Study on Drag Reduction of Suspended Flow with Extra Fine Sediment

2010 ◽  
Vol 439-440 ◽  
pp. 1567-1571
Author(s):  
Chang Jun Zhu

In view of the abnormal phenomenon that a flood peak increased in August 2004 and July 2005 along the lower Yellow River, the mechanism of this abnormal phenomenon is studied. It is found that the flood increase was due to the decrease the channel roughness in the propagation of high concentrated flood carrying the extra fine sediment which was discharged from xiaolangdi reservoir. In view of this, the equation of drag reduction rate is derivated under variable k pattern, and is applied to the reality. The results show that the equation is reliable and has important role in flood control and calculation in water level with hyperconcentration flow. The study of this paper only is a try and discuusion, and need to be improved.

2011 ◽  
Vol 71-78 ◽  
pp. 1318-1323 ◽  
Author(s):  
Qing An Li ◽  
Han Dong Liu ◽  
Yu Kun Zhao

Xiaolangdi Reservoir undertakes 90% of the Yellow River runoff and 100% of sediment discharge. To ensure the long-term utilization of Xiaolangdi reservoir is the key to prevent the flood in the lower reaches of the Yellow River. Take Luokou Hydrologic Station located in the lower reaches of the Yellow River as an example, conduct an analysis from the aspects of sediment retaining of Xiaolangdi Reservoir, scouring and deposition condition of river channel in the lower reaches of the Yellow River, water level performance for years of different flow of ten times’ water-sediment regulation, predict on the sand blocking operation period of Xiaolangdi Reservoir, water level of specific flow of river channel in the lower reaches of the Yellow River and scouring and deposition condition of river channel, which has played a reference role for the flood control in the lower reaches of the Yellow River.


2009 ◽  
Vol 52 (10) ◽  
pp. 2997-3003
Author(s):  
YongSheng Yuan ◽  
JiChun Wu ◽  
YiJun Zuo ◽  
JieRen Chen

2018 ◽  
Vol 246 ◽  
pp. 01045
Author(s):  
Shimin Tian ◽  
Yi Zhao ◽  
Yuanjian Wang ◽  
Enhui Jiang ◽  
Shoubing Yu

The total water amount into the Yellow River estuary is significantly reduced with the construction of a series of reservoirs in the Yellow River, which has a lot of adversely effects on the fishes and fishery resources in the estuary. This research analyzes the impacts of the reservoirs on the runoff and discharge in the Lower Yellow River and the estuary, and pays more attention to the influences of the reduction of water amount on the estuarine ecology and fishes. As a large reservoir nearest to the estuary in the Lower Yellow River, the operation of Xiaolangdi Reservoir plays an important role on the ecological restoration of the lower reaches of the Yellow River and the estuary. Two ecological operation schemes are proposed based on the ecological demands of the estuarine fishes and the actual operation of the Xiaolangdi Reservoir in recent years. One scheme is proposed only on the basis of the estuarine ecological water demands and another scheme takes consideration of ecological water demands and the actual status of the water resources in the Lower Yellow River synthetically. Finally, the feasibility of the two schemes are analyzed according to the actual situation of water storage of the reservoirs in the Yellow River in 2017.


2018 ◽  
Vol 246 ◽  
pp. 01019
Author(s):  
Tao Li ◽  
Jun-hua Zhang ◽  
Guoming Gao ◽  
Huaibao Ma

Sandbar development would stop the water and sediment exchange between main river and tributary and even influence the normal reservoir opeartion. From the surveyed data of reservoir built many years ago, it shows that when there is a bar in tributary mouth, the tributary volume below the bar will become nullification during the period of flood control or water and sediment regulation of reservoir. There are more tributaries in Xiaolangdi reservoir than the others that it occupies 41.3% of the total initial volume of tributary volume. Obviously, the effective use of tributary volume has been important influenced by comprehensive utilization efficiency of reservoir scheduling, such as flood control, sedimentation reduction and comprehensive utilization. Results of Xiaolangdi Reservoir mobile-bed physical model experiments show that tributary is equivalent to lateral extension of river bed, the tributary intrusion deposition process have strongly relations with the factors, such as original topography, river bed deposition shape and its regime, process with input discharge and input sediment, and method of reservoir regulation. The variation trends of main river and tributary terrain forecasted by model test are basically in accordance with field surveyed data. The results could be used for research, design, and forecasting of reservoirs in sediment-laden river.


2011 ◽  
Vol 214 ◽  
pp. 265-270
Author(s):  
Jun Yan ◽  
Biao Liang ◽  
Hui Cao ◽  
Yu Hua Zhang

Analyzed the sediment-transport process in high sediment-laden river, the new concept and calculating method for sediment-transport water volume are proposed. Based on field data of sediment and water volume in the Lower Yellow River from 1950 to 2000, the sediment-transport water volume and unit sediment-transport water volume in LYR are calculated. Meanwhile, relations between them and influencing factors are confirmed to calculate efficient sediment-transport water volume after construction of the Xiaolangdi reservoir.


2018 ◽  
Vol 4 (3) ◽  
pp. 189
Author(s):  
Dian Wahyu Jatmiko

Madukoro area located on the northern coast of Semarang City has been prone to flooding caused by rainfall and seawater high-tide. Ineffective flood control management and land subsidence are considered as the cause of this problem. In order to understand land subsidence effect and flood control performance, location, water surface height of the inundation in West Flood Canal, western part of Madukoro area need to analyze. Flood analysis was conducted using HEC-HMS software and rational method. Flow hydraulics on five channels, i.e. the West Flood Canal, Ronggolawe River, Karangayu River, Arterial Channel and Madukoro were analyzed using HEC-RAS software. Increasing levee level and additional water pumps in Madukoro and Ronggolawe were chosen as flood control alternatives. Its performance was investigated through software simulation. The results showed total runoff volume in all drainage channels for 2-years return period discharge was about 80% of capacity with 0.7 m water depth. Runoff volume in West Flood Canal with 50-years return period discharge was about 40%. Land subsidence 4 cm/year affected the water level increase on West Flood Canal. Operation of 2 - 4 pump units could not significantly decrease water level at flood peak, yet increase flood recession time 6 - 8 hours. 


Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 915 ◽  
Author(s):  
Tao Bai ◽  
Xia Liu ◽  
Yan-ping HA ◽  
Jian-xia Chang ◽  
Lian-zhou Wu ◽  
...  

Given the increasingly worsening ecology issues in the lower Yellow River, the Xiaolangdi reservoir is chosen as the regulation and control target, and the single and multi-objective operation by ecology and power generation in the lower Yellow River is studied in this paper. This paper first proposes the following three indicators: the ecological elasticity coefficient (f1), the power generation elasticity coefficient (f2), and the ecological power generation profit and loss ratio (k). This paper then conducts a multi-target single dispatching study on ecology and power generation in the lower Yellow River. A genetic algorithm (GA) and an improved non-dominated genetic algorithm (NSGA-II) combining constraint processing and feasible space search techniques were used to solve the single-objective model with the largest power generation and the multi-objective optimal scheduling model considering both ecology and power generation. The calculation results show that: (1) the effectiveness of the NSGA-Ⅱcombined with constraint processing and feasible spatial search technology in reservoir dispatching is verified by an example; (2) compared with the operation model of maximizing power generation, the power generation of the target model was reduced by 0.87%, the ecological guarantee rate was increased by 18.75%, and the degree of the impact of ecological targets on the operating results was quantified; (3) in each typical year, the solution spatial distribution and dimensions of the single-target and multi-target models of change are represented by the Pareto-front curve, and a multi-objective operation plan is generated for decision makers to choose; (4) the f1, f2, and k indicators are selected to analyze the sensitivity of the five multi-objective plans and to quantify the interaction between ecological targets and power generation targets. Ultimately, this paper discusses the conversion relationship and finally recommends the best equilibrium solution in the multi-objective global equilibrium solution set. The results provide a decision-making basis for the multi-objective dispatching of the Xiaolangdi reservoir and have important practical significance for further improving the ecological health of the lower Yellow River.


2011 ◽  
Vol 219-220 ◽  
pp. 71-75
Author(s):  
Jie Hu ◽  
Ling Han ◽  
Qing Fang Gao ◽  
Peng Jun Liu

Fractal theory was used to study the rules of Yellow River’s food happening. The author put forward a method, grid method, to calculate the riverway’s fractal dimension. After comparing the fractal dimensions and flood peak discharges of the Lower Yellow River parts, some helpful conclusions have been achieved. At a certain scale range, riverway of the Lower Yellow River shows some fractal characteristics, that is self-similarity. The fractal dimension of the Lower Yellow River changes with the flood peak discharge. Usually, the bigger the fractal dimension, the more curving the river way, the bigger the flood peak discharge, the bigger the possibility that flood happens. As a result, the fractal dimension can be regarded as a quantitative index to predict flood.


2011 ◽  
Vol 403-408 ◽  
pp. 228-234
Author(s):  
Jun Yan ◽  
Biao Liang ◽  
Yu Hua Zhang ◽  
Hui Cao

Analyzed the sediment-transport process in high sediment-laden river, the new concept and calculating method for sediment-transport water volume are proposed. Based on field data of sediment and water volume in the Lower Yellow River from 1950 to 2000, the sediment-transport water volume and unit sediment-transport water volume in LYR are calculated. Meanwhile, relations between them and influencing factors are confirmed to calculate efficient sediment-transport water volume after construction of the Xiaolangdi reservoir. Results gained from these functions are consistent well with the facts of real water-sediment regulation in LYR.


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