龙刘水库联合运用对黄河上游径流量变化的影响

Influences of Longyangxia and Liujiaxia Reservoirs Joint Operation on Runoff of Upper Reaches of Yellow River

为分析龙刘水库联合运用对黄河上游径流变化的影响,选取黄河上游八个水文站1950-2009年径流资料,根据水量平衡原理还原水库运用后径流序列,采用Mann-Kendall趋势分析法、突变检验法及小波分析法,分析了龙刘水库运用前后兰州站与下河沿站实测与还原年径流量的变化特征。结果表明,实测与还原序列都存在显著的下降趋势,实测序列突变年份为1987年,还原序列为1990年;实测序列与还原序列都存在3-5、6-9、14-17、23-27年四类周期变化尺度,兰州站与下河沿站实测径流序列的主周期都依次为25、16、8和4年,兰州站还原序列主周期依次为23、8、4年,下河沿站还原序列主周期依次为24、4、8年。说明龙刘水库的联合运用加剧了径流序列下降的趋势,有促使序列突变提前的可能性,且对径流序列的周期变化产生了一定的影响。

Based on the runoff data from 1950 to 2009 of eight stations in the upper reaches of the Yellow River, the impacts of Longyangxia and Liujiaxia reservoirs joint operation on runoff were analyzed. The runoff series after reservoir operation were restored by water balance. The annual runoff characteristics of observed and restored series in both Lanzhou and Xiaheyan stations were analyzed by Mann-Kendall trend analysis, sudden change test and wavelet analysis method. The results show that significant downward trend exists in observed and restored runoff series; the abrupt change in observed and restored runoff series occurred in 1987 and 1990, respectively; the periodic oscillations in observed and restored runoff series had occurred at the temporal scales 0f 3-5, 6-9, 14-17and 23-27 years; observed runoff series of Lanzhou and Xiaheyan stations had main periods of 25, 16, 8 and 4 years; restored runoff series of Lanzhou sta tion had main periods of 23, 8, and 4 years; restored runoff series of Xiaheyan station had main periods of 24, 4 and 8 years. It demonstrates that Longyangxia and Liujiaxia reservoirs joint operation will aggravate the downward trend, move up the abrupt change year and affect the periodic variation of runoff series in some extent.