Use of satellite altimetry and imagery for monitoring the volume of small lakes

This study presents three complementary approaches to determine the volume of water in small lakes (<;100ha) by combining satellite altimetry data and high-resolution (HR) images. The first two are empirical and use synchronous ground measurements of the water volume and the satellite data. The results demonstrate that altimetry and imagery can be effectively and accurately used to monitor the temporal variations of the lake (R²_altimetry=0.98, RMSE_altimetry=5.0%, R²_imagery=0.90, and RMSE_imagery=7.4%). The third method combines altimetry (to measure the lake level) and satellite images (of the lake surface) to estimate the volume changes of the lake and produces the best results (R²=0.98) of the three methods, demonstrating the potential of future Sentinel and SWOT missions to monitor small lakes and reservoirs for agricultural and irrigation applications.