User guide BGS Coastal Vulnerability Index version 1

Coastal vulnerability indexing is a GIS-based analysis tool for indicating multi-hazards and interdependencies within the coastal zone of Great Britain (GB). The mainland of Great Britain is surrounded by over 11 000 miles of coastline. It is a very diverse coastline both in terms of geology and geomorphology, ranging from the high chalk cliffs of Sussex to the flat expanses of The Wash and Morecambe Bay. The coast has been shaped by the continual forces of erosion from the wind, waves and tide and the characteristics and composition of the coastline dictate the degree of its vulnerability. The winter storms of 2013-14 starkly demonstrated the vulnerability of the GB coastline to erosion and overtopping but during media enquiries it became clear that a national picture of the sections of coastline susceptible to erosion didn’t exist. The Coastal Vulnerability Index (CVI) has been created to bring together a suite of data to fill this knowledge gap. With climate change forecasts of an increase in the frequency and intensity of winter storms, BGS has developed a coastal vulnerability index (CVI), drawing on existing BGS datasets and expertise, and we intend to work in collaboration with other organisations to help manage these changes in the future. The CVI will offer anyone with assets or an interest in the coastline around Great Britain access to easy-to use indexes linked to geohazard data. This will allow users to interpret potential interdependencies in terms of erosion, flooding, habitat and other vulnerabilities. Version 1 of the CVI represents the natural geological coastline (around the mainland of GB only) as if no coastal defences or made ground are present. Due to their complex geometry, the coastlines of N and W Scotland have not been included in version 1. This will be of particular value in areas where coastal defences are no longer maintained. Future versions of the CVI will include all coastal defences and made ground.