A framework for assessing uncertainties in climate change impacts: Low‐flow scenarios for the River Thames, UK

A probabilistic framework is presented for combining information from an ensemble of four general circulation models (GCMs), two greenhouse gas emission scenarios, two statistical downscaling techniques, two hydrological model structures, and two sets of hydrological model parameters. GCMs were weighted according to an index of reliability for downscaled effective rainfall, a key determinant of low flows in the River Thames. Hydrological model structures were weighted by performance at reproducing annual low‐flow series. Weights were also assigned to sets of water resource model (CATCHMOD) parameters using the Nash‐Sutcliffe efficiency criterion. Emission scenarios and downscaling methods were unweighted. A…