Seasonal hydroclimatological variability in near-natural UK river basins

Given heightened concerns about climate and human impacts upon hydrology, there is a need to quantify temporal and spatial variability in water availability, and to establish climate-flow associations to predict future water stress. In the UK context, most climate-river flow research has been undertaken using runoff records with often: (1) spatially restricted coverage; (2) sparse density; (3) anthropogenic influences. Around 100 catchments with near-pristine flow records, and providing a relatively even coverage of the UK, were used to derive seasonal flow indices (winter, spring, summer, autumn) for the 1975-2005 period. Catchments were then clustered based on these indices to identify regions with similar hydro-climatic behaviours. A comparative analysis of correlation between flow indices and climate indices aimed at (1) characterising spatial patterns of seasonal flows in the country; (2) identifying in which regions climate drivers exert the strongest control on seasonal flows.