黑河流域上游水沙变化特征及成因分析

目的]研究黑河流域上游干流的水沙时空变化特征及其成因,为流域生态保护和水资源开发利用提供科学依据。方法]选取黑河上游干流主要水文站近60a的实测径流、输沙及降雨资料,通过采用Mann-Kendall秩相关检验法、累积距平法和相关分析法,研究水沙变化特征及驱动因子。结果]黑河上游干流径流量总体上从20世纪80年代以后呈增加趋势;输沙量从20世纪70年代开始呈不显著增加趋势,但莺落峡水文站输沙量从2001年开始呈显著下降趋势。结论]降水增加是影响黑河上游径流量增多的重要原因;水土流失导致了札马什克站和祁连站输沙量的增加,而水库拦沙是莺落峡水文站输沙量显著减少的主要原因。

Variations of Runoff and Sediment Load and its Causes in Upper Reaches of Heihe River Basin

Objective] The objective of this study was to analyze the characteristics and causes of the spatial-temporal changes of the annual runoff and annual sediment at the main hydrologic stations on the stem stream of the Heihe River, in order to provide decision basis for the ecological environment protection and water resource utilization.Methods] The runoff, sediment and rainfall data form main hydrologic stations on the stem stream of the Heihe River during 1956 to 2015 were collected. Methods including Mann-Kendall trend test, cumulative anomalies and correlation analysis were applied.Results] The results indicated that the runoff of the upper reaches of Heihe River had an obvious increasing trend from 1956 to 2015, with high flow during the period from the 1980s to the 2000s. Meanwhile, the sediment load was in a slightly increasing trend from 1970s to 2000s, but the sediment load of the Yingluoxia station had an obvious decreasing trend from 2001.Conclusion] The increasing precipitation was one of the main contributions to runoff rise. In addition, the soil erosion caused the increase of the annual sediment load of the Zhamashike and Qilian station. Sediment captured by water reservoir was found to be the major cause of the decrease of sediment load in the Yingluoxia station.