Groundwater regeneration

The values shown in this map are based on the grid cell-based water balance model mGROWA (Forschungszentrum Jülich), which uses as input data climate, land use, topography, soil map and geological maps. In mGROWA, the total outflow in daily resolution is first calculated on the basis of the respective precipitation quantity and the calculated actual evaporation. The water storage and leaching movement in up to 5 soil layers as well as possible capillary ascent from groundwater are taken into account. The calculated daily values are then aggregated for longer periods (here 1981-2010). Subsequently, the total drainage is divided into the drain components direct drainage and groundwater regeneration. Groundwater regeneration is understood to mean the part of the total runoff that enters groundwater as infiltrating leachate. Net groundwater regeneration takes into account possible evaporation losses due to capillary ascent from groundwater. In the multi-annual average, net groundwater formation can be equated with the multi-year groundwater drainage (base drain).