Climate change impact assessment on various components of the hydrological regime of the Malše River basin

Climate change impacts on water cycle at regional scale have been recently very investigated and discussed issue. This study focuses on changes of not only total runoff but also others water balance components: soil water content and evapotranspiration, in a monthly step. The climate change was described using outputs of two different global circulations models, ECHAM and HadCM based on two divergent scenarios (optimistic B1 and pessimistic A2) according to the IPCC. The simulation of water cycle was processed in the mesoscale Malse basin (437 km²) in southern Bohemia using distributed physically based hydrological model SWIM. The outputs for the time horizon 2050 were assessed in comparison with mean values from the representative period 1987-1998.

The study indicates vulnerability against predicted changes of both temperature and precipitation patterns referred to the selected scenarios. A decrease of total runoff was expected; however, hydrological balance will be different particularly in the monthly pattern within a year. The aim of this article is to describe the impact on various hydrological balance components.