Our study area is the Spreewald UNESCO Biosphere Reserve, a 320 km2 fen wetland located 70 km southeast of Berlin. It is divided in Upper and Lower Spreewald, and its main tributary is the River Spree, which along with the River Malxe feed about 80% of the total balanced runoff (Grüneberg, 2021). The Upper Spreewald is characterised by an extensive branching network of natural streams and man-made canals and ditches. In the 1930s began the construction of cascade-like reservoir belts which act as dams for water retention.
The Spreewald offers irreplaceable ecosystem services such as regulation of greenhouse gases fluxes, conservation of habitat and biodiversity, production of grassland biomass and navigation for recreational activities (Grossmann and Dietrich, 2012). Due to the high reliance on water of aquatic ecosystems, water-related tourism and socio-economic development, ensuring sufficient water availability in both quantity and quality is of crucial importance for the preservation of the uniqueness of the region.
However, as a region with a long-term negative climatic water balance (P-ET), the already delicate water balance is further threatened by the potential impacts of climate change: an increase in air temperature in all seasons—which translates into an increase in potential evapotranspiration—and a shift in precipitation from summer to winter (Pohle, Koch and Grünewald, 2012). Furthermore, the long-term artificially-augmented flow of the River Spree—due to the discharge of sump water from the active open-cast lignite mines—has been decreasing in the last three decades due to the planned phasing-out of the mining activity in the region of Lusatia.
Projekt Period: 2023-2026