Time filter

Source Type

Yu S.,Yellow River Institute of Hydraulic Research | Tian S.,Yellow River Institute of Hydraulic Research
River Sedimentation - Proceedings of the 13th International Symposium on River Sedimentation, ISRS 2016 | Year: 2017

The paper analyzes the form of the Yellow River Delta and its driving factor, based on coastlines in 1855, 1937, 1976 and 2013, and nearshore wave characteristics. The Yellow River Estuary was influenced by human beings in low degree from 1855 to 1976, therefore in the state of natural swing and nearly uniformly transporting huge sediment to nearshore of the Delta. The coastlines developed towards the Bohai Sea with relatively regular arc shape. Exterior normal of the coastline is in good accordance with strong wave from north east, which indicates that wave is the main factor controlling the Yellow River Delta coastline. The Yellow River has entered to the Sea by the Qingshuigou Course since 1976. And since then it has been strongly influenced by human intervene for nealy 40 years. The only one course to the Sea has brought about continuous extension by deposition in the current estuary, unceasing erosion of the other zone or beach degradation near coastal protection work, which lead to deformation form. It is suggested that regulation of the Yellow River Estuary should follow the principle of frequent shifting of a single course so that the coming sediment is able to be relatively well distributed along the shore. © 2017 Taylor & Francis Group, London.


Wu X.,China Railway SIYUAN Survey and Design Group Co. | Xu L.,Yellow River Institute of Hydraulic Research
IOP Conference Series: Earth and Environmental Science | Year: 2017

Yellow River is the river in which the ice flood occurs most frequently in China, hence, the Ice flood forecasting has great significance for the river flood prevention work. In various ice flood forecast models, the flow velocity is one of the most important parameters. In spite of the great significance of the flow velocity, its acquisition heavily relies on manual observation or deriving from empirical formula. In recent years, with the high development of video surveillance technology and wireless transmission network, the Yellow River Conservancy Commission set up the ice situation monitoring system, in which live videos can be transmitted to the monitoring center through 3G mobile networks. In this paper, an approach to get the ice velocity based on single view metrology and motion tracking technique using monitoring videos as input data is proposed. First of all, River way can be approximated as a plane. On this condition, we analyze the geometry relevance between the object side and the image side. Besides, we present the principle to measure length in object side from image. Secondly, we use LK optical flow which support pyramid data to track the ice in motion. Combining the result of camera calibration and single view metrology, we propose a flow to calculate the real velocity of ice flood. At last we realize a prototype system by programming and use it to test the reliability and rationality of the whole solution. © Published under licence by IOP Publishing Ltd.


News Article | May 12, 2017
Site: www.eurekalert.org

HOUSTON -- (May 12, 2017) -- U.S. and Chinese geologists studying China's Yellow River have created a new tool that could help Chinese officials better predict and prevent the river's all-too-frequent floods, which threaten as many as 80 million people. The new tool, a physics-based formulation to calculate sediment transport, can also be applied to study the sustainability of eroding coastlines worldwide. Known in Chinese as the Huanghe, the Yellow River holds a central but dichotomous place in history. As the cradle of Chinese civilization, it is often called the "mother of China." But its floods, including several of the deadliest natural disasters in recorded history, also have earned it the name "China's sorrow." Each identity -- the fertile nurturer and the wanton killer -- derives from the same feature: The Yellow River washes about a billion tons of sediment each year from the Loess Plateau to the Bohai Sea, and in so doing, it has a tendency to become so clogged that it not only floods but literally changes course, jumping to a new channel miles away. "The Huanghe is probably the most-studied fine-grained river in the world," said Rice University sedimentologist Jeffrey Nittrouer, a primary author of the new study about the Yellow River that appears online this week in Science Advances. "Despite that, the typical formulae and relationships that are used to describe sediment flux in most other rivers simply do not work for the Huanghe. They consistently underpredict the sediment load of the river by a factor of 20." In the study, Nittrouer and lead author Hongbo Ma, a postdoctoral researcher from China who joined Rice in 2014, used the latest techniques in sediment sampling and 3-D river-bottom mapping to create a "universal sediment transport formulation." The formulation is the first physics-based sediment transport model capable of accurately describing how the Huanghe carries sediment. "In terms of sediment transport, the Haunghe is almost the perfect river," Ma said. "Its bottom is nearly flat and featureless, which means it can use almost all of its energy for moving sediment." Nittrouer, an assistant professor of Earth science who has studied dozens of rivers on three continents, said he has not seen anything like the Huanghe. "In typical lowland sand-bed rivers - like the Amazon, the Mississippi, you name it - only about 40 to 60 percent of the energy is used to transport sediment downstream. In the Yellow River, well over 95 percent of the energy is available to move sediment." Nittrouer and Ma first visited the Huanghe in summer 2015 as part of a four-year, $2 million study funded by the National Science Foundation (NSF). Their intent was to examine the geological, socio-economic and engineering lessons from China's decadeslong effort to control the Huanghe and direct the growth of its delta into the Bohai Sea. "The Haunghe moves so much sediment that it is extremely efficient at generating new land each year and is therefore the best place for us to learn about how to use sediment from rivers to enhance delta sustainability," Nittrouer said. "The example closest to home is the Mississippi River, where there are significant efforts to replenish coastal Louisiana. But an even more pressing reason to study the Yellow River is that 80 million people live in its floodplain and are threatened by its floods. The potential for human suffering is enormous. The aim of our work is to mitigate Huanghe floods, while developing techniques through research that are transferable so as to evaluate river systems worldwide." Ma and Nittrouer said they will never forget their first attempt to create a 3-D map of the Huanghe bottom. They were planning to make a detailed picture of the river bed using a sonar system that Nittrouer had previously used to map several other rivers systems. In all previous studies, he'd found that the channel contained bedform features similar to sand dunes of deserts. "I took one look at the readout on the boat and thought the instrument was broken," Nittrouer said. "The bottom looked flat as glass." Ma said, "Only when we brought the data back to the lab did we see that there were features, but the aspect ratio was such that we could not see them on the boat." For example, when Nittrouer imaged the bottom of the Mississippi River, he typically saw bedforms up to 10 meters tall and spaced about 200 to 300 meters apart. In contrast, the data from the Yellow River showed 1-meter-tall dunes every 500 to 2,000 meters. Using that data and other measurements from the lower Huanghe, including from its sprawling delta, Ma created a physics-based formulation capable of accurately predicting the flux -- the volume of sediment transported for a given time period -- in the Huanghe. "The aim is to look at the connectedness, in terms of sediment movement and water flow, among the river, the delta and the near-shore marine region," said Ma, who chose to become a sedimentologist following the devastating 2008 Sichuan earthquake in China. While still an undergraduate at Tsinghua University, Ma joined a lab that was studying the potential flooding that could result from dam breaches caused by landslides in the 2008 quake. The potential loss of life from the floods was greater than the 90,000 people killed or injured by the quake itself, and Ma became fascinated with creating technologies that could help prevent such large floods. "I was born and grew up far from the Haunghe in the northeastern Heilongjiang Province, but I, like many Chinese, deeply feel the sorrow of the Huanghe, which has killed millions over the past 2,000 years, and I bear the sorrow of all the flooding hazards in mind in conducting my research," he said. Ma said he hopes the new formula may prove useful to Chinese engineers who manage the flow of water and sediment from dams along the Huanghe. For example, engineers have for decades tried to reduce the risk of Huanghe floods by periodically scouring the river bottom with massive releases of sediment-depleted lake water. Ma said one finding from the new model is that such scouring may inadvertently increase the risk of flooding in certain parts of the river because although it clears silt, it also creates a rough-textured riverbed that reduces the amount of energy the river can use to move sediment. "Our formula indicates this will lower sediment transport efficiency by an order of magnitude," he said. "Additionally, the added drag produced by dunes could increase water stage and leave the system prone to levee overtopping during flood events. This threat may be unique to the case of the Haunghe." Judy Skog, program director in the NSF's Directorate for Geosciences, which funded the research through its Coastal Science, Engineering and Education for Sustainability Program, said, "Understanding the flow of sediment in rivers is important to the large number of people around the world who live near rivers. This study can lead to predictions of when and where rivers transport sediment, and to an understanding of how that sediment flow is affected by conservation and management efforts, such as the removal of dams." Additional co-authors include Rice's Andrew Moodie, the University of Illinois at Urbana-Champaign's Kensuke Naito and Gary Parker, Tsinghua University's Xudong Fu and Baosheng Wu and the Yellow River Institute of Hydraulic Research's Yuanfeng Zhang and Yuanjian Wang. The research is supported by NSF and the National Natural Science Foundation of China. VIDEO is available at: High-resolution IMAGES are available for download at: CAPTION: China's flood-prone Huanghe, or Yellow River, washes about a billion tons of sediment each year from the Loess Plateau to the Bohai Sea. The sediment-laden river not only floods but literally changes course every few years, jumping to a new channel miles away. (Image courtesy of Wikimedia Commons) CAPTION: The mouth of the Huanghe, or Yellow River, in China's Bohai Sea, as seen from NASA's Landsat satellite in 1999. The river's sediment constantly rebuilds the delta, which is extensively engineered to control flooding and protect coastal development. U.S. researchers hope lessons from the Huanghe could aid efforts to rebuild coastal Louisiana. (Image courtesy of NASA and Wikimedia Commons) A copy of the paper is available at: http://advances. This release can be found online at news.rice.edu. Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,879 undergraduates and 2,861 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for happiest students and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl. .


Jiang D.,CAS Yantai Institute of Coastal Zone Research | Fu X.,Yellow River Institute of Hydraulic Research | Wang K.,Beijing Normal University
Quaternary International | Year: 2013

Based on SPOT Vegetation NDVI data, streamflow data and meteorological data, the variation of vegetation cover, measured by the Normalized Difference Vegetation Index (NDVI), and its response to freshwater inflow, precipitation and temperature in the Yellow River Delta and its buffer zones have been investigated for the period 1998-2009. The results show that NDVI has a remarkable regional and seasonal difference. The farther from the Yellow River Channel and the nearer to the Bohai Sea Coastline, the smaller the NDVI value, as influenced by the interaction between freshwater and saltwater on vegetation. Seasonally, high NDVI values appear in summer (August) and low in spring (April). From 1998 to 2009, growing season NDVI significantly increases in the Yellow River Delta. Summer and autumn NDVI have a similar trend pattern to growing season NDVI, while spring NDVI significantly decreases. NDVI shows different strengths of correlation with freshwater inflow, precipitation and temperature respectively and these correlations vary in different seasons and months. Freshwater inflow is a key factor for vegetation dynamics and NDVI variation. Climate features play a dominant role in seasonal variation in vegetation cover. However, the impacts of freshwater inflow and climate variables on vegetation have been greatly modified by a range of human activities such as land use pattern and land use change as well as water diversion from the Yellow River. Overall, the results of this study can be helpful for decision-making of regional ecological protection and economic development. © 2012 Elsevier Ltd and INQUA.


Ma Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Huang H.Q.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Nanson G.C.,University of Wollongong | Li Y.,Yellow River Institute of Hydraulic Research | Yao W.,Yellow River Institute of Hydraulic Research
Geomorphology | Year: 2012

The Yellow River in China carries an extremely large sediment load. River channel-form and lateral shifting in a dynamic, partly meandering and partly braided reach of the lower Yellow River, have been significantly influenced by construction of Sanmenxia Dam in 1960, Liujiaxia Dam in 1968, Longyangxia Dam in 1985 and Xiaolangdi Dam in 1997. Using observations from Huayuankou Station, 128. km downstream of Xiaolangdi Dam, this study examines changes in the river before and after construction of the dams. The temporal changes in the mean annual flow discharge and mean annual suspended sediment concentration have been strongly influenced by operation of theses dams. Observations of sediment transport coefficient (ratio of sediment concentration to flow discharge), at-a-station hydraulic geometry and bankfull channel form observed from 1951 to 2006 have shown that, although variations in flow and sediment load correspond to different periods of dam operation, changes in channel form are not entirely synchronous with these. The channel has been subject to substantial deposition due to the flushing of sediment from Sanmenxia Dam, resulting in a marked reduction in bankfull cross-sectional area. Flows below bankfull had a greater impact on channel form than higher flows because of very high sediment load. At-a-station hydraulic geometry shows that the variation of channel cross-sectional area below bankfull in this wide and relatively shallow system largely depends on changes in width. Such at-a-station changes are significantly influenced by (1) events below bankfull and (2) overbank floods. Bankfull depth is the main component of channel adjustment in that depth adjusts synchronously with channel area. The channel adjusts its size by relatively uniform changes in depth and width since 1981. Channel morphology is not the product of single channel-forming flow frequency. It is determined by the combination of relatively low flows that play an important role in fine sediment transport and bed configuration as with relatively high flows that are effective at modifying the channel's morphology. The sediment transport coefficient is a useful index for efficiently guiding the operation of the dams in a way that would minimize channel changes downstream. Sedimentation over the nearly 60. years of study period caused the lower Yellow River to aggrade progressively, the only significant exception being the two years following completion of Sanmenxia Dam. © 2011 Elsevier B.V.


Chen J.J.,Yellow River Institute of Hydraulic Research
Applied Mechanics and Materials | Year: 2014

Suction jet scheme has brought forward sediment suspension transport work parameter in the scheme of water and sediment transporting and sediment adding in discharge water before the flood season of Xiaolangdi Reservoir. Suction jet system starts suspended sediments as per 1% natural bottom slope of Xiaolangdi Reservoir while jet pump eject muddy water, which forms into density current and transport forward, and makes longitudinal deposition in the process of sediment transport. Transport distance shall be 1,264~1,903m while 50% longitudinal attenuation of sediments as effective transport distance. Bottom slope of sediment deposition is reduced to 6.7% with obscure longitudinal attenuation of sediments and can transport to longer distance. © (2014) Trans Tech Publications, Switzerland.


Yu S.,Yellow River Institute of Hydraulic Research
Advances in Science and Technology of Water Resources | Year: 2016

In order to examine the effect and possible influence of the implementation of two-bank regulation of the wandering lower Yellow River, through summary of the background of implementation and the expected effect, project and social environmental problems regarding two-bank regulation are analyzed. Although the flood control situation in the lower Yellow River Basin is improved, there exist some problems, such as the insufficient sediment transport capacity of the wandering lower river and the deteriorated river regime of some lower channels. Two-bank regulation can generate a narrow deep channel through spur dikes or other regulation projects, cause most of the sediment to be transported by floods due to the large sediment transport capacity of the narrow deep channel and the operation of the Xiaolangdi Reservoir, and eliminate adverse river regimes, such as transverse rivers and inclined rivers. It is pointed out that the main problems regarding two-bank regulation are as follows: large floods are still likely to occur in the lower Yellow River, the regulation project leads to rises in the water lever, the increasing sediment-carrying capacity causes the discharged sediment to influence the narrow channels in Shandong Province and the Yellow River Estuary, and the implementation of regulation projects leads to land ownership problems, diversion of water from the Yellow River, and environmental impacts. © 2016, Editorial Board of Advances in Science and Technology of Water Resources, Hohai University. All right reserved.


Zeng X.,Wuhan University | Hu T.,Wuhan University | Guo X.,China Institute of Water Resources and Hydropower Research | Li X.,Yellow River Institute of Hydraulic Research
Water Resources Management | Year: 2014

This paper proposes a new water transfer triggering mechanism for multi-reservoir system to divert water from abundant to scarce regions with a constant diversion flow in an inter-basin water transfer-supply project. Taking into account of the uncertain nature of inflow, the storage of reservoir is taken as a signal for decision-making to indicate water abundance or water scarcity. In this study, a set of rule curves based on storage of donor reservoir and storage of recipient reservoir are used together to determine when to start water transfer. To initiate water diversion to each recipient reservoir effectively, several water transfer rule curves of the donor reservoir are set for each recipient reservoir respectively in the multi-reservoir system with one donor reservoir and several recipient reservoirs, which is the main difference in comparison with other water transfer triggering mechanisms. In addition, a systematic framework is developed to integrate the water transfer rule curves with hedging rule curves to simultaneously solve the water transfer and water supply problems, since they interact with each other during the operation process. In order to verify the utility of the new water transfer triggering mechanism, an inter-basin water transfer-supply project in China is used as a case study and an improved particle swarm optimization algorithm (IPSO) with a simulation model is adopted for optimizing the decision variables. The results show that the proposed water transfer triggering mechanism can improve the operation performances of the inter-basin system. © 2014 Springer Science+Business Media Dordrecht.


Yang L.,Yellow River Institute of Hydraulic Research
Applied Mechanics and Materials | Year: 2014

After introducing the basic definition, technical principle and applied scope of elastic wave CT technology, the paper makes a detailed introduction of the development process of elastic wave CT technology domestic and overseas and main technical problems it faces and believes that the imagining precision of elastic wave CT is often influenced by various factors such as the observation system, test precision, imaging method and error control. Thereinto, the hot issue in the research is put onto the study about inversion algorithm and the paper also elaborates the research direction and development tendency of current inversion algorithm at home and abroad. © (2014) Trans Tech Publications, Switzerland.


Yao W.,Yellow River Institute of Hydraulic Research | Xu J.,CAS Institute of Geographical Sciences and Natural Resources Research
Environmental Earth Sciences | Year: 2013

Fluvial suspended sediment has multi-fold environmental implications and the study of the variation in suspended sediment load (SSL) of rivers is important both in environmental earth sciences and in river environmental management. Based on data collected for the upper Yellow River of China in the past 50-60 years, the purpose of this study is to elucidate the impact of human activity and climate change on SSL, thereby to provide some knowledge for the improvement of the drainage basin management. The results show that the SSL of the upper Yellow River exhibited a remarkable decreasing trend. A number of reservoirs trapped a considerable amount of sediment, resulting in a reduction in SSL at Toudaoguai station, the most downstream station of the upper Yellow River. The analyses based on Mann-Kendall'U and double-mass plot indicate some turning points, which were caused by the Liujiaxia and Longyangxia Reservoirs, two major reservoirs on the upper Yellow River. The implementation of soil and water conservation measures reduced the runoff coefficient, and therefore, the intensity of soil erosion. The climate change also played a role in reducing sediment yield. The increase in air temperature enhanced the evapo-transpiration and reduced the runoff, by which the SSL decreased. The decreased frequency of sand-dust storms reduced the amount of wind-blown, sand and dust to the river reaches located in desert, also reducing the SSL. Seven influencing variables are selected to describe the changing human activity and climate. As some of the influencing variables are strongly inter-correlated, the principle component regression was used to establish the relationship between SSL and the influencing variables. The squared multiple correlation coefficient is R 2 = 0.823. Some further research is suggested with the minerals and pollutants related with the SSL. © 2013 Springer-Verlag Berlin Heidelberg.

Loading Yellow River Institute of Hydraulic Research collaborators
Loading Yellow River Institute of Hydraulic Research collaborators