Influence of Social and Environmental Factors on FEMA Claims During Flood Disasters in St. Louis, MO.

Environmental and social factors are thought to be potential risk factors of flooding, one of the most significant climate hazards, yet quantitative evidence based on empirical data remains limited. This study investigates factors that influence the association between precipitation of three declared disasters and Federal Emergency Management Agency (FEMA) flood claims with damage in St. Louis, Missouri. It also explores the use of Directed Acyclic Graph (DAG) for variable selection, finding its limitations. Using publicly available ZIP Code Tabulation Area (ZCTA)-level data, the analysis examines this association and its variation by a set of environmental and social factors, which were drawn from the literature. Elevation, tree canopy, impervious surface, and redlining variables were positively associated with an increase in the flood claims by precipitation. Elevation and tree canopy provided counterintuitive results, which require future investigation. The findings suggest the role of social determinants in flood risk and environmental justice concerns.