Dissecting land subsidence along United States coasts through hazard characterization and exposure disparities
In the authors' words
Land subsidence is a widespread coastal hazard that exacerbates flooding and infrastructure degradation. Here, we present the first national-scale characterization of land subsidence hazard and exposure of population groups and infrastructure systems across 20 United States coastal states, explicitly accounting for spatial dependence. Using more than 190 million vertical land motion measurements derived from radar satellite imagery and ground observations, we develop a national-scale map that classifies subsidence into low-, moderate-, and high-hazard levels. Nationally, 71.5% of coastal areas subside faster than 0.1 centimeters per year, with the Gulf Coast experiencing the highest rates. At the national level, subsidence is best characterized by the heavy-tailed Generalized Extreme Value distribution, while uplift is characterized by the Generalized Pareto distribution. We further identify disproportionate exposure among disadvantaged communities and critical infrastructure systems. These findings offer a foundation for resilient coastal planning and equitable adaptation of infrastructure systems. Most coastal areas of the United States are sinking, with the Gulf Coast and disadvantaged communities facing the highest risk, according to an analysis of more than 190 million satellite and ground-based measurements of land elevation change. The study characterizes the statistical distribution of vertical land motion rates and identifies significant subsidence clusters nationwide, providing a quantitative basis for targeted mitigation and adaptation.
Appeared: Thursday, September 24. Communications Earth & Environment. Peer-reviewed journal.