Claudia Patricia Urbano-Latorre

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 1,078 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, risk affects 3.7% of San Andrés (247 elements; 178.9 ha) and 3.3% of Providencia and Santa Catalina (185 elements; 36.9 ha), with risk concentrated along the eastern and northeastern coast of San Andrés and the northern coast and inter-island isthmus of 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 by area (89.1% in San Andrés; 80.1% in Providencia and Santa Catalina) and account for 95% of the high-risk area in Providencia and Santa Catalina. Block-level outputs (50 and 57 affected city blocks, respectively) can support coastal and the land-use planning in defining setback zones and prioritizing mangrove restoration. This study highlights the need for integrated coastal management that link community, technical modeling, spatial planning, and ecosystem preservation.

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 1,078 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, risk affects 3.7% of San Andrés (247 elements; 178.9 ha) and 3.3% of Providencia and Santa Catalina (185 elements; 36.9 ha), with risk concentrated along the eastern and northeastern coast of San Andrés and the northern coast and inter-island isthmus of 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 by area (89.1% in San Andrés; 80.1% in Providencia and Santa Catalina) and account for 95% of the high-risk area in Providencia and Santa Catalina. Block-level outputs (50 and 57 affected city blocks, respectively) can support coastal and the land-use planning in defining setback zones and prioritizing mangrove restoration. This study highlights the need for integrated coastal management that link community, technical modeling, spatial planning, and ecosystem preservation.