Lakes and reservoirs store the largest mass of liquid water on the land surface. They provide diverse and complex aquatic ecosystems, unique aesthetic appeal, and readily accessible freshwater sources to societal use. Although considered “lentic” (hydrologically stationary), lakes are often highly dynamic and are an integrated component of the global drainage system. They interact with river discharge, groundwater fluxes, and glacial mass balances, and function as both “sentinels” and “regulators” of climatic and environmental changes. A substantial proportion of the global lakes are also manmade reservoirs, which regulate natural streamflow and affect downstream water supply and sediment regimes. Tracking the dynamics of lake water storage is fundamental to understanding the spatiotemporal disparity in global freshwater resources, which is essential for addressing the increasing challenge in water security during the Anthropocene.

This seminar will provide a global perspective on the abundance and recent (decadal-scale) changes of lake water resources, as well as their implications to catchment hydrology, lacustrine management, and broader societal impacts. The seminar will identify the latest advances in data infrastructure for global lake monitoring, and will discuss the importance and challenges of data and method synergy from multi-mission Earth-observing satellites, including the newly launched Surface Water and Ocean Topography (SWOT) mission. The recent global lake dynamics will be attributed to primary driving mechanisms including anthropogenic climate change, climate variability, and direct human water consumption and managements. Hotspots such as arid hinterlands and High Mountain Asia will be highlighted to further illustrate the essential roles of lake water resources for regional water security and a holistic understanding of the global hydrological cycle under climate change.