Vulnerability of Coastal Infrastructure and Communities to Extreme Storms and Rising Sea Levels: An Improved Model for Grenada and Its Dependencies

Abstract

Coastal areas of Grenada in the south-eastern Caribbean are particularly vulnerable to the adverse impacts of climate change. The effects of increasingly powerful hurricanes, sea-level rise, and reef degradation are often compounded by local anthropogenic activities. Many communities reside in low-lying areas, with development and infrastructure concentrated along the coast. Wave/storm surge models based on historic hurricanes Ivan and Lenny, and a hurricane with a predicted 100-year return period, were used to assess coastal inundation under different storm and sea-level rise scenarios. Coupled Tomawac and Telemac models were used in conjunction with high-resolution LiDAR data to provide a full vulnerability assessment across all coastal zones. Results were combined with census data at the Enumeration District level to assess impacts on the built environment. Qualitative and quantitative estimates were derived for the impact on natural features, land use, and infrastructure supporting critical economic activity in Grenada’s coastal zones. Estimation of both spatial extent and inundation depth improved the estimation of likely coastal impacts and associated costs at the national level. A general increase in extent and severity of inundation was predicted with projected future sea-level rise, with the potential for disruption to major coastal infrastructure evident in all scenarios, risking serious social and economic consequences for local communities. Coastal communities using poorer-quality building materials were most severely affected. This integrated method of assessment can guide disaster planning and decision-making to reduce risk and aid resilience in hurricane-prone regions.