Monitoring seasonal water level changes in global lakes and reservoirs

Lakes and reservoirs are an important part of the earth's hydrosphere, and their water level changes are important indicators of climate and ecological changes. The monitoring and discussion of the seasonal variation characteristics of lakes and reservoirs around the world is conducive to strengthening the scientific understanding of the global water resources status and providing technical support for water resources management and planning. In this study, we selected lakes and reservoirs of more than 50km² as the research object, and used ICESat-2 ALT13 data to quantify the seasonal water level change characteristics of 841 lakes and 178 reservoirs around the world from 2021 to 2022 by extracting lake masks, constructing water level time series, and eliminating outliers, and explored the relationship between them and driving factors in combination with meteorological factors such as precipitation and evaporation. The results show that the seasonal water level change of natural lakes is 0.87m, the seasonal water level change of reservoirs is 4.23m, and the seasonal change of reservoirs is five times that of natural lakes. Precipitation, evaporation and temperature have a certain impact on the change of water level, and the influence of meteorological factors on natural lakes is greater than that of reservoirs, which also indicates that human activities have a greater impact on water levels in reservoirs than on natural lakes.