Applied Geophysical Methods in Integrated Groundwater Mapping – Danish Case
Presented on Wednesday, March 18, 2015
Theis Raaschou Andersen, Dr.1, Peter Thomsen2 and Torben Bach3, (1)Centre for Applied Research & Development, VIA Building, Energy & Environment, VIA University College, Horsens, Denmark, (2)Water and Natural Resources, Aarhus, Rambøll, Aarhus N, Denmark, (3)GeoScene3D Team, I-GIS, Riskov, Denmark
Urbanization, pollution and general water scarcity have the implications that large parts of the world population will become more depended on groundwater resources. To obtain and maintain a sustainable water supply based on groundwater, accurate hydrogeological models are crucial in order to understand the water cycle.
In 1998 The Danish Government initiated a large nation groundwater mapping program. The use of applied geophysical methods has been an important part of this program in a close collaboration between geophysicist, geologist and hydrologist. An optimized workflow has been established, ensuring optimal use of geophysical results in the geological and hydrological modeling. This multi-disciplinary collaboration means that the final models are as accurate and reliable as possible, and there for the best tools in the further management of the groundwater resource.
Close cooperation between the public administration, universities and consulting companies have been an important part in optimizing the groundwater mapping strategy. Geophysical methods have been improved and new developed. An open national database for the geophysical data has been established and integrated software packages for processing data and building geological models have been developed in form of the Aarhus Workbench and GeoScene3D.
Surveying with complementary geophysical applications have been used to map the extension of aquifers. An accurate airborne TDEM system has been developed. The SkyTEM system is in many aspects a unique system, measuring with great accuracy for early times. Pulled Array Seismic has been developed for improving the efficiency of collecting seismic data. Shallow aquifers have been mapped with different types of ERT (Electrical Resistivity Tomography) applications, and lately with multi-configured GCM equipment (DualEM421). The MNR method is used to obtain information about porosity, transmissivity and hydraulic conductivities. Especially measurement of hydraulic conductivities, alternatively to estimate a value, contributes to minimize uncertainties on hydrological models.
Theis Raaschou Andersen, Dr.
Centre for Applied Research & Development, VIA Building, Energy & Environment, VIA University College, Horsens, Denmark
Theis Raaschou Andersen is a lecturer at VIA University College in Horsens University, Denmark. Throughout his Ph.D. study at the University of Aarhus he investigated the geology and groundwater flow in buried tunnel valleys. During his time as a scientist he has built up a base of experience with geological interpretive models as well as groundwater models. Furthermore he has experience of sedimentologic investigations of glacial sediment deposits, glacial stratigraphic investigations, mineralogy and grain size distribution, and hydrogeological investigations.
Peter Thomsen
Water and Natural Resources, Aarhus, Rambøll, Aarhus N, Denmark
Peter Thomsen is a respected geophysicists currently employed at Ramboll, a large consultant company operating in most parts of the world. For the last 15 years he has been involved in the Danish national groundwater mapping program. He graduated (M.Sc. in environmental geophysics) from University of Aarhus in 1998, and apart from Ramboll, has been employed as a research assistant at the University of Aarhus, Geoscience. In this position Thomsen had a great influence on development of geophysical equipment, setting up standards and optimizing measurement procedure used in the geophysical mapping program.
Torben Bach
GeoScene3D Team, I-GIS, Riskov, Denmark
Torben Bach is a Danish Geophysicist with a long experience within software development and Geophysics including oil and gas exploration, groundwater mapping and geophysical mapping.
