Climate analysis as a basis for a sustainable water management at the Lusatian Neisse

Current and future climate conditions and their impact on water balance, ecosystems, air quality and bio and agro-climatology were investigated in the region of the Lusatian Neisse within the two EU -projects – NEYMO and KLAPS. This work focuses on the climate analysis of the region at the German-Polish border as a preliminary step for a hydrological analysis of current and future conditions. Observed climatological data were processed and analysed using the indicators air temperature, precipitation, sunshine duration, potential evapotranspiration and the climatic water balance (CWB). The latter defines the difference between precipitation and potential evapotranspiration and is a measure for the climatological water availability in the region. Observations were used to statistically downscale data from Global Circulation Models under various scenarios regarding greenhouse gas emissions (A1B, RCP 2.6, RCP 8.5) and applying the WETTREG-method for regionalization. In total, 50 climate projections for periods up until the end of the 21st century were analysed, with the application of the mentioned indicators. For the period 1971-2010, increasing trends of temperature, precipitation, sunshine duration and potential evapotranspiration were found. This leads to a reduced CWB in the summer half-year (SHY), which could be partly compensated by an increase in the winter half-year (WHY). Trends of temperature, sunshine duration and potential evapotranspiration remain positive for the far future (2071-2100), but precipitation decreases. These climatic conditions aggravate water availability, especially in the SHY. Impacts on water management are very probable and were therefore further investigated in the NEY MO project that applied hydrological models.