Advancing Flood Resilience in Grand Isle, Louisiana, in the United States of America, through Remote Sensing and GIS

Abstract. Flood risk in low-lying coastal zones is escalating due to a combination of climate change, land subsidence, and shifting land use patterns. This study develops a high-resolution flood-prone zone and resilience map for Grand Isle, Louisiana, employing remote sensing and GIS tools. The methods integrate supervised Land Use Land Cover (LULC) classifications, Cellular Automata-Markov modeling, hydrological indices (TWI, TPI, CTI), and multi-factor flood resilience metrics. Between 2015 and 2035, barren land more than doubled, and water bodies increased by over 33 km², indicating significant environmental degradation. By 2035, nearly 94% of the island is projected to lie within high-risk flood zones, while over 90% of the land is categorized as having very low resilience. These findings stress the urgent need for adaptive land use planning, ecological restoration, and infrastructure elevation to enhance flood resilience in Grand Isle.