To what extent does climate change result in a shift in Alpine hydrology? A case study in the Austrian Alps

The quantification of the effect of climate change on the hydrological water balance components within a catchment is invaluable for future planning within the water sector (municipal and industrial water supply, hydropower, irrigation, snowmaking). As the regional effect of global warming is somewhat uncertain, the provision of quantitative estimates with error bands is essential. Many studies only take one or a very limited sample of climate change scenarios into account. In this paper, the hydrological response to a number of regional climate change model scenarios for the end of the 21st century within the catchment of the Kitzbüheler Ache in Austria is investigated by means of a distributed hydrological model. These regional climate scenarios originate from the European PRUDENCE project. The results show a shift from a rainfall and snowmelt-dominated flow regime to a rainfall-dominated flow regime for all scenarios. A future decrease in snowmelt and a shortening in snow cover duration is observed, with an increase in winter flow, and a decrease in spring, summer and autumn flow. The typical low-flow period during winter shifts to a low-flow period during late summer and autumn. However, the magnitude of the effects depends strongly on the choice of scenario. Average annual snowmelt reduction ranges from 31 to 81%, average annual runoff reduction from 6 to 33% and average annual evapotranspiration increase from 6 to 20%. These uncertainties are also presented for a monthly and a seasonal time step. These values and observations provide for a future vision within a mountainous catchment in the European Alps. Normal future planning is within a shorter time frame (20–30 years within the water sector), but this future vision puts realistic planning in a wider context.Editor Z.W. Kundzewicz; Associate editor R.L. WilbyCitation Laghari, A.N, Vanham, D. and Rauch, W., 2012. To what extent does climate change result in a shift in Alpine hydrology? A case study in the Austrian Alps. Hydrological Sciences Journal, 57 (1), 103–117.