This study investigates how future climate change is likely to affect the water resources in Denmark. The main focus is on groundwater resources because the water supply in Denmark is entirely based on groundwater. A physically-based, distributed hydrological model is used to simulate the changes in recharge, groundwater head and stream discharges in a 5263 km2 catchment in western Denmark. The model system MIKE SHE is used to simulate the hydrological response and the catchment is resolved using a horizontal discretization of 500 x 500 m2.

We analyse this problem by retrieving high resolution climatological output data from the regional climate model HIRHAM (Danish Meteorological Institute), which dynamically downscales the climate change signals from the coarser resolution global climate model HadAM3H (Hadley Centre), with the concentrations of greenhouse gases and aerosols based on the IPCC SRES A2 emissions scenario. The climate output used is daily precipitation, temperature and potential evapotranspiration at a 12x12 km resolution for two time slices, one for a  control period representing recent climate (1961-1990) and one for the scenario climate for the future(2071-2100).