Roughness Map - WAsP

ofciftciofciftci Global Mapper UserPosts: 15Trusted User
edited April 2012 in Raster Data
Is there any solution yet for compatibility issues with WAsP roughness maps? There are a few threads about this problem but no one seems to have found a proper solution.

Let me sum up the problem once again. I use Corine Land Cover data to generate roughness maps for energy assessment purposes. First, pull in CLC data and then create roughness grid with just one click thanks to GM. If I try to export roughness map as WAsP map format right away, I end up with a useless map. GM assigns values for roughness areas whereas WAsP uses polylines which have two values as Rough_R and Rough_L. When GM tries to export the map as WAsP format, it assigns the same value for both Rough_R and Rough_L and this results in many inconsistencies in the map.

I have seen some workarounds like creating buffers between roughness areas, then manually editing values but this is not an exact solution. We can't know for sure how these buffer areas affect the calculation as well. I think it would be appreciated if GM had the ability to do this conversion smoothly as some users seem to be having trouble with the same issue.


  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2012
    There isn't a special solution for this yet (we were kind of hoping WaSP would make their handling of roughness areas easier to use to avoid a messy workaround, but I don't know if this will happen). The best workaround for now is to create the buffers with a small negative distance to shrink the roughness areas so they don't touch each other since this is the problem. Really with roughness areas the ROUGH_L and ROUGH_R don't make sense as you really just need a roughness value inside the area and other areas can cover the outside areas, but Wasp doesn't quite work that way. Because of this the ROUGH_R value will be the roughness inside the area (for clockwise areas) and you can then edit the ROUGH_L to be an invalid roughness for the very tiny stripe between areas after shrinking them.


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