Interest new piece of research published in Water Resources Research, which:

• Produces flood hazard estimates using spatiotemporal rainfall data from new convection permitting climate projections (UKCP Local)
• Finds the UKCP Local rainfall data gives higher estimates of flood hazard compared to standard climate change uplift approaches
• Indicates that representing full spatiotemporal rainfall and its future change is crucial for future flood risk assessment

Plain language summary

Climate change is making rainfall more extreme. However, the detailed change in the space and time characteristics of rainfall are not well known and not represented in flood risk assessment. Instead, standard practice uses spatially uniform rainfall derived from historical records and increases them by a fixed percentage uplift to account for the impact of climate change. These uplifts are generated from climate model simulations that are analysed to determine average rainfall changes. Failure to account for the changing space-time characteristics of rainfall means that this standard approach likely mis-estimates future changes in flooding. To test this hypothesis, we use high space and time resolution predictions of future rainfall patterns considering climate change to drive a detailed flood inundation model over the Bristol and Bath urban region in south-west UK. Flood hazard is projected to increase in future, with increases greater when using full space-time rainfall data rather than the standard uplift approach. This has important implications for how we estimate changes in flooding from changing rainfall with global warming.