Average annual potential evaporation height as grass reference evaporation (HAD)

The potential evaporative heights calculated according to equation (1) can be numerical methods of MÜLLER-Westermeier (1995) map which already appears in the accompanying text to the maps of the precipitation height is described in detail. Using a Height file in the 1 km² grid was first the required input sizes, in this case monthly values of relative sunshine duration and air temperature, on the grid interpolated. For both sizes, all available stations with 30-year-old measurement rows in. For accuracy reasons, the relative duration of sunshine at solar altitudes 15° used for mapping to potentially existing horizontal shields to eliminate at the stations.