Spatial dynamic analysis and thematic mapping of vulnerable communities to urban floods

Natural disasters, particularly floods, have increasingly impacted urban areas globally. Previous research has not adequately analyzed the vulnerability to floods of populations based on race and ethnicity. This study aims to examine demographic changes over the past two decades in five southern US cities and determine whether minority and non-minority populations have moved closer to or farther from flood-prone areas. Using a spatial clustering approach, the study identifies geographical clusters of the white and minority populations within the 100-year floodplain. In general, the white people are moving away from floodplain areas in Birmingham and Jackson. Except for Charleston, the highest populations clustered in floodplains were minority communities (the African American and Hispanic). In Birmingham, both the White and the African American populations in floodplains have decreased due to the federal and local governments' relocating populations through acquisition projects. The African American in Jackson, Birmingham, and New Orleans were particularly vulnerable to flooding. Houston and New Orleans had also significant increases in the Hispanic and Asian populations within floodplains. The findings can help federal and local governments and communities understand spatial and temporal pattern dynamics between minorities and the White, which assists for effective decision making and equitable solutions to vulnerable communities. •The White and minorities experience different vulnerabilities spatially and temporally.•The Hispanic, Asian and other communities increasingly gathered in 100-year floodplains.•The Black agglomerated in 100-year floodplains in Jackson and Birmingham.•The Black moved away from 100-year floodplains in Charleston and New Orleans.•Racial and ethnic dynamics to floods need to be considered for urban flooding decision making.