Influence of water diversion on spatial and temporal distribution of flow field and total phosphorus (TP) concentration field in Taihu Lake

Abstract

In order to evaluate the overall impact of water diversion on Taihu Lake, this paper carries out numerical simulation of the temporal and spatial distribution of the flow field and the TP concentration field in Taihu Lake based on measured data during the water diversion period by using the Euler–Lagrange method. The results show that: (1) the Pearson coefficient of monitoring points in the East Lake area increases significantly during the water diversion period, indicating that the diversion of water may indirectly influence water quality; (2) the diversion of water has a significant influence on the flow rate of the simulated stations in Taihu Lake, and the influence is Taipu (103%) > Gongwan (60%) >East Lake (31%); (3) when the amount of water flow transfer from the Wangyu River to the lake is greater than 100 m3/s, the mean concentration of TP in the Center and East lakes increases significantly (more than 50%). The recommended water diversion discharge is to be controlled in the range 100–200 m3/s and the total water diversion yield between 1.56 and 2.59 billion m3/a.