1961—2010年讨赖河山区径流变化特征及其驱动因素

以1961—2010年讨赖河山区气温、降水和径流资料为基础，综合运用线性趋势、距平百分比、重标极差、Mann-Kendall突变检测、小波变换和多元线性回归等多种数理分析方法，研究了讨赖河山区径流的年内和年际变化规律，并探讨了气候变化和人类活动对径流变化的影响。结果表明：径流年内分配极不均匀且呈单峰型分布，汛期径流占年径流的比重为62.11%。径流经历了“丰-枯-丰-枯”4次波动，在1984年发生由多到少的显著性突变，但整体呈不显著减少趋势且具有持久性。径流在22年准周期上振荡最为明显，经历了“少-多-少-多-少-多-少”7次循环交替，2010—2015年径流可能再次偏多。近50年来山区气温呈“稳定波动-快速上升”变化，降水量呈显著增加趋势，但山区降水转化为径流的比例减少。气温升高和降水量增加引起的蒸散发增加，同时气候变化和人类活动共同作用下的地表覆盖类型的变化均对径流变化产生影响。

Variation Characteristics of the Mountainous Runoff and Its driving Forces in the Upper Reaches of the Taolaihe River during 1961-2010

Responses of water resources to climate change in arid regions are important for sustainable development of society, economy and ecological environment. Based on the annual mountainous runoff data measured by Binggou hydrological station of the Taolaihe River during 1961-2010, along with the monthly mean temperature and total precipitation datasets, the runoff change characteristics were analyzed by using linear tendency, proportional departures, Mann-Kendall mutation test, R/S analysis, complex wavelet transform method. The effect of climate change on runoff was also studied using multiple linear regression models. The results showed that: the intra-annual distribution of the runoff was extremely uneven. The annual runoff was mainly contributed by those occurred from June to October with a proportion of 62.11%. The annual runoff experienced "abundance-wither-abundance-wither" four fluctuations with a significant mutation from high to low in 1984, but it totally represented an insignificantly decreasing trend at a rate of -0.10×10⁸ m³/10a. The Hurst index was 0.67, which indicates that the decreasing trends will last in the near future. The annual runoff had obviously seven oscillations in the time scale of 22 a. According to its periodic regularity, it will be abundant during 2010-2015. The annual mean temperature firstly represented a weakly increasing trend and then quickly increased, while the annual precipitation significantly increased in the recent 50 years. The effect of climate change to the runoff in different periods was variable. The multiple linear regression results revealed that the runoff was closely related with precipitation before 1984. However, temperature, precipitation and evaporation had together become main factor that influenced the runoff variation after 1984. On the other hand, the change of the land cover due to climate change and human activities also impacted on the runoff change to some extent.