关键词: 整体水文改变程度, CRITIC法, 水库串并混联运行, 长江上游

Abstract: It is inevitable that joint operation of cascade reservoirs in the upper Yangtze River will exert certain effects on the runoffs in the lower river channel. We selected Beibei, Gaochang and Yichang stations as controlling cross-sections, and used IHA method to identify fourteen hydrological indexes that are influenced by the operation of reservoirs. We studied the varying trends of these indexes and the degree of hydrology variations under cascade reservoirs’ operation modes of series, parallel and series-parallel. The results show that: ① as the number of cascade reservoirs in operation increases, the variations in hydrology of mainstream Yangtze River tend to increase; ② joint operation of cascade reservoirs significantly decreases water flow during flood season; meanwhile, the maximum discharge throughout the year tends to decrease, and vice versa; ③series operation will delay maximum discharge and parallel operation will reinforce the evenness of discharge process during flood season; the variation of hydrological regime caused by series-parallel operation is mostly affected by the operation mode and climate change, series-parallel operation has low impact on the hydrological regime of Yichang station.

Key words: overall variations of hydrological regime, CRITIC method, series, parallel and series-parallel operation of reservoirs, upper Yangtze River