The Arizona Department of Water Resources has released the first Land Subsidence Monitoring Report (Right. Yellow areas define subsidence monitoring areas. Credit, ADWR) The Executive Summary explains:
In 1997, the Arizona Department of Water Resources created a land subsidence monitoring program. The program initially focused on monitoring land subsidence in the east valley of the Phoenix Metropolitan area using survey - grade GPS equipment. In 2002, ADWR was awarded a 3-year $1.3 million NASA grant to expand the land subsidence monitoring program to include Interferometric Synthetic Aperture Radar data (InSAR). Upon completion of the NASA grant in 2005, ADWR quickly migrated to a land subsidence program that primarily utilized InSAR data using GPS surveying to support the program. With the InSAR data, ADWR has identified more than 25 land subsidence features in Arizona, collectively covering more than 1,100 square miles of the state (Figure 1). In addition, the program now cooperates with 12 entities whose financial assistance allows the Department to fund the InSAR data collection. ADWR provides land subsidence maps for download from ADWR’s website. As of May 2013, 163 land subsidence maps are available for download and are used on a daily basis by geologists, hydrologists, engineers, planners, surveyors, floodplain managers, GIS analysts, and water resources managers.