Impact of climate change on water availability

Abstract

Climate change affects all elements of the water balance: precipitation, evapotranspiration and runoff. Decreasing annual precipitation by 55 mm and increasing annual evaporation by 47 mm leads to a decrease in annual water availability by 102 mm in the Upper Danube river basin when comparing the periods 2036-2060 with 1971-2000 when choosing the REMO Regional Baseline Scenario. The highest impact was found at the northern edge of the Alps, where water availability decreases by up to 400 mm. This article analyses the impact of the changed water balance on the discharge regime. We conclude a reduction of discharge between 60 and 370 m3/s at the catchment outlet in Achleiten until 2060. A serious change in monthly discharge was found during summer, when discharge in Achleiten decreases by almost 40 % until 2060, while the annual maximum shifts from summer to spring.