Influence of cold-temperature stagnation phenomenon induced by reservoir impoundment on downstream water temperature in spawning period of four major Chinese carps
MAO Jingqiao1*, HUI Erqing2
1. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China; 2. China Three Gorges Corporation, Beijing 100038, China
Abstract：Based on the long-term water body temperature and meteorological data observed at a few key hydrological stations located upstream and downstream of Three Gorges Dam, the monthly average and five-year average water body temperatures were analyzed. The variation characteristics of water body temperature between Three Gorges Dam and Gezhou Dam as well as downstream of Gezhou Dam before and after the impoundment of Three Gorges Reservoir were clarified during the spawning period of four major Chinese carps. By generalizing the factors influencing the water body temperature diffe-rences before and after the impoundment, the temperature differences and the contribution of stagnation effect are quantified. The results show that the water body temperature changs greatly in April and May at Yichang Station after the impoundment. During the spawning period of carps from May and June, the monthly average water temperature is decreased by 1.40 and 0.49 ℃, respectively. The water temperature at Yichang station is decreased by 1.26, 1.71, 0.79, and 0.08 ℃ from March to June caused by the impoundment and a cold-temperature stagnation phenomenon is observed. However, the average monthly water temperature during this period at that station is still within the most suita-ble water temperature range for carps to spawn. The effect of the impoundment of Three Gorges Dam on water body temperature between Three Gorges Dam and Gezhou Dam as well as downstream of Gezhou Dam for the spawning sites of the carps is in a controllable range, which provides a manageable space for performing subsequent continuous ecological operation in reproduction of the carps.
毛劲乔*,惠二青. 四大家鱼产卵期水库滞冷效应对下游水温影响[J]. 排灌机械工程学报, 2020, 38(7): 691-696.
MAO Jingqiao*,HUI Erqing. Influence of cold-temperature stagnation phenomenon induced by reservoir impoundment on downstream water temperature in spawning period of four major Chinese carps. Journal of Drainage and Irrigation Machinery Engin, 2020, 38(7): 691-696.
