摘要
Interdisciplinary and comprehensive field work combining hydraulic and geophysical experiments yielded an improved understanding of the fractured and partly karstified Kohlenkalk aquifer in the Hastenrather Graben near Aachen, Germany. The aquifer is used for drinking water production and located in a geologically and tectonically complex area shaped by various tectonic events. A workflow which combines implicit 3D structural modeling with hydrogeological conceptual model building enabled determining hydrogeological boundary conditions at specific boundary cross sections, calculating the aquifer volume, and analyzing the hydraulic influence of faults on the aquifer system. Electrical resistivity tomography, seismic refraction tomography, well logging, and a coring campaign combined with available maps and additional literature research served as basis for the setup of the 3D structural model. This 3D model comprises all important structural elements, including the fault system, deep folded structures, and thrusts in the graben center. Integration of geological structure and hydraulic studies yielded a conceptual model of the hydrogeology, describing the Kohlenkalk aquifer and neighboring layers. Hydraulic conductivity of the aquifer system varies between 6.0 × 10−7 and 6.4 × 10−4 m s−1 with a decreasing trend from the NE graben shoulder to the graben center. Analysis of piezometric heads and resulting groundwater contour maps indicated four hydrogeological units which are partly limited by faults. Data on groundwater recharge as well as anthropogenic influences on the groundwater resources are part of the conceptual model.