Effect of sea level rise on the overtopping of English coastal defences

Hames, Dominic; Gouldby, Ben

Abstract

With a rise in sea levels, there is a consequent increase in the risk to coastal communities of the severity and magnitude of flood events. However these increased risks are not spatially consistent, and the type and nature of a coastal defence may influence the change in the risk at a location, and to what extent levels of mitigation may need to be implemented. This paper therefore investigates the impact of the change in risk of coastal flooding around England as a result of sea level rise. It involves the application of components of an existing risk-based coastal flood risk analysis method for a subset of almost 600 defences to rises in sea levels up to 1m. The resulting analysis shows that overtopping rates increase at a much greater rate for low return period events, which can be in excess of 100 times. The analysis also shows that the change in overtopping rate is a function of the defence type, with the relative changes for sloping defence structures significantly greater than for vertical defence structures

• Presentation Conference Type: Conference Paper (Published)
• Conference Name: FLOODrisk 2020 – 4th European Conference on Flood Risk Management
• Start Date: Jun 22, 2021
• End Date: Jun 24, 2021
• Acceptance Date: Jan 1, 2020
• Publication Date: 2021-06
• Deposit Date: Jan 11, 2023
• Publicly Available Date: Jan 12, 2023
• Publisher: Budapest University of Technology and Economics
• Series Title: FLOODrisk2020
• Book Title: FLOODrisk2020
• DOI: https://doi.org/10.3311/FloodRisk2020.11.13
• Keywords: Sea level rise; overtopping; coastal defences
• Public URL: https://uwe-repository.worktribe.com/output/10336980
• Publisher URL: https://repozitorium.omikk.bme.hu/handle/10890/15522
• Additional Information: This conference was delayed by one year and then held online due to the COVID-19 pandemic.