Aerial Image Analysis of Changes in Wetlands between 2019 and 2023 in the Barataria and Breton Sound Basins of Coastal Louisiana

Abstract

Loss of marshlands in the Mississippi Delta plain of Louisiana threatens the future of the region’s economy, one which is heavily reliant on coastal wetland resources. This study builds on previous remote sensing investigations over the Barataria and Breton Sound Basins to make increasingly detailed assessments of changes occurring in coastal wetlands of southern Louisiana from both human extractive activities and repeated hurricanes. Analysis over the past four years (2019 to 2023) using NDWI from aerial image acquisitions revealed that there has been a widespread increase in relatively deep-water coverage (and corresponding losses of marshland coverage) since 2019 over most of the Barataria and Breton Sound Basins. Scouring of formerly shallow water cover and widespread erosion of brackish and fresh marshland shorelines followed the storm surges of Hurricanes Zeta (2020) and Ida (2021). Heightened fragmentation of marshland edges and interior pond features based on patch metric analysis implied that different types of damage inflicted on coastal wetlands of southeastern Louisiana from tropical storms can be characterized using aerial remote sensing.