conor.coady

Rogier, it would also be good to understand what gaps I can keep between for example forestry polygons, as this is often how they come in parcels of forestry with forestry access tracks between. I also feel the industry in general is using only 0.5 roughness length for forestry, as opposed to a roughness length relating to different tree heights. In some ways this also relates and depends on what displacement height is used? What is your view on these two approaches?

Thanks Rogier. This certainly shines a light on the subject. It would be great to get more of this info into the WAsP Help doc to better describe the limitations of WAsP, but appreciating the new developments.

WAsP is limited to 10 roughness changes. The recommended size of a roughness map however, I believe is 20km by 20 km. In any case, with online sources of roughness, we often end up using polygons for things like forestry or water bodies, inside a background roughness. Polygons next to one another, which is the more accessible form of online mapping, gives twice as many roughness changes as single lines of roughness change (as intended in WAsP). In short with any sort of detail 10 roughness changes are arrived at very quickly and often quite near to the wind farm we are modelling. Are there any plans to increase the number of roughness changes WAsP can model, or are we better off using a smaller roughness map with the added detail. What is the guidance and where is the balance?