Assessing hurricane storm surge risk under near-past climate conditions to inform land-use planning in small Caribbean islands: San Andrés, Providencia, and Santa Catalina, Colombia

Storm surge is one of the most destructive coastal hazards associated with tropical cyclones, yet detailed assessments remain scarce for small Caribbean islands. This study assesses hurricane storm surge flood risk in the Archipelago of San Andrés, Providencia, and Santa Catalina, Colombia, under near-past climate conditions (1980-2010) for 100- and 500-year return periods. Storm surge was simulated from a synthetic tropical cyclone dataset of 1078 tracks; a composite risk index was then constructed by combining the hazard with a vulnerability index based on elevation, proximity to drainage and coastline, land-use, and population density. Exposed elements were identified and classified as residential, economic, functional, or ecological. Under the 500-year return period, the risk footprint covers 3.7% of San Andrés and 3.3% of Providencia and Santa Catalina, with risk concentrated along the eastern and northeastern coast of San Andrés and the northern coast and the channel between Providencia and Santa Catalina. The exposure analysis identifies 247 elements in San Andrés and 185 in Providencia and Santa Catalina. Economic and residential elements dominate exposed assets by count (49.8% and 38.1% in San Andrés), while ecological elements, predominantly mangroves, dominate exposed area (89.1% in San Andrés and 79.9% in Providencia and Santa Catalina). In Providencia and Santa Catalina, ecological elements account for approximately 95% of the exposed-element area classified as high risk. 50 city blocks in San Andrés and 57 in Providencia and Santa Catalina intersect risk zones under the 500-year return period, supporting coastal and land-use planning in defining setback zones and prioritizing mangrove restoration. This study highlights the need for integrated coastal management that links community, technical modeling, spatial planning, and ecosystem preservation.