Assessing and modeling impacts of different inter-basin water transfer routes on Lake Taihu and the Yangtze River, China

作者：Li, Yiping; Tang, Chunyan; Wang, Chao^*; Tian, Wei; Pan, Baozhu; Hua, Lei; Lau, Janet; Yu, Zhongbo; Acharya, Kumud

来源：Ecological Engineering, 2013, 60: 399-413.

DOI：10.1016/j.ecoleng.2013.09.067

• EFDC
• Inter-basin water transfer
• Multi objective optimization method
• Lagrangian particle tracking
• Water age

To enhance water exchange and alleviate eutrophication in Lake Taihu, the third largest freshwater lake in China, four different inter-basin water diversion named Route One to Four, have been implemented or planned to flush pollutants out of Lake Taihu by transporting freshwater from Yangtze River. Due to the shallowness and large size of Lake Taihu, it is quite complex to set the optimal transferred inflow rate for each route or the combination of routes to maximize the benefits for improving the lake's water exchange with minimum economical cost and environmental impact. In this study, the appropriate transferred inflow rates and environmental impacts of the different water transfer routes on both Lake Taihu ("receiver") and the Yangtze River ("supplier") were assessed using the concept of water age and Lagrangian particle tracking based on a three-dimensional Environmental Fluid Dynamic Code (EFDC) model. The results showed that the appropriate flow rates were quite different from the single route diversion to the combination of routes, depending on priorities such as lowest economical cost and high-est water quality improvement for specific lake regions or the entire lake. Two optimal combinations of routes to achieve specific results in different seasons were determined to improve the water exchange of the lake. During the algal bloom seasons, the objective of the combination focused on enhancing water exchange in the specified lake regions such as Meiliang Bay and Zhushan Bay. The optimal flow rates for Route One to Route Four were 80, -70 ("-" means outflow), 100 and 20 m(3)/s, respectively. In the non-algal bloom seasons, the combination concentrated on lowering water ages in the entire lake. The optimal flow rates for Route One to Route Four were 90, -40, 70 and 20 m(3)/s, respectively. The results suggested that the Yangtze River Diversion, as an emergency stopgap measure, played important roles on enhancing water exchange in the lake, but had minimal impact on the Yangtze River. The findings of this study provide useful information for the local government and decision-makers to better understand the physical and hydrological processes of water transfer projects and to assist in managing the water transfer projects.

• 出版日期2013-11
• 单位河海大学; 长江水利委员会长江科学院; 浙江省水利河口研究院