Multiscale temporal variability of flow-sediment relationships during the 1950s-2014 in the Loess Plateau, China
Multiscale temporal variability of flow-sediment relationships during the 1950s-2014 in the Loess Plateau, China
复制标题
1950-2014年中国黄土高原流量-泥沙关系的多尺度时间变化
DOI：
10.1016/j.jhydrol.2018.06.044
复制
发表时间：
2018
影响因子：
6.4
通讯作者：
Sivapalan Murugesu
中科院分区：
文献类型：
--
作者：
Gao Guangyao;Fu Bojie;Zhang Jianjun;Ma Ying;Sivapalan Murugesu
水流-沉积物关系提供了对集水区内物质侵蚀和运输的深入了解。调查跨多个时间尺度的水沙关系可以揭示与自然和人为变化对集水区的影响有关的趋势。选取黄河主要泥沙来源地黄土高原14个主要流域，提取1950 -2014年的水沙关系时间格局。该研究揭示了土地利用/覆盖变化（LUCC）对水流-沉积物关系变化的可量化影响。1970-1999年水土保持措施和2000年以来的植被恢复活动导致的LUCC导致年径流量、产沙量和含沙量显著减少。不同水流条件下的日均含沙量也有较大幅度的降低。水沙关系揭示了不同阶段和时间尺度的时间依赖性。2000年以前，年、月水沙关系基本上可以用线性函数来描述，日水沙关系可以用幂律的泥沙关系曲线来描述。随着植被恢复的进行，水沙关系逐渐减弱，难以用一个清晰的关系来描述。这表明整个时期水沙关系的变异性主要受到植被恢复活动的调节。此外，泥沙浓度表现出线性减少的关系，在土地利用/覆盖处理的面积。通过这种方式，本研究揭示了生态恢复措施在控制流域水沙关系时间变异中的作用。
Flow-sediment relationships provide insights into the erosion and transport of materials within catchments. Investigating the flow-sediment relationships across multiple timescales can reveal trends related to the effects of natural and human-caused changes to catchments. This study chose fourteen main catchments in the Loess Plateau of China, which are the major sediment sources of Yellow River, to extract the temporal patterns of flow-sediment relationships during the 1950s–2014 period. The study revealed quantifiable effects of land use/cover changes (LUCC) on the variability of flow-sediment relationships. The LUCC induced by the soil and water conservation measures (SWCMs) during 1970–1999 and vegetation restoration campaign since 2000 resulted in significant reductions of annual streamflow, sediment yield and sediment concentration. The mean daily sediment concentration under different flow conditions also decreased greatly. The flow-sediment relationships revealed time dependence over different stages and time scales. Before 2000, the annual and monthly flow-sediment relationships could be generally characterized by the linear functions, and the power-law sediment rating curve was able to describe the daily flow-sediment relationship. As vegetation restoration campaign took effect, the flow-sediment relationship became much weaker, which could not be described by a clear relationship. This suggests that the variability of flow-sediment relationships over the entire period was mainly regulated by the vegetation restoration campaign. In addition, the sediment concentration exhibited a linear decreasing relationship with the area under land use/cover treatment. In this way, the study has brought out the roles of ecological restoration measures in controlling the temporal variability of flow-sediment relationships at the catchment scale.