Dynamic simulation of sediment resuspension and its effect on water quality in Lake Taihu, China

Quantitative studies on sediment release fluxes and their impact on water quality are important for water pollution control, ecological restoration, water safety, and human health. In this study, we conducted high-frequency, synchronous field observations of meteorology, hydrology, and water quality to determine the relationship between sediment release rate and wind speed in the central region of Lake Taihu. We combined these results with our previous findings from other regions to establish the temporal–spatial variation in sediment release patterns for this lake. We then calculated the annual total nitrogen (TN) and total phosphorus (TP) release fluxes. We constructed an environmental fluid dynamics code (EFDC) model; we then loaded the temporal–spatial variation parameters and simulated the effects on different TN and TP concentrations. Overall, the following results were observed: (1) the critical wind speed at which sediment was first suspended in the central region of the lake was 4 m/s, and the fitted curve of the sediment release rate and wind speed was r = 144.7x−100 (R2 = 0.851); and (2) the annual TN and TP release fluxes of Lake Taihu were approximately 3,086 and 740 tons, respectively. This research would provide a basis for decision-making regarding pollution control in this region.