An Integrated Geophysical/Geological Model of the CLIWAT Project Area Föhr as Basis for Groundwater Modelling

In the EU project CLIWAT sixteen institutions investigate the groundwater situation in the North Sea coastal areas from Belgium to northern Denmark to simulate consequences of climate change for the groundwater systems and water supply. The North Sea island of Föhr is part of a pilot area. For a better understanding of the current groundwater situation several geophysical surveys were carried out including an airborne survey with the transient electromagnetic system SkyTEM and high resolution reflection seismic surveys from surface and in boreholes with P- and S-waves. The results reveal glacial structures as Quaternary buried valleys as well as a glaciotectonic thrust fault complex. They were located with a combined interpretation of geophysical results and geological information of boreholes. Both of these structures influence the groundwater systems. An integrated geological-geophysical 3D model supports groundwater modelling.