Abstract

The groundwater levels along the California/Mexico border near the East Mesa, U.S.A. and the Andrade Mesa, Mexico have been controlled by the All-American Canal (AAC) System since its construction during the 1940s. Seepage from the unlined AAC has altered the ground water gradient and has provided a source for wells on many small farms on the Mexican side of the border. The US is planning to line the ACC which will undoubtedly alter the present distribution of near-surface water and groundwater. This study utilizes interferometric synthetic aperture radar (InSAR) to characterize the present state of land deformation due to groundwater level changes. 30 interferograms spanning 9 years (1992 to 2000) are averaged (stacked) to observe vertical land surface deformation. Stacking is required because significant atmospheric noise is convolved with the displacement signals in this area. Two shorter stacks are used to compare changes in the displacement field between 1992-1997 and 1996-2000. Satellite-based InSAR observations are valuable in areas where water issues straddle international boundaries due to inconsistent and unreliable ground-based measurements.