Analysing the effect of climate changes on streamflow using statistically downscaled GCM scenarios

Abstract

Abstract This paper discusses the potential impact of climate changes on the streamflow of the Alzette river basin in the Grand‐duchy of Luxembourg. A statistical relationship between observed daily temperature and precipitation to surface and upper‐atmospheric circulation predictor variables from the National Centre for Environmental Prediction (NCEP) reanalysis data is formulated for the period of 1961 to 1990. Future implementation is performed with predictor variables from the coupled HadCM3A2a atmosphere‐ocean general circulation model experiments from the U.K. Meteorological Office, for the periods 2036 to 2065 and 2070 to 2099. To analyse the impact of climate change on the streamflow of the study area, downscaled future local scenarios are applied as input to WetSpa, a spatially distributed hydrological model in which runoff is simulated as a function of rain intensity, soil moisture and terrain characteristics. The results of the hydrologic simulation indicate that there will be a significant increase in the magnitude and frequency of future flooding in the basin.