黄河首曲气候变化及其对黄河断流的影响

Climate Changes over First Meander of Yellow River and Their Effects on Cutoff in Lower Reaches

利用黄河首曲气候资料和黄河上游年径流量资料以及黄河下游断流资料，分析了黄河首曲气候变化特征，气候变化对径流量的影响，黄河首曲气候变化与黄河下游断流的关系。结果表明，黄河首曲大部分区域降水量年际变化呈下降趋势，降水量的年际变化存在2～4，6～7，10～11a的年周期振荡特征。黄河首曲气温年际变化趋势呈上升趋势，增温速度均大于全国增温速度。1983年之前气温距平以偏冷为主，1984年之后持续偏暖。唐乃亥年径流量存在4-5，14-16a的年际周期振荡变化。降水量年际波动曲线与径流量年际波动基本一致。1990-1999年属高温少雨时段，也是径流偏枯时期。黄河首曲降水量与同期黄河下游利津站断流天数曲线呈明显的反相位分布，黄河上游关键区、敏感区气候变化对黄河水资源的影响重大。

By using meteorological data in the area of the first meander of the Yellow River and data of both annual runoff in the upper reaches and the cutoff in the lower reaches, climate changes in the meander area and their effects on annual runoff in the upper reaches and the cutoff in the lower reaches were analyzed. Results showed that in the meander area, annual precipitation tended to decrease and fluctuated in three periods of 2-4, 6-7 and 10 - 11 years. The mean annual temperature was remarkably greater than that of other areas in China. The departure of annual temperature was low before 1983, and high after 1984. Annual runoff of the Tangnaihai fluctuated in two periods of 4-5 and 14-16 years. The waves for annual precipitation in the meander area and annual runoff of the Tangnaihai were basically agreed. The mean annual temperature was high, sometimes, whereas annual precipitation and annual runoff were low in 1990s. The fluctuated trends of annual precipitation in the meander area and the cutoff in the lower reaches were on the contrary. The climate changes in the key and sensitive area of the upper reaches of the Yellow River greatly affect the water resources of the region.