Monitoring Global Lake and Reservoir Dynamics from Space

Abstract:

Lakes and artificial reservoirs are an important component of the hydrologic cycle and the earth system at large These surface water stores and the ecosystems they support provide significant sources of freshwater, food, and energy. Despite their importance, little is known about lake and reservoir storage and their interactions with the hydrologic cycle at the global scale. This study leverages the global vantage point of satellite remote sensing to help answer a key question; what are the monthly, seasonal, and interannual lake and reservoir storage dynamics globally? We estimated storage change of the world’s large lakes and reservoirs (with nominal surface area greater than 100 km²) by combining surface water extent observations derived from Sentinel-1 Synthetic Aperture Radar (SAR) observations with water surface elevation observations derived from Sentinel-3 radar altimetry. We harnessed the Google Earth Engine cloud computing platform to provide the computational resources necessary for such a global analysis. Better understanding of the temporal and spatial dynamics of the world’s lakes has far reaching implications for the study of earth systems. Better quantification of surface water stored in lakes and reservoirs can lead to improved understanding of basin scale hydrology. Improved knowledge of reservoir operations will help better quantify the impacts of dam development and management in developing regions around the world.