Hurricane Ian, a Category 4 storm, struck Florida’s Lee County on Sept. 28, 2022, bringing wind speeds of 155 miles per hour and a storm surge of up to 13 feet – the highest in Southwest Florida in 150 years. After the disaster, assessing the extent of damage quickly is crucial for rescue, recovery, and emergency planning. Traditional field reconnaissance can be labor-intensive, costly, and risky, with delays due to the severity of destruction and accessibility issues. To overcome these challenges, Florida Atlantic University researchers have developed a novel technique using remote sensing technology to provide rapid and high-resolution damage assessments after a hurricane.
Using aerial imagery data and LiDAR, the researchers identified the hardest-hit areas of Estero Island in Southwest Florida and estimated structural damage. They compared pre- and post-storm changes in the island’s structure, noting the first application of a multi-faceted approach linking damage assessment to post-storm changes in barrier islands. Published in the Journal of Marine Science and Engineering, the study found that 2,427 structures were impacted by Hurricane Ian, with 170 suffering extensive damage, totaling more than $200 million in assessed value. The most affected buildings were single-family homes and multi-unit residences, with around 158 structures severely damaged due to partial or complete roof failure.
The study revealed that the majority of structures with 30 to 50 percent structural damage were single-family and multi-unit residences, while the heavily damaged areas were located in the central and northern parts of Estero Island. The most affected structures were low-rise condominiums, shopping centers, and stores. Seven mobile home subdivisions were classified as “severely damaged” or “destroyed.” Despite analyzing buildings constructed between 1963 and 2019, there was no correlation between ground elevation or year built and the extent of the damage, emphasizing other factors influencing vulnerability. Findings can help improve disaster planning and develop new policies for coastal development in storm-exposed regions.
Spatial analysis showed that areas with minimal or no damage clustered in the southern and central parts of Estero Island, mainly on the landward side. The presence of saltwater marshes in the southern portion may have dissipated storm-wave energy, reducing the impact on structures in that area. Post-storm debris and sand deposition were observed across the island, with sediment deposition on roadways and the backside of the barrier. Ponding water inland near buildings indicated the extent of inundation caused by the storm. The remote sensing technology used in this study is transferable to other areas and can enhance emergency response efforts following natural disasters.
Researchers utilized LiDAR tools to extract building footprints and heights pre- and post-storm for beach morphology analysis. Profile graphs were created to visualize elevation changes, and building footprints were overlaid on post-storm imagery to estimate damaged buildings and levels of damage to each structure. As technology continues to advance, this approach can offer high-resolution coverage for prioritizing emergency responses post-disaster events. By understanding the impact of Hurricane Ian on Estero Island, stakeholders can implement strategies to mitigate damage risks and improve resilience in vulnerable coastal areas.
