Lake Water Ecological Simulation for a Typical Alpine Lake on the Tibetan Plateau

Abstract

Lakes on the Tibetan Plateau (TP) serve as both indicators of and safeguards against climate change, playing a crucial role in the aquatic ecosystems of the TP. While considerable attention has been devoted to studying the thermal and dynamic processes of TP lakes, research focusing on their ecological variations has been limited. In this study, we selected Namco, a representative lake on the TP, to investigate its water ecological processes using the AQUATOX lake ecological model. Long-term ecological variations spanning from 1980 to 2020 were analyzed based on lake observations. Our results revealed a consistent increase in water nutrients, particularly total nitrogen (WTN), and total phosphorus (WTP), over the study period. Additionally, the concentrations of chlorophyll-a (Chl-a) and water gross and net primary production (WGPP and WNPP) exhibited a significant upward trend. Despite the persistent state of poor nutrition in the lake, the ecological conditions improved. Multiple linear regression analysis indicated that the concentrations of WGPP, WNPP, and Chl-a were more sensitive to the local climate and hydrology compared to WTN and WTP. A continuously warming climate would heat up the lake water body, further enhancing primary production and improving water quality in the future. This study provides insights for lake limnological and ecological research and can be used to inform water management strategies in high-altitude alpine regions.