Surface Runoff, Percolation, Total Runoff and Evaporation from Precipitation 2012

Areas connected to the sewerage system generate surface runoff. It depends on buildings and the impervious covers of non-built-up areas. The highest (dark blue) values mainly occur in the city centre. 02.13.1 Surface Runoff from PrecipitationMore information

At first glance, the Percolation map seems surprising. It indicates that almost the same amount of precipitation seeps away in the city centre as in the forests. Less densely built-up residential areas on the periphery show considerably higher percolation rates, however. Increasing values are recorded in areas with few connections to the sewerage system. 02.13.2 Percolation from PrecipitationMore information

The map reveals that the total runoff is high in the extremely impervious inner city areas (S-Bahn ring). The runoff is about half of that in less densely built-up residential areas on the periphery. Compared to the runoff of the pervious areas on the outskirts or in the areas surrounding Berlin, Berlin appears to be an “island” with greatly increased runoff. 02.13.3 Total Runoff from PrecipitationMore information

When comparing the Percolation without Consideration for Impervious Coverage map and the Percolation map (which does consider impervious coverage) conditions differ greatly in some cases between the two. 02.13.4 Percolation from Precipitation without Consideration for Impervious CoverageMore information

Evaporation is reduced in impervious areas and due to a lack of vegetation, as the runoff is 2 or 3 times as high as under natural conditions. This is often the case in the inner city. In areas with surface-near groundwater, increased evaporation is caused by the capillary rise of groundwater into the soil zone that is influenced by evaporation. 02.13.5 Evaporation from PrecipitationMore information