Create Roughness Grid From Landcover Layer...

This option, available in the Analysis Menu, allows you to generate a grid (and optionally areas) of roughness length values from a land cover layer. When you select this option, the following dialog appears allowing you to setup the roughness calculation:

The roughness grid is useful for wind power applications and can be exported to a WindSim GWS file as a roughness layer or the  roughness areas can be exported to a WaSP .map file.

Several land cover data sets useful for roughness length calculation have built-in roughness conversion tables available:

  • CORINE Land Cover (Summer Roughness)
  • CORINE Land Cover (Winter Roughness)
  • ESA CCI (Climate Change Initiative) Land Cover
  • GlobCover Land Cover Map ESA 2009
  • GlobCover Land Cover Map ESA 2020
  • GlobeLand30 (Global Land Cover)
  • NLCD - US National Land Cover Database
  • VCF - Vegetation Continuous Fields (GLCF from MODIS)

Custom roughness tables can be defined in a roughness_tables.txt file in the user data file path listed on the Configuration > General > Advanced dialog. A sample roughness_tables.txt file can be found here.

Specify Bounds...