Written by IEEE | June 13, 2017 | Updated: December 7, 2017
Areas of California in the San Joaquin Valley are sinking due to excessive pumping of groundwater for use during droughts. To help understand how groundwater pumping is affecting the land, the California Department of Water Resources commissioned NASA’s Jet Propulsion Laboratory to help to collect and analyze data from satellite radar data and images.
With the land in the valley subsiding, or sinking, as much as 28 feet in some areas, this is a major concern since changes in the land can cause damage to groundwater wells, roads, bridges and levees.
In order to find out the measurements of the land subsidence, NASA’s Jet Propulsion Laboratory (JPL) compared satellite and airborne interferometric synthetic aperture radar (InSAR) images of Earth’s surface. Images were used from 2006 through today in order to create maps that showed the land changes. The technology is accurate to a half-inch level.
The entire report and maps were put together using images from multiple satellites from all over the world. Data was used that was collected over the years by the European Space Agency’s Sentinel-1A, NASA’s airborne Uninhabited Aerial Vehicle Synthetic Aperture Radar, Japan’s PALSAR and Canada’s Radarsat-2.
Data and images will continue to be collected by satellites and analyzed, as well as mapped, to help monitor the subsidence of the land in the San Joaquin Valley.