Adjustment in the main-channel geometry of the lower Yellow River before and after the operation of the Xiaolangdi Reservoir from 1986 to 2015

The channel geometry in a fluvial river is significantly affected by the flow and sediment regimes, and the response behavior of channel dimensions usually varies widely to different management strategies from the upstream reservoir. Therefore, it is significantly crucial to investigate the variation of the channel geometry in response to changing flow and sediment conditions and quantify the influence of the latter in the sedimentation reduction and flood releasing in lower reaches downstream of the dam. In this study, three laboratory experiments on the physical model covering the typical braided reach HGK&#8212;JHT downstream of the Xiaolangdi Reservoir in the lower Yellow River are carried out, under the discharge of 2000 m3/s, 3000 m3/s, and 4000 m3/s respectively and with the corresponding constant suspended sediment concentration of 8.0 kg/m3. Results indicate that (i) spatially, the erosion and deposition in studied channel reach distributed alternately along the course which performs typical evolution properties of the braided river, corresponding to the total erosion amount of 2.27&#215;106 m3, 10.29&#215;106 m3, and 7.98&#215;106 m3 for three magnitude of discharges; and (ii) four representative adjustment patterns are listed based on the observed cross-sectional geometry after each experiment, including the lateral widening pattern, vertical incision pattern, composite pattern and geometrical stable pattern where sectional geometry rarely changes during the period of experiment; and (iii) the quantity &#958;=B1/2/H where B and H is the width and depth of the main channel zone is selected as the typical indicator to determine the variation of the channel stability. It is discovered that &#958; in the reaches upstream of section FJS have rather larger values, implying relatively wider and shallower sectional geometry and lower channel stability which is closely associated with the levee safety. And moreover, the quantity &#958; generally has lower values, that is, higher channel stability with the increase of experiment discharge; Besides, through the method of nonlinear regression analysis, the empirical relations for HGK&#8212;JHT Reach are developed between the main channel dimensions and incoming flow erosion intensity F=(Q2/S)/106 where Q is the discharge and S is the corresponding sediment concentration. In general, the calculated results are generally consistent with the measured values, as the riverbed degradation and the variation of sectional area increase exponentially with a stronger erosion intensity F.This paper may provide some practical basis for the study of channel evolution in sediment-laden rivers.

Research on the Numerical Simulation of Silting in Floodplain and Scouting in Main Channel of Over-Bank Flooding in the Lower Yellow River

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.3692 ◽

2011 ◽

Vol 255-260 ◽

pp. 3692-3696

Author(s):

Xiao Lei Zhang ◽

Dong Po Sun ◽

Feng Ran Zhang

Keyword(s):

Numerical Simulation ◽

Mathematical Model ◽

Yellow River ◽

Main Channel ◽

River Channel ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Water And Sediment ◽

Simulation Results ◽

Set Up

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.

Study on Ecological Scheduling of the Xiaolangdi Reservoir Based on the Ecological Needs of Estuarine Fishes

MATEC Web of Conferences ◽

10.1051/matecconf/201824601045 ◽

2018 ◽

Vol 246 ◽

pp. 01045

Author(s):

Shimin Tian ◽

Yi Zhao ◽

Yuanjian Wang ◽

Enhui Jiang ◽

Shoubing Yu

Keyword(s):

Yellow River ◽

River Estuary ◽

The Yellow River ◽

Large Reservoir ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Estuarine Fishes ◽

Water Demands ◽

Xiaolangdi Reservoir ◽

Water Amount

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.

Shaping and maintaining a medium-sized main channel in the Lower Yellow River

International Journal of Sediment Research ◽

10.1016/s1001-6279(12)60034-1 ◽

2012 ◽

Vol 27 (3) ◽

pp. 259-270 ◽

Cited By ~ 9

Author(s):

Chun-hong HU ◽

Jian-guo CHEN ◽

Qing-chao GUO

Keyword(s):

Yellow River ◽

Main Channel ◽

Lower Yellow River ◽

The Lower Yellow River

Study on the Single-Multi-Objective Optimal Dispatch in the Middle and Lower Reaches of Yellow River for River Ecological Health

Water ◽

10.3390/w12030915 ◽

2020 ◽

Vol 12 (3) ◽

pp. 915 ◽

Cited By ~ 1

Author(s):

Tao Bai ◽

Xia Liu ◽

Yan-ping HA ◽

Jian-xia Chang ◽

Lian-zhou Wu ◽

...

Keyword(s):

Power Generation ◽

Equilibrium Solution ◽

Yellow River ◽

Ecological Health ◽

Elasticity Coefficient ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Multi Objective ◽

Constraint Processing ◽

Xiaolangdi Reservoir

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.

The High Efficient Sediment-Transport Water Volume in the Lower Yellow River

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.403-408.228 ◽

2011 ◽

Vol 403-408 ◽

pp. 228-234

Author(s):

Jun Yan ◽

Biao Liang ◽

Yu Hua Zhang ◽

Hui Cao

Keyword(s):

Sediment Transport ◽

Transport Process ◽

Yellow River ◽

Water Volume ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Calculating Method ◽

High Efficient ◽

Xiaolangdi Reservoir ◽

High Sediment

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.

Response of Erosion and Deposition of Channel Bed, Banks and Floodplains to Water and Sediment Changes in the Lower Yellow River, China

Water ◽

10.3390/w11020357 ◽

2019 ◽

Vol 11 (2) ◽

pp. 357 ◽

Cited By ~ 1

Author(s):

Xiaofei Liu ◽

Changxing Shi ◽

Yuanyuan Zhou ◽

Zhenkui Gu ◽

Huijuan Li

Keyword(s):

Yellow River ◽

Water Discharge ◽

Sediment Concentration ◽

Main Channel ◽

River Channel ◽

Lower Yellow River ◽

Main Research ◽

The Lower Yellow River ◽

Water And Sediment ◽

Geomorphic Units

River channel change can be very sensitive to environmental change and human activities and it has been one of the main research topics in fluvial geomorphology. In this study, repeated channel geometric measurements were used to investigate the channel adjustment to water and sediment changes of the lower Yellow River in China in the past few decades. With a high sediment concentration and large variations of water discharge, the lower Yellow River has a much active channel in its form and location, which has hindered previous research efforts to study long-term differentiated erosion/deposition of different geomorphic units in the channel. In this study, we divided each of four typical channel across-sections at hydrological stations in the lower Yellow River into different units according to the geomorphological features, and give a detailed investigation of erosion/deposition processes of these geomorphic units and the interactions between them besides the influence of incoming water and sediment conditions. The results show that with a significant decreasing trend of both the annual runoff and sediment load of the river and abrupt changes in 1985–1996, the overall siltation trend in the river channel before 1990 had been replaced by a slight erosion trend after 2006. In the earlier period, the siltation in the upstream wandering and transitional reaches mainly occurred on floodplains and that in the downstream straight reaches principally on main channel bed. In the later period, erosion occurred mainly on high and low bank slopes in the wandering reaches and on main channel bed in the transitional reaches. The erosion became weak in the wandering reaches after 2010, continued in the transitional reaches, and was still relatively minor in the straight reaches, reflecting the downstream hysteresis channel response to changes in water and sediment discharges down dams. Our results suggest that the seasonal erosion/deposition of a geomorphic unit of the river channel can be attributed to the changes in water and sediment discharges as well as to the interaction between geomorphic units. Siltation on the main channel bed could be attributed to erosion on the bank slopes in both the sections in the wandering and transitional reaches, and erosion of the main channel bed in flood seasons was negatively related with the mean water discharge at the two sections in the straight reaches. This result implies that fixing the bank slopes in the wandering and transitional reaches and raising the water discharge in the straight reach in flood seasons are favorable options for controlling the development of the two-level perching channel of the lower Yellow River.

Channel geometry adjustments in response to hyperconcentrated floods in a braided reach of the Lower Yellow River

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133318776492 ◽

2018 ◽

Vol 42 (3) ◽

pp. 352-368 ◽

Cited By ~ 3

Author(s):

Jie Li ◽

Junqiang Xia ◽

Meirong Zhou ◽

Shanshan Deng ◽

Zenghui Wang

Keyword(s):

Sediment Transport ◽

Yellow River ◽

Empirical Relation ◽

Characteristic Parameter ◽

Transport Rate ◽

Channel Geometry ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Sediment Transport Rate ◽

Braided Reach

Hyperconcentrated floods with more than 200–300 kg/m3 sediment concentrations often occur in the Lower Yellow River (LYR) during flood seasons, which leads to unique fluvial processes in the braided reach of the LYR. The investigation of channel geometry adjustments in response to hyperconcentrated floods can not only help to gain a better understanding of associated fluvial processes, but also is significant for making flood control strategies in the braided reach. In this study, pre- and post-flood bankfull channel dimensions in the braided reach were calculated based on the observed cross-sectional profiles in 15 years with the occurrence of hyperconcentrated flood events. Adjustments in channel geometry at section- and reach-scales were investigated, with several factors influencing adjustments in reach-scale channel geometry being analyzed. It indicates that the mean sediment transport rate was a key factor influencing the adjustment index, although pre-flood channel geometry and sediment deposition can also affect the index to some extent. An empirical relationship was developed between the characteristic parameter representing the pre- and post-flood channel geometries and mean sediment transport rate in hyperconcentrated floods. Eleven datasets were used to calibrate the parameters in the empirical relation, with the datasets in 1973, 1988, 1995, and 2002 verifying the relation. The calculated post-flood characteristic parameter of channel geometry using the empirical relation agreed well with observed data, and the proposed method can be used to predict the reach-scale adjustment of channel geometry during hyperconcentrated floods in alluvial rivers.

Reservoir Sedimentation and Transformation of Morpho-Logy in the Lower Yellow River during 10 Year’s Initial Operation of the Xiaolangdi Reservoir

Journal of Hydrodynamics ◽

10.1016/s1001-6058(11)60319-3 ◽

2012 ◽

Vol 24 (6) ◽

pp. 914-924 ◽

Cited By ~ 10

Author(s):

Jian-guo Chen ◽

Wen-hao Zhou ◽

Qiang Chen

Keyword(s):

Yellow River ◽

Reservoir Sedimentation ◽

Initial Operation ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Xiaolangdi Reservoir

Response of reach-scale bankfull channel geometry to the altered flow and sediment regime in the lower Yellow River

Geomorphology ◽

10.1016/j.geomorph.2014.01.017 ◽

2014 ◽

Vol 213 ◽

pp. 255-265 ◽

Cited By ~ 30

Author(s):

Junqiang Xia ◽

Xiaojuan Li ◽

Tao Li ◽

Xiaolei Zhang ◽

Quanli Zong

Keyword(s):

Yellow River ◽

Channel Geometry ◽

Lower Yellow River ◽

The Lower Yellow River