Assessing lake and reservoir storage change from remote sensing data at a global scale

Lakes and reservoirs monitoring is of sheer interest, as in-situ gauging station coverage is dwindling at a global scale. Water storage change show the impact of not only domestic consumption, low water maintenance in rivers or crop irrigation, but also the impact of climate change. In this frame, different approaches are explored in this study to be able to follow from space remote sensing data the lake storage change, either from water height or surface.

For the ESA CCI Lake Storage Change option, we focus on a few lakes distributed around the world to establish a methodology suitable at a global scale to different lake behaviors. In particular for highly varying water bodies, the automatic production and use of hypsometric curve is investigated This approach is yet suitable for volume variations only.

Complementary to this first approach, an image inpainting algorithm applied to digital elevation models around water bodies is developped to assess their total bathymetry (either for lake or reservoir) where the pixels to be reconstructed are the ones underneath the lake surface. The first results show encouraging estimations that may lead in the near future to the assessment of total water volume of lake and reservoir at a global scale. With the recent launch of SWOT that will provide an unprecedented coverage worldwide, the estimation of global water storage change has a bright future.