1956-2010年新疆焉耆盆地径流变化特征及驱动力分析

Analyzing the variation and driving forces of the runoff in Yanqi Basin,Xinjiang during 1956-2010

根据新疆焉耆盆地3个水文站1956-2010年的月径流量监测数据,应用不均匀系数、集中度、变化幅度等指标,分析了近55 a来焉耆盆地融雪径流的变化规律,并采用主成分分析法讨论了径流变化的驱动机理.结果表明:焉耆盆地的年径流量呈"减少-增加-减少"的变化趋势;总体上,1956-1986年间呈缓慢减少趋势,1987-2002年间出现呈显著增加趋势,2003-2010年间呈显著减少趋势;径流主要集中在夏季,春季径流量最少.随着时间的推移,开都河与黄水沟径流年内分配不均匀性与径流年内分配集中度减小,清水河径流年内分配不均匀性与径流年内分配集中度增加;开都河、黄水沟与清水河径流年内分配绝对变化幅度总体上随时间增加而呈先减小后增加的趋势,相对变化幅度随时间增加而减小.焉耆盆地径流变化的影响因素可以归纳为农业活动、气象因素与人口增加等.

The variation of monthly runoff in Yanqi Basin was studied based on the observations of three key hydrological control stations from 1956 to 2010 and by using indexes such as non-uniformity coefficient, concentration degree and variation amplitude. The driving forces of runoff variation were also analyzed by using principal component analysis. The study found that： 1 ） The changing trend of annual runoff in Yanqi Basin was＂ de- crease-increase-decrease＂, as a whole. It decreased slowly during 1956 - 1986, increased remarkably during 1987 -2002, and then decreased remarkably during 2003 -2010; stream flow concentrated mainly in summer; 2） As time went on, the non-uniformity and concentration degree of annual runoff of the Kaidu River and the Huangshui River were decreasing, while the non-uniformity and concentration degree of annual runoff of the Qingshui River were increasing; 3 ） The absolutely variation amplitude of annual runoff of the Kaidu River, Huangshui River and Qingshui River increased first, then decreased, while the relatively variation amplitude of annual runoff decreased with the time; 4） Agricultural activities, meteorological factors and population increase were the driving forces of runoff variation in Yanqi Basin.