How Much Water is Stored in Lakes? Estimation of Global Lake Volume with a Geo-Statistical Approach

Abstract:

Lakes are key components of biogeochemical and ecological systems across a variety of spatial scales. Knowledge about their distribution, volume, and residence time is crucial in understanding their properties and interactions within the Earth system, yet global information is scarce with minimal consistency across regions. The aim of this study was to develop a geo-statistical model to estimate the volume of all global lakes over 10 hectares (0.1 km²) based on surrounding terrain information and trained with existing lake volume data. The residence time of each lake was then estimated by using global discharge estimates at high spatial resolution from the HydroSHEDS database. Our total global lake volume estimate of 187,381 km³ for 1,491,753 lakes is largely driven by a few large lakes and mirrors previous estimates. However, this figure differs by nearly 50% from previous estimates when removing the water storage of the 10 largest lakes. The resulting database—termed HydroLAKES— is the first spatially resolved object-oriented baseline dataset, where each lake is treated as an individual polygon and comes with a suite of morphometric attributes.