Diversion of the paleo‐Yellow River channel in the Qingtongxia area of Ningxia, China: Evidence from terraces and fluvial landforms

2019 ◽  
Vol 55 (11) ◽  
pp. 7285-7303
Author(s):  
Hong Chen ◽  
Guo‐dong Bao ◽  
Wei Shi ◽  
Jian‐min Hu
Keyword(s):  
2011 ◽  
Vol 255-260 ◽  
pp. 3692-3696
Author(s):  
Xiao Lei Zhang ◽  
Dong Po Sun ◽  
Feng Ran Zhang

The 2-D water and sediment mathematical model which reflects silting in floodplain and scouting in main channel of over-bank flooding in the Lower Yellow River has been set up in this paper. Through carrying on 2-D water and sediment numerical simulation of the “96.8” typical flood, the author studied influence of over-bank flooding on flood travel and transverse exchange. The primary simulation results show that, adopting the over-bank flooding for silting in floodplain and scouting in main channel effectively guaranteed and expanded transverse exchange between floodplain and main channel and maintained the river channel vigor. This can relieve “secondary suspended river” states in the Low Yellow River to a certain extent; at the same time, the different magnitudes of over-bank floods have different effect of silting in floodplain and scouting in main channel.


2020 ◽  
Author(s):  
Qiao Shuqing ◽  
Shi Xuefa ◽  
Yonggui Yu ◽  
Limin Hu ◽  
Lin Zhou ◽  
...  

<p>The fluvial sediment to the sea is the base of coastal geomorphology and biogeochemical processes, and its transport is an important pathway to the global biogeochemical cycle. The Yellow River is one of globally well-known large rivers because of high sediment load and Chinese Mother River. Its channel shifts frequently because of high sediment load and steep river-channel gradient in the lower reaches . The terminal channel has shifted more than 50 times since 1855 and the last two changes in 1976 and 1996. Furthermore, Yellow River Conservancy Commission has began to implement Water-Sediment Regulation Scheme (WSRS) since 2002, to increase the main channel discharge capacity and to reduce deposition in the reservoirs and river channel. Surface sediment, multi-core and gravity sediment cores, remote sensing images and bathymetric data near the Yellow River delta were collected to study the impact of WSRS and river terminal change together with the water and sediment discharge at the gauging station. Especially, <sup>7</sup>Be, <sup>210</sup>Pb and <sup>137</sup>Cs, grain size, sediment color and TOC/TN was measured to show sedimentary record of WSRS and channel shift on inter-and intra-annual time scale. The results show that the fresh sediment from Yellow River  during 2014 WSRS period can be transported eastward more than 80 km off the rivermouth, while cannot pass 38° easily. Meanwhile the sediment can penetrate as deep as 12 cm. The subaerial delta area is mostly stable after 2002, and its balance is mainly controlled by the surrounding artificial coastline. The subaqueous delta changed from trapping about 4.6×10<sup>8</sup> t to being eroded ~ 3.1×10<sup>8</sup> t and 1.1×10<sup>8</sup> t each year during the three stages of 1976-1996, 1996-2002 and 2002-2014. It is proposed that the subaerial delta area will change little except for the Q8 outlet area, while the subaqueous delta evolution mostly depend on the Huanghe material besides the hydrodynamic conditions. In addition, the aim of WSRS to scour the lower riverbed will recede in future. This study deepens our understanding of the fluvial sediment disperse pattern and sedimentation under the influence of human activities and hydrodynamic conditions.</p><div>Acknowledgements</div><div> <div>This study was supported by National Programme on Global Change and Air-Sea Interaction (GASI-GEOGE-03) and the Natural Science Foundation of China (U1606401).</div> </div>


1999 ◽  
Vol 11 (3) ◽  
pp. 231-236 ◽  
Author(s):  
ZHANG Zhen-ke ◽  
◽  
WANG Su-min ◽  
SHEN Ji ◽  
XIA Wei-lan ◽  
...  

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1136
Author(s):  
Teng Su ◽  
Heqing Huang ◽  
Yuanyuan Zhou ◽  
Guoan Yu

Dam operation has been widely deployed to mitigate the risks of ice jam flooding, but it may result in a decrease in the discharging capacities of downstream river channels. The Ningxia-Inner Mongolia reach of the Huanghe River (Yellow River) has historically suffered numerous disasters caused by ice jam flooding, and three large dams have been jointly operated to mitigate such risks since 1968. Whilst the resultant significant increases in both the annual runoff and mean water temperature during the ice jam flooding seasons helped to shorten the freezing-up duration and reduce the thickness of the ice cover, a significant channel shrinkage occurred in the reach when the dam operation took place under the input of a relatively larger amount of sediment from the upstream. In the new flow regime that commenced in 2008, a detailed examination of the river channel-form adjustments and the resultant changes to the discharging capacities identified a slight increase in the discharging capacity of the channel along the entire study reach. This was mainly due to a significantly smaller amount of sediment load being carried by a slightly increased annual runoff. Whilst it was demonstrated that the dam operation was still an effective means for mitigating the risk of ice jam flooding in the Ningxia-Inner Mongolia reach under the new flow regime, care needs to be taken when the favorable flow-sediment condition changes. Furthermore, the effectiveness of the dam operation appeared to vary significantly at the channel sections of different planforms; thus, more detailed studies are required.


2021 ◽  
Vol 267 ◽  
pp. 01015
Author(s):  
Wang Huiliang ◽  
Li Hui ◽  
Di Danyang ◽  
Yan Dengmin

Ecological water is the basic condition to maintain river health in a water-deficient basin. The evaluation and spatial distribution of ecological water are significance to the allocation of water resources under the concept of ecological civilization. In this paper, the connotation and composition of value of ecological water are defined from the perspective of ecosystem material circulation. Based on the emergy theory, the quantitative methods of different types of ecological water value are proposed. Combined with the spatial autocorrelation analysis method, the analysis method of spatial distribution and aggregation characteristics of watershed ecological water value is established. We took the Yellow River Basin as an example, and estimated and analysed its ecological water value and the spatial distribution characteristics according to the 9 regions of basin. The results showed that: In the Yellow River Basin, the single water value of the ecological water in the river channel is 17.45-24.36 yuan, the single water value of the sediment transport water is 2.42-7.28 yuan, and the single water value of the ecological water outside the river channel is 10.87-16.61 yuan. Ecological water value presents obvious difference in the space. Both outside and inside the river course, the high concentration areas of ecological water value are in the middle and lower reaches, while the low concentration areas are in the lower reaches, which indicates that we should consolidate the ecological water value in the middle and lower reaches and enhance the water value in the upper reaches. The research results have guiding significance for the allocation of ecological water in each province and region.


2021 ◽  
Vol 66 (23) ◽  
pp. 3059-3070
Author(s):  
Xiao Wu ◽  
Yongyong Fan ◽  
Houjie Wang ◽  
Naishuang Bi ◽  
Zuosheng Yang ◽  
...  

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