长江中游灌溉涵闸引水条件变化及对策建议

Change of water diversion condition of irrigation gates in Middle Yangtze River and relevant suggestions

长江中游地区是我国重要的农业生产基地。三峡水库蓄水后,受流量过程变化、同流量水位下降等影响,长江中游不同河段各保证率水位发生不同程度的调整。结合实测资料分析表明,三峡蓄水前长江中游灌溉涵闸引水保证率仅为52.3%,2004-2011年降至46.8%;根据水库调洪演算及一维水沙数值模拟结果,分析得到蓄水20年后引水保证率为51.1%左右。为满足长江中游沿线平均灌溉引水需求,宜昌保证率75%的下泄流量需增加5 171m3/s,通过优化水库调度方式很难实现这一目标,建议提高灌溉闸自身建设标准。

The Middle Yangtze River region is an important agricultural production base. After the operation of TGR（Three Gorges Reservoir） , the water level of certain guaranteed rate adjusts with the change of the flow process and the decline of the water level under the same discharge. In this paper, based on the measured da ta pre and post impounding, the analysis shows that the guaranteed rate of water diversion irrigation before impounding was 52.3% , it declined to 46.8% in 2004 2011 ; According to the reservoir flood routing and onedimensional watersediment numerical simulation, the guaranteed rate is about 51.1% in 20 years after impounding. If the guaranteed rate of water diversion irrigation reaches the expected value of 75% , the aver age along the middle reaches of the Yangtze River, the Yichang discharge of guarantee rate 75% should be in creased by 5 171 m3/s. Since the optimization of reservoir operation is difficult to achieve this goal, sugges tions are given to improve the selfconstruction standard of irrigation gates.