Driving forces of changes in the water and sediment relationship in the Yellow River

Abstract

The world is composed of various river basins. Within a specific river basin, water and sediment dynamics, and the relationship between them, can be assessed to reflect the basin's functions and services. Due to its changing nature, understanding and balancing the relationship between water and sediment is a global concern and is crucial for the sustainable management of river basins, especially for the Yellow River (YR), which is one of the most sediment-laden rivers in the world. Here, we used the past 60years of runoff and sediment load observations to investigate the middle reach of the YR, i.e., the Loess Plateau (LP), the source of nearly 90% of the sediment load of the river. We found that a sharp (58%) reduction of sediment after 1979 was mainly (59%) caused by a water yield decrease. Engineering and vegetation measures have induced land surface modifications, which are responsible for 76% of the water reduction. These measures have been implemented as part of a coordinated set of soil and water conservation, and sediment control polices. We propose the cessation of such construction and the maintenance of a sustainable (i.e., minimal water consumption) vegetated ecosystem on the LP for soil conservation, and the establishment of an integrated basin-wide ecosystem and land use management regime for sustainable water use and sediment regulation.

Using sediment rating parameters to evaluate the changes in sediment transport regimes in the middle Yellow River basin, China

“…A similar conclusion was drawn by Fan, Shi, Zhou, and Shao (), who studied the nearby Ningxia–Inner Mongolia reaches of the Yellow River. The above two studies, however, contradict the findings by Wang et al (), who found that the temporal change in the streamflow–SSC relationship was remarkable for the main channel of MYRB. Such inconsistency suggests that the changes in sediment transport regimes could vary among different watersheds because of the various landforms and watershed characteristics over the MYRB, which needs be evaluated comprehensively.…”

“…The sediment transport regime in a watershed may change over time for both natural and anthropogenic causes, as the MYRB demonstrated in the last few decades. Sediment transport regimes in the MYRB have been investigated in previous studies (Rustomji, Zhang, Hairsine, Zhang, & Zhao, ; Wang, Fu, Liang, Liu, & Wang, ; Zhao et al, ). However, no consensus exists on how sediment transport regimes may change in a scenario of decreasing streamflow and sediment load.…”

Evaluating spatial variation of suspended sediment rating curves in the middle Yellow River basin, China

“…Another limitation of this study is the exclusion of spatial heterogeneity for the distribution of check dams when analysing the spatial variation of SRCs. According to Wang, Fu, Liang, Liu, and Wang (), 59% of the sediment load reduction in the middle YRB was attributed to a decrease in water yield, which was mainly caused by human‐induced land surface modifications, including the construction of check dams. The locations of check dams are highly nonuniform, with nearly 90% located in the Hekou‐Longmen section and the upper catchments of the Beiluo River (Liu, Gao, Ma, & Dong, ).…”

The Changing Relationship Between Rainfall and Surface Runoff on the Loess Plateau, China

“…The Loess Plateau, which has suffered from severe water and soil erosion (Fu, 1989), has been the focus of unprecedented large‐scale soil conservation measures, such as returning farmland to forests and grass planting since 1999 (Wang et al, 2017). Although erosion has been well controlled by these measures, water discharge in most parts of the plateau has declined significantly in recent years (Gao et al, 2016; Miao et al, 2010; Wang et al, 2017; Zhao et al, 2017; Zheng et al, 2019). Many studies have explored changes or variability of runoff and precipitation for watersheds of the plateau after implementation of the soil conservation measures.…”