Mobility Behaviors Shift Disparity in Flood Exposure in U.S. Population Groups

TL;DR

This study introduces a mobility-based metric for flood exposure, revealing significant disparities among U.S. populations based on race, income, and education, highlighting mobility's role in flood risk beyond residential location.

Contribution

It develops a novel mobility-based flood exposure metric and uncovers disparities in flood risk linked to human mobility patterns across different socio-demographic groups.

Findings

Disadvantaged groups have higher mobility-based flood exposure.

Mobility behaviors extend flood risk beyond residential areas.

Mobility-based exposure reveals disparities not captured by residence alone.

Abstract

Current characterization of flood exposure is largely based on residential location of populations; however, location of residence only partially captures the extent to which populations are exposed to flood. An important, though yet under-recognized aspect of flood exposure is associated with human mobility patterns and population visitation to places located in flood prone areas. This study analyzed large-scale, high-resolution location-intelligence data to characterize human mobility patterns and the resulting flood exposure in counties of the United States. We developed the metric of mobility-based exposure based on dwell time in places located in the 100-year floodplain. The results of examining the extent of mobility-based flood exposure reveal a significant disparity across race, income , and education level groups. Black and Asian, economically disadvantaged, and undereducated populations are disproportionally exposed to flood due to their daily mobility activities, indicating a pattern contrary to residential flood exposure. The results suggest that mobility behaviors play an important role in extending flood exposure reach disproportionally among socio-demographic groups. Mobility-based flood exposure provides a new perspective regarding the extent to which floods could disrupt people's life activities and enables a better characterization of disparity in populations' exposure to flood hazards beyond their place of residence.