Developing a novel GIS-based index for physical coastal vulnerability

Coastal zones globally face escalating risks from climate-induced hazards, such as shoreline erosion, saltwater intrusion, and flooding resulting from rising sea levels. The United Kingdom possesses one of the longest and most rapidly eroding coastlines in Europe, attributable to multiple factors. This research develops a novel Physical Coastal Vulnerability Index (PCVI) to evaluate the susceptibility of UK coastlines. The index incorporates both established and newly identified parameters, including coastal landslides, and is applied to eight case study areas: four in England, two in Scotland, and one each in Northern Ireland and Wales. The assessment covers 402 km of coastline and results indicate that over 43% of the coastline is classified as High vulnerable, highlighting several stretches that are acutely susceptible to coastal hazards. Additionally, 2.7% of the coastline is considered Very High vulnerable, representing the most critical zones that require immediate intervention and long-term adaptation strategies to mitigate future risks. In comparison, more than 37% of the coastline is categorised as Moderate vulnerable, while only 16.4% is classified as having Low vulnerability. Results revealed that England and Scotland exhibit higher levels of physical coastal vulnerability compared to Wales and Northern Ireland. Specific areas, such as Trimingham, Holderness, Durdle, and Lancashire in England, are particularly at risk of hazards particularly coastal landslides due to their varied geographical characteristics. In contrast, Dundee in Scotland has the highest vulnerability because it lacks natural protections such as dunes. Kinmel Bay in Wales and Antrim in Northern Ireland are classified as having the lowest vulnerability due to their geographical locations and features. Based on these results, GIS vulnerability maps were created to illustrate the extent of coastal vulnerability. The results indicate that coastal vulnerability is not uniform across the UK, with England identified as the most vulnerable hotspot. To our knowledge, this is the first study to evaluate these case study areas together while combining both new and existing parameters. The research methodology used in this study can be applied to similar areas, regardless of their geographical location. The findings are valuable for local and national policymakers, providing essential insights to help implement strategies for the urgent protection of these vulnerable coastal areas.