Protection Potential of Aquifer Covering Strata (WMS)

The visualisation of the protection potential of aquifer covering strata is a contribution of the State Geological Surveys (SGD) to describe the groundwater bodies as part of the reporting commitment for implementing the European Water Framework Directive. The indicated protection potential refers to the upper contiguous aquifer based on the specifications of the LAWA working guideline and suggests a categorisation of good, medium or poor protection potential. Depending on the availability of adequate digital information to assess the protection potential, two approaches have been established by the federal states. Approach 1: Using conventional empirical methods, the states of Berlin, Brandenburg, Hesse, Mecklenburg-Vorpommern, Lower Saxony, North Rhine-Westphalia, Rhineland-Palatinate, Saarland, Saxony and Schleswig-Holstein have classified existing spatial information (from HÜK 200 or other state-specific basic information) and / or point information (profiles of boreholes) regarding their potential protective effect towards the intrusion of contaminants and have interpreted these according to LAWA guidelines. Approach 2: In the states of Baden-Württemberg, Bavaria, Hamburg, Saxony-Anhalt and Thuringia a methodology – developed by the SGD´s – for the determination of the protection potential of aquifer covering strata (HÖLTING et al., Geol. Jb. C 63, Hannover 1995) was applied. It concludes in more differentiated statements, however, it requires comprehensive information on percolation rate / groundwater recharge, available field capacity of the soil, rock type and thickness of the aquifer covering strata, the structural properties of the hard rocks and artesian conditions. The classification is based on a scoring system and was translated according to LAWA standards. Areas of stagnant surface water and areas with insufficient information density have not been rated.