Author(s): Luo Lin; Deng Yun; Zhao Wenqian; Li Jia
Keywords: Deep reservoir; 3-D temperature field; 2-D/3D numerical modeling applicability
Abstract: The Sichuan province, southwestern China, has plentiful hydropower resources. The assessment of environmental impact for development of this type of projects is very important. For a large-scale deep reservoir, one of the planning projects, the temperature field or stratified behavior and/or outflow temperature is a key issue for ecosystem concern, especially during the spawning season for aquatic animals. Hence, the prediction of the outflow temperature is a pronounced task to assess the environment impact for this hydropower project. Based on the 2-D computation of the temperature field, which is described in a separate paper, the detailed 3-D temperature distribution near the dam and the outflow temperature were studied. The results showed that strong 3-D effect caused by power station intakes, and the different temperature distribution with the 2-D results under some circumstances. The 3-D effect is weaker with the water depth. When the reservoir operates in high-depth period, the 3-D and 2-D results were nearly agreed with each other. However, in low-depth operation, the quite difference of the temperature field was observed. The reasons for the above behavior have been discussed, and applicability of 2-D or 3-D numerical modeling for deep reservoir is investigated.