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

TL;DR

Mangroves in Florida significantly reduce storm surge damages to properties, with effects varying spatially and by storm intensity, highlighting their importance in flood risk mitigation.

Contribution

This study quantifies the spatially variable effects of mangroves on storm surge damages using high-resolution models, revealing nuanced impacts on property losses during hurricanes.

Findings

Mangroves reduce property surge losses by $67 million annually in Collier County.

Mangroves decreased damages by 14% during Hurricane Irma and 30% during Hurricane Ian.

Presence of mangroves always reduces flood losses landward of mangroves, but effects vary seaward.

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.