Geospatial Vulnerability Framework for Identifying Water Infrastructure Inequalities

Abstract

Recent infrastructure failures in the United States have brought attention to the ways and extent to which water security is unevenly distributed in urban areas. For many marginalized communities, infrastructure interdependencies (e.g., water, wastewater, stormwater, transportation) have created significant vulnerabilities in the face of aging or inadequate water treatment and delivery systems. In these communities, cascading failures precipitated by environmental hazards such as flooding often propagate across multiple infrastructure systems, sometimes resulting in poor water quality and/or lack of access to water for significant periods. However, little is known about how specific environmental and social factors combine with water infrastructure vulnerability and interdependencies to create enduring infrastructure inequalities. This paper presents a geospatial vulnerability framework for identifying water infrastructure inequalities, using the City of Tampa, Florida, to demonstrate the framework. For this framework, we integrate geographic information systems (GIS) analysis of environmental hazards, a factor analytic model of sociodemographic data, and a network topology-based performance indicator for the water distribution network. The resulting framework models the environmental and social vulnerabilities, quantifies hydraulic vulnerability and infrastructure interdependence, and maps their distributions across the urban environment. We find that the highest levels of social and environmental vulnerabilities in Tampa are present in low-income areas and communities of color that have high hydraulic vulnerability and infrastructure interdependency, which creates pockets of low resilience capacity.