Study on pollution traceability based on the optimized hydrodynamic model of Tai Lake

This research optimized a hydrodynamic model based on in-situ measurement experiments, which can evaluate the transport process of pollution groups from inflowing lake sources with different wind conditions and their effects on the sensitive area in Tai Lake. The results showed that the wind drag coefficient (Cs) was 0.001–0.0028 when the wind speed was 1–12 m/s, and the particle trajectory is validated well by the methods of Thiessen polygon and Lagrange particle tracking, which proves that this hydrodynamic model was optimized successfully. During the water diversion period, the results showed that the Northwest Area and Gong Bay are the most important pollution flux sources to the sensitive area. Under northwest wind condition, the pollution flux proportion from Northwest Area and Gong Bay is 65 and 17%, respectively. Under southeast wind condition, the pollution flux proportion from Northwest Area and Gong Bay is 48 and 27%, respectively. Namely, pollution control to the upstream watershed of the Northwest Area and improving the water quality (TP< 0.065 mg/L; TN< 1.2 mg/L) from the Wangyu river are the effective methods to reduce the pollution risks for the sensitive area.