Abstract
The availability of lake bathymetry maps is imperative for estimating lake water volumes and their variability, which is a sensitive indicator of climate. It is difficult, if not impossible, to obtain bathymetric measurements from all of the thousands of lakes across the globe due to costly labor and/or harsh topographic regions. In this study, we develop a new digital lake bathymetry model (DLBM) using the step-wise water recession method (WRM) to generate 3-dimensional lake bathymetric maps based on the digital elevation model (DEM) alone, with two assumptions: (1) typically, the lake’s bathymetry is formed and shaped by geological processes similar to those that shaped the surrounding landmasses, and (2) the agent rate of water (the thickness of the sedimentary deposit proportional to the lake water depth) is uniform. Lake Ontario and Lake Namco are used as examples to demonstrate the development, calibration, and refinement of the model. Compared to some other methods, the estimated 3D bathymetric maps using the proposed DLBM could overcome the discontinuity problem to adopt the complex topography of lake boundaries. This study provides a mathematically robust yet cost-effective approach for estimating lake volumes and their changes in regions lacking field measurements of bathymetry, for example, the remote Tibetan Plateau, which contains thousands of lakes.
Highlights
Terrestrial lakes are an important component of global and regional water cycles since they contribute the most to, and are very sensitive indicators of, worldwide nonfreezing lake water storage [1]
By applying assumption (1), the bathymetric map generated by our model is theoretically the natural surface, which means we can use the surrounding slopes as the initial condition to simulate the lake’s bathymetry; subsequently applying assumption (2), the thickness of the sediment layer is directly proportional to the water depth due to the uniform deposition rate
The water recession method (WRM) is an imitation of water recession, which means that the whole calculation process is similar to the process in which the lake gradually dries up as the water level decreases
Summary
Siyu Zhu 1,2 , Baojian Liu 1 , Wei Wan 1, *, Hongjie Xie 3 , Yu Fang 2 , Xi Chen 1 , Huan Li 1 , Weizhen Fang 1 , Guoqing Zhang 4 , Mingwei Tao 2 and Yang Hong 1,5, *.
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