Environmental injustice and flood risk: a conceptual model and case comparison of metropolitan Miami and Houston, USA

This article outlines a conceptual model and comparatively applies it to results from environmental justice (EJ) studies of flood risk in the Miami, Florida, and Houston, Texas, metropolitan areas. In contrast to most EJ studies of air pollution, which have found that socially vulnerable groups experience disproportionate risk, distributive EJ studies of flooding reveal inconsistent findings regarding the relationship between social vulnerability and flood exposure. Counterintuitively (from a conventional EJ perspective), some pre-flood EJ studies have found that socially advantaged people experience the highest residential exposure to flood risks. To integrate those anomalous findings within an EJ perspective, our conceptual model focuses on (1) the differential capacities of social groups to deploy/access protective resources for reducing the threat of loss, even while they reside amid flood-prone environments, and (2) both flood hazards and water-based benefits. Application of this model in Miami reveals that environmental injustices materialize as socially privileged groups expose themselves to residential flood risks by seeking coastal amenities, as the costs of mitigating risks are conveyed to the broader public; in the process, socially vulnerable residents are relegated to areas with air pollution and/or inland flood risks, where they experience constrained access to protective resources and coastal amenities. Findings from Houston better align with conventional EJ expectations—with flood zones disproportionately inhabited by socially vulnerable people—because many coastal lands there are used by petrochemical industries, which produce major residential-environmental disamenities. Results underscore the need to consider protective resources and locational benefits in future empirical research on the EJ implications of flood hazards.