Experimental study of sediment transport processes and size selectivity of eroded sediment on steep Pisha sandstone slopes

2020 ◽  
Author(s):  
Pan Zhang ◽  
Pingqing Xiao ◽  
Chunxia Yang
Keyword(s):  
Sediment Transport ◽  
Flow Velocity ◽  
Overland Flow ◽  
Yellow River ◽  
Transport Processes ◽  
The Yellow River ◽  
Size Selectivity ◽  
Coarse Sediment ◽  
Sediment Particles ◽  
Slope Flow

<p>The Pisha sandstone area on the Ordos Plateau of China is the primary source of coarse sediment of the Yellow River. Sediment size distribution and selectivity greatly affect sediment transport and deposition. Hence, sediment transport processes and size selectivity by overland flow on Pisha sandstone slopes were investigated in this study. Experiments were run with Pisha sandstone soil (bulk density of 1.35 g/cm<sup>3</sup>) under rainfall intensities of 87 and 133 mm/h with a 25° slope gradient, and the duration of simulated rainfall is 1 h. Sediment and runoff were sampled at 2-min intervals to examine the size distribution change of the eroded sediment. The particle composition, enrichment rate, fractal dimension, and time distribution characteristics of median grain size (d<sub>50</sub>) of eroded sediment were comprehensively analyzed. Statistical analyses showed that the erosion process of Pisha sandstone slope mainly transported coarse sediment. More than 40% of eroded sediment particles were coarse sediment, which will become the main sediment in the lower reaches of the Yellow River bed. The particle size of eroded sediment tended to gradually decrease with the continuous rainfall but remained larger than the background value of Pisha sandstone soil after refinement. The fractal dimension was positively correlated with the slope flow velocity, while the d<sub>50</sub> was negatively correlated with the slope flow velocity. Overall, these findings show a strong relationship between the sediment transport and flow velocity, which indicates that the selectivity and transportation of sediment particles on the Pisha sand slopes is mainly influenced by the hydrodynamic parameters of overland flow. This study provides a methodology and data references for studying the particle selectivity characteristics of eroded sediment and provides a scientific basis for revealing the mechanism of erosion and sediment yield in the Pisha sandstone area of China.</p>

Particle-size distribution of transported sediment in the Pisha sandstone slope under the influence of complex erosion

2021 ◽  
Author(s):  
Pan Zhang ◽  
pingqing Xiao
Keyword(s):  
Particle Size ◽  
Water Conservation ◽  
Yellow River ◽  
Water Erosion ◽  
The Yellow River ◽  
Erosion Process ◽  
Coarse Sediment ◽  
Combined Action ◽  
Sediment Particles ◽  
Soil And Water

<p>Coarse sediment of the Yellow River in the complex erosion area of the Pisha sandstone region of the Ordos Plateau is deposited on the downstream riverbed, posing a threat to the flood control safety of the river. The study of sediment particles in this erosion process can deepen the understanding of the erosion process, provide a theoretical basis for the establishment of an erosion prediction model, reveal the internal law of composite erosion, and guide the planning and design of soil and water conservation and the allocation of soil and water conservation measures. In this study, complex erosion indoor tests were carried out through the artificial rainfall-wind-freezing-thawing cycle solid model. The enrichment rate (ER), fractal dimension, and median diameter (d<sub>50</sub>) of soil particles were used to quantify the size distribution characteristics of sediment particles under different erosion dynamics. The coarse sediment was first transported in the process of soil erosion because of the special texture and terrain characteristics of Pisha sandstone soil. Moreover, the degree of heterogeneity of sediment under complex erosion was larger than that under water erosion. The effect of wind could aggravate the instability of the erosion dynamic system. Under the combined action of freezing-thawing, wind, and water, the particle size composition changed greatly, and the erosion energy was extremely unstable. The effect of complex erosion created conditions for the coarse sediment transportation. Under the freezing-thawing-wind-water combined action, the particle size of eroded sediment was the coarsest, and that of water erosion was the smallest. We concluded that the reason why the Pisha sandstone area has become the core area of the concentrated source of coarse sediment in the Yellow River is related not only to the special nature of the Pisha sandstone soil itself but also to the effect of complex erosion.</p>

scholarly journals Sediment Variation Characteristics of Major Rivers in the Middle Reaches of the Yellow River

2021 ◽  
Vol 5 (5) ◽  
pp. 20-26
Author(s):  
Yaxi Cai ◽  
Xiaodong Yang
Keyword(s):  
Sequence Analysis ◽  
Sediment Transport ◽  
River Basin ◽  
Yellow River ◽  
The Yellow River ◽  
Sediment Discharge ◽  
Variation Characteristics ◽  
Major River ◽  
Kendall Method ◽  
Hydrological Station

The sediment sequence analysis of Mann-Kendall method based on major rivers of 10 hydrological station in the middle reaches of the Yellow River [1]. The results show that: The main rivers in the middle reaches of the Yellow River hydrologic station sediment overall showed a trend of decreased significantly. Sediment discharge of all stations except Gao Jiachuan station have reached the maximum in 1956-1969s [2-3]. Among various hydrologic station sediment discharge of inter-generational are generally shows the tendency of reducing year by year. Calculate the sediment transport of major river basin of Yellow River, which average is 0.63.

The Analysis on the Effect of Silt Arrester System Construction in Small Watershed Runoff Sediment and the Evaluation of the Ecological Environment

2012 ◽  
Vol 518-523 ◽  
pp. 4782-4785
Author(s):  
An Li Ma ◽  
Bao Ku Yin
Keyword(s):  
Sediment Transport ◽  
Yellow River ◽  
Monitoring And Evaluation ◽  
Shanxi Province ◽  
Ecological Environment ◽  
The Yellow River ◽  
System Construction ◽  
Small Watershed ◽  
Monitoring Method ◽  
Small Watersheds

The monitoring and evaluation on silt arrester system of small watersheds involves monitoring indicators, data collection, analysis and evaluation etc. The Yellow River Water Conservancy Committee carried out a "small watersheds of the Loess Plateau model project" from 2005 to 2010 in the Yellow River sandy area. The project has 12 small watershed silt arresters, one of which is in Yonghe county of Shanxi province. This article takes the work of sediment transport monitoring in Yonghe silt arrester system as an example and describes the monitoring method, content, and finally analyzes the influence of silt arrester system construction and sediment transport on ecological environment.

scholarly journals Sediment transport under increasing anthropogenic stress: Regime shifts within the Yellow River, China

AMBIO ◽  
2020 ◽  
Vol 49 (12) ◽  
pp. 2015-2025
Author(s):  
Shuang Song ◽  
Shuai Wang ◽  
Bojie Fu ◽  
Yanxu Liu ◽  
Kevin Wang ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Yellow River ◽  
Regime Shifts ◽  
The Yellow River ◽  
Anthropogenic Stress ◽  
Stress Regime

scholarly journals Study on the influence of vegetation change on runoff generation mechanism in the Loess Plateau, China

2020 ◽  
Author(s):  
Xueli Zhang ◽  
Yue Yu ◽  
CaiHong Hu ◽  
Jianhua Ping
Keyword(s):  
Loess Plateau ◽  
Vegetation Change ◽  
Overland Flow ◽  
Yellow River ◽  
Generation Mechanism ◽  
Underlying Surface ◽  
The Yellow River ◽  
Runoff Generation ◽  
The Loess Plateau ◽  
Related Factors

Abstract In recent years, the amount of water and sediment in the Yellow River Basin has dropped drastically. This paper selected 125 rainfall and flood data points from 1965 to 2015, combined hydrological methods and mathematical statistics to analyze the hydrological factors and runoff generation mechanism, and combined the underlying surface conditions of the Gushanchuan Basin. The characteristics of change revealed the temporal and spatial variation characteristics and related factors of the runoff generation mechanism in the basin. The results showed that the Gushanchuan Basin is still dominated by HOF runoff, but the runoff generation mechanism also has changed with changes in the underlying surface, which are reflected in increased runoff components, the reduced proportion of HOF runoff, and the increased proportion of saturation-excess overland flow (SOF) runoff and mixed runoff. We analyzed the variation law of underlying surface in the basin, which indicated that the increase in the forest grass area was the main factor affecting changes in the watershed runoff generation mechanism. This research will enable a deeper understanding of the runoff generation mechanism of the main soil erosion areas in the Loess Plateau, reveal variations in the runoff generation mechanism in the Yellow River.

scholarly journals MODELING SEDIMENT TRANSPORT IN THE YELLOW RIVER MOUTH

2011 ◽  
Vol 1 (32) ◽  
pp. 13
Author(s):  
Haibo Zong ◽  
Pingxing Ding ◽  
Fengyan Shi
Keyword(s):  
Sediment Transport ◽  
Yellow River ◽  
Sediment Resuspension ◽  
River Mouth ◽  
Sediment Concentration ◽  
The Yellow River ◽  
Numerical Studies ◽  
Wave Effects ◽  
Coastal Sediment Transport ◽  
Yellow River Mouth

Yellow River is famous for its high sediment concentration, which carries a huge amount of sediment into Bohai Sea during the flood season. In the mouth of Yellow River, the suspended sediment concentration (here after: SSC) are relatively high and the average depth is generally shallow. Recent studies indicated that in the shallow and micro-tide area, wave usually is a primary mechanism for bottom sediment resuspension. Most numerical studies of sediment transport in the Yellow River mouth didn't include the wave effects. To analyze the sediment transport in the Yellow River mouth with wave effect, a Coastal Sediment Transport Modeling System (CSTMS) was applied in this study.

scholarly journals Seasonal Variations in Dissolved Organic Carbon in the Source Region of the Yellow River on the Tibetan Plateau

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2901
Author(s):  
Xiaoni You ◽  
Xiangying Li
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Yellow River ◽  
Source Region ◽  
Precipitation Amount ◽  
Transport Processes ◽  
The Yellow River ◽  
Deposition Flux ◽  
The Tibetan Plateau ◽  
Permafrost Degradation

Rivers as the link between terrestrial ecosystems and oceans have been demonstrated to transport a large amount of dissolved organic carbon (DOC) to downstream ecosystems. In the source region of the Yellow River (SRYR), climate warming has resulted in the rapid retreat of glaciers and permafrost, which has raised discussion on whether DOC production will increase significantly. Here, we present three-year data of DOC concentrations in river water and precipitation, explore the deposition and transport processes of DOC from SRYR. Results show that annual mean concentrations of riverine DOC ranged from 2.03 to 2.34 mg/L, with an average of 2.21 mg/L. Its seasonal variation is characterized by the highest concentration in spring and summer (2.65 mg/L and 2.62 mg/L, respectively), followed by autumn (1.95 mg/L), and the lowest in winter (1.44 mg/L), which is closely related to changes in river runoff under the influence of precipitation and temperature. The average concentration of DOC in precipitation (2.18 mg/L) is comparable with riverine DOC, while the value is inversely related to precipitation amount and is considered to be the result of precipitation dilution. DOC deposition flux in precipitation that is affected by both precipitation amount and DOC concentration roughly was 86,080, 105,804, and 73,072 tons/yr from 2013 to 2015, respectively. DOC flux delivered by the river ranged from 24,629 to 37,539 tons/yr and was dominated by river discharge. Although permafrost degradation in SRYR is increasing, DOC yield is not as significant as previously assumed and is much less than other large rivers in the world.

scholarly journals Response of the parameters of excess infiltration and excess storage model to land use cover change

2020 ◽  
Vol 68 (2) ◽  
pp. 99-110 ◽  
Author(s):  
Yuexiu Wen ◽  
Caihong Hu ◽  
Guodong Zhang ◽  
Shengqi Jian
Keyword(s):  
Land Use ◽  
Overland Flow ◽  
Yellow River ◽  
The Yellow River ◽  
Model Parameters ◽  
Runoff Generation ◽  
The Loess Plateau ◽  
Infiltration Capacity ◽  
Infiltration Excess ◽  
Generation Mechanisms

AbstractThe Loess Plateau is the main source of water in Yellow River, China. After 1980s, the Yellow river water presented a significant reduction, what caused the decrease of the Yellow river discharge had been debated in academic circles. We proceeded with runoff generation mechanisms to explain this phenomenon. We built saturation excess runoff and infiltration excess runoff generation mechanisms for rainfall–runoff simulation in Jingle sub-basin of Fen River basin on the Loess Plateau, to reveal the influence of land use change on flood processes and studied the changes of model parameters under different underlying conditions. The results showed that the runoff generation mechanism was mainly infiltration-excess overland flow, but the flood events of saturation-excess overland flow had an increasing trend because of land use cover change (the increase of forestland and grassland areas and the reduction of cultivated land). Some of the model parameters had physical significances，such as water storage capacity (WM), infiltration capacity (f), evapotranspiration (CKE), soil permeability coefficient (k) and index of storage capacity distribution curve (n) showed increasing trends, and index of infiltration capacity distribution curve (m) showed a decreasing trend. The above results proved the changes of runoff generation mechanism from the perspective of model parameters in Jingle sub-basin, which can provide a new perspective for understanding the discharge reduction in the Yellow River basin.

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