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Offshore

Location Climate Monthly statistics Histogram Scatter table 2D Directional rose Scatter table 3D Persistency Coverage of windows Number of windows Delay until next window Data of Past Events Timeseries plot Vector map Timeseries download Quick Stats

Near Shore

Location simple model Seabed profile Location ray model Climate Monthly statistics Histogram Scatter table 2D Directional rose Scatter table 3D Persistency Coverage of windows Number of windows Delay until next window Timeseries download

Seabed profile (used for bottom friction simple model)

Dissipation of wave energy due to bottom friction is caused by the orbital velocity of the water particles near the bottom. The shallower the water or the longer waves travel over shallow water, the more energy will be dissipated. You are asked to specify the seabed profile along the seaward normal. Point of departure is the currently selected nearshore location, with coast normal direction and seabed-level as specified in the nearshore selection screen. This nearshore location is the first point of the seabed profile listed. Note that, by definition, the nearshore point is situated at the shoreline (distance is 0m). Water-level and coast normal direction at the nearshore location cannot be changed in this screen: return to the nearshore location selection screen to change one of these. Water-level is taken to be constant along the seabed profile. Here you can change the seabed-level (and thus the depth) at the nearshore location.

There is no simple rule of thumb telling you when to switch on bottom friction. In most cases, dissipation due to bottom friction can be ignored. You should turn on bottom friction if the water is shallow (in relation to the longest wave) over a large coastal area. In the nearshore validation document, we included a case in the Arabian Gulf where bottom friction is essential. If in doubt, perform computations with and without bottom friction. You could do this as demo user at the demo location.

User Controls

Name	Type	Default	Description
Distance	Editable text field		Distance (m) to the nearshore location per vertex of the seabed profile. Add at least 1 distance (and the related seabed-level) to switch on bottom friction. Consecutive distances must be non-decreasing. Zero-length profile segments are accepted but they do not influence the results. If you do not enter any distances, bottom friction is effectively turned off.
Seabed-level	Editable text field		Seabed-level (m) per vertex of the profile. Add at least 1 seabed-level (and the related distance) to switch on bottom friction. Consecutive seabed-levels must be non-increasing.
Reset	Push button		Re-installs the default profile
OK	Push button		End this input screen to bring up the season selection screen or output selection screen for the nearshore climate.