Catchment units in karst regions

The Karst catchment units layer consists of the unit areas from which similar groundwater flow behaviour towards the karst spring can be expected. In particular, it allows for the phenomenon typical of karst regions that a subunit of the catchment can drain in different directions according to the hydrological conditions and therefore can feed several karst systems or springs (diffluence). The information in the categories Karst regions and Karst groundwater, respectively, is based on hydrogeological 3D models (KARSYS approach). It was developed, with the support of the cantons, by the Swiss Institute for Speleology and Karst Studies SISKA and is published by the Federal Office for the Environment FOEN.