Detection of aquifer system compaction and land subsidence using interferometric synthetic aperture radar, Antelope Valley, Mojave Desert, California

TLDR

InSAR has great potential to detect and quantify land subsidence caused by aquifer system compaction. InSAR maps with ±10 mm range‑displacement resolution were produced for a ∼10³ km² groundwater basin in Antelope Valley, California, using ERS‑1 satellite data. InSAR data show that recent subsidence patterns (1993–1995) largely match historical trends (1926–1992), align with land‑use changes, agree with coupled groundwater‑flow and compaction model predictions, exhibit only minor discrepancies likely due to uncertain sediment properties, and can help constrain model parameters when combined with groundwater level and geological information.

Abstract

Interferometric synthetic aperture radar (InSAR) has great potential to detect and quantify land subsidence caused by aquifer system compaction. InSAR maps with high spatial detail and resolution of range displacement (±10 mm in change of land surface elevation) were developed for a groundwater basin (∼10 3 km 2 ) in Antelope Valley, California, using radar data collected from the ERS‐1 satellite. These data allow comprehensive comparison between recent (1993–1995) subsidence patterns and those detected historically (1926–1992) by more traditional methods. The changed subsidence patterns are generally compatible with recent shifts in land and water use. The InSAR‐detected patterns are generally consistent with predictions based on a coupled model of groundwater flow and aquifer system compaction. The minor inconsistencies may reflect our imperfect knowledge of the distribution and properties of compressible sediments. When used in conjunction with coincident measurements of groundwater levels and other geologic information, InSAR data may be useful for constraining parameter estimates in simulations of aquifer system compaction.