利用黄河高寒区吉迈(达日县)水文站、国家气象局达日、玛多观测站1959—2007年,共计49 a水文、气象及部分冻土监测资料,采用峰型度及丰枯率指数、Mann-Kendall时间序列突变点及趋势检验方法、小波分析法、灰色关联分析等统计方法,分析径流年际、年内变化特征,探讨径流长期变化主要影响因素,并建立核主成分支持向量机(KPCA-LSSVM)预测模型,对未来2011—2014年径流情势进行分析。结果表明,由于区域气候、下垫面条件变化及人为因素影响,不同时期作用于水资源的主导因素存在差异,径流时间序列存在明显突变点,为1961、1999和2005年;黄河源区径流2002—2006年间存在不显著减少趋势,小波分析表明未来3~9 a内,年径流量将略高于1990—2007年间的平均值;1983年后冻结期气温升高,季节性冻土退化较为明显,对于径流的补给减少,是地区河道水资源减少的原因之一;模型预测结果显示,由于降水对于径流的延迟作用和气温升高引起冻融关系变化等原因,2011—2014年水源区河川径流量与多年平均值相比减少25.3%。

In this paper, time series of 49 years monthly runoff, temperature, precipitation and part of the permafrost monitoring data recorded at Jimai control hydrometrical station and Maduo and Dari weather stations in the upper Yellow River high cold region were studied. The annual variation, interannual variation, main influencing factors of river water resources, were investigated using peak pattern analytical method, rate change of wetness-dryness analytical method, Mann-Kendall test, wavelet analysis and grey relational analysis, etc. The river water resources regime in 2008-2014 were obtained by Kernel Principle Component Analysis and Least Square-Support Vector Machines prediction model. The results showed that river runoff demonstrates obvious evolutionary characteristics, the year 1961 is the first catastrophe point at which the runoff begins an upward tendency, it begins to reduce after 1982, until 1999 the second catastrophe point which brought a significantly downward tendency. The results of wavelet analysis and the trend prediction analyses show that the hydrological regime in this area will be little more than the 1990s which will last 3-9 years; after 1986, the maximum seasonal frozen depth reduced, which exacerbated the total annual runoff reduction in upper Yellow River. The prediction results indicate that the river water resources in 2011-2014 will reduce by 25.3% the annual average water resources.