The Spree region is one of the warmest and driest regions in Germany. A further increase in droughts and low water periods, especially in the summer half-year, is expected. The decline or phasing out of lignite mining in the Lusatian region will reduce the volumes of water available for pumping over decades. In the metropolitan region of Berlin, the demand for water is expected to continue to rise.
The problem is evident at the Leibsch UP/Spree gauge, which lies above the SpreeWasser:N focus region: in five of the last six years, the required minimum discharge has been undershot, in some cases significantly.
In order to project the consequences of climate change and lignite phase-out on the Spree inflow as well as to develop and model adaptation measures, a number of models are being developed using input from WP 2 (Climatic & Hydrological Extremes), among others.
Discharges simulated with the eco-hydrological model SWIM serve as input data for the ecological and groundwater modeling, respectively. The ecological model (QSim) allows simulation of water temperatures, oxygen/nutrient budgets, algal/zooplankton development, and suspended sediment concentrations. In addition, approaches to simulate sulfate transport in the Spree River are being developed. The groundwater model (MODFLOW) describes the dynamics of the aquifer in the catchment area of the Lower Spree.