Modelling the effects of the Saalian glaciation on the NW European geohydrological system
Het modelleren van de effecten van de Saale ijstijd op het noordwest Europese geohydrologisch systeem
Weert FHA van , Leijnse A
RIVM Report 715201001
It is thought that groundwater velocities under glacial conditions may increase considerably favouring the dissolution of salt domes wherein radoactive waste disposals are planned. A groundwater flow modelling study has been carried out to test geohydrological responses on glacial conditions. The basis of this groundwater model is formed by the hydrogeological model defined by the RGD. Three different hydrogeological units are distinguished. The effects of different stages of the Saalian glaciation on the geohydrological system of NW Europe are simulated. Results of the modelling study with the European groundwater model suggest relatively high groundwater velocities during glaciations. Extreme high velocities may develop when the snout of the glacier is overlying the thin, pinched out parts of the aquifer. Areas with reduced subglacial meltwater infiltration which are assumed to be favourable areas for subglacial channelling and tunnelling processes coincide with areas where many relics of these processes (channel fills and eskers) are observed. Drainage of the highly pressurized groundwater mainly takes place in the proximal proglacial lakes, seas, discontinuous permafrost zones and rivers.