Study of Elevation Role in Representing Sociodemographic Status and Susceptibility to Flooding in Birmingham, Alabama

Abstract

Flood events continue to disproportionately impact low-income and minority groups in Jefferson County, especially in the highly urbanized regions and other areas undergoing major land-use modifications. This paper analyzes the socio-demographic factors, such as race and income, which define the spatial distribution and vulnerability of the population residing in high flood-risk zones. 2D deterministic flood model and risk maps were developed for Jefferson County using HEC RAS and ArcGIS software, and the socio-demographic data were analyzed using JMP software. Correlation and regression data analysis show flash flooding impacts affluent and low-income neighborhoods. However, approximately 73% of the census tracts impacted by flooding are predominantly African American neighborhoods (85% and higher). A statistically significant positive correlation exists between the median household income (MHI) and the average elevation (AE). The White neighborhoods have a strong positive correlation with the AE and MHI correlation with AE and MHI. The median value of owned property units strongly correlates with MHI in the high flood-risk zones. At the same time, the median value of owned property units is moderately correlated with the AE levels in the high flood-risk zones. The correlation between AE and MHI for the median value of owner-occupied units shows an increasing trend with increasing property value. Similarly, higher educational attainment levels show a growing trend in income and AE, especially with those having a bachelor’s degree or higher education showing a positive association. Thus, recognizing these differences in the socio-demographic factors and their impact on perceived vulnerability can help address the disproportionate impact of flooding on the identified vulnerable groups and raise public awareness.