InSAR measurements of subsidence in the Central Valley, California from 2007 – present

Inhalt:
Subsidence caused by groundwater pumping in the rich agricultural area of California’s Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with cm accuracy. For this study, we have obtained and analyzed Japanese PALSAR data for 2007 – 2011 and Radarsat-2 data for 2014 – 2015. We are currently processing data from the Canadian Radarsat-1 for 2011 – 2013, and ESA’s Sentinel-1A for 2015 – present. As multiple scenes were acquired during these periods, we can also produce histories of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. Geographic Information System (GIS) files have been furnished to decision-makers at the California Department of Water Resources to enable better management of groundwater resources and for further analysis of the 4 dimensional subsidence time-series maps.