are carried out at multiple time points, the
time point could be specified in Datagroup Timepoint in MDW-file.
The following examples showed different scenarios of spatial-varying and time-varying wave
boundnary conditions. It is a stand-alone wave model with 2 boundaries, i.e., Boundary West
and Boundary South. The Boundary West is devided into 6 segments and the Boundary
South is devided into 9 segments. For each segments, different parameters such as Wave
Height, Period, Direction, Dirspreading could be defined at different time point in the BCW-file.
The 3 examples show the following 3 scenarios:
1 Multiple time points and spatial uniform wave boundary conditions.
2 One/multiple time points and space-varying wave boundary conditions
3 Multiple time points and space-varying wave boundary conditions, with time-varying but
spatial uniform wind field

Deltares

85 of 124

D-Waves , User Manual

Example 1
If one would like to have a wave model with uniform wave boundary conditions along one
boundary line for multiple time points, one should add them to Datagroup General as follows:

= 02.00
=
=
=
=
=
=
=
=
=
=
=

Carrara
001
Carrara test run
false
stationary
nautical
2006-01-05
timeseries.bcw
2.0
2.0

DR
AF

In Datagroup TimePoint the following should be added:

[WaveFileInformation]
FileVersion
[General]
ProjectName
ProjectNr
Description
Description
OnlyInputVerify
SimMode
DirConvention
ReferenceDate
TSeriesFile
WindSpeed
WindDir
...

...
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
...

=
=
=
=

6.0000000e+001
0.0000000e+000
0.0000000e+000
0.0000000e+000

=
=
=
=

1.2000000e+002
0.0000000e+000
0.0000000e+000
0.0000000e+000

=
=
=
=

1.8000000e+002
0.0000000e+000
0.0000000e+000
0.0000000e+000

=
=
=
=

2.4000000e+002
0.0000000e+000
0.0000000e+000
0.0000000e+000

In Datagroup Boundary the following should be added:
...
[Boundary]
Name
Definition
StartCoordX
EndCoordX
StartCoordY
EndCoordY
SpectrumSpec
SpShapeType
PeriodType
DirSpreadType
PeakEnhanceFac
GaussSpread
[Boundary]

86 of 124

=
=
=
=
=
=
=
=
=
=
=
=

Boundary West
xy-coordinates
5.0000000e+005
5.0000000e+005
4.9274090e+006
4.7885805e+006
parametric
jonswap
peak
power
3.3000000e+000
9.9999998e-003

Deltares

Files of Delft3D-WAVE

Name
Definition
StartCoordX
EndCoordX
StartCoordY
EndCoordY
SpectrumSpec
SpShapeType
PeriodType
DirSpreadType
PeakEnhanceFac
GaussSpread
...

=
=
=
=
=
=
=
=
=
=
=
=

Boundary South
xy-coordinates
5.0000000e+005
6.2226400e+005
4.7608150e+006
4.7608150e+006
parametric
jonswap
peak
power
3.3000000e+000
9.9999998e-003

’Boundary West
’non-equidistant’
20060105
’minutes’
’linear’
’time
’WaveHeight’
’Period’
’Direction’
’DirSpreading’
8.2400 -171.0700 2.0000
8.2400 -171.0700 2.0000
8.2400 -171.0700 2.0000
8.2400 -171.0700 2.0000
8.2400 -171.0700 2.0000
’Boundary South
’non-equidistant’
20060105
’minutes’
’linear’
’time
’WaveHeight’
’Period’
’Direction’
’DirSpreading’
8.4700 -147.8800 2.0000
8.4700 -147.8800 2.0000
8.4700 -147.8800 2.0000
8.4700 -147.8800 2.0000
8.4700 -147.8800 2.0000

’

DR
AF

...
location
time-function
reference-time
time-unit
interpolation
parameter
parameter
parameter
parameter
parameter
0.00 5.5300
60.00 3.5300
120.00 1.5300
180.00 3.5300
240.00 1.5300
location
time-function
reference-time
time-unit
interpolation
parameter
parameter
parameter
parameter
parameter
0.00 1.2700
60.00 3.2700
120.00 1.2700
180.00 3.2700
240.00 3.2700

The -file, which is defined in section A.2.3, for the uniform boundaries with multiple
time points should be then:

’

unit
unit
unit
unit
unit

’[min]’
’[m]’
’[s]’
’[N^o]’
’[-]’

unit
unit
unit
unit
unit

’[min]’
’[m]’
’[s]’
’[N^o]’
’[-]’

’

Example 2

If one would like to have a wave model with space-varying wave boundary conditions, one
should add them to Datagroup General as follows:
[WaveFileInformation]
FileVersion
[General]
ProjectName
ProjectNr
Description
Description
OnlyInputVerify
SimMode
DirConvention

Deltares

= 02.00
=
=
=
=
=
=
=

Carrara
001
Carrara test run
false
stationary
nautical

87 of 124

D-Waves , User Manual

ReferenceDate
TSeriesFile
WindSpeed
WindDir

= 2006-01-05
= timeseries.bcw
= 2.0
= 2.0

...

In Datagroup TimePoint the following should be added:

=
=
=
=

6.0000000e+001
0.0000000e+000
0.0000000e+000
0.0000000e+000

In Datagroup Boundary the following should be added:

=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=

Boundary West
xy-coordinates
5.0000000e+005
5.0000000e+005
4.9274090e+006
4.7885805e+006
parametric
jonswap
peak
power
3.3000000e+000
9.9999998e-003
2.7765670e+004
5.5531340e+004
6.3297008e+004
8.3297008e+004
1.1106268e+005
1.3882834e+005

=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=

Boundary South
xy-coordinates
5.0000000e+005
6.2226400e+005
4.7608150e+006
4.7608150e+006
parametric
jonswap
peak
power
3.3000000e+000
9.9999998e-003
0.0000000e+000
1.0000000e+003
1.0000000e+004
2.0377330e+004
4.0754660e+004
6.1131988e+004
8.1509320e+004
1.0188665e+005
1.2226398e+005

DR
AF

...
[Boundary]
Name
Definition
StartCoordX
EndCoordX
StartCoordY
EndCoordY
SpectrumSpec
SpShapeType
PeriodType
DirSpreadType
PeakEnhanceFac
GaussSpread
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
[Boundary]
Name
Definition
StartCoordX
EndCoordX
StartCoordY
EndCoordY
SpectrumSpec
SpShapeType
PeriodType
DirSpreadType
PeakEnhanceFac
GaussSpread
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
CondSpecAtDist
...

...
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
...

The -file, which is defined in section A.2.3, should be like:

88 of 124

Deltares

Files of Delft3D-WAVE

DR
AF

...
location
’Boundary West
’
time-function
’non-equidistant’
reference-time
20060105
time-unit
’minutes’
interpolation
’linear’
parameter
’time
’
unit ’[min]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
0.00
5.5300 1.8600 1.8600 1.9100 1.8400 1.7100...
8.2400 8.2400 8.2400 8.2400 8.4700 8.4700...
-171.0700 -173.5300 -173.5300 -167.2300 -160.5600 -154.3000...
2.0000 2.0000 2.0000 2.0000 2.0000 2.0000
60.00 3.5300 3.8600 1.8600 3.9100 3.8400 3.7100...
8.2400 8.2400 8.2400 8.2400 8.4700 8.4700...
-171.0700 -173.5300 -173.5300 -167.2300 -160.5600 -154.3000...
2.0000 2.0000 2.0000 2.0000 2.0000 2.0000
location
’Boundary South
’
time-function
’non-equidistant’
reference-time
20060105
time-unit
’minutes’
interpolation
’linear’
parameter
’time
’
unit ’[min]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’WaveHeight’
unit ’[m]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Period’
unit ’[s]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’

Deltares

89 of 124

D-Waves , User Manual

DR
AF

parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’Direction’
unit ’[N^o]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
parameter
’DirSpreading’
unit ’[-]’
0.00 1.2700 1.2700 1.2700 1.2700 1.3600 1.6000 1.3400 3.3400 3.0500...
8.4700 8.4700 8.4700 8.4700 8.1600 7.3500 7.1200 7.1200 7.0800...
-147.8800 -147.8800 -147.8800 -147.8800 -178.7700 173.9500 175.0400 175.0400 -179.1200
2.0000 2.0000 2.0000 2.0000 2.0000 2.0000 2.0000 2.0000 2.0000
60.00 3.2700 1.2700 1.2700 3.2700 3.3600 3.6000 3.3400 3.3400 3.0500...
8.4700 8.4700 8.4700 8.4700 8.1600 7.3500 7.1200 7.1200 7.0800...
147.8800 -147.8800 -147.8800 -147.8800 -178.7700 173.9500 175.0400 175.0400 -179.1200...
2.0000 2.0000 2.0000 2.0000 2.0000 2.0000 2.0000 2.0000 2.0000

Example 3

If one would like to have a wave model with space-varying wave boundary conditions, with
time-varying but spatial uniform wind field, one should add them to Datagroup General as
follows:
[WaveFileInformation]
FileVersion
[General]
ProjectName
ProjectNr
Description
Description
OnlyInputVerify
SimMode
DirConvention
ReferenceDate
TSeriesFile
...

= 02.00
=
=
=
=
=
=
=
=
=

Carrara
001

Carrara test run
false
stationary
nautical
2006-01-05
timeseries.bcw

In Datagroup TimePoint the following should be added:
...
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
WindSpeed
WindDir
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
WindSpeed
WindDir
[TimePoint]
Time
WaterLevel

90 of 124

=
=
=
=
=
=

6.0000000e+001
0.0000000e+000
0.0000000e+000
0.0000000e+000
20.0
20.0

=
=
=
=
=
=

1.2000000e+002
0.0000000e+000
0.0000000e+000
0.0000000e+000
15.0
15.0

=
=

1.8000000e+002
0.0000000e+000

Deltares

Files of Delft3D-WAVE

XVeloc
YVeloc
WindSpeed
WindDir
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
WindSpeed
WindDir
...

=
=
=
=

0.0000000e+000
0.0000000e+000
10.0
10.0

=
=
=
=
=
=

2.4000000e+002
0.0000000e+000
0.0000000e+000
0.0000000e+000
2.0
2.0

=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=

=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=

DR
AF

In Datagroup Boundary the following should be added:

The -file, which is defined in section A.2.3, should be the same as that in Example 2.

Deltares

91 of 124

D-Waves, User Manual

Space-varying wave boudnary conditions using for UNIBEST coupling
(-file)
For the coastline model UNIBEST, wave computations can be required representing a wave
climate. Such a wave climate is schematized into several wave conditions and corresponding
wind conditions. These wave and wind conditions can be defined all in one file: the so-called
-file. This file must be added to the working directory of the wave model. Only
when this file is present in the working directory, wave computations will be carried out for all
wave conditions in the -file. In this way a large number of wave conditions can
be computed in a batch mode.

File type:
Restrictions:
Example:

List of wave and wind conditions for UNIBEST model with no time
points
free formatted/unformatted.
maximum record length in the (free) formatted file is 132.
formatted file of a

File contents:

* Name of main SCO file: NZ_STORM.SCO
UNIBEST *(MORSYS/UNIBEST)
10 *total number of wave conditions
theta ms H0
U10
theta_wind
* Hm0 Tp
◦
(m) (m/s) (N◦ )
* (m) (s) (N )
1.0
5
330
4
0.2 0
0
1.5
5
310
4
0.1 0
0
3.0
8
350
4
0.4 0
0
2.2
7
270
4
0.3 0
0

DR
AF

A.2.8.3

Description of parameters:

Hm0 [m]
Tp [s]

theta [N◦ ]

ms [-]

H0 [m]

U10 [m/s]
Theta_wind [N◦ ]

Significant wave height in metres; this value will be prescribed on all
specified wave boundaries.
Peak period of the energy spectrum. This value will be prescribed
on all specified wave boundaries.
Mean wave direction according to the Nautical or Cartesian convention (in degrees). This value will be prescribed on all specified wave
boundaries.
Width energy distribution. This is the directional standard deviation in
degrees if the option Degrees is chosen in the sub-window Spectral
space or it is the power m if the option Cosine power is chosen in
the same above sub-window.
The additional water level over the entire wave model. The water
level is measured positively upward from the same datum from which
the bottom levels are taken.
Wind velocity at 10 m elevation.
Wind direction at 10 m elevation according to the convention, specified in the sub-window Constants.

Remarks:
On the third line of the md-vwac file the amount of wave conditions is given. In the mdwfile or in the WAVE-GUI an equal amount of time points must be prescribed matching
with the amount of wave conditions in the md-vwac file.
The defined wave boundary conditions are overruled by the prescribed wave conditions
in the md-vwac file.

92 of 124

Deltares

Files of Delft3D-WAVE

A.2.8.4

Time- and space-varying wave boundary conditions: TPAR file
TPAR files containing non-stationary wave parameters. A TPAR file is for only one section of
the boundaries. For space-varying, the user has to define multiple TPAR files. The TPAR file
has the string TPAR on the first line of the file and a number of lines which each contain 5
numbers:

1 Time (ISO notation),
2 Hs,
3 Period (average or peak period depending on the choice given in the Swan Spectral Space
under Edit Spectral space),
4 Peak Direction (Nautical or Cartesian, depending on the settings in the Physical parameters),
5 Directional spread (in degrees or as power of Cos depending on the choice given in the
Swan Spectral Space under Edit Spectral space).
Example of a TPAR file (for example, the filename is TPAR01.bnd):

4.2 12. -110. 22.
4.2 12. -110. 22.
1.2 8. -110. 22.
1.4 8.5 -80. 26.
0.9 6.5 -95. 28.

DR
AF

TPAR
19920516.1300
19920516.1800
19920517.0000
19920517.1200
19920517.2000

Thus in the mdw file, the corresponding segment is:
...
[Boundary]
Name
Definition
StartCoordM
EndCoordM
StartCoordN
EndCoordN
SpectrumSpec
Spectrum
...

=
=
=
=
=
=
=
=

Bound1
grid-coordinates
0
0
0
39
from file
TPAR01.bnd

The boundary section is defined in MN format.
A.2.9

Spectral input and output files

There are two types of Spectrum files:

files containing stationary or non-stationary 1D spectra (usually from measurements)
files containing stationary or non-stationary 2D spectra (from other computer programs or
other SWAN runs).
The structure of the files containing 1D or 2D spectra is described below (there is no relation
with the definition of the boundary file generated by WAM or WAVEWATCH III). 1D and 2D
files can be used for one or more than one location. The spectral frequencies (and directions
in the case of a 2D spectrum) do not have to coincide with the frequencies and directions used
in the present WAVE (SWAN) run (in a nested run SWAN will interpolate to these frequencies
and directions). The co-ordinates of locations in the 1D and 2D files are ignored when SWAN
reads this.

Deltares

93 of 124

D-Waves , User Manual

This appendix describes the format of the files for spectral input (command BOUNDARY) and
output (commands SPEC and NEST) by SWAN. The files are recognised by SWAN or another
reading program by the presence of the keyword SWAN and a version number on the first line
of the file. This description is valid for version number 1.
These files contain the following information:

co-ordinates of locations
frequencies
directions (if used for 2D)
time (if time-dependent)
spectral energy or variance densities (and aver. dir. and dir. spread if 1D)

Example of a 1D non-stationary spherical co-ordinates file:

DR
AF

SWAN 1
Swan standard spectral file, version
$ Data produced by SWAN version 40.41
$ Project:’projname’ ;
run number:
’runnum’
TIME
time-dependent data
1
time coding option
LONLAT
locations in spherical co-ordinates
2
number of locations
1.00 1.00
1.20 1.00
RFREQ
relative frequencies in Hz
25
number of frequencies
0.0418
0.0477
0.0545
0.0622
0.0710
0.0810
0.0924
0.1055
0.1204
0.1375
0.1569
0.1791
0.2045
0.2334
0.2664
0.3040
0.3470
0.3961
0.4522
0.5161
0.5891
0.6724
0.7675
0.8761
1.0000
QUANT
3
number of quantities in table
VaDens
variance densities in m2/Hz
m2/Hz
unit
-0.9900E+02
exception value
CDIR
average Cartesian direction in degr
degr
unit
-0.9990E+03
exception value
DSPRDEGR
directional spreading
degr
unit
-0.9000E+01
exception value

94 of 124

Deltares

Files of Delft3D-WAVE

6.3
6.5
6.7
6.7
6.6
6.3
5.8
15.2
22.9
11.5
11.0
10.9
12.1
13.0
13.5
13.7
14.0
14.6
14.9
15.1
15.3
15.5
15.6
15.7
15.9

date and time

DR
AF

19680606.030000
LOCATION 1
0.3772E-03 190.1
0.1039E-02 190.2
0.2281E-02 190.3
0.3812E-02 190.3
0.4255E-02 190.3
0.2867E-02 190.1
0.1177E-02 189.6
0.3892E-03 192.0
0.8007E-03 244.5
0.6016E-02 251.4
0.1990E-01 251.0
0.3698E-01 249.9
0.3874E-01 248.1
0.2704E-01 246.6
0.1672E-01 247.0
0.1066E-01 247.7
0.5939E-02 247.3
0.3247E-02 246.5
0.1697E-02 245.9
0.8803E-03 245.6
0.4541E-03 245.5
0.2339E-03 245.4
0.1197E-03 245.5
0.6129E-04 245.5
0.3062E-04 245.3
LOCATION 2
0.7129E-02
67.2
0.3503E-01
67.5
0.1299E+00
68.2
0.5623E+00
69.7
0.1521E+01
71.4
0.3289E+01
74.0
0.4983E+01
77.2
0.4747E+01
79.9
0.2322E+01
79.4
0.1899E+01 341.1
0.1900E+01 314.6
0.6038E+01 324.3
0.8575E+01 326.1
0.4155E+01 325.1
0.1109E+01 322.8
0.7494E+00 323.1
0.4937E+00 323.1
0.2953E+00 323.3
0.1661E+00 323.6
0.9788E-01 323.7
0.5766E-01 323.8
0.3397E-01 324.0
0.2001E-01 324.1
0.1179E-01 324.2
0.6944E-02 324.2

25.3
21.7
19.7
18.0
18.0
18.8
20.3
22.0
30.7
56.2
39.4
31.9
31.0
30.5
32.9
33.3
33.3
33.7
34.0
33.8
33.6
33.5
33.4
33.3
33.2

Example of a 2D stationary Cartesian co-ordinates file:
SWAN 1
Swan standard spectral file, version
$ Data produced by SWAN version 40.41
$ Project:’projname’ ;
run number:’runnum’
LOCATIONS
locations in x-y-space
2
number of locations
0.00 0.00
22222.22 0.00
RFREQ
relative frequencies in Hz
25
number of frequencies

Deltares

95 of 124

DR
AF

0.0418
0.0477
0.0545
0.0622
0.0710
0.0810
0.0924
0.1055
0.1204
0.1375
0.1569
0.1791
0.2045
0.2334
0.2664
0.3040
0.3470
0.3961
0.4522
0.5161
0.5891
0.6724
0.7675
0.8761
1.0000
CDIR
24
7.5000
22.5000
37.5000
52.5000
67.5000
82.5000
97.5000
112.5000
127.5000
142.5000
157.5000
172.5000
187.5000
202.5000
217.5000
232.5000
247.5000
262.5000
277.5000
292.5000
307.5000
322.5000
337.5000
352.5000
QUANT
1
VaDens
m2/Hz/degr
-0.9900E+02
FACTOR
0.422574E-11
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0

D-Waves , User Manual

96 of 124

spectral Cartesian directions in degr
number of directions

number of quantities in table
variance densities in m2/Hz/degr
unit
exception value

0
0
0
0
0
0
0
0

817

8018

574

Deltares

Files of Delft3D-WAVE

DR
AF

0 0 0 0 0 0 0 0 0 0 0 0 39230 2532 38
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 92174 4477 68
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 99010 1946 29
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 47054 131 2
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 13228
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 39417
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 61269
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 29738
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 2161
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
2
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0
0 0
0 0 0 0 0 0 0 0 0
FACTOR
0.675611E-06
51 242 574 956 1288 1482 1481 1286 957 579 244 51 0 0 0
0 0 0 0 0 0 0 0 0
129 610 1443 2402 3238 3725 3724 3234 2406 1454 613 128 0 0 0
0 0 0 0 0 0 0 0 0
273 1287 3054 5084 6846 7872 7869 6837 5091 3076 1295 271 0 0 0
0 0 0 0 0 0 0 0 0
665 3152 7463 12402 16712 19229 19221 16690 12419 7518 3172 662 0 0 0
0 0 0 0 0 0 0 0 0
1302 6159 14608 24275 32688 37618 37603 32644 24309 14716 6198 1296 0
0 0 0 0 0 0 0 0 0
2328 10989 26020 43341 58358 67109 67080 58281 43401 26213 11058 2317
0 0 0 0 0 0 0 0 1
3365 15922 37712 62733 84492 97150 97110 84380 62820 37991 16021 3349
0 0 0 0 0 0 0 0 1
3426 16230 38440 63939 86109 99010 98969 85995 64027 38724 16331 3410
0 0 0 0 0 0 0 0 0
2027 9612 22730 37790 50909 58529 58505 50841 37843 22898 9672 2018 0
0 0 0 0 0 0 0 0 0
672 3178 7538 12535 16892 19440 19432 16870 12552 7594 3198 669 0 0 0
0 0 0 0 0 0 0 0 0
101 479 1135 1890 2542 2924 2923 2539 1892 1144 482 101 0 0 0
0 0 0 0 0 0 0 0 0

Deltares

0 0
0 0 0
0 0 0
0 0 0
0 0

97 of 124

D-Waves , User Manual

43 57
0 0 0
1 1 1
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0

66 66
0 0
1 1 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0
0 0 0
0 0

57 43 26 11 2 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0

11 26
0 0 0
0 0 1
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0

DR
AF

2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0 0 0 0 0
0 0 0 0 0

Note that the true variance or energy densities are obtained by multiplying each number with
the factor given under the keyword FACTOR.
A.2.10

Space-varying wind field

This feature has been made available as a special feature in Delft3D-WAVE. It can not (yet) be
switched on in the WAVE-GUI. The user can include this functionality by adding the keyword
Meteofile in the MDW-file. The keyword should specify the file containing the spacevarying wind data. If one wishes to specify wind fields that vary in space but are constant
in time, one should simply incorporate the same wind field data block twice in one file. This
generates a wind field that is constant in time.
Remarks:
The keyword Meteofile can be added both in Datagroup General as in Datagroup
Domain. When the keyword is added in Datagroup General, the wind will be incorporated in all domains. When the keyword is added in Datagroup Domain, the wind will
be incorporated in that domain only.
The Meteofile may occur more than once in the MDW-file to specify multiple sets of
meteorological data (also within a Datagroup).
Example 1
If one would like to add two meteofiles containing an x-component and y-component for spacevarying wind, respectively, and apply the wind to all domains of the WAVE simulation, one
should add them to Datagroup General as follows:
[WaveFileInformation]
FileVersion
[General]
ProjectName

98 of 124

= 02.00
= Siu-Lam

Deltares

Files of Delft3D-WAVE

ProjectNr
Description
Description
Description
OnlyInputVerify
SimMode
DirConvention
ReferenceDate
ObstacleFile
MeteoFile
MeteoFile
[TimePoint]
....

=
=
=
=
=
=
=
=
=
=
=

001
Tutorial Delft3D-WAVE
Siu Lam model
SWAN wave model using a curvilinear grid
false
quasi-stationary
nautical
2005-10-01
obst_data_keyw.obs
xwind.wnd
ywind.wnd

Example 2

= 02.00

DR
AF

[WaveFileInformation]
FileVersion
[General]
ProjectName
ProjectNr
Description
Description
Description
OnlyInputVerify
SimMode
DirConvention
ReferenceDate
ObstacleFile
[TimePoint]
....
[Domain]
Grid
BedLevel
DirSpace
NDir
StartDir
EndDir
FreqMin
FreqMax
NFreq
Output
MeteoFile
MeteoFile
[Domain]
Grid
BedLevel
DirSpace
NDir
StartDir
EndDir
FreqMin
FreqMax
NFreq
Output
[Boundary]
....

If one would like to add the same meteorological files, but apply them only in the domain with
grid siu_lam_coarse.grd, one should add them to Datagroup Domain as:

=
=
=
=
=
=
=
=
=
=

Siu-Lam
002
Tutorial Delft3D-WAVE
Siu Lam model, 2 domains
SWAN wave model using 2 curvilinear grids
false
quasi-stationary
nautical
2005-10-01
obst_data_keyw.obs

=
=
=
=
=
=
=
=
=
=
=
=

siu_lam_coarse.grd
siu_lam_coarse.dep
circle
36
0.000000000000000000e+000
0.000000000000000000e+000
5.000000074505806000e-002
1.000000000000000000e+000
24
true
xwind.wnd
ywind.wnd

=
=
=
=
=
=
=
=
=
=

siu_lam_fine.grd
siu_lam_fine.dep
circle
36
0.000000000000000000e+000
0.000000000000000000e+000
5.000000074505806000e-002
1.000000000000000000e+000
24
true

Remark:
When applying space-varying wind in only one or some of the domains, the user should

Deltares

99 of 124

D-Waves, User Manual

be aware of the fact that the transition in wind forcing from one domain to the other may
be not smooth.
In many cases the space varying wind data is provided by a meteorological station. This
data is often defined on a different grid than the computational grid used in Delft3D-WAVE.
Translating these files into files defined on the (curvilinear) grid of the computational engine is
often a lengthy process and can result in huge files. This special feature facilitates the reading
of the meteorological data on its own grid and interpolates the data internally to the grid of
Delft3D-WAVE.
Delft3D-WAVE can handle wind data on several different types of grids:
Space-varying wind on the computational (SWAN) grid
Space-varying wind on an equistant grid
Space-varying wind on a curvilinear grid
Space-varying wind on a Spiderweb grid

1
2
3
4

A.2.10.1

DR
AF

For these types of meteorological input, fixed formats have been set-up, that completely define a dataset. This form of meteorological input is also used by Delft3D-FLOW, see (Delft3DFLOW UM, 2013). In Delft3D-FLOW, also the atmospheric pressure is read from the meteorological files and used in the simulation. This is not (yet) available in Delft3D-WAVE. In the
following sections, generic descriptions of the formats of the meteorological input types are
given. In these descriptions the atmospheric pressure is also considered. This is not relevant for Delft3D-WAVE and may be excluded. For Space-varying wind on the computational
(SWAN) grid, both x_wind, y_wind and air_pressure are given in one file. Similarly, for
Space-varying wind on a Spiderweb grid, both wind_speed, wind_from_direction
and p_drop (atmospheric pressure drop) are specified in one file. This format must also be
used for a Delft3D-WAVE simulation, for which the atmospheric pressure (drop) is then not
used.
Space-varying wind on the computational (SWAN) grid
File contents

Filetype
File format
Filename
Generated

100 of 124

Time-series for space varying wind velocity components (east-west
and south-north) and atmospheric pressure, defined on the computational grid. The file consists of a header, followed by datablocks
containing the wind and pressure fields at times specified using a
standardised time definition above each datablock. The header specifies the type of file and the input it contains using a number of keywords. The keywords are case insensitive and the order of the keywords is not fixed.
ASCII or binary.
Free formatted or unformatted, keyword based.

Some offline program.

Deltares

Files of Delft3D-WAVE

Header description:
Value

Description

FileVersion

1.03

version of file format

Filetype

meteo_on_computational_grid

meteo input on computational grid

NODATA_value

free

value used for input that is
to be neglected

n_quantity

number of quantities specified in the file

quantity1

x_wind

quantity2

y_wind

quantity3

air_pressure

Keywords

wind in x-direction
wind in y -direction

DR
AF

air pressure

unit1

m s-1

unit
of
quantity1,
meters/second

unit2

m s-1

unit
of
quantity2,
meter/second

unit3

Pa or
mbar

unit of quantity3, Pa or
millibar

Time definition and data block description
Keywords

Value

Description

Time

fixed format described below

time definition string

The time definition string has a fixed format, used to completely determine the time at which
a dataset is valid. The time definition string has the following format:

TIME minutes/hours since YYYY-MM-DD HH:MM:SS TIME ZONE, e.g.
360 minutes since 2008-07-28 10:55:00 +01:00

The format of the string is completely fixed. No extra spaces or tabs can be added between
the different parts of the definition. The time definition is followed by the datablock of input
values corresponding to the specified time. The data block consists of three subsequent
blocks containing the velocity component in M-direction, the velocity component in N-direction
and the atmospheric pressure, respectively. All three quantities are given for Nmax by Mmax
points, where the first value in the dataset corresponds to cell (1, 1) on the grid. Every next
line in the dataset then corresponds to a row on the grid. The time definition and the data
block — for all three quantities — are repeated for each time instance of the time-series.

Deltares

101 of 124

D-Waves, User Manual

File version and conversion
The current description holds for FileVersion 1.03. The table below shows the latest
modifications in the file format (and version number).
FileVersion

Modifications

1.03

No changes for this meteo input type, but for the meteo types meteo_on_equidistant_grid and meteo_on_curvilinear_grid

1.02

No changes for this meteo input type, but for the meteo type meteo_on_spider_web_grid

1.01

Changed keyword MeteoType to FileType

Changed fixed value of input type (Keyword Filetype) from Svwp to
meteo_on_computational_grid (meteo_on_flow_grid is also allowed)

DR
AF

Restrictions:
Keywords are followed by an equal sign ’=’ and the value of the keyword.
When a keyword has value free the value of this keyword is free to choose by the user.
When only one value is given for a keyword, this keyword has a fixed value and when 2
or more options are shown, the user can choose between those values.
Times must be specified exactly according to the time definition. See the examples
shown in this section.
The contents of the file will not be checked on its domain.
The wind components are specified at the cell centres (water level points) of the computational grid.
Input items in a data block are separated by one or more blanks (free formatted file
only).
Remarks:
The time definition in the meteorological file contains the number of minutes or hours
since a reference data and time in a certain time zone. The reference time and time
zone may differ from those of the simulation. The computational engine will search
in the meteo file for the simulation time and interpolate between neighbouring times if
necessary. Possible differences in time zone will be accounted for by shifting the meteo
input data with the difference. The reference times within the time definition string may
vary in a meteo file, i.e. it is possible to attach new input with a different reference time,
behind the last data block.
Comments can be added after #’s.
Example

Model area of 25 ∗ 33 grid points (Mmax = 25; Nmax = 33). The input data is printed in
Courier, comments are printed behind #’s.

102 of 124

Deltares

Files of Delft3D-WAVE

Figure A.1: Definition wind components for space varying wind

# Time definition
# Wind component west to east
# Wind component south to north
# Atmospheric pressure
# Time definition
# Wind component west to east
# Wind component south to north
# Atmospheric pressure
# Time definition
# Wind component west to east
# Wind component south to north
# Atmospheric pressure
# Time definition
# Wind component west to east
# Wind component south to north
# Atmospheric pressure

DR
AF

Time = 0.0 minutes since 2008-09-20 10:30:00 +01:00
{33 records with 25 values each}
{33 records with 25 values each}
{33 records with 25 values each}
Time = 340.0 minutes since 2008-09-20 10:30:00 +01:00
{33 records with 25 values each}
{33 records with 25 values each}
{33 records with 25 values each}
Time = 600.0 minutes since 2008-09-20 10:30:00 +01:00
{33 records with 25 values each}
{33 records with 25 values each}
{33 records with 25 values each}
Time = 1240.0 minutes since 2008-09-20 10:30:00 +01:00
{33 records with 25 values each}
{33 records with 25 values each}
{33 records with 25 values each}

Remarks:
To obtain the wind direction according to the nautical convention, the wind direction is
reversed.
The wind is specified in terms of its components along the west-east (x_wind) and
south-north (y_wind) co-ordinate system, see Figure A.1. These definitions differ
from the nautical convention (used for uniform wind), which is specified relative to true
North, see Figure A.2.

Deltares

103 of 124

D-Waves, User Manual

Figure A.2: Definition sketch of wind direction according to Nautical convention

Space-varying wind on an equistant grid
File contents
Time-series of a space varying wind and atmospheric pressure defined on an equidistant (Cartesian or spherical) grid.
File format
Free formatted or unformatted, keyword based.
Generated
Some offline program.

DR
AF

A.2.10.2

Remark:
The keywords are case insensitive.

Header description for the wind velocity files:
Keywords

Value

Description

FileVersion

1.03

version of file format

Filetype

meteo_on_equidistant_grid

meteo input on equidistant grid

NODATA_value

free

value used for input that is to be
neglected

n_cols

free

number of columns used for wind
datafield

n_rows

free

number of rows used for wind
datafield

grid_unit

m or
degree

unit of distances on the grid
in both x- and y -direction

x_llcorner

free

x-coordinate of lower left corner
of lower left grid cell (in units
specified in grid_unit

y_llcorner

free

y -coordinate of lower left corner
of lower left grid cell (in units
specified in grid_unit

104 of 124

Deltares

Files of Delft3D-WAVE

Keywords

Value

Description

x_llcenter

free

x-coordinate of centre of lower
left grid cell (in units specified in

grid_unit
y_llcenter

y -coordinate of centre of lower

free

left grid cell (in units specified in

grid_unit
free

gridsize in x-direction in units
specified in grid_unit

free

gridsize in y -direction in units
specified in grid_unit

n_quantity

quantity1

x_wind or
y_wind

number of quantities specified in
the file

DR
AF

the velocity component given in
unit unit1

unit1

m s-1

unit
of
metre/second

quantity1:

The user must specify the location of the equidistant grid on which the meteorological data
is specified. If one has the location of the lower left corner of the lower left grid cell, one can
specify the starting point of the grid using keywords x_llcorner and y_llcorner. If
one has the location of the cell centre of the lower left grid cell, one should use the keywords
x_llcenter and y_llcenter. Using the first option, the first data value is placed at
(x_llcorner+ 21 dx, y_llcorner+ 12 dy ), which is the cell centre of cell (1,1). Using the latter
option, the first data value is placed at (x_llcenter, y_llcenter), which is again the cell centre
of cell (1,1), i.e. the data values are always placed at the cell centres of the meteorological
grid. Note that the lower left grid cell is defined to be the grid cell with index (1,1). When using
the option of meteorological data on a separate curvilinear grid, the origin and orientation
of the data set can be chosen freely with respect to the grid on which it is specified, see
section A.2.10.3 for details.
Time definition and data block description for the wind velocity files
Keywords

Value

Description

Time

fixed format described below

time definition string

The time definition string has a fixed format, used to completely determine the time at which
a dataset is valid. The time definition string has the following format:
TIME minutes/hours since YYYY-MM-DD HH:MM:SS TIME ZONE, e.g.
360 minutes since 2008-07-28 10:55:00 +01:00

The format of the string is completely fixed. No extra spaces or tabs can be added between the

Deltares

105 of 124

D-Waves, User Manual

different parts of the definition. The time definition is followed by the datablock of input values
corresponding to the specified time. The data block contains values for the wind velocity in
x- or y -direction for n_cols by n_rows points, starting at the top left point. The time definition
and the data block are repeated for each time instance of the time-series.
The atmospheric pressure file
The header for the atmospheric pressure is similar to that of the wind velocity files, except for
the following differences.
Value

Description

quantity1

air_pressure

air pressure

unit1

Pa or mbar

unit of quantity1: Pascal or
millibar

Keywords

DR
AF

The specification of the time definition and the data block is fully conform the wind velocity
files.
File version and conversion

The current description holds for FileVersion 1.03. The table below shows the latest
modifications in the file format (and version number).
FileVersion

Modifications

1.03

Use of keyword Value_pos to indicate the position of the lower left
corner of the grid replaced by use of the combination of keywords:
x_llcorner and y_llcorner
or
x_llcenter and y_llcenter

1.02

1.01

No changes for this meteo input type, but for the meteo type meteo_on_spiderweb_grid
Changed keyword MeteoType to FileType

Changed fixed value of input type (Keyword Filetype) from ArcInfo
to meteo_on_equidistant_grid

Restrictions:
The contents of the file will not be checked on its domain.
Keywords are followed by an equal sign ’=’ and the value of the keyword.
When a keyword has value free, the value of this keyword is free to choose by the user.
When only one value is given for a keyword, this keyword has a fixed value and when 2
or more options are shown, the user can choose between those values.
Times must be specified exactly according to the time definition. See the examples
shown in this section.
The atmospheric pressure file must use the same grid definition and time frame as the
files for the wind velocity components.
The unit of the meteo grid must be the same as the computational grid, i.e. both with
grid_unit = [m] or both with grid_unit = [degree].
Input items in a data block are separated by one or more blanks.

106 of 124

Deltares

Files of Delft3D-WAVE

The wind components are specified at the cell centres (water level points) of the numerical grid.

The wind components are specified in the west-east (x_wind) and south-north directions (y_wind).

Remarks:
The time definition in the meteo files contains the number of minutes or hours since
a reference date and time in a certain time zone. The reference time and time zone
may differ from those of the simulation. During a simulation the computational engine
will search in the meteo file for the current simulation time and interpolate between
neighbouring times if necessary. Possible differences in time zone will be accounted for
by shifting the meteo input data. The reference times within the time definition string
may vary in a meteo file, i.e. it is possible to attach new input with a different reference
time, behind the last data block. Consecutive times must always be increasing in the
input file.
Comments can be added after pound signs (#). These are not read.
Example of a file containing wind in x-direction (west-east)

DR
AF

The data blocks in this example are the result of the following FORTRAN statements:
do j = nrows,1,-1
write(out,*) (xwind(i,j),i=1,ncols)
enddo

The x-wind velocity file for a 3 (n_cols) by 4 (n_rows) grid has the following layout:
FileVersion
=
1.03
filetype
=
meteo_on_equidistant_grid
NODATA_value
=
-999.000
n_cols
=
3
n_rows
=
4
grid_unit
=
degree
x_llcenter
=
-12.000
y_llcenter
=
48.000
dx
=
0.12500
dy
=
0.083333333
n_quantity
=
1
quantity1
=
x_wind
unit1
=
m s-1
TIME =
0.0 hours since 2008-01-15 04:35:00 +00:00
2
3.0 3.6
3
4.5 2
2.2 1
2.3
1.2 0.7 -0.4
TIME =
6.0 hours since 2008-01-15 04:35:00 +00:00
-1.1 -2.3 -3.6
-3.2 0.8 1.1
2.2 -1
-1.6
1.2 -0.7 -0.4

This results in an x-component of wind velocity given - in [m/s] - on a spherical, 3 by 4,
equidistant grid, with grid sizes given by dx and dy (in degrees) and where the centre point
of the lower left cell of the grid lies in (longitude, latitude) (-12.0, 48.0) on the globe. Data is
given at two times: 0 and 6 hours since January 15th, 2008, 4:35 AM, in UTC+0.

Deltares

107 of 124

D-Waves, User Manual

Space-varying wind on a curvilinear grid
File contents
Time-series of a space varying wind and atmospheric pressure defined on a curvilinear (Cartesian or spherical) grid.
File format
Free formatted or unformatted, keyword based.
Generated
Some offline program.
Remark:
The keywords are case insensitive.
Header description for the wind velocity files:
Value

Description

FileVersion

1.03

version of file format

Filetype

meteo_on_curvilinear_grid

NODATA_value

free

Keywords

meteo input on curvilinear grid
value used for input that is to be
neglected

DR
AF

A.2.10.3

grid_file

free.grd

first_data_value grid_llcorner or

name of the curvilinear grid file on
which the data is specified
see example below

grid_ulcorner or
grid_lrcorner or
grid_urcorner

data_row

grid_row or
grid_column

see example below

n_quantity

number of quantities specified in
the file

quantity1

x_wind or
y_wind

the velocity component given in
unit unit1

unit1

m s-1

unit
of
metres/second

quantity1:

Time definition and data block description for the wind velocity files
For a description of the time definition and data block see section A.2.10.2.
The atmospheric pressure file
For a description of the atmospheric file see section A.2.10.2.

108 of 124

Deltares

Files of Delft3D-WAVE

File version and conversion
The current description holds for FileVersion 1.03. The table below shows the latest
modifications in the file format (and version number).
FileVersion

Modifications

1.03

Fixed bug in interpolation of data from meteo grid to computational grid:
Conversion script mirrored data set erroneously. This was treated correctly by meteo module. Fixed both the conversion script and the meteo
module together: Required modification in meteo input file:
Change first_data_value = grid_llcorner into grid_ulcorner or
vice versa

or
Change first_data_value = grid_lrcorner into grid_urcorner or
vice versa
No changes for this meteo input type, but for the meteo type meteo_on_spiderweb_grid

DR
AF

1.02

1.01

Changed keyword MeteoType to FileType

Changed keyword Curvi_grid_file to Grid_file

Changed fixed value of input type (Keyword Filetype) from Curvi to
meteo_on_curvilinear_grid

Restrictions:
The restrictions for space varying wind and pressure on a separate curvilinear grid are
the same as for space varying wind and pressure on an equidistant grid, described in
section A.2.10.2. A differerence is that the data values on the curvilinear grid are not
specified in the cell centres, but in the grid points (cell corners).
The unit of the meteo grid must be the same as the computational grid, i.e. both with
grid_unit = [m] or both with grid_unit = [degree].
Remark:
The remarks for space varying wind and pressure on a separate curvilinear grid are
the same as for space varying wind and pressure on an equidistant grid, described in
section A.2.10.2.

Deltares

109 of 124

D-Waves, User Manual

DR
AF

Figure A.3: Illustration of the data to grid conversion for meteo input on a separate curvilinear grid

Example:

A file for input of x-velocity (in west-east direction) on a 4 (n_rows) by 5 (n_cols) curvilinear grid, where the meteorogical data is mirrored vertically with respect to the grid, has the
following layout:
FileVersion
=
1.03
filetype
=
meteo_on_curvilinear_grid
NODATA_value
=
-999.000
grid_file
=
curviwind.grd
first_data_value =
grid_llcorner
data_row
=
grid_row
n_quantity
=
1
quantity1
=
x_wind
unit1
=
m s-1
TIME =
0.0 minutes since 1993-06-28 14:50:00 -02:00
1
2
3
4
5
6
7
8
9 10
11 12 13 14 15
16 17 18 19 20
TIME =
600.0 minutes since 1993-06-28 14:50:00 -02:00
1
2
3
4
5
6
7
8
9 10
11 12 13 14 15
16 17 18 19 20

This results in an x-component of velocity given - in [m/s] - on the curvilinear grid specified in
file . The data set will be mirrored such that the first value of the data (upper
left corner, in the example ’1’) corresponds to the lower left corner of the grid (point (1,1)) and
a row of data corresponds to a row on the grid, see Figure A.3. Data is given at two times: 0
and 600 minutes since June 28th, 1993, 14:50 PM, in UTC-2.

110 of 124

Deltares

Files of Delft3D-WAVE

Space-varying wind on a Spiderweb grid
Cyclone winds are governed by a circular motion, combined with a cyclone track. This type
of wind is generally very difficult to implement on a curvilinear grid. This feature facilitates the
reading of the so-called Spiderweb files and interpolates the wind and pressure data internally
to the computational grid. A special feature of the space varying wind and pressure on the
Spiderweb grid is that it can be combined with one of the other meteorological input options
described in this manual, i.e. to either uniform wind and pressure, or to one of the space
varying wind and pressure options, see section A.2.10.
File contents

File format
Generated

Time-series of a space varying wind and atmospheric pressure defined on a Spiderweb grid. This grid may be specified in Cartesian
or spherical coordinates.
Free formatted or unformatted, keyword based.
Some offline program.

Remarks:
The keywords are case insensitive.
Space varying wind and pressure on a Spiderweb grid is added to other wind input and
the wind fields are interpolated and combined in and around the cyclone.

DR
AF

A.2.10.4

Header description of the Spiderweb wind and pressure file:
Keywords

Value

Description

FileVersion

1.03

version of file format

Filetype

meteo_on_spiderweb_grid

meteo input on Spiderweb grid

NODATA_value

free

value used for input that is to be
neglected

n_cols

free

number of gridpoints in angular
direction

n_rows

free

number of gridpoints in radial
direction

grid_unit

m or
degree

unit of the Spiderweb grid

spw_radius

free

radius of the spiderweb given in
units given by spw_rad_unit

spw_rad_unit

unit of the Spiderweb radius

spw_merge_frac

[0.0,1.0]

fraction of the Spiderweb radius
where merging starts of the background wind with the Spiderweb
wind. Default is 0.5

air_pressure
_reference

air_pressure_default_from
_computational_engine

Both keyword and value are too
long to fit on one line.
Reference value related to
p_drop is the default air pressure
of the computional engine

Deltares

111 of 124

D-Waves, User Manual

Figure A.4: Wind definition according to Nautical convention

Value

Description

DR
AF

Keywords

or free

or the value specified.
If missing, p_drop is extracted
from the actual atmospheric
pressure.

n_quantity

number of quantities specified in
the file

quantity1

wind_speed

wind speed given in unit unit1

quantity2

wind_from_direction

direction where the wind is coming from given in unit unit2

quantity3

p_drop

drop in atmospheric pressure
given in unit unit3

unit1

m s-1

unit
of
metres/second

degree

unit of quantity2: degrees

Pa or
mbar

unit of quantity3: Pascal or
millibar

unit2
unit3

quantity1:

Time definition and data block description
For a description of the time definition see section A.2.10.2.
Cyclone track information:
For each time in the time series of space varying wind and pressure on a Spiderweb grid, the
position of the cyclone eye (and thus also the spiderweb grid) must be given, as well as the
drop of atmospheric pressure in the cyclone eye.

112 of 124

Deltares

DR
AF

Files of Delft3D-WAVE

Figure A.5: Spiderweb grid definition

File version and conversion

The current description holds for FileVersion 1.03. The table below shows the latest
modifications in the file format (and version number).
FileVersion

Modifications

1.03

No changes for this meteo input type

1.02

Changed the use of keyword n_rows and n_cols. The radius of the
cyclone is divided in n_rows rings of width: spw _radius/n_rows [m]
and the circle is divided in n_cols parts of 2π/n_cols [rad].

1.01

Changed keyword MeteoType to FileType

Changed fixed value of input type (Keyword Filetype) from Spiderweb to meteo_on_spiderweb_grid

Restriction:
The restrictions for space varying wind and pressure on a Spiderweb grid are the
same as for space varying wind and pressure on an equidistant grid, described in section A.2.10.2.
Remarks:
The remarks for space varying wind and pressure on a separate curvilinear grid are
the same as for space varying wind and pressure on an equidistant grid, described in
section A.2.10.2.
The Spiderweb grid is circular and the definitions of the number of rows n_rows and
the number of columns n_cols is therefore different then for the other meteo input
formats. For the Spiderweb grid, the number of rows determines the grid size in radial direction. The number of columns defines the grid size in angular direction. See
Figure A.5.

Deltares

113 of 124

D-Waves, User Manual

The wind is specified according to the nautical convention, i.e. wind from the true North
has direction zero and the wind turns clockwise with an increasing angle. See Figure A.4.
Example:
A file for input of space varying wind and pressure on a 5x3 Spiderweb grid, has the following
layout:

DR
AF

FileVersion
= 1.03
filetype
= meteo_on_spiderweb_grid
NODATA_value
= -999.000
n_cols
= 3
n_rows
= 5
grid_unit
= degree
spw_radius
= 600000.0
spw_rad_unit
= m
air_pressure_reference = air_pressure_default_from_computational_engine
n_quantity
= 3
quantity1
= wind_speed
quantity2
= wind_from_direction
quantity3
= p_drop
unit1
= m s-1
unit2
= degree
unit3
= Pa
TIME
=
0.0 hours since 1997-07-14 03:00:00 -06:00
x_spw_eye
= 115.1
y_spw_eye
= 18.9
p_drop_spw_eye = 5300.0
1.38999
1.38261
1.38315
1.28251
1.34931
1.22571
1.27215
1.31214
1.32451
1.38999
1.86592
2.87732
1.43899
1.24912
2.21519
60.0000
180.0000
270.0000
28.7500
20.0000
31.2500
42.5000
53.7500
65.0000
49.3400
60.2400
81.5200
51.4100
62.0000
43.1200
5301.280
5294.490
5156.240
5043.460
5112.040
5264.020
5140.020
5202.520
5411.210
5294.730
5285.760
5235.250
5242.530
5156.190
5124.240
TIME
=
1.0 hours since 1997-07-14 03:00:00 -06:00
x_spw_eye
= 114.8
y_spw_eye
= 18.8
p_drop_spw_eye = 5250.0
1.35763
1.35763
1.35763
1.35763
1.87273
2.24784
1.92214
2.47836
2.17266
1.87662
2.72116
2.82375
1.26585
2.24146
2.38722
159.0000
346.5200
290.6400
342.3200
282.1400
20.2400
10.7500
25.5300
36.4500
61.8400
81.6200
45.5100
49.5250
56.7500
75.1300
5314.520
5104.490
5287.240
5124.240
5285.760
5252.420
5152.460
5247.040
5222.020
5242.020
5223.520
5475.210
5244.270
5211.210
4998.110

114 of 124

Deltares

Files of Delft3D-WAVE

DR
AF

This results in the following set of meteo data. Velocities given in [m/s] and pressure drops in
[Pa] on a Spiderweb grid which is given in spherical coordinates (grid_unit = degree). The
cyclone and spiderweb grid have a radius of 600 km. The grid is 5x3, which means the radius
is divided in five parts of 120 km and the 360 degrees are divided in 3 parts of 120 degrees
each. Wind speeds, wind directions and pressure drops are given at two times: 0 and 1.0
hour since July 14th, 1997, 03:00 AM, in UTC-6. Between these two times the cyclone eye
moves from (longitude, latitude) (115.1, 18.9) to (114.8, 18.8) on the globe and the pressure
drop in the cylcone eye decreases from 5300.0 [Pa] to 5250.0 [Pa].

Deltares

115 of 124

DR
AF

D-Waves, User Manual

116 of 124

Deltares

B Definition of SWAN wave variables
In SWAN a number of variables, mostly related to waves are used in input and output. The
definitions of these variables are conventional for the most part.
HSIGN

significant wave height (Hs in [m]), defined as:

sZ Z
Hs = 4
E(ω, θ) dωdθ
where E(ω, θ) is the variance density spectrum
mean absolute wave period (in s) of E(ω, θ), defined as:

Tm01

where ω is the absolute radian frequency, determined by the Doppler shifted
dispersion relation.
mean wave direction (in ◦ , Cartesian or Nautical convention), as conventionally
defined (Kuik et al., 1988).

DR
AF

DIR

−1
−1
RR
RR
ωE(σ, θ) dσdθ
ωE(σ, θ) dωdθ
RR
RR
= 2π
= 2π
E(σ, θ) dσdθ
E(σ, θ) dωdθ

TM01

sin(θ)E(σ, θ) dσdθ
[DIR] = arctan R
cos(θ)E(σ, θ) dσdθ

RTP

DSPR

relative peak period (in s) of E(σ) (equal to absolute peak period in the absence
of currents)
the one-sided directional width of the spectrum (directional spreading or directional standard deviation, in 0), defined as:
2

DSP R =

180
π

2 Z

2π

2 sin

θ − θ̄
2

D(θ) dθ

and computed as conventionally for pitch-and-roll buoy data (Kuik et al. (1988);
this is the standard definition for WAVEC buoys integrated over all frequencies):




2
π
DSP R
=2 1−

180
MS

Deltares


R
R
2 Z
2 !1/2 
E(σ, θ) dσ
E(σ, θ) dσ
cos(θ) R
sin(θ) R
dθ +
dθ

E(σ) dσ
E(σ) dσ

As input to SWAN in the commands BOUNDPAR and BOUNDSPEC the directional distribution of incident wave energy is: D(θ) = A{cos(θ)}[M S] at all
frequencies. [MS] is not necessarily an integer number.
[MS] is, for this directional distribution, related to the one-sided directional spread
of the waves (DSPR) as follows:

117 of 124

dspr (in ◦ )

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
15.
20.
30.
40.
50.
60.
70.
80.
90.
100.
200
400
800

37.5
31.5
27.6
24.9
22.9
21.2
19.9
18.8
17.9
17.1
14.2
12.4
10.2
8.9
8.0
7.3
6.8
6.4
6.0
5.7
4.0
2.9
2.0

DR
AF

DISSIP

WLEN

[MS]

D-Waves, User Manual

energy dissipation per unit time due to the sum of bottom friction, whitecapping
and depth induced wave breaking (in W/m2 of m2 /s, depending on command
SET)
the mean wavelength,

R p
−1
k E(σ, θ) dσdθ
W LEN = 2π R p−1
k E(σ, θ) dσdθ

see command QUANTITY (where p = 1 is default)
STEEPNESS wave steepness, computed as:
STEEPNESS =

TRANSP

VEL

FORCE

118 of 124

HSIGN
WLEN

fraction of breakers [-] in expression of Battjes and Janssen (1978), see section 2.1.
RR
energy
transport with components Px =
ρgcx E(σ, θ) dσdθ and Py =
RR
ρgcy E(σ, θ) dσdθ with x and y of the problem co-ordinate system, except in the case of output with BLOCK command in combination with command
FRAME, where x and y relate to the x-axis and y -axis of the output frame.
current velocity with components in x and y direction of the problem co-ordinate
system, except in the case of output with BLOCK command in combination with
command FRAME, where x and y relate to the x-axis and y-axis of the output
frame.
wave induced force per unit surface area (gradient of the radiation stresses)
with x and y of the problem co-ordinate system, except in the case of output
with BLOCK command in combination with command FRAME, where x and y

Deltares

Definition of SWAN wave variables

relate to the x-axis and y -axis of the output frame.

Fx = −

∂Sxx ∂Sxy
−
,
∂x
∂y

and

Fy = −

∂Syx ∂Syy
−
∂x
∂y

where S is the radiation stress tensor:

Z
1
2
Sxx = ρg
n cos θ + n −
E dσdθ
2
Z
Sxy = Syx = ρg n sin θ cos θE dσdθ
Syy = ρg
URMS
UBOT

E dσdθ

and n is the ratio of group velocity over phase velocity.
root-mean-square value of the orbital motion near the bottom
root-mean-square
value of the maximum of the orbital motion near the bottom
√

Ubot =

2Urms

numerical loss of energy equal to cθ E(ω, θ) across boundaries θ1 =[dir1] and
θ2 =[dir2] of a directional sector (see command CGRID)
the elevation of mean water level (relative to still water level) induced by the
gradient of the radiation stresses of the waves
Smoothed Peak wave period. This value is obtained as the maximum of a
parabolic fitting through the highest bin and two bins on either side of the highest
one of the discrete wave spectrum. This ’non-discrete’ or ’smoothed’ value is a
better estimate of the ’real’ peak period compared to the quantity RTP.

DR
AF

LEAK

1
n sin θ + n −
2
2

SETUP
TPS

Cartesian direction convention: the direction is the angle between the vector and the positive x-axis, measured counter-clockwise (the direction where the waves are going to or where
the wind is blowing to).
Nautical direction convention: the direction of the vector from geographic North measured
clockwise + 180◦ (the direction where the waves are coming from or where the wind is blowing
from).

Deltares

119 of 124

DR
AF

D-Waves, User Manual

120 of 124

Deltares

C Example of MDW-file Siu-Lam
In this appendix the MDW-file for the Siu Lam case is provided . Generated by
the WAVE-GUI 4.94.00:

= 02.00
Siu-Lam
001
Tutorial Delft3D-WAVE
Siu Lam model
SWAN wave model using a curvilinear grid
false
stationary
nautical
2005-10-01
siu_lam_obstacles.obs
2.0000000e+001
2.5500000e+002

= 1.0800000e+003
= -1.0000000e+000
= 0.0000000e+000
= 0.0000000e+000

=
=
=
=
=
=
=
=
=
=
=
=

DR
AF

[WaveFileInformation]
FileVersion
[General]
ProjectName
ProjectNr
Description
Description
Description
OnlyInputVerify
SimMode
DirConvention
ReferenceDate
ObstacleFile
WindSpeed
WindDir
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
[TimePoint]
Time
WaterLevel
XVeloc
YVeloc
[Constants]
WaterLevelCorrection
Gravity
WaterDensity
NorthDir
MinimumDepth
[Processes]
GenModePhys
WaveSetup
Breaking
BreakAlpha
BreakGamma
Triads
TriadsAlpha
TriadsBeta
BedFriction
BedFricCoef
Diffraction
DiffracCoef
DiffracSteps
DiffracProp
WindGrowth
WhiteCapping
Quadruplets
Refraction
FreqShift
WaveForces
[Numerics]
DirSpaceCDD
FreqSpaceCSS

Deltares

=
=
=
=

1.2600000e+003
0.0000000e+000
0.0000000e+000
0.0000000e+000

=
=
=
=

1.4400000e+003
1.5000000e+000
0.0000000e+000
0.0000000e+000

=
=
=
=
=

0.0000000e+000
9.8100004e+000
1.0250000e+003
9.0000000e+001
5.0000001e-002

=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=

3
false
true
1.0000000e+000
7.3000002e-001
false
1.0000000e-001
2.2000000e+000
jonswap
6.7000002e-002
false
2.0000000e-001
5
true
true
Komen
true
true
true
dissipation

=
=

5.0000000e-001
5.0000000e-001

121 of 124

D-Waves, User Manual

=
=
=
=
=
=
=
=

0
false
false
false
siu.loc
true
true
true

=
=
=
=
=
=
=
=
=
=

siu_lam.grd
siu_lam.dep
circle
36
0.0000000e+000
0.0000000e+000
5.0000001e-002
1.0000000e+000
24
true

=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=

Boundary 1
orientation
west
parametric
gauss
peak
degrees
3.3000000e+000
3.3000000e+000
counter-clockwise
1.5000000e+003
0.0000000e+000
5.0000000e+000
2.5500000e+002
4.0000000e+000
9.0000000e+003
1.0000000e+000
5.0000000e+000
2.5500000e+002
4.0000000e+000

= 2.0000000e-002
= 2.0000000e-002
= 2.0000000e-002
= 9.8000000e+001
= 4

DR
AF

RChHsTm01
RChMeanHs
RChMeanTm01
PercWet
MaxIter
[Output]
TestOutputLevel
TraceCalls
UseHotFile
WriteCOM
LocationFile
WriteTable
WriteSpec1D
WriteSpec2D
[Domain]
Grid
BedLevel
DirSpace
NDir
StartDir
EndDir
FreqMin
FreqMax
NFreq
Output
[Boundary]
Name
Definition
Orientation
SpectrumSpec
SpShapeType
PeriodType
DirSpreadType
PeakEnhanceFac
GaussSpread
DistanceDir
CondSpecAtDist
WaveHeight
Period
Direction
DirSpreading
CondSpecAtDist
WaveHeight
Period
Direction
DirSpreading

122 of 124

Deltares

DR
AF
T

T
DR
AF
PO Box 177
2600 MH Delft
Boussinesqweg 1
2629 VH Delft
The Netehrlands

+31 (0)88 335 81 88
sales@deltaressystems.nl
www.deltaressystems.nl

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.5
Linearized                      : No
Page Count                      : 136
Page Mode                       : UseOutlines
Author                          : Deltares
Title                           : D-Waves User Manual
Subject                         : 
Creator                         : LaTeX hyperref
Producer                        : ps2pdf
Keywords                        : Deltares, User, Manual, Wavedynamics
Create Date                     : 2018:04:18 05:54:28+02:00
Modify Date                     : 2018:04:18 05:54:28+02:00
Trapped                         : False
PTEX Fullbanner                 : This is MiKTeX-pdfTeX 2.9.6588 (1.40.18)

EXIF Metadata provided by EXIF.tools

D Waves User Manual Waves_User_Manual

Navigation menu

Versions of this User Manual:

Views

Navigation