Flood Risk and the Built Environment: Big Property Data for Vulnerability and Environmental Justice Analysis

Yilei Yu, Arizona State University
Dylan Connor, Arizona State University
Aaron Flores, Arizona State University
Sara Meerow, Arizona State University

Over 2.4 million properties, both residential and commercial, could face chronic flooding by the century’s end. Despite FEMA’s role in defining Special Flood Hazard Areas (SFHAs), regulating new developments, and mandating flood insurance, the efficacy of these policies remains uncertain. This article relies on advancements in urban analytics and causal inference to scrutinize the accuracy of SFHAs in identifying flood-prone structures and evaluate the quality and condition of buildings within and outside these areas. Our study, based on a new database covering over 100,000 flood-prone buildings in Houston, Texas, reveals that 56 percent of at-risk structures lie outside SFHAs, with a disproportionate concentration in Black and Hispanic neighborhoods. Notably, we demonstrate that buildings outside of FEMA zones are more likely to be of substandard quality, poorly maintained, and uninsured. While SFHA-related policies may mitigate vulnerability, limitations in flood mapping could also exacerbate disparities across neighborhoods. Addressing existing knowledge gaps concerning interactions across different forms of vulnerability, our findings indicate that at-risk socially vulnerable communities also contend with greater structural and financial vulnerability. In conclusion, we propose that advancements in urban analytics can assist in rectifying limitations in existing flood assessments, enabling better planning for future flood events.

No extended abstract or paper available

 Presented in Session 123. Urban Historical GIS: Public Health