Using InSAR and GPS to detect ground subsidence in Pahrump Valley, southern Nevada/California.

摘要

Synthetic aperture radar interferometry (InSAR) has been developed for use in many applications, such as detecting ground movement on volcanoes, tracking glacial progression, and monitoring fault rupture. This study uses interferometry and global positioning systems (GPS) to detect ground subsidence due to groundwater withdrawal in Pahrump Valley in southern Nevada and California. The main community in the area is Pahrump, with a current population of 29,000. The only source of water for the town is the valley fill aquifer, which is currently over-drafted annually. Twenty-one radar images were obtained and processed using the Diapason 3.1 (beta version) interferometry processing package. GPS data were obtained using Trimble 4000 ssi receivers and geodetic choke-ring antennas on fourteen USGS and NDOT benchmarks along SR 160 and 372. Although there are magnitude discrepancies between the interferometry and GPS data, both investigations show subsidence occurring in the valley.