黄河皇甫川流域水沙关系特性及关键驱动因素

以黄河中游皇甫川流域为研究区,基于1960—2015年的实测日径流和日悬移质输沙量数据,采用双累积曲线法和水沙关系曲线法两种方法,对研究区洪水悬移质泥沙的环路特性进行探究。结果表明:皇甫川流域多年平均径流量为1.11亿m~3,平均输沙量为0.31亿t,均呈显著下降趋势,减少速率分别为0.033 1亿m~3/a和0.0101亿t/a;1979、2003年为水沙系列转折年,表现出明显的阶段特性;多年水沙关系曲线可用幂指数拟合,水沙关系未出现明显偏离;植被恢复和水保工程对流域泥沙减少起到重要作用;典型洪水场次条件下水沙C-Q(Concentration-Discharge)环路表现为顺时针、逆时针、逆"8"字形、正"8"字形和线形5种类型,分别描述了次洪水泥沙输移的不同特征。

Study on characteristics of water-sediment relationship and key influencing factors in Huangfuchuan Watershed of Yellow River

Double mass curve(DMC)method and rating curve method were applied to explore the loop characteristics of the suspended sediment concentration based on measured daily discharge and suspended sediment runoff from 1960 to 2015 of Huangfuchuan Basin in the midstream of the Yellow River. The results show that the average annual runoff and the mean sediment runoff was 111 million m³ and 31 million tons respectively. Significant reduction tendency was revealed with a reduction rate of 0. 0331 billion m³/a and 0. 0101 billion t/a, respectively. 1979 and 2003 were two turning years, exhibiting distinct phase characteristics. In addition, the rating curve can be fitted with a power exponent function and the relation between discharge and sediment does not show significant deviation. Vegetation recovery together with soil and water conservation projects play an important role in sediment reduction. Finally, there are 5 patterns of Concentration-Discharge(C-Q)relation loops for typical hydrological events, including clockwise, counterclockwise, figure-eight, reverse figure-eight and linear loops, which describe different sediment transport features during a flood.