Monitoring the location and magnitude of land subsidence in the greater Houston-Galveston region, which comprises Harris, Galveston, and adjacent counties in southeastern Texas, is critical to understanding the impact of groundwater use on the landscape. These subsidence data provide valuable information for local, regional, and state agencies interested in land elevation change, flooding, and critical infrastructure maintenance.
Interferometric synthetic aperture radar (InSAR) is a remote sensing technique that uses satellites to measure the movement of the land surface through the comparison of radar images collected at different time periods. This technique is one of several methods utilized by the Harris-Galveston Subsidence District (HGSD) to monitor subsidence in the region. InSAR allows for the analysis of vertical movement of the land surface throughout the region at a higher spatial resolution. For additional information on this technique, please visit https://www.earthscope.org/what-is/insar/.
In 2019, the HGSD, in partnership with the Fort Bend Subsidence District (FBSD), initiated a research project with subject matter experts at Southern Methodist University to process and analyze the deformation of the land surface from 1992 through 2023 using multi-temporal InSAR techniques. This research project also involved the investigation of subsidence impacts, such as fault reactivation, and localized features, such as hydrocarbon fields and salt domes. The results of this research included spatially and temporally variable land surface deformation data (see https://hgsubsidence.org/science-research/district-research/research-insar-monitoring/).
In alignment with objectives in HGSD’s current Science and Research Plan, the application of routine InSAR analyses will enhance subsidence monitoring and provide a better understanding of land surface deformation in the region. Areas of interest will focus on Harris, Galveston, and Fort Bend counties as well as portions of adjacent counties, including Brazoria, Wharton, Waller, Montgomery, Liberty, and Chambers counties.
HGSD, in cooperation with FBSD, is collaborating with technical experts at the Conrad Blucher Institute at Texas A&M University-Corpus Christi to develop an application for InSAR analysis as a monitoring tool that will allow for the tracking and detection of land surface deformation over time throughout the region. This project will involve the integration of multi-disciplinary datasets for a regional and holistic approach to monitoring changes in the land surface.
This project will be completed in the summer of 2026.
