College of Energy and Power Engineering, Lanzhou University of Technology, 287 Langongping Road, Lanzhou, Gansu Province, China.
Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, Gansu Province, China.
Environ Sci Pollut Res Int. 2019 May;26(14):13702-13716. doi: 10.1007/s11356-018-2096-x. Epub 2018 May 25.
For many event-based, high-sediment yield rivers draining arid zones, where erosion activities in the watershed and fluvial erosion in the stream channel are nearly equally important in sediment transport, determination of fluvial sediment dynamics are of great importance in establishing reliable strategies to manage environmental changes in watershed scale. Wash load rating curve indicating watershed characteristic changes and Ackers and White's bed load function (wash load excluded) used for determining bed load transport dynamics are distinguished for the first time to recognize the true sediment transport mode in the lower Huangshui River, which is the largest tributary of the upper Yellow River, contributing a lot to the wash load of the Inner Mongolia desert reach of the Yellow River and causing complicated water-sediment response. Based on the continuous and detailed hydrological data monitored at the Minhe gauge station, our results indicated that the sediment transport regime has altered since the 1980s in response to the eco-environmental changes mainly due to urbanization, with suspended sediment concentration (SSC) decreased by 50% on average compared with the natural state (1950-1980). The combined use of wash load rating curve and theoretical bed load function derived an estimate of total sediment transport due to comprehensive ecological management since the 2000s to be 3.43 × 107 t for the lower Huangshui River, among which the total bed load is 1.40 × 107 t, and the wash load is 2.03 × 107 t. The transport ratio of wash load to total bed load is 1.45:1.
对于许多以事件为基础、高泥沙产率的干旱区河流，流域侵蚀活动和河道冲刷在输沙中几乎同等重要，因此，确定河道泥沙动力学对于在流域尺度上建立可靠的环境变化管理策略非常重要。冲刷负荷率曲线指示流域特征变化，Ackers 和 White 的推移质函数（排除冲刷负荷）用于确定推移质输移动力学，首次用于识别黄河最大支流湟水下游的真实输沙模式，该模式对黄河内蒙古沙漠段的冲刷负荷有很大贡献，并导致复杂的水沙响应。基于民和测站连续、详细的水文数据，我们的结果表明，自 20 世纪 80 年代以来，由于城市化等生态环境变化，输沙机制发生了变化，与自然状态（1950-1980 年）相比，悬浮质浓度（SSC）平均下降了 50%。冲刷负荷率曲线和理论推移质函数的综合使用，估计了 2000 年代以来综合生态管理导致的湟水下游总输沙量为 3.43×107t，其中总推移质为 1.40×107t，冲刷负荷为 2.03×107t。冲刷负荷与总推移质的输送比为 1.45:1。
