MIKE 21 BW - Wave Disturbance Parameters

Reference Manual
164 MIKE 21 BW - © DHI
Remarks and hints
When you specify the spatial range of your output data (1DH module only)
you also have to specify the number of points you would like to save, N
points
.
The output result is interpolated to a grid having the constant spatial resolu-
tion of J
last
-J
first
+1/N
points
.
In case you use a structured mesh of the bathymetry we recommend you to
use the suggested default value of N
points
(=J
last
-J
first
+1). For unstructured
meshes we recommend you to use a larger value of N
points
, in order to have a
high resolution in the surf and swash zone. Further it is recommended (for
unstructured meshes) to save the entire profile of data, i.e. keep the default
values of J
first
and J
last
.
5.4.3 Wave disturbance parameters
Figure 5.47 A number of wave disturbance parameters can be extracted from a
MIKE 21 BW simulation including detailed sub-area statistics
The wave disturbance coefficient is defined as the ratio of the significant
wave height relative to the incoming significant wave height. If e.g. the wave
height at a given position is 0.5 m and the incoming (offshore) wave height is
2.0 m, then the wave disturbance coefficient is 0.5/2.0 = 0.25, or 25%.
Output parameters
The results from the wave disturbance calculation are stored in a data file
(.dfs2) with up to 3 items:
 Significant wave height, H
m0
 Wave disturbance coefficient, H
m0
/H
m0
, incoming
 Time of arrival of the first wave that is used in the calculation