调水新格局下太湖水生态功能提升研究

Aquatic Ecological Function Improvement of Taihu Lake Based on New Water Diversion Scenario

摘要: 太湖“二引三排”调水新格局是保障湖区水生态安全的重要方式，但其对太湖水生态功能的改善效果如何仍少有报道。以太湖为研究区域，模拟研究了新增新孟河调水在不同情境下对太湖湖区水龄、水质和水生态等水生态功能的影响。结果显示，太湖水龄和叶绿素a (Chl-a)的浓度随调水流量的增加而降低，水龄降低了6.2%~9.0%，Chl-a下降了13.5%~21.5%，调水对两者具有明显的缓解效果。然而，调水流量的增加也引起了湖区总氮总磷的显著增加，现状水质下分别升高了1.2%~9.9%和6.3%~13.8%，但水质优化后，两者分别下降了3.7%~6.2%和6.3%~8.8%。因此，新孟河现状调水需要综合考虑水量和水质因素，入湖水质提升可以有效提升太湖的水生态功能，研究结果可为太湖流域水安全保障提供科学依据和技术支撑。

Abstract: The new pattern of water diversion in the Taihu Lake, known as “two diversions and three drainage”, is an important way to ensure the water ecological safety. However, the effect of the new water diversion on the improvement of the water ecological functions in Taihu Lake is rarely reported. This study simulated the impact of the Xinmenghe water diversion on the water age, water quality, and water ecology of the Taihu Lake under different scenarios. The results show that the water age and Chlorophyll a (Chl-a) concentration in the lake decrease as the diversion flow increases, with the water age decreasing by 6.2%~9.0% and Chl-a decreasing by 13.5%~21.5%, showing significant mitigation effects on the water age and Chl-a. However, the increased flow with the current water quality significantly increased the total nitrogen and total phosphorus in the lake, with an increase of 1.2%~9.9% and 6.3%~13.8%, respectively. After optimizing the water quality, the total nitrogen and total phosphorus decreased by 3.7%~6.2% and 6.3%~8.8%, respectively. Therefore, both water quantity and water quality should be comprehensively considered in terms of Xinmenghe diversion. The improved water quality of inflow from Xinmenghe diversion can effectively enhance the ecological functions of the Taihu Lake. These results could provide scientific basis and technical support for the water security protection of Taihu Lake.