| Title | GeoSurf -The development of a new measuring tool for an efficient planning of shallow geothermal systems |
|---|---|
| Authors | Bertermann, D; Walker-Hertkorn, S; Kübert, M; Schmidt, D; Schwarz, H; Müller, J |
| Year | 2016 |
| Conference | European Geothermal Congress |
| Keywords | electrical resistivity tomography, geophysical measurements, very shallow geothermal systems, soil properties, Res2Dinv, Wenner array |
| Abstract | Within the GeoSurf project it is intended to develop a measuring tool, which measures the electrical resistivity to derive soil properties (e.g. grain size, moisture content) for a precise estimation of its geothermal capability. The tool should enable a more efficient planning of very shallow horizontal geothermal collector systems and their special forms like heat baskets. In the course of this project the electrical resistivity of particular soil types were measured with the geoelectrical device 4point light from (L-GM) Lippmann - Geophysikalische Messgeräte (http://www.l-gm.de/en/en_resistivity.html). These measurements were realised in the first field survey 2015 to define a range of electrical resistivity for different types of soil and their distinct properties to check if a clear and accurate differentiation of soil types is possible by electrical resistivity measurements. Therefor different transects of electrical resistivity tomography (ERT) were performed on a sandy soil body in Eltersdorf/Erlangen and additionally in a clay pit near Buttenheim. Both test areas are located in the northern part of Bavaria (Germany). For the geoelectrical investigation up to 75 electrodes with an electrode spacing of 1 m were used and the Wenner array was selected. To get more detailed information about the measured soil, two 2 m deep test pits were excavated (Fig. 1). |