Investigating ways to predict channel changes to inform flood risk management now and in the future

Abstract

Floods can cause severe and rapid changes in rivers. They can erode river banks and deposit vast quantities of sediment. This can impact on land-use, infrastructure (such as bridges and culverts), and properties where flood risk is increased. Understanding these natural processes, and where they are more likely to occur, can inform risk assessment, and identify opportunities to work with nature. Approaches to identify geomorphological actitivity in rivers have been reviewed to determine which could have potential to create a nationwide assessment of river channel change in England and Wales. Two existing approaches and two novel approaches have been tested and validated against fluvial audits to determine how well they identify geomorphological activity. One of the new approaches developed though the research was used to create a national scenario library of erosion maps representing different sediment sizes, channel roughness, and rainfall probabilities. Such information could be used to plan for future change, prioritise channel maintenance activity to locations with greatest risk or opportunity, and deliver sustainable flood risk and environment management.