Changes in roughness (2004-01-29)

[Old Forum Archivist]

Thank a lot for this forum.



I know that WAsP is limited to a maximum of 10 changes in roughness in his model. We normally have huge maps that can contain more than 10 changes in roughness in more than one direction. What are the impliction on the AEP if for exemple I have ocean less then 10 km (the distance necessary to stabilize the wind profil after a change in roughness) from the met mast and just after the 10th changes in roughness ? Is WAsP able to "see" the speed-up effect of the ocean?



Am I understanding right the change in roughness model?



Thanks for you help.

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WAsP will look at the entire map when analysing the roughness changes. Even if there are more then 10 roughness change lines in one direction, WAsP will not skip the 11th roughness area and beyond. Rather, the program will merge and average some of the smaller roughness bands, in order to get 'the full picture'.



You can always insert a roughness rose as a child of a prediction site, and see how WAsP interprets the different roughness areas and transforms these into the rose. Once you have inspected the roughness rose, you should delete it again from the hierarchy, so that WAsP uses the map for roughness input again (unless you really want the rose to determine the calculations).



WAsP Team

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