Improving flood risk management in small, rapid response catchments under climate change

Rainfall extreme events have become more frequent and intense, with a predicted steeper increase in the future. For this reason, understanding the rainfall relationship with runoff is crucial for planning and managing potential impacts on urban and natural environments, notably flood impacts. Small catchments are a relevant portion of new planning developments in Scotland and the UK. These catchments are often neglected by climate change flooding policies and regulations, as they require high resolution inputs. UKCP18-Local, a new a high spatiotemporal-resolution climate model derived product, has the potential to provide a better understanding of climate change impacts in smaller catchments.

This project aims to provide a methodology for high resolution and accurate modelling of climate change in small catchments. The results of the modelling are expected to provide better guidance for local regulation authorities and policy makers. In a first step, this project will access the flaws of current regulations and systems in place. Then, a selection of suitable datasets and potential data transformations will be checked. This will include processes such as quality control of rain gauge datasets and bias correction of UKCP-18-Local projections. Next, an appropriate hydrological model will be chosen. Aiming for accuracy in small catchments, this model will be expected to adequately model the hydrological processes at a high resolution. Products to accurately describe antecedent moisture conditions will be checked and generated if needed; routing processing at high resolution will also be accessed. Finally, the results of this project will aim to provide guidance on how to adequately model flood risks in small catchments, particularly under climate change scenarios.