窟野河流域径流演变及其驱动因素分析

以黄土高原典型流域窟野河流域为对象,采用有序聚类方法,诊断了近60 a来实测径流演变的阶段性特征,在此基础上,分析了不同阶段实测径流与气候要素之间的响应关系,初步揭示了径流演变的驱动机制。结果表明：近60 a来窟野河流域实测径流量以1980年和1998年为分割点总体呈现阶段性减少趋势,其中,1999年以来减少尤其明显。不同阶段的年降水、径流关系有一定差异,相比而言,汛期（6-10月份）的月降水量与径流量具有相对较好的相关关系;非汛期（11-5月份）的月降水径流关系点群散乱,在月平均气温低于5℃时,月径流量与月平均气温具有较好的正相关性。窟野河流域汛期产流受高强度降水支配,人类活动对河川径流演变的影响有增大趋势。

Analysis of runoff evolution and factor of driving force in Kuye river catchment

Taking Kuye river catchment as an object and using method of sequential cluster analysis,the paper detected the phase feature of runoff evolution. It then analyzed the response relationship of runoff and climate elements in different phases,and initially revealed the regulation of driving force of runoff evolution. The results indicate that the measured runoff at Wenjiachuan station in Kuye River catchment presented a general decrease trend in recent 60 years with significant changes starting in 1980 and 1998, and decreased clearly since 1999. The relationship between precipitation and runoff of annual scale in different phases has certain difference. The correlation between monthly precipitation and runoff in flood season from June to October is better; but in dry season from November to May,the correlation between monthly precipitation and runoff is random. When the temperature of monthly mean is below 5℃,monthly runoff exponentially correlates to mean temperature. The runoff in flood season is dominated by high intensity rainfall while human activities play a principle role on river runoff evolution.