关键词: 枯水, 水库调度, 中长期水文预报, 水库群联合蓄水, 长江中下游, 2016年洪水

Abstract: A regional extraordinary flooding occurred in the middle and lower Yangtze River in July 2016, during which reservoirs co-regulation played an important role in the flood protection. Serious drought occurred immediately after the flood and the water levels of the main stream of middle and lower Yangtze River and the two lakes (Dongting Lake and Poyang Lake) kept dropping, becoming a severe low water event in September compared with history data. In order to probe into the cause of the low flow and summarize the evolution law, we reduced the process of low flow in Autumn 2016 by water balance method and the hydrograph curve. The results show that a smaller natural flow and joint impoundment of reservoir group were the main causes leading to the serious low water level in the middle and lower Yangtze River and the two lakes. In 2020, with more reservoirs being put into operation, the impact of reservoir impoundment after flood season on low water regime of middle and lower Yangtze River would keep enlarging and become normal. To solve this problem, further research including the medium and long term hydrological forecasting technology and reservoir group joint impounding scheme are discussed.

Key words: low water, reservoir regulation, medium and long term hydrological forecast, joint impoundment of reservoir group, middle and lower Yangtze River, 2016 flooding