Translations:Einzugsgebiet/22/en

The runoff coefficient of the impermeable areas (after covering the initial losses) is set at [math]\displaystyle{ \Psi = 1 }[/math]. When determining the portion of impermeable areas for a sub-basin, you must take into account that not all paved or sealed surfaces actually drain into a sewer system. The continuous provision of wetting and depression losses is achieved by continuously balancing the corresponding storages and the evaporation.