Development of a global bathymetric dataset for lakes and reservoirs

Abstract:

Lakes are vital natural resources for life on earth, however, the quality of ecosystem services they provide is experiencing disruptions mainly due to climatic changes and/or anthropogenic interventions. To ensure the sustainability of future lake systems through management and restoration practices, it is required to improve our understanding of the water balance and physical and biogeochemical processes in these lake systems. That, in the first place, requires accurate and detailed knowledge on lakes geophysical conditions and morphology, especially bathymetry that is a key component in modeling lake systems. Bathymetry describes many features of the lakes such as stage-storage relationships, mixing and transport, near-the-bottom interactions, ecosystem characteristics, and water balance. However, due to difficulties in the measurement of underwater topography there is limited knowledge about bathymetry of the lake systems worldwide. Previous efforts in development of global lake datasets are mostly limited to bathymetric maps of some of the major lakes around the world (out of millions), local bathymetry datasets, and estimations of basic lake parameters such as surface area, volume, and average depth. In this study, we present the GLObal Bathymetry (GLOBathy) dataset, developed for more than 1.4 million lakes around the world using the HydroLAKES dataset. The bathymetry data is estimated using geo-statistical and GIS-based approaches and is built upon the lakes in a well-established global dataset, HydroLAKES. The geo-statistical relationships developed for estimation of bathymetric parameters were validated using a set of more than 1,500 lakes located in different geographical locations around the world and with diverse geophysical characteristics.