Vulnerability Mapping in the British Overseas Territories

In 2016 Environment Systems carried out a modelling exercise to assess the vulnerability of five UK Overseas Territories (OTs) in the Caribbean to storm surge and flooding events, their impact on infrastructure and human life. The OTs included in this exercise were Anguilla, British Virgin Islands (BVI), Tristan da Cunha, Montserrat and Turks and Caicos.

Anguilla Storm Surge
This map shows the potential damage risk of storm surge on marine and terrestrial areas over Anguilla
This work has been brought into sharp focus by the extreme 2017 hurricane season (Maria and Irma). The new project on which we are now embarked uses pre and post hurricane satellite imagery to validate the model on Anguilla with a second phase of work applying that model to the BVI.

Part of the work consists of creating an inland flood risk model which is focused on the conditions and parameters of the ground surface. In addition, we have created a model that maps the extent of the storm surge. This storm surge risk model was generated and scored using Environment Systems’ own SENCE methodology. It takes into account prevailing conditions on the sea floor, the effect Natural Capital such as coral reefs, mangroves and forest can have on counteracting the energy in the waves. The validation was undertaken through expert interpretation of very high-resolution imagery together with data collected from news and social media accounts often accompanied by images of damage extents.

The high-level purpose of the work is to generate data for governance and policy but it goes far beyond that to practical measures such as ensuring that emergency vehicles are strategically parked and evacuation areas are suitably located and notified. In addition, the models help indicate areas for action for example for tree planting, future planning proposals and help in landscape design. The models also inform natural capital accounting by placing a monetary value on natural assets that stimulate tourism for example.