Short-term hydrodynamic features of Chinese sturgeon spawning ground under reservoir regulation conditions
Mao Jingqiao1,2, Li Zhi2, Dai Huichao1,2, Ke Yun2
1.State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, Jiangsu 210098, China; 2.College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China
The water level of Three Gorges Reservoir(TGR)reached to 175 meters in 2010, indicating this hydropower project had started its normal operation. Chinese sturgeon spawning ground is located at downstream of Gezhouba reservoir immediately and the water level of the ground is affected by regulation of both reservoirs. Since hydrodynamics in the ground can play a crucial role in multiplication of Chinese sturgeon, effects of regulation of both reservoirs on the hydrodynamic characteristics of Chinese sturgeon spawning ground are investigated to explore its suitability for reservoir regulation of a hydraulic project. A three-dimensional hydrodynamic model is built for the Chinese sturgeon spawning ground from Gezhouba to Yichang reach. The short-term hydrodynamic characteristics of the spawning ground are studied by simulation method at two water levels at which two spawning events were observed in 2011. It is shown that the bottom layer flow, which is directly related to multiplication of Chinese sturgeon, is smooth and stable, but there is local turbulence in two streams mixing regions and in bumpy areas of the bed. The stream velocity is varied from 0.8 to 1.4 m/s; a higher velocity is observed in the downstream of Dajiang Power Station and Erjiang Power Station, but the highest velocity is found in the downstream of at Erjiang Power Station. The fluid domains with a stream velocity suitable for Chinese sturgeon spawning are ranged respectively from the end of the training levee in the downstream of Dajiang Power Station to the first 1/3 portion of the central separation levee in the river, and from the end of the central separation levee to 700 m extension in the downstream of the separation levee.
MAO Jin-Qiao-,,LI Zhi- et al. Short-term hydrodynamic features of Chinese sturgeon spawning ground under reservoir regulation conditions[J]. Journal of Drainage and Irrigation Machinery Engin, 2014, 32(5): 399-403.
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