黄河下游近50年径流量变化特征及影响因素

Characteristics and Influence Factors of Runoff Variation in the Lower Reaches of the Yellow River in the Last 50 Years

应用Mann-Kendall趋势性检验和突变性检验法、双累积曲线法、GM(1,1)模型等方法,对黄河下游1962—2012年径流量和降水量的变化特征及规律进行了深入探讨,以期对黄河下游水资源调配,防洪减灾提供科技支撑。结果表明:降水量减少趋势不显著,突变时间为1964年,径流量减少趋势显著,突变时间为1979年。降水量和径流量变化具有明显的阶段性,降水量以1986年为界,分为丰水期、枯水期两个阶段,径流量以1979年、1985年为界,分为枯—丰—枯3个阶段,黄河目前处于枯水期。采用双累积曲线法定量分析了降水量和人类活动对径流量的影响程度。结果表明:突变时刻前,降水量和径流量同步变化,呈现正相关,突变时刻后,人类活动是影响径流量变化的主要因素,人类活动和降水量对径流量的作用比例分别为68%和32%。利用GM(1,1)模型预测了未来5年降水量和径流量的变化趋势,表明未来5年降水量和径流量将会有所增加。

In order to provide scientific support for the development of water resources allocation and flood control in the lower reaches of Yellow River, the characteristics and patterns of the precipitation and runoff had been discussed. The resuIts showed that the decrease of precipitation was not significant, and the year of abrupt change was 1964 while the runoff decreased significantly, and the year of abrupt change was 1979. The changes of precipitation and runoff have obvious stage. The precipitation can be divided into two stages as the boundary of 1986, the abundant water period and the low water period. The runoff can be divided into dry-wet-dry three stages as the boundary of 1979, 1985, respectively; the Yellow River is still in the dry season, too. The effeets of precipitation and human activities on runoff were quantitatively analyzed by using double cumulative curve method. The results showed that the changes of precipitation and runoff were synchronized with the change of time. The impacts of human activities and precipitation on the runoff are 68% and 32%o, respectively, and the human activity is the key factor affecting the runoff in the lower reaches of Yellow River. Finally, the precipitation and runoff change trend of the lower reaches of Yellow River has been analyzed and predicted in the next five years by using the GM （1,1） model. The results show that the precipitation and runoff will slowly increase in the next five years.