A GIS-based flood hazard mapping in the Alsen St./Irma Lee Community Village in the Louisiana state of USA

Flooding poses a significant threat to the Alsen St/Irma Lee Community Village in East Baton Rouge Parish, driven by its low-lying terrain, complex hydrological dynamics, and inadequate drainage systems. This study integrates Geographic Information Systems (GIS) with the Soil and Water Assessment Tool (SWAT) to delineate catchments, analyze flood risks, and incorporate Land Use/Land Cover (LULC) changes between 1990 and 2025. Unlike conventional GIS-based flood assessments that often rely on static floodplain mapping or hydraulic models, this study employs a dynamic hydrological approach to capture the interplay between LULC changes and flood dynamics. Urban expansion, reflected in a 16.30 % (1.23 ​km 2 ) increase in built-up areas, and vegetation loss, marked by a 6.5 % (1.52 ​km 2 ) decline in closed forest cover, have intensified runoff and reduced natural water retention, increasing flood vulnerability. The study identifies 22 sub-basins contributing significantly to flood risks, with a 1-m flood depth scenario impacting 63 ​% of the community, endangering 1163 residents, 101 ​km of road networks, and 39 ​km of railway infrastructure. Validation with historical 2023 flood data demonstrates the model's robustness, achieving an RMSE of 0.002 and an NSE of 0.9983. In comparison to traditional methodologies, such as static hydraulic modeling, this approach incorporates temporally dynamic LULC changes, providing a more comprehensive and predictive framework for flood risk assessment for areas with limited data. These findings emphasize the need for proactive flood mitigation measures, including improved drainage systems, flood barriers, and community preparedness programs. Integrating LULC dynamics with hydrological modeling, this study offers a replicable framework that enhances the understanding of urbanization-driven flood risks in data-scarce regions, advancing both theory and practice in flood risk management.