The focus of current hydrological research on climate change is centred on the reaction of glaciers and runoff; impacts on soil moisture remain widely neglected. The study by Ole Rössler of the Institute of Geography at the University of Bern, which was published in the renowned journal Water Resources Research analyses the impact of the climate on soil moisture in a high mountain catchment in order to facilitate the development of mitigation and adaptation strategies. Two regional climate models were downscaled using three different approaches to drive a hydrological model. For the period of 2070–2100 the results of the so called ensemble forecast show large changes in temperature, resulting in decreasing snow and ice storage and earlier runoff, but only small changes in evapotranspiration. The occurrence of dry spells was found to fluctuate greatly, the potential for soil moisture depletion and drought is highly variable both space and time. All the results indicate that summer soil moisture decreases, which leads to more frequent declines below a critical soil moisture level and an advanced evapotranspiration deficit. Forests up to an elevation of 1800 m a.s.l. are likely to be threatened the most, while alpine areas and most pastures remain nearly unaffected.
