Using Radar Remote Sensing from Space to Monitor Dams

Monitoring dams is critical for identifying vulnerabilities affecting its performance and managing the risk of failure. Traditionally, dam monitoring is performed by a combination of visual surveillance and instrumentation. American Society of Civil Engineers (ASCE) has been giving a D grade for the nation's 91,000-plus dams since the beginning of the grading system (1998) to date. The traditional approach can be subjective and laborious, considering the monitoring needs in the United States. This study presents the Interferometric Synthetic Aperture Radar (InSAR) application for monitoring deformations at dam sites to understand its vulnerability. The study evaluates the use of InSAR at three (two in India and one in the United States) dam sites to monitor its safety. The Sentinel-1 and ENVISAT Advanced Synthetic Aperture Radar (ASAR) images were processed using Persistent Scatterers Interferometry (PSI). Results indicate that, combined with traditional methods, remote sensing using radar offers an opportunity for long-term dam monitoring and the development of a deformation-based early warning system.