Analysis of the Driving Mechanism of Water Environment Evolution and Algal Bloom Warning Signals in Tai Lake

Abstract

Understanding the evolution characteristics and driving mechanisms of eutrophic lake ecosystems, especially over long time scales, remains a challenge. Little research on lake ecosystem mutation has been conducted using long-term time series data. In this study, long-term water quality indicators, as well as ecological indexes, natural meteorological factors, and socio-economic indexes, were collected for Tai Lake to enable us to study the environmental evolution of the lake ecosystem. The key time nodes and early warning signals of the steady-state transformation of Tai Lake were also identified, which could provide a theoretical basis for early indication of the transformation of lake ecosystems. Furthermore, the characteristics and driving mechanism of the lake’s ecosystem evolution were analyzed based on the physical and chemical indexes of its sediments and its long-term water quality indexes. The results show that the early warning signals (variance, autocorrelation, and skewness) of ecosystem mutation included abnormal changes 10 years before the steady-state change, and the evolution of Tai Lake was driven by the complex nonlinear effects of biological, physical, chemical, and socio-economic factors in the lake basin. These results have important theoretical and practical value for pollution control and the management of eutrophic lakes.