南水北调中线工程对汉江中下游的影响分析

EFFECTS OF WATER TRANSFER FROM THE DANJIANGKOU RESERVIOR ON THE MIDDLE AND LOWER REACHES OF THE HANJIANG RIVER

本文分别计算了丹江口水库１９６９－１９９０年实际下泄流量过程和大坝加高向黄淮海地区调水１５×１０９ｍ３后下泄过程在２０２０水平年下汉江中下游各点的水位流量过程，比较了两者的水位流量差①，分析了丹江口水库调水对汉江中下游各点水位和流量的影响以及引起的灌溉用水和航运的变化。结果表明，丹江口水库调水后，丹江口水库下游各点的多年平均水位、流量将下降，流量过程趋于缓和，洪水流量减少，枯水流量增加；灌溉取水量减少，破坏状况加重，枯水期航运流量增加，但中水期航运时段减少。最后，作者对汉江中下游补偿工程提出了建议。

Employing the data from 1969 to 1990, the authors compared the water table and streamflow after heightening the dam and transferring water to north in 2020 with those at eight sites down the Danjiangkou Reservoir.The assessment of the impacts of water transfer from the Danjiangkou Reservoir on the middle and lower reaches of the Hanjiang River,including streamflow process, water tables,navigation and irrigation water use, was done. The results indicated that the annual average water tables and streamflows down the Danjiangkou Reservoir would decrease after water transfer.The runoff process would be more even due to the decrease in flood flow and the increase in dry period flow.The duration of flood streamflow would be shortened,while the duration of dry season streamflow would be lengthened.The diverted water quantity for irrigation in four large irrigated districts would be decreased,accompanying with more serious water shortage.The navigation condition in low-flow period would be improved due to enlargine the regulating capacity of the Danjiangkou Reservoir, but the middle-flow navigation duration would be shortened.Finally,the ideas on the compensating engineering at the middle and lower reaches of the Hanjiang River were proposed.