Subsidence and Uplift in the Coastal Plain Near Houston, Texas, Mapped in Spatial Detail from Space

Abstract

Interferometric synthetic aperture radar (InSAR) is a powerful tool that uses radar signals to measure deformation of the Earth's crust in spatial detail at a high degree of measurement resolution. Interferograms developed from repeat-pass radar imagery of the Houston-Galveston area acquired in 1996-97 from Earth-orbiting satellites reveals subsidence landward of Galveston Bay and some localized uplift near the coast. Historically, land subsidence in the greater Houston area attributed to the withdrawal of subsurface fluids has increased the frequency and intensity of coastal and riverine flooding. Since 1977, management efforts to reduce ground-water pumpage and increase the imported surface-water supply to industries and municipalities along Galveston Bay, especially near the Houston Ship Channel, have largely arrested subsidence in these near-coastal areas. However, during this same period, increased ground-water pumpage resulting in ground-water-level declines and subsidence have occurred landward in the Jersey Village area, where InSAR detected a maximum of 35 millimeters (mm) of subsidence between January 1996 and December 1996 and revealed nearly 700 square kilometers affected by more than 5 mm of subsidence. Other areas showing small changes are the developing Kingwood area near Lake Houston (uplift) and Galveston Island (subsidence).