Dams Safety: Review of Satellite Remote Sensing Applications to Dams and Reservoirs

Remote sensing is the collection and interpretation of information of an object, area or phenomenon by a recording device that is not in physical or intimate contact with the object or phenomenon under study. It generally refers to the use of satellite borne or airborne sensors to capture the spectral and spatial relations of objects and materials on Earth from the space. This is done by sensing and recording reflected or emitted electromagnetic radiation from the objects. A brief history of satellite remote sensing is given in this review but the bulk of it is devoted to the scientific satellites launched into orbit and their sensors tracking, and presenting changes in water resources fields. The used technologies and satellite systems for monitoring movements and changes include American GNSS, GPS, the Russian GLONASS, Europe’s European Satellite Navigation System (GALILEO), China’s COMPASS/BeiDou, the Indian (IRNSS); Japan’s (QZSS) and many others. Details are presented on the present (LANDSAT), the Moderate Resolution Imaging Spectroradiometer (MODIS), as well as Synthetic Aperture Radar (SAR), and RADARSAT, JERS‐1, and ERS, which are developed by various countries, especially the USA. These sensors have the refined capability of providing estimates of variables, which depending on the purpose and design of the sensor, can follow critical issues related to water management problems. This review presents examples of actual studies carried out including; building databases of small dams and lakes on regional scale, derivation of volume vs. elevation and surface area vs. elevation of hundreds of reservoirs around the world, various bathymetric reservoir surveys, siltation of reservoirs and catchment areas erosion problems, monitoring of water quality changes, and above all monitoring dam deformation and stability problems of dams. The presented case studies cover the use of these different sensor together with the imagery used, their sources, methods of interpretation, validation and gives presentation of the end results. This review, which is only a very brief presentation of satellite remote sensing applications concludes that; in spite of the large volume of research done on this subject so far, which this review cites some of them , the expected future developments in satellite remote sensing technology coupled with advances in algorithms and models used in refining satellite imagery and validating the results will bring more accurate results and less laborious treatment work in addition to wider scope of applications.