National Hydrological Modelling of Climate Adaptation Impacts for the UK

Climate Change is likely to have a significant effect on river flows and associated floods and droughts in the coming decades. As such, it is key to understand the nature and severity of these changes and the potential costs and benefits of potential impact mitigation strategies at both a catchment and national scale. We have developed and demonstrated a methodology for national scale modelling of river flows under twelve climate forcing scenarios and have evaluated the impacts of potential adaptation strategies with regards to river flow.

This work forms part of the OpenCLIM project, which aims to create a scalable framework that enables users to integrate models and datasets from across a range of sectors (such as urban development, hydrology, and heat risk). This integrated, cross-sectoral approach is necessary to capture the complexities of climate response and will enable users to explore the potential impacts of climate change and adaptation strategies.

A spatially distributed, physically based hydrological model (SHETRAN-UK) has been setup for 701 catchments across Great Britain and Northern Ireland. Both uncalibrated and auto-calibrated simulations were run for historical periods and future climate scenarios (using UKCP18 regional climate projections). Strong model performance across the country allowed for analysis of the effect of climate change and storylined urban development on future river flows and the impact of potential adaptation strategies, specifically relating to floods and droughts.

Results from an urban development model were used to represent potential change in urban areas while natural flood management strategies were implemented by increasing woodland cover and storage in the model. Flows from the models were then fed into models for estimating economic flood damages.

This talk will discuss the methods and findings from the project, comparing them to other studies and will discuss the relevance of continued investigations into modelling climate/adaptation impacts as well as the lessons learnt regarding autocalibration and the high-performance computing approach (DAFNI & JASMINE).