来水与用水对黄河下游断流的影响分析

Analysis of the Influence of In flow and Water Use on Cut-out in the Lower Yellow River

本文分时段、河段从来水和用水的角度探讨了造成黄河卜游断流的原因，通过分析得出如I；结论：2～5月份下游断流的主要原因是下游引黄耗水量大幅度增加和中游区间来水的减少；汛期下游断流的原因主要是全网耗水的增加、中游区间来水的减少和龙羊峡、刘家峡水库进入汛期蓄水运用阶段影响；龙、刘水库非汛期的补水有助于缓解厂游断流的程度，但中游区间来水的减少和上游引黄耗水量的增加削弱了龙、刘水库的补水作用；全河特别是下游引黄时间的提前导致下游首次发生断流的日期也相应前提。

The reasons causing cut out of the Yellow River are studied from different aspects, i. e., inflow and water using in various periods and breaches in the paper. The analysis came out to the following conclusions: the main reasons the Yellow River cut out in February to May are the tremendous increase in water use from the river for irrigation and inflow from the middle reaches decrease; however,during the flood period, the reasons for cut out in the river are mainly the increase of water use along the river, inflow decrease from middle reaches, and hongyangxia and Liujiaxia pr0ects starting flood storage operation; water discharge from Longyangxia and Liujiaxia reserviors are helpful to alleviate the seriousness of cut out in the lower Yellow River, but it is counteracted by the decrease of inflow from middle and the increase of water use in the upper reaches. Advances of water use for irrigation from the river, especially in the lower Yellow River, lead to the cut out date advanced accordingly.