丹江流域水沙变化特征分析

丹江流域是南水北调中线工程重要水源地，近年来受多种因素影响，径流泥沙情况发生了很大变化，准确把握其变化趋势对水资源管理及水土保持工作意义重大。该文基于荆紫关水文站1958～2015年径流和悬移质输沙量资料，运用Mann-Kendall 检验法、距平累积法、滑动t检验法以及双累积曲线法，阐明了丹江流域近60年径流量和悬移质输沙量变化特征，定量分析了各影响因素在径流泥沙变化中的作用。结果表明：丹江流域径流量与悬移质输沙量年际变化大，呈显著下降趋势，1958～1972、1982～1989年为丰水丰沙期，1972～1981年与1990～2015年处于枯水枯沙期，径流量和悬移质输沙量分别在1983年与1989年发生突变。人为因素和降水的贡献率分别为58.8%和41.2%，说明人为因素特别是水利水土保持工程是引起丹江流域输沙变化的主要因素。

Characteristics Analysis of Runoff and Sediment Variation in Danjiang River Watershed

Danjiang River basin is the important water source of south-to-north water transfer project. Affected by various factors, the runoff discharge and sediment load have changed greatly in recent years. Understanding the discharge and sediment variation is great significance for water resource management and soil and water conservation policy implementation. Based on the runoff and suspended load sediment discharge data during the 1958-2015 periods in Jingziguan hydrological station, runoff and suspended load sediment discharge variation characteristics were studied by using of the non-parametric Mann-Kendall trend test, sliding t test. The occurrence of abrupt changes was detected using double mass curve method. The controlling factors of runoff and suspended load sediment discharge were also identified in this paper. The trend test results represent that the annual runoff and sediment load have decreased significantly. It was in a period of rich runoff and rich sediment before 1972 and from 1982 to 1989, and in a period of low runoff and low sediment from 1972 to 1981 and from 1990 to 2015. The abrupt change years of runoff and sediment were in 1983 and 1989 respectively. We used quantitative method to separate out the effects of climate change (rainfall) and human activities on changes in runoff and sediment discharge. Climate change was estimated to account for 41.2%, whereas human activities accounted for 58.8%. Human activities appear to have played a more prominent role compared to rainfall (climate change) to suspended load sediment discharge.