Climate Change Impact on Flood and Drought Risks in the Danube Basin: an Integrated Modeling Study

Abstract

As a consequence of climate change, extreme rainfall events may become more frequent and intense in the future, while periods of drought may become longer. To study the effects of climate change on river discharge and the risk of flooding and droughts in the Upper Danube basin, we employed very-high resolution regional climate model data together with a partially physically-based rainfall-runoff model. It appeared that the regional climate model reproduces the amount and spatial distribution of precipitation in the area fairly well, but nevertheless results in an overestimation of the Danube river discharge in summer. In contrast, the extreme river discharge levels seem to be underestimated. For the future, the simulations suggest a change in the seasonal pattern of the discharge of the Upper Danube, with more runoff in winter and spring and lower water levels in summer and autumn. The results also indicate a significant increase in extreme discharge levels, due to more frequent and more intense heavy rainfall events. Further research is however necessary to assess the reliability of the model predictions and to take uncertainties into account.