LAND SUBSIDENCE IN COSTAL TEXAS: LOCATIONS, RATES, TRIGGERS, AND CONSEQUENCES

Land subsidence and sea level rise are well-known ongoing problems that are negatively impacting the entire Texas coast. While ground-based monitoring techniques using long-term Global Positioning System (GPS) records provide accurate subsidence rates, they are labor intensive, expensive, time consuming, and spatially limited. In this study, Interferometric Synthetic Aperture Radar (InSAR) data and techniques were used to map locations and quantify rates of land subsidence in the Texas Costal Bend region during the period from October 2016 to July 2019. InSAR-derived land subsidence rates were validated against GPS-derived rates. Factors controlling the observed land subsidence rates and locations were investigated. Consequences of spatiotemporal variability in land subsidence rates in Costal Texas were examined. Results indicate: (1) land subsidence rates in Coastal Bend exhibit both spatial and temporal variabilities, (2) InSAR-derived land subsidence rates were consistent with GPS-derived deformation rates, (3) land subsidence in Coastal Texas is attributed mainly to oil and ground water extraction as well as vertical movements along growth faults, and (4) land subsidence increased both flood frequency and severity in Coastal Texas. Our results provide valuable information regarding not only land deformation rates in the Texas Coastal Bend region, but also the effectiveness of interferometric techniques in other coastal rural areas around the globe.