Deciphering River Flood Change (FLOODCHANGE)

Many major and devastating floods have occurred around the world recently. Their number and magnitude seems to have increased but such changes are not clear. More surprisingly, the exact causes of changes remain a mystery. Although, drivers such as climate and land use change are known to play a critical role, their complex interactions in flood generation have not been disentangled. The main objectives of this project are to understand how changes in land use and climate translate into changes in river floods, what are the factors controlling this relationship and what are the uncertainties involved. We decipher the relationship between changes in floods and their drivers by analysing the processes separately for different flood types such as flash floods, rain-on-snow floods and large scale synoptic floods. We then use data from catchments in transects across Europe to build a probabilistic flood-change model that explicitly describes the change mechanisms. The model is unconventional as it does not take a reductionist approach but conceptualises the dominant flood change processes at the catchment scale. We test the model on long high-quality flood data series. We use the model as well as the temporal and spatial data variability to quantify the sensitivity of floods to climate and land use change and estimate the uncertainties involved. The data are already available to me or will be made available through my excellent contacts in Europe. For the first time, it will be possible to systematise the effects of land use and climate on floods which will provide a vital step towards predicting how floods will change in the future.