Erisman JW2012-12-122012-12-121990-06-30http://hdl.handle.net/10029/260374Abstract niet beschikbaarFor each station in the Air Quality Monitoring Network in The Netherlands, where wind speed and wind direction are measured, roughness length values were calculated from the standard deviation of wind direction. The agreement between values presented here and those obtained by other methods is good. The uncertainty is estimated to be a factor 2. For each 1 x 1 km2, 5 x 5 km2 and 10 x 10 km2 gridcell over The Netherlands roughness length values were estimated using detailed information about landuse and forest characteristics. A comparison of these maps with those presented in the literature showed good agreement. Comparison of the grid average z0 values with those of the LML stations showed reasonable agreement, except for those which are surrounded by roughness elements in the near vicinity of the measuring location and for those which are situated in areas with very low roughness lengths. The uncertainty in the grid average z0 values is assumed to be about 40 - 60%.24 pen15ruwheidslengtelml stationskaarten van nederlandReport2012-12-12