The spatially variable effects of mangroves on flood depths and losses from storm surges in Florida

Abstract

Mangroves modify storm surges with impacts on property damages, but these effects vary spatially and by storm intensity. We use high-resolution, kilometer-scale flood and loss models to examine variability in mangrove effects on surge losses to properties, spatially and by storm intensity, in Florida. We estimate that mangroves reduce property surge losses by $67 million annually in Collier County in southwestern Florida. More than 50% of this reduction occurs for storms with return periods under 30 years. Mangroves in Florida reduced storm surge damages by 14% during Hurricane Irma (2017) and 30% during Hurricane Ian (2022). We show that mangrove presence always reduces flood losses for properties landward of mangroves. Inside mangroves, their effect is a net reduction in damages, though in some locations, especially for more seaward properties, mangroves can increase storm damages. These findings underline the importance of mangrove presence in determining property damages during hurricanes.