GIS-based determination of the mean long-term groundwater recharge in Lower Saxony

This paper presents the findings of a collaborative research project of the Geological Survey of Lower Saxony (NLfB) and the Programme Group Systems Analysis and Technology Evaluation (STE) of Research Centre Jiilich on the GIS-based determination of the mean long-term groundwater recharge in Lower Saxony using high-resolution digital data (Dorhofer and others 2001). The model calculations were performed on the basis of the water-balance model GROWA (Kunkel and Wendland 2002) with a spatial resolution of 100x100 m2. The accuracy of the calculated groundwater recharge values for the period 1961-1990 was verified on the basis of data from gauging stations and displayed a good agreement between observed runoff values and model results.