Numerical Study on the Characteristics of Eutrophication and Algal Growth in Taihu Lake, China

An ecological dynamics model of algal growth was coupled with a two-dimensional lake hydrodynamic model to examine the eutrophication problem in Taihu Lake, China. The model included three water quality variables: chlorophyll-a (chl-a), total phosphorus (TP) and total nitrogen (TN). The model was used to investigate the wind-induced current and the characteristics and drivers of TP distribution and algal growth. The simulation results showed that wind-induced circulation in Taihu Lake is strongly dependent on wind conditions, shorelines, and the topography of the lake. Flow patterns differed widely in different regions of the lake, leading to differences in the extent of eutrophication. The main factors influencing algal growth were temperature and TP, with temperature and TP concentration thresholds controlling the occurrence of algal blooms in Taihu Lake obtained from numerical analysis. Modeling of the different regions of the lake confirmed that Meiliang Bay and West Zone are ‘critical' areas where algal blooms are likely to occur.