Collapses on the riverbank: what happened to the Lower Yellow River?

Author(s):  
Lu Gao ◽  
Xiangzhou Xu

<p>Riverbank collapses frequently occur in the lower reaches of the Yellow River, China, which result in a great loss of farmland and significant hydro-morphological evolution in the channel. A combination of field investigation and remote sensing analysis was conducted to understand the current status of riverbank collapse in the Shandong Reaches of the lower Yellow River. The results show that the planar failure and upward-concave collapse were the main types of river failures in these reaches. Taking the Jiyang section as an example, the average lateral dynamic displacements in the Jiyang section were 2.8 and 11.4 m, the retreat areas were 248.8 and 835.0 m<sup>2</sup> and the maximum lateral dynamic displacement were 7.4 and 26.0 m during the periods 3/31/2016-4/18/2017 and 04/18/2017-5/10/2018, respectively. Factors such as the soil properties, upstream river-control works, and channel bends may change the probability of downstream riverbank collapse. Building materials that are effective, low-cost and environmental friendly, and easy to use, are anticipated in the river management projects to protect the riverbanks and improve the ecological environment in the study area.</p>

2021 ◽  
Author(s):  
Lu Gao ◽  
Xiangzhou Xu ◽  
Ying Zhao ◽  
Paolo Tarolli

<p><strong>Abstract</strong>: Riverbank collapses frequently occur in the lower reaches of the Yellow River, China, which cause environmental changes around the riverbanks and result in a great loss of farmland. An analysis was carried out to understand the riverbanks of the Jiyang Reach via Google Earth. The results show that the three representative segments in the Jiyang Reach, the maximum annual-lateral displacement and average retreat area were 26.0 m/a and 1083.8 m<sup>2</sup> during the period 3/31/2016–5/10/2018, respectively. Several factors such as the soil properties, upstream river-control works, bridge piers, and channel bends may change the river flow direction and the scour intensity, thereby increasing the probability of downstream riverbank collapse, which are all causes of riverbanks collapse in the lower Yellow River. Field investigation and research data show that the lower reaches of the Yellow have serious bank-collapse disasters and their riverbanks are still in an unstable state.</p><p><strong>keywords:</strong> Riverbank collapse; Yellow River; Channel evolution; Riverbank protection</p>


2015 ◽  
Vol 14 (8) ◽  
pp. 1933-1939
Author(s):  
Xianqi Zhang ◽  
Weiwei Han ◽  
Xiaofei Peng ◽  
Cundong Xu

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 338
Author(s):  
Chuanshun Zhi ◽  
Wengeng Cao ◽  
Zhen Wang ◽  
Zeyan Li

High–arsenic (As) groundwater poses a serious threat to human health. The upper and middle reaches of the Yellow River are well–known areas for the enrichment of high–arsenic groundwater. However, little is known about the distribution characteristics and formation mechanism of high-As groundwater in the lower reach of the Yellow River. There were 203 groundwater samples collected in different groundwater systems of the lower Yellow River for the exploration of its hydrogeochemical characteristics. Results showed that more than 20% of the samples have arsenic concentrations exceeding 10 μg/L. The high-As groundwater was mainly distributed in Late Pleistocene–Holocene aquifers, and the As concentrations in the paleochannels systems (C2 and C4) were significantly higher than that of the paleointerfluve system (C3) and modern Yellow River affected system (C5). The high-As groundwater is characterized by high Fe2+ and NH4+ and low Eh and NO3−, indicating that reductive dissolution of the As–bearing iron oxides is probably the main cause of As release. The arsenic concentrations strikingly showed an increasing tendency as the HCO3− proportion increases, suggesting that HCO3− competitive adsorption may facilitate As mobilization, too. In addition, a Gibbs diagram showed that the evaporation of groundwater could be another significant hydrogeochemical processes, except for the water–rock interaction in the study area. Different sources of aquifer medium and sedimentary structure may be the main reasons for the significant zonation of the As spatial distribution in the lower Yellow River.


2021 ◽  
Vol 316 ◽  
pp. 107468
Author(s):  
Zhigang Sun ◽  
Shiji Li ◽  
Kangying Zhu ◽  
Ting Yang ◽  
Changxiu Shao

2017 ◽  
Vol 42 (13) ◽  
pp. 1952-1962 ◽  
Author(s):  
Jie Li ◽  
Junqiang Xia ◽  
Meirong Zhou ◽  
Shanshan Deng ◽  
Xiaolei Zhang

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 712
Author(s):  
Kaifeng Li ◽  
Wenhua Gao ◽  
Li Wu ◽  
Hainan Hu ◽  
Panpan Gong ◽  
...  

Obvious spatial expansion of human settlement occurred in the lower Yellow River floodplain during the Longshan period, but the external factors driving this expansion remain unclear. In this study, we first delineated the hydroclimatic changes at both regional and local scales within and around the lower Yellow River floodplain and then examined the relationships of human settlements with hydroclimatic settings between the pre-Longshan and Longshan periods. The results indicate that the site distribution, site density and hydroclimatic conditions exhibited significant shifts during the pre-Longshan and Longshan periods. In the pre-Longshan period, the intense East Asian summer monsoon and abundant monsoon-related precipitation caused widespread development of lakes and marshes in the lower Yellow River floodplain. As a result, the circumjacent highlands of the lower Yellow River floodplain contained concentrated human settlements. However, the persistent weakening of the East Asian summer monsoon and consequent precipitation decline, in conjunction with accelerated soil erosion due to decreasing forest vegetation and strengthening of human activities on the upstream Loess Plateau in the Longshan period, are likely to have jointly caused both shrinking and faster filling of preexisting lakes and marshes. Subsequently, a large area of arable land had been created in the lower Yellow River floodplain and thus was occupied by locally rapid increasing population, resulting in the notable spatial expansion of human settlements during the Longshan period.


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