A place-based framework for assessing flood-related socio-economic vulnerability in the Yazoo-Mississippi Delta

The Yazoo-Mississippi Delta (YMD) is characterized by persistent riverine flood exposure alongside long-standing socio-economic inequality and uneven adaptive capacity. This study examines three spatial dimensions relevant to flood-related social vulnerability in the Delta: socio-economic susceptibility, lack of adaptive capacity, and the threat of riverine flooding. Using the Global Delta Risk Index (GDRI) as a guiding framework, 31 indicators were selected to represent socio-economic susceptibility and adaptive-capacity conditions at the census-tract scale. Indicators were min-max normalized and aggregated using PCA-based indicator weights derived from dominant factor loadings adjusted by component variance explained. Flood exposure was derived from FEMA’s National Risk Index (NRI), while Getis-Ord Gi* hotspot analysis was used to identify statistically significant spatial clustering. Semi-structured interviews with local emergency-management and planning officials were incorporated to contextualize spatial patterns and interpret locally relevant constraints. Results indicate that elevated socio-economic susceptibility is concentrated in portions of Tunica, Bolivar, Leflore, and Holmes Counties, with additional clusters in Sunflower, Humphreys, Sharkey, and Quitman Counties. Limited adaptive capacity is especially pronounced in Bolivar, Washington, and Leflore Counties, with additional elevated clusters in Humphreys, Sunflower, and Sharkey Counties. Riverine flood exposure is highest along the Mississippi River corridor and central Delta floodplain, particularly in portions of Leflore, Tallahatchie, Quitman, Sharkey, and Issaquena Counties. Rather than estimating probabilistic flood risk, the study provides a place-based spatial assessment of socio-economic conditions and flood exposure relevant to environmental justice, and resilience planning in a historically marginalized U.S. delta region.