Lake eutrophication, exacerbated by high-intensity anthropogenic forcing, threatens water ecological security and the sustainable development of fisheries. Accurately evaluating lake eutrophication is the basis for effective management of the water environment. This study aimed to study eutrophication and its anthropogenic forcing in Chagan Lake, which is surrounded by agricultural areas with irrigation discharge as the primary water source. The spatiotemporal evolution characteristics of lake eutrophication and the anthropogenic forcing factors were analyzed based on the long-series multi-source data and modified eutrophication index. The results showed that (1) the average trophic state of Chagan Lake was eutrophic according to the modified eutrophication index (TLI = 58.31) and the nutrient level was higher in summer, reaching hypertrophy (TLI 61.49); (2) the maximum pollution footprint affecting the lake reached 34.7 km2, with a maximum buffer zone radius of 1 km; (3) the gross domestic product of primary industry, total sown area, and rice field area were the main anthropogenic factors leading to the lake eutrophication, with contribution rates of 64.43%, 13.09%, and 10.23%, respectively. Multidimensional management strategies for maximum pollution footprint, buffer zone radius, and contribution of anthropogenic factors were used to improve the water quality of the lake. The findings provided scientific support for the management of water environment of Chagan Lake and guided the formulation of "one lake, one policy."
Keywords: Anthropogenic forcing; Chagan Lake; Modified eutrophication index; Pollution footprint; Water management strategies.
© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.