A coastal exposure index for Ireland: relative hazard exposure and the protective role of coastal habitats

This paper presents the first national-scale index of relative exposure to climate hazards along the coastline of the Republic of Ireland. Using the Coastal Vulnerability Model within the InVEST® software suite, the study assessed approximately 8,575 km of coastline at 250 m intervals. The Coastal Exposure Index integrates shoreline type, relief, coastal habitats, 30 years of wind and wave records, storm surge levels and sea-level rise rates. Population and cultural heritage exposure were also assessed, while sensitivity analyses tested how model modifications and alternative ranking methods affected outcomes.

The results show that exposure is highly site-specific and cannot be simplified to a sheltered east coast and exposed west coast. The west coast contains the largest extent of “Very High Exposure” coastline, while eastern local authorities also contain disproportionately high exposure relative to their coastline length and population. Coastal habitats potentially reduce exposure along 38 per cent of Ireland’s coastline. The authors recommend the conservation and restoration of these habitats, alongside appropriately designed engineered defences, as a critical opportunity to reduce future risk. They also recommend integrating the index with demographic, socioeconomic and governance factors to move towards a more comprehensive assessment of coastal vulnerability and risk.