Workpackage 5

WP5. Hydrological and geophysical test-bench modeling

WP leader: Associate Professor Steen Christensen (AU)

Groundwater models are traditionally constructed from geological and hydrological data. This WP is working on a synthetic hydrogeological test-bench to test the improvement of the hydrological model when the traditional data are supplemented by extensive geophysical data. Two to three hydrogeological settings typical to Northern Europe and North America will be generated synthetically in high spatial resolution. Then categorical depositional geologies are generated by, for example, T-PROGS (Carle, 1999) while variation in, for example, hydraulic conductivity within each category is simulated as correlated random fields (Deutsch and Journel, 1998). The hydrogeological setting forms the basis for high-resolution complex groundwater modeling of sets of hydrological data and predictions and for picking typical geological data sets (lithology in boreholes). It also forms the basis for three-dimensional simulation of geophysical (e.g., geoelectric or electromagnetic) data.

With the test-bench, comparisons and verifications of the tools developed in WP4 are made. First, the geophysical data are inverted and used in combination with the geological data to develop a simple groundwater model which is then calibrated to fit the hydrological and inverted geophysical data (e.g., Dam and Christensen, 2003). This resembles how it is done today. Second, the developments of WP4 are included. This two-step procedure allow a thorough quantification of the improvement (and change of bias and uncertainty) obtained by including geophysical data in the construction of the groundwater models (Doherty and Christensen, 2011; Omre and Lødøen, 2004).