Arizona Department of Water Resources Land Subsidence Monitoring Program Using Interferometric Synthetic Aperture Radar

The Arizona Department of Water Resources (ADWR) Land Subsidence Monitoring program has been greatly enhanced by the use of Interferometric Synthetic Aperture Radar (InSAR).  ADWR’s InSAR program started in 2002 with the awarding of a three year NASA Earth Science grant in cooperation with the University of Texas at Austin Center for Space Research and the Vexcel Corporation.  ADWR and its cooperators developed the InSAR program during the three years of the grant. 

 In 2005, ADWR began collecting and processing monthly level 0 raw SAR data from the European Space Agency and Canadian Space Agency, producing time-series interferograms for the greater Phoenix and Tucson metropolitan areas. Since 2005 the program has developed important partnerships with numerous State, County, and Local Agencies, and Water Districts and Water Companies who provide annual contributions to help support the data collection costs.  These partnerships have provided ADWR the necessary resources to expand the data collection area for the InSAR program to include numerous groundwater basins in central and southern Arizona in Maricopa, Pinal, Pima, La Paz, and Cochise Counties. 

 Through these efforts ADWR has identified more than fifteen active land subsidence features and determined the spatial extent, deformation rates, and time-series history of each land subsidence feature.  The process of collecting, processing, and interpreting InSAR data has resulted in ADWR producing land subsidence maps for each land subsidence feature covering different time periods. These maps are now available to the public through ADWR’s website (www.azwater.gov).

 Engineers, hydrologists, geologists, and scientists greatly benefit from the InSAR data to identify and evaluate areas of subsidence, uplift, earth fissures, faults, and many other geologic features.  InSAR data are used by those involved in the fields of water resources, structural engineering, geological engineering, hydrological engineering, land planning, and surveying.