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Rivers flow across aeolian dunes and develop braided stream channels. Both aeolian and fluvial sediment supplies regulate sediment transport and deposition in such a cross-dune braided river. Here we show a significant selective deposition in response to both aeolian and fluvial sediment supplies in the Ulan Buh desert braided channel. This selective deposition developed by the interaction between the flows and the Aeolian-fluvial sediment supplies, making the coarser sediments (>0.08 mm) from aeolian sand supply and bank erosion to accumulate in the channel center and the finer fluvial sediments (<0.08 mm) to be deposited on the bar and floodplain surfaces and forming a coarser-grained thalweg bed bounded by finer-grained floodplain surfaces. This lateral selective deposition reduces the downstream sediment transport and is a primary reason for the formation of "above-ground river" in the braided reach of the Upper Yellow River in response to aeolian and fluvial sediment supplies. [ABSTRACT FROM AUTHOR]

Based on four field investigations during 2003 and 2009 along the Yellow River mainstream, we examined the distributions, seasonal variations and transport features of organic carbon, with a focus on the impacts of human activities (reservoir construction and regulation scheme). The results showed that organic carbon transport processes in the Yellow River were different from other major rivers. Particulate organic carbon (POC) dominated in the Yellow River and it mainly originated from the Loess Plateau. POC levels in suspended sediment (POC %) ranged between 0.25% and 2.20% and more than 80%of POC concentrated in the particles with grain size smaller than 16 µm. On time scale, dissolved organic carbon (DOC) correlated negatively with discharges, indicating the influence of dilution effect. Along the river on spatial scales, DOC in the Qinghai-Tibet Plateau was closely related with temperature while DOC in the Loess Plateau showed the concentration effect, due to the abundant human input and the high ratio of evaporation to precipitation. Organic carbon in the Yellow River was very refractory and about 90% of POC and 70% of DOC cannot be degraded. Due to the high turbidity, the Yellow River suffers more impacts from the reservoirs in the transport of total suspended solids (TSS) and organic carbon. Ratios of DOC/POC ranged between 2.0 and 12 in the reservoirs and organic carbon was mainly in the dissolved from. POC deposited in the reservoirs of the Yellow River achieved 0.0033 Gta-1, about 8 times its annual POC flux discharged to the ocean. During the 2008 Water and Sediment Regulation (WSR) period, DOC and POC fluxes was as high as 1.1x1010 g and 2.2x1011 g respectively, accounting for 35% of annual DOC flux and 56% of the annual POC flux to the ocean. Discharges and material fluxes to the ocean decline sharply due to the reservoir construction while large amounts of water and sediment are transported to the ocean in such a short WSR period. These two human disturbances totally altered the processes of substance transport in the Yellow River, and may change the water chemical characteristics in the coastal zones. [ABSTRACT FROM AUTHOR]

Soil erosion and terrestrial deposition of soil organic carbon (SOC) can potentially play a significant role in global carbon cycling. Assessing the fate of SOC during erosion and subsequent transport and sedimentation is of critical importance. Using hydrological records of soil erosion and sediment load, and compiled organic carbon (OC) data, budgets of the eroded soils and OC induced by water in the Yellow River basin during 1950-2010 were analyzed. The Yellow River basin has experienced intense soil erosion due to integrated impact of natural process and human activity. Over the period, 134.2 ± 24.7 Gt of soils and 1.07 ± 0.26 Gt of OC have been eroded from slope lands based on a soil erosion rate of 1.7-2.5 Gtyr-1. Among the produced sediment, approximately 63% of it was deposited on land, while only 37% was discharged into the ocean. For the OC budget, approximately 0.53 ±0.18 Gt (49.5%) was buried on land, 0.25±0.14Gt (23.5%) was delivered into the ocean, and the remaining 0.289 ± 0.202 Gt (27 %) was decomposed during the erosion and transport processes. This validates the commonly used assumption that 20-40% of the eroded OC would be oxidized after erosion. Erosion-induced OC transport in the basin likely represents an atmospheric carbon source. In addition, about half of the terrestrially redeposited OC (around 49.4%) was buried in reservoirs and behind silt check dams, revealing the importance of dam sedimentation in trapping the eroded OC. Although with several uncertainties to be better constrained, the obtained budgetary results provide a means of assessing the potential fates of the eroded OC within the Yellow River basin. [ABSTRACT FROM AUTHOR]

Our planet is increasingly threatened by degradation in water quantity and quality due to climate change, population growth and development pressures. Water shortage is one of the most challenging environmental problems to humankind in the 21st century under the changing climate. Water shortages and scarcity escalate risks to food security and economic viability. For decades, water management has been dominated by supply oriented paradigm of expanding the capacity of accessible water (e.g. building dams). While large scale infrastructure projects provided effective solutions for chronic water crises in the past, they have come at expensive, irreversible and delayed ecological, economic and social costs. As more questions are raised concerning over reliance on infrastructure solutions, discussions about a sustainable future suggest a greater focus on the demand side of the equation is needed. In this paper, we use multi-recursive and runoff coefficient analysis methods to analyze the annual runoff of the mainstreams (Kuye River, Tuwei River, Wuding River and Jialu River) in the middle reaches of Yellow River. The main objective is to estimate the impacts of climate change and human activity on water resources in the study area and test the potential of water demand management to lessen the gap between supply and demand. Results show remarkable drop in the average annual runoff as a combined effect of climate change and human activity. Moreover, results show that human activities are the direct reason for the changes of river runoff, and the proportion of human activities account the biggest is Wuding river, next is Kuye river, Jialu river is smallest, these changes lead to the decrease of river runoff, and even drying up in recent years. This result highlights the importance of using WDM to diminish the increasing gap between demand and supply. Motivated by this, the paper presents a comprehensive framework for implementation WDM in the middle reaches of Yellow River. The framework includes a wide range of instruments: legislative, economic, technological and educational. The core step of the framework, collaboration among water planners, water service providers and end-users lies as an essential mechanism for achieving long term trade-offs between ecological and socio-economic water needs. [ABSTRACT FROM AUTHOR]

Ice disasters occurred frequently in Ningxia-Inner Mongolia reach, and safety of the Yellow River, people's lives and property security are seriously threatened. In this paper ice control condition in the Upper Yellow River is introduced for the first time to clarify the relationship between flow routing and ice control security. Based on the feature of flow routing during ice control period, the improved method for different reaches and periods is proposed in this paper. Three sections in the Ningxia-Inner Mongolia reach of the Upper Yellow River are selected as research objects. The 10-day flow data of sections over the past 20 years are used for parameter calibration, training and verification. To investigate the method performance, we applied a number of criteria factors (Relative Error, Root Mean Square Error, Mean Absolute Error, and Correlation Coefficient) and two methods, conventional method and improved one. The results demonstrate that the improved method which considers ice impact factors such as data on freeze-up and break-up, channel storage increment, temperature, has consistently superior performance in comparison with the conventional method. The accuracy and superiority of the improved method are verified by comparative methods. [ABSTRACT FROM AUTHOR]

Recently suspended river, where formed both in tributary and in main stream of Ningxia-Inner Mongolia reaches in the Upper Yellow River, severely threatens people's lives and property safety downstream. In this paper, taking Ningxia-Inner Mongolia reaches for the example, water and sediment are regulated by cascade reservoirs upstream, which can form artificial controlled flood, to improve the relationship of water-sediment and slow down the speed of sedimentation rate. Then, multi-objective optimal operation model of cascade reservoirs is established with four objectives: ice and flood control, power generation, water supply, water and sediment regulation. Based on optimization technique of feasible search space, the non-dominated sorting genetic algorithm (NSGA-II) is improved and a new multi-objective algorithm, Feasible Search Space Optimization-Non-dominated Sorting Genetic Algorithm (FSSO-NSGA-II) is innovatively proposed in this paper. The best time of water and sediment regulation is discussed and the regulation index system and scenarios are constructed in three level years of 2010, 2020 and 2030. After that regulation efforts and contribution to sediment transportation are quantified under three scenarios. Compared with history data in 2010, the accuracy and superiority of multi-objective model and FSSO-NSGA-II are verified. Even more, four-dimensional vector coordinate systems are proposed innovatively to represent each objective and sensitivity of three scenarios are analyzed to clarify the impact on regulation objectives by regulation indexes. At last, relationships between four objectives are revealed. The research findings provide optimal solutions of multi-objectives optimal operation by FSSO-NSGA-II, which have an important theoretical significance to enrich the methods of water and sediment optimal operation by cascade reservoirs, guiding significance to water and sediment regulation implementation and construct water and sediment control system in the whole Yellow River basin. Research Highlights: We establish an multi-objective optimal operation model with four regulation objectives. We proposed a improved multi-objective algorithm (FSSO-NSGA-II) based on feasible search space optimization. Regulation index system and three scenarios are constructed. Four-dimensional vector coordinate systems are proposed to represent each objective and sensitivity of scenarios are analyzed. Relationships between four objectives are revealed. [ABSTRACT FROM AUTHOR]

Based on remote sensing data and investigations, this paper focuses mainly on a general evaluation of environmental quality in the middle-upper areas of the Yellow River region using GIS technology, Arc/Info, and ArcView. In this paper, the upper areas of the Yellow River regions are divided into three parts: the north-east Qinghai-Tibet Plateau ecosystem areas, the Erdos Plateau-Hetao Plain ecosystem areas, and the Loess-Plateau ecosystem areas. The study analyses the current environmental situation and the overall environmental quality in each ecosystem area and determines the law of distribution of environmental quality in the three areas. Finally, the paper provides some suggestions to improve the ecological environment in each area, in the hope of yielding a scientific foundation based on planning ecological environment protection in the Yellow River basin. [ABSTRACT FROM AUTHOR]

There is increasing recognition of the problems facing China in meeting the growing water demand in the Yellow River basin, the ’cradle of Chinese Civilization’ and a critically important agricultural and industrial region. Meaningful debate on the range and relative costs of options available to policy-makers in addressing the problem depend fundamentally on an accurate understanding of basin water resources. Unfortunately, the ability of outsiders to participate in the debate and for Chinese, with their long history of water management, to contribute to similar discussions elsewhere in the world is hindered to some extent by a lack of understanding of differences in water accounting systems and concepts. This paper attempts to address this problem by describing the water accounting system used in the Yellow River basin and elsewhere in China. The paper shows that the primary difference between water accounting methodologies in the Yellow River and those typically applied elsewhere is related to supply accounting in general and groundwater accounting in particular Although not currently included in its water accounting system, Chinese concepts of environmental water use, when included, will also differ substantially from those familiar to outside researchers. In terms of factual Yellow River balances, the paper highlights the apparent declining trend in basin rainfall and runoff and the dramatic growth in industrial and domestic water use. Together declining supply and rising demand will increasingly cause policy-makers to face hard choices in assessing their water planning options. These choices will only become more difficult as managers in the Yellow River, as elsewhere in the world, try to incorporate ecological needs in the water accounting equation. [ABSTRACT FROM AUTHOR]

In the late 1990s, China’s Yangtze and Yellow River Basins suffered devastating natural disasters widely attributed to the degradation of soil and water resources. The Government of China responded with a number of major environmental programs, the most expensive and influential of which, the Grain for Green (GfG) Program, was implemented widely from 1999. Under the GfG Program—also known as the Sloping Land Conversion or Conversion of Cropland to Forest Program—the central government compensates farmers to convert cropland on steep slopes or otherwise ecologically sensitive areas to forest or grassland. Its long-term success depends on households’ ability to make sustainable changes to their household income streams and income diversification strategies. In this paper, we use a difference-in-difference estimation approach to examine the role of migration as a household-level response to the GfG Program, testing the extent to which individuals migrate following a reduction in land available for farming. Importantly, we exploit 15 years of data on migration decisions and establish that participating and non-participating households were on parallel migration paths before the program, thus refuting a key threat to causality in a difference-in-difference model. We find that participating families do, in fact, choose migration as an income diversification strategy more frequently than non-participants. The program effects varied over time but peaked post-Great Recession in 2011 when migration rates in GfG households exceeded those of non-GfG households by 5.9% points (p = 0.003) or about 26%. Our findings should encourage policymakers that families are making long-term adjustments to their livelihood strategies to avoid poverty in anticipation of the eventual withdrawal of government supports. [ABSTRACT FROM AUTHOR]

This paper describes a very rare, hand-coloured, unusually large (over 13 m2) manuscript map of China about which, in addition to our own copy, only two more copies are known. The map shows the territory of the Ming Chinese empire (1368–1644) in the seventeenth century. It was prepared in 1691 by the famous Japanese Buddhist monk, Sōkaku (1639–1720). The paper highlights several historical and geographical details of the period and the most interesting history of the map. [ABSTRACT FROM AUTHOR]

A statistically based runoff-yield model is proposed in this paper. The model considers spatial heterogeneities of rainfall, soil infiltration capacity and soil water storage capacity that are main factors controlling runoff-yield process. It assumes that the spatial variation of rainfall intensity at each time step can be characterized by a probability density function, which is estimated by matching the hyetograph through goodness-of-fit measure, whereas the spatial heterogeneities of soil infiltration capacity and soil water storage capacity are described by parabola-type functions. Surface runoff is calculated according to infiltration excess mechanism; the statistical distribution of surface runoff rate can be deduced with the joint distribution of rainfall intensity and soil infiltration rate, thus obtaining a quasi-analytical solution for surface runoff. Based on saturation excess mechanism, the groundwater flow (flows below the ground are collectively referred to as groundwater flow) is calculated by infiltration and the probability distribution of soil water storage capacity. Consequently, the total runoff is composed of infiltration excess and saturation excess runoff components. As an example, this model is applied to flood event simulation in Dongwan catchment, a semi-humid region and a tributary of Yellow River in China. It indicates that the proposed runoff-yield model could achieve acceptable accuracy. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Yellow River, is designated as 'the cradle of Chinese civilization' and played a key role not only in the country's economic development but also in the historic and cultural identity of the Chinese people. With the rapid economic development and population growth, water demand for industry and households has increased significantly in the Yellow River basin; this has caused an increasing gap between water supply and demand. Competing water demands triggered conflicts between disparate water users on different scales such as the rich and the poor, or between different sectors and regions, such as domestic and agriculture, agriculture and industry, upstream and downstream, rural and urban areas, etc. Ensuring equity in water supply for conflicting water users is one of the major challenges that facing water managers and in particular water management in the Yellow River basin. In this paper, a method has been developed to calculate the Gini coefficient of water use as an indicator to measure the equality in domestic water supply. A dual domestic water use structure model is employed for this purpose. The developed method is subsequently applied to assess the equality in domestic water supply in the Yellow River. Data of population growth, domestic water use and economic development over the time period 1999-2006 are used to calculate the Gini coefficient of water use over the same length of period. The result shows a decreasing trend in Gini coefficient of domestic water use in the Yellow River basin after 2001 which means domestic water use is becoming more and more equitable in the basin. The study justifies that the Gini coefficient of water use can be used and recommended as a useful tool for the water management especially in the context of global change. [ABSTRACT FROM AUTHOR]

The present paper provides a scientific assessment of the inter-decadal variability of the Asian summer monsoon and its significant effect on precipitation patterns in China. The paper consists of four parts. The first part shows the observed inter-decadal weakening of the Asian summer monsoon since the end of 1970s. The second part describes the impact of the weakening Asian summer monsoon on precipitation in China, which caused the major monsoon rainbelt to shift southward from North China to South China over about 30 years, with a 60-80 oscillation dominating. The third part projects the future change of the Asian summer monsoon in the warmer climate by using IPCC AR4 climate models. It has been found that major monsoon rainfall belts in East Asia will move northward in the 2040s, with summer precipitation in North China increasing considerably and stably. Finally, in the fourth part, the implication of the adaptation to the above climate change and related water management will be discussed including the water transport engineering project from the Yangtze River to the Yellow River and North China. [ABSTRACT FROM AUTHOR]

Water resources allocation in a river basin is customarily determined based on long-term mean water availability. However, inter-annual variability of water resources caused by climate fluctuation should also be considered in order to keep an effective and flexible allocation policy. This paper analyzes the historical evolution of the water resources allocation system in the Yellow River basin of China. Based on the concept of water use flexible limit to water shortage and actual water use data from 1988-2006, a set of flexible limits to water shortage adapted to the Yellow River basin has been proposed. This includes total water use flexible limit to water shortage for all provinces, which is approximately 70%; and the different water use flexible limits to water shortage for each social sector, which are approximately 90% for agriculture, 85% for domestic use, and 50% for other industries. It offers a simple, yet effective, method for future water resources allocation in the Yellow River basin to achieve the optimal use of water resources. It likewise provides a beneficial reference for water resources management in the water deficient regions of China. [ABSTRACT FROM AUTHOR]

Owing to the influence of global change, land cover and land use have changed significantly over the last decade in the cold and arid regions of China, such as Madoi County which is located in the source area of the Yellow River. In this paper, land-use/cover change and landscape dynamics are investigated using satellite remote sensing (RS) and a geographical information system (GIS). The objectives of this paper are to determine land-use/cover transition rates between different cover types in the Madoi County over 10 years e.g., from 1990 to 2000. Second, the changes of landscape metrics using various indices and models are quantified. The impact factors of LUCC (Land-Use land cover Change) are systematically identified by integrating remote sensing as well as statistical data, including climate, frozen soil, hydrological data and the socio-economic data. Using 30 m×30 m spatial resolution Landsat (Enhanced) Thematic Mapper (TM/ETM+) data in our study area, nine land cover classes can be discriminated. Our results show that Grassland, Marshes and Water Bodies decrease notably, while oppositely, Sands - Gobi and Barren land increase significantly. The number of lakes with an acreage larger than six hectares decreased from 405 in 1990 to 261 in 2000. Numerous small lakes dried out. The area of grassland with a high cover fraction decreased as well, while the surface area of grassland with a medium level of cover fraction increased. The medium cover fraction grassland mainly originates from high cover fraction grassland. The desertification of land is a serious issue. (ii) The inter-transformations between Grasslands, Barren Land, Sands, Gobi, Water Bodies and Marshes are remarkable. The Shannon-Weaver Diversity Index (SWDI), the Evenness Index (EI) and the extent of Landscape Heterogeneity (LH) has improved. Marshes have become more fragmented hence, with less connected patches. (iii) In the recent 30 years, average annual temperature, the power of evaporation and the index of dryness did increase significantly. Moreover, soil moisture content (SMC) decreased and the drought trend accelerated. The degradation of frozen soil has impacted on the decrease of surface water area and induced a drop in groundwater levels. Monitoring LUCC in sensitive regions would not only benefit from a study of vulnerable ecosystems in cold and high altitude regions, but would provide scientifically based decision-making tools for local governments as well. [ABSTRACT FROM AUTHOR]

Based on graphical and quantitative methodology of landscape ecology and Geo-information Tupu, this paper studies the landscape spatial-temporal evolution characteristics of the Yellow River Delta (YRD), which was built up by periodic physical swings of the Yellow River (YR) rump channel during 1855-2000. According to the research on spatial-temporal evolution of YRD and YR rump channel, we conclude that the Qingshuigou channel has reached its limit and a new flow channel for YR should be built up sooner or later. It suggests that the shift of YR channel should abide by its natural rules of flowing through depressions among previous channels and could be carried out by artificial efforts. The paper discusses the problems and alternate ways out for treatment of the high content of silt in the YR flow at the estuary. [ABSTRACT FROM AUTHOR]

The objective of this paper is to examine a deficit in surface water for the lower reaches of the Yellow River. The methods suggested in this paper to diagnose water shortage problems are simple and practical The results show that the lower reaches of the Yellow River are areas without sufficient water to meet the needs of irrigation, domestic, and industrial uses. The completion of the Sanmenxia reservoir and Xiaolangdi reservoir relax the conflict between water need and supply However if the hydrologic status becomes pessimistic with an exceedence probability of over 80 percent, then the water supply is still severe in the lower reaches of the Yellow River The water resources in the lower reaches of the Yellow River to Tianjin and Qingdao cities are very limited and unstable. The most feasible options to offset the water deficiency in the lower reaches of the Yellow River are: (a) to obtain water from the Yangzi River; (b) to obtain more water from middle and upper reaches through regulation; (c) to conduct a comprehensive water saving program. [ABSTRACT FROM AUTHOR]

This paper presents a rapid forecast model for simulating hyperconcentrated sediment-laden floods in the Lower Yellow River. The model is a hybrid of a conventional one-dimensional mathematical model for unsteady sediment-laden flow and an artificial neural networks model for encapsulation of numerical results. The former provides detailed river flood routing information under typical scenarios, whereas the latter extracts modeling outputs from the former and establishes a station-specific model for efficient flood forecasting. Three typical floods that occurred in the Lower Yellow River in 1977, 1982, and 1996 are simulated. Not only the hybrid model predictions are found to be in close agreement with measured data, but also the computational speed is significantly enhanced. It is found that sediment transport is of significance with regard to the flooding behavior of hyperconcentrated flows. Therefore, the model presented herein is of particular use for rivers with high sediment concentration. [ABSTRACT FROM AUTHOR]

System simulation has proved to be an effective tool for planning and improving the performance of a construction process in many successful case studies. However, with the aid of a three dimensional (3D) visualization system, simulation technology will be engaged to its farthest-reaching potential. This paper presents a geographic information system (GIS)-based visual simulation method, in which system simulation techniques are integrated with visualization techniques. The GIS-based visual simulation system (GVSS) was developed by the authors. The GVSS is a simulation tool offering powerful planning, visualizing, and querying capabilities that facilitate the detection of logic errors in simulation models. The software also helps to understand the comprehensively complex modeled construction process, and is capable of organizing vast amounts of spatial and nonspatial data involved in simulation. A hydroelectric project, which will take place on the Yellow River in the northwest of China, is used as an example. An optimum equipment set scheme is determined by simulating a variety of scenarios taking place under different construction conditions. Likewise, other parameters, such as the construction sequence of dam blocks, the monthly intensity of the concrete process, and the construction appearance at the middle and end of each year, are obtained. Meanwhile, the complex processes of dam construction are demonstrated dynamically using 3D animation, which provides a powerful tool for quickly and comprehensively understanding the whole construction process. The GVSS has proven to be a helpful and useful tool for the design and management of concrete dams. [ABSTRACT FROM AUTHOR]

The Yellow River is the second largest river in China with an annual run-off of 58 billion m3 but its lower course is drying up every year, significantly affecting industrial and agricultural production and the livelihood of the people living alongside the river. This paper analyses the human and natural factors responsible for this phenomenon. The paper concludes with a suggested strategy and countermeasures to mitigate the drying up of the river, including (1) strengthening the unified administrative management and water rights management in the watershed; (2) employing economic measures to promote water conservation as a general policy; (3) developing new water projects and increasing the ability to regulate flow in the watershed; and (4) implementing the South to North Water Transfer Project. [ABSTRACT FROM AUTHOR]

Using field measurements of frazil jams from 1982 to 1989 in the Hequ Reach of the Yellow River, this paper discusses both the mechanism of evolution of a frazil jam, and the associated variation in water level. The variation in water level depends not only on the thickness of the frazil jam but also on the ice discharge. An empirical power-law relationship between the dimensionless ice thickness and Froude number is established. It has been found that the critical Froude number (under an ice cover condition) describing the transition from an ice jam to a hanging dam (overloaded ice jam) is about 0.075, with a dimensionless ice thickness of about 0.4. Interestingly, the results from the St. Lawrence River show a similar tendency with similar limits. [ABSTRACT FROM AUTHOR]

This paper presents results from a 20-year (1990-2009) simulation by RegCM3 with both 45- and 15-km horizontal resolutions. The research focuses on the source region of Yellow River and its surrounding area, which is located on the northeast edge of the Tibetan Plateau with its very complex topography. Driven by the ECMWF ERA-interim reanalysis data, RegCM3 displays reasonable ability to reproduce the spatial patterns, annual cycles, and the interannual variabilities of regional surface climate, though the model shows wet and cold bias. The model's performance is more close to observation for the source region of Yellow River than the other part of the analysis region, and the application of high resolution of 15 km demonstrates better skill with less bias for mean climate and larger correlation coefficients for interannual variability at most stations. However, the high-resolution simulation shows little advantage for reproducing the variations of precipitation and surface air temperature with altitude. The RegCM3 model also generally reproduces the probability distribution functions (PDFs) of surface climate and, consequently, the occurrence of climatic extremes and extreme indices. The simulation with high resolution again proves to be more reliable to generate climatic extremes over complex terrain of the source region of the Yellow River, related to its better representation of complex terrain and local processes. [ABSTRACT FROM AUTHOR]

The Ning-Meng reach of the Yellow River in China is located in a high-latitude area, and river freezes up and breaks up every year, leading to ice flood and disaster. Since the 1990s, due to the rising winter temperatures, river channel shrinkage and impacts of reservoir operation, the river ice regime of the Ning-Meng reach has changed. This paper investigated reservoir operation effect on river ice regime by eliminating the impact of climatic conditions, and the test method could be applied to other rivers, where similar anthropogenic impacts can be suspected to affect the river ice regime. The results show that compared to the statistics when there were no reservoirs, the duration of ice freezing days reduced 8-33 days, and the ice cover thickness was 16-25 cm thinner than that without reservoirs. The average number of ice flood incidents per year decreased from 11.61 to 3.25, and the number of disasters reduced from 1.69 to 1.41. Moreover, the changes induced by reservoirs joint operation may vastly exceed that by single reservoir operation. The smaller is the distance to the upstream reservoir, the more obvious is the impact from the reservoir. [ABSTRACT FROM AUTHOR]

In the last decade, much has been learned about the network of interactions in Bronze Age Eurasia, and the importance of the steppe pastoralists in the creation of this network. However, the mechanisms that enabled societies in ancient China (both those bordering on and distant from the steppe) to participate in the Bronze Age Eurasian arena are still poorly understood. Based on the latest archaeological discoveries in China, this article focuses on the participation of four regions of ancient China: the Ejin River Transfer Zone (ERTZ); the western Hexi corridor; central Inner Mongolia; and the middle Yellow River valley. The article analyzes all significant innovations, materials, and technologies transmitted via the Eurasian network and adopted in ancient China, with an emphasis on metallurgy and the variations in the mechanism of its adoption across different societies during the Bronze Age. The introduction of metallurgy into the ERTZ was an economic imperative, although it was profoundly affected by the political landscape in the middle Yellow River valley. Through analysis and comparison, this paper argues that the participation of different societies of ancient China in the Bronze Age Eurasian network can best be understood in the local and regional contexts, which were deeply embedded in their natural and cultural landscapes, rather than as the result of the pull from the steppe pastoralists alone. [ABSTRACT FROM AUTHOR]

Complex block-flexure slope toppling is observed in interbedded sandstone and slate in the upper Yellow River, China. Block toppling is observed in the relatively hard sandstone and flexural toppling is observed in the relatively soft slate. The evolution of toppling slope deformation is characterized by long-term progress and spatial variability. In order to study these characteristics, field investigations, adit prospecting, borehole drilling, sonic tests and numerical simulation were carried out. In addition, the effect of the structure, the composite mode of the rock mass, the unloading fissures and geomorphology are discussed. Furthermore, we explored the toppling mechanisms and simulated it numerically; on this basis, the slope evolution is divided into four stages. Results obtained from the numerical simulation compared well with field investigation data (investigation data, rock sonic survey and strata dip statistics). Comparative studies have demonstrated that the analytical methods presented in this paper are appropriate for back analysis of the toppling evolution process. The result showed that this toppling slope has not yet entered the later progressivity failure stage and is currently limited to collapse at shallow levels, whereas the deep-seated rock mass will remain stable for a long time. This study might provide reference for a stability evaluation and hazard prevention analysis for rock toppling. [ABSTRACT FROM AUTHOR]

The Ningxia-Inner Mongolia Reach, in the upper Yellow River, is one of the most serious reaches suffering from ice flood disaster in China. Firstly, according to its characteristics of ice condition evolution and ice disaster, the concept of ice disaster risk of Ningxia-Inner Mongolia Reach was defined, the risk factors of ice disaster were discussed, and the theory and method of 'risk identification-risk estimation-risk assessment-risk management' for the ice disaster risk analysis of Ningxia-Inner Mongolia Reach was proposed. Then, the comprehensive evaluation model of ice disaster risk was established using the projection pursuit, fuzzy clustering and accelerating genetic algorithm method. Finally, the ice disaster risk grade was formulated, and the ice disaster risk of 1991-2010 for the Ningxia-Inner Mongolia Reach was evaluated in this paper. The results show that the application results were consistent with the practical characteristics of water regime, meteorological and ice condition, revealing the rationality of the risk evaluation model. This study aims at enriching and developing the theory and method for the ice disaster risk analysis and providing scientific decision basis for the ice-prevention preparedness of Ningxia-Inner Mongolia Reach, in the upper Yellow River. [ABSTRACT FROM AUTHOR]

Purpose: Few studies have described the bacterial community structures of turbid rivers. In this paper, the characteristics of the bacterial community in the water and surface sediment of the Yellow River, China, the largest turbid river in the world, were studied. Materials and methods: Water and sediment samples were collected from six sites along the river. Bacterial community composition was determined using the 16S ribosomal RNA (rRNA) gene clone library technique. The relationship between environmental parameters and bacterial diversity was analyzed. Results and discussion: A total of 1,131 gene sequences were obtained and clustered into 639 operational taxonomic units (at the 97 % identity level), with Proteobacteria as the predominant phylum. The Shannon index for water samples ranged from 3.39 to 4.40 and was generally higher than that in other rivers; this was probably due to the high suspended particulate sediment (SPS) concentration in the Yellow River, which can provide more habitats for both aerobic and anaerobic bacteria. Also, the bacterial diversity of the water samples was slightly higher than that of the surface sediment samples. The bacterial diversity of water increased along the river in the downstream direction, while there was no trend for the sediment. Redundancy analysis indicated that pH, dissolved organic carbon (DOC), and SPS were the main factors controlling the water bacterial community in the Yellow River, and pH, nitrate-nitrogen, and water content were the main factors for the surface sediment bacterial community. Conclusions: This study indicated that the bacterial diversity of the Yellow River is generally higher than that in other rivers, suggesting that SPS plays an important role in regulating bacterial diversity and community structure in aquatic environments. [ABSTRACT FROM AUTHOR]

Siltation of coarse sediment in the river channel is the main cause of flooding and dike burst on China's Yellow River, and the loess are thought as the coarse sediment sources of the lower reach of the Yellow River. The Ningxia-Inner Mongolia reaches of the Yellow River flow through an extensive area of aeolian desert, with flood events occurring frequently in this region. In this paper, we investigate the trace element contents of the coarse sediment in the Ningxia-Inner Mongolia reaches of the Yellow River. The main chemical components of the coarse sediments consist of 28 trace elements. Correlation analysis and factor analysis of 21 of these trace elements indicates that Ti and Zr are stable indicators of the coarse sediment sources. Comparing the spatial distribution of some of the main trace elements to major sources and riverbed sediment of the main reaches of the Yellow River suggests that the coarse sediments deposited in the Ningxia-Inner Mongolia reaches are mostly controlled by the local sediment sources. The results of R-factor analysis further proved that desert sand, riverbank material, and the Ten Tributaries are the primary sources of the coarse sediment in the Ningxia-Inner Mongolia reaches of the Yellow River. [ABSTRACT FROM AUTHOR]

ABSTRACT Due to the temporal decoupling of water and sediment sources in a large river basin, a flood from a sediment source area with high suspended sediment concentration (SSC) may be diluted by flow from a major runoff source area with low SSC. In this paper, this dilution effect is considered for 145 flood events from the Yellow River, China. Two indices ( β1 and β2) describing the dilution effect are proposed, based on water and sediment from the clear water source area and the coarse sediment producing area. Regression equations between channel sedimentation ( Sdep) and β1 and β2 are established based on flood events and annual data, respectively. The results show that dilution reduces channel sedimentation in the lower reaches by 34∙1% and that this is related to a reduced frequency of hyperconcentrated flows in the lower reaches. The Longyangxia Reservoir for hydro-electric generation has stored huge quantities of clear runoff from the upper Yellow River during high-flow season since 1985, greatly reducing the dilution of the hyperconcentrated floods and therefore enhancing sedimentation in the lower reaches. For the purpose of reducing sedimentation, changing the operational mode of the Longyangxia Reservoir to restore the dilution effect is suggested. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Variation of streamflow and sediment load in the Yellow River basin has received considerable attention due to its drastic reduction during the past several decades. This paper presents a detailed investigation on the changes of streamflow and sediment load from 1952 to 2011 using monthly observations at four gauging stations along the Yellow River. The results show significant decreasing trends for both streamflow and sediment load at all four gauging stations over the past 60 years. The wavelet transform demonstrated discontinuous periodicities from 1969 to 1973 and after 1986 due to the construction of large reservoirs and implementation of numerous soil and water conservations practices. The sediment rating curves with the power-law function was applied to investigate the relationship between discharge and sediment load. The results indicate distinct variations of the relationship between streamflow and sediment and implied significant hydro-morphological changes within different periods. The reducing sediment supply from the source region and the increased erosive power of the river are detected at Lanzhou station, while the decrease of the transport capacity at Toudaoguai is caused by severe siltation. Significant changes in the relationship between streamflow and sediment load are found at Huayuankou and Gaocun stations, which are largely induced by evident sediment income and trapping effects of large reservoirs. It is estimated that numerous reservoirs have strongly altered the regime and magnitude of streamflow and trapped large amount of sediment, leading to severe siltation and evident reduction of their total volumes. A decrease in precipitation, incoming water from the upper reaches, soil and water conservation measures as well as water consumption contribute most to the significant reduction of streamflow. The decrease of sediment load mainly resulted from various soil and water conservation measures and trapping in reservoirs from 1986 to 2011. [ABSTRACT FROM AUTHOR]

Soil salinity has been known to be problematic to land productivity and environment in the lower Yellow River Delta due to the presence of a shallow, saline water table and marine sediments. Spatial information on soil salinity has gained increasing importance for the demand of management and sustainable utilization of arable land in this area. Apparent electrical conductivity, as measured by electromagnetic induction instrument in a fairly quick manner, has succeeded in mapping soil salinity and many other soil physical and chemical properties from field to regional scales. This was done based on the correlation that existed between apparent electrical conductivity and many other soil properties. In this paper, four spatial prediction methods, i.e., local polynomial, inverse distance weighed, ordinary kriging and universal kriging, were employed to estimate field-scale apparent electrical conductivity with the aid of an electromagnetic induction instrument (type EM38). The spatial patterns estimated by the four methods using EM38 survey datasets of various sample sizes were compared with those generated by each method using the entire sample size. Spatial similarity was evaluated using difference index (DI) between the maps created using various sample sizes (i.e., target maps) and the maps generated with the entire sample size (i.e., the reference map). The results indicated that universal kriging had the best performance owing to the inclusion of residuals and spatial detrending in the kriging system. DI showed that spatial similarity between the target and reference maps of apparent electrical conductivity decreased with the reduction in sample size for each prediction method. Under the same reduction in sample size, the method retaining the most spatial similarity was universal kriging, followed by ordinary kriging, inverse distance weighed, and local polynomial. Approximately, 70 % of total survey data essentially met the need for retaining 90 % details of the reference map for universal kriging and ordinary kriging methods. This conclusion was that OK and UK were two most appropriate methods for spatial estimation of apparent electrical conductivity as they were robust with the reduction in sample size. [ABSTRACT FROM AUTHOR]

Abstract: Wetlands in irrigated agricultural areas have great environmental benefits as agricultural pollution sinks; but agricultural development and water resources redistribution have caused these wetlands to diminish rapidly worldwide. This is the case in the YinNan Irrigation District (YNID) in the upper reaches of the Yellow River in China, where wetlands once flourished as the result of large amount of irrigation diversion and low irrigation efficiency. In this paper, we presented an analytical study on the impact of irrigation water saving practices on wetland distribution in YNID; we also discussed the effect of considering wetland water consumption as beneficial or efficient use on the overall water use efficiency. The study area has a maximal wetland to farmland areal ratio of 10.5% during the irrigation season due to recharges from canal seepage and field percolation; and 45% of the wetland area remains as the permanent pool area during the non-irrigation season. The observed maximum water table rise in the irrigation season is 1.5m. The current irrigation system efficiency in YNID is 0.30, which is a product of the field level efficiency of 0.68 and the conveyance efficiency of 0.44. Our analysis presented in this paper shows that improving the application efficiency to 0.90 at the field level will reduce the maximum water table rise by 0.53m, causing the wetland area to shrink by 17% and the subsequent wetland water consumption to decrease by 11%; further improving conveyance efficiency to 0.60 will reduce the maximum water table rise by 0.95m, causing the wetland area to shrink by 30% and the subsequent wetland water consumption to decrease by 19%. These results indicate that water saving at the conveyance level will have greater impact on wetland water use than that at the field level. If wetland water consumption is considered as efficient use, this fraction of the irrigation water loss becomes efficient use, which will increase the system efficiency proportionally by the percentage of wetland water consumption. The amount of wetlands, and thus additional beneficial wetland water use, is directly dependent on the amount of traditional water losses, such as wetland consumption here. The key question then becomes: where lies the optimum level or the acceptable balance between increasing efficiencies at irrigation scheme level while providing optimal beneficial use for wetlands. [Copyright &y& Elsevier]

The irrigated areas in the northern region of China are important food production areas. Therefore, studies on the variability of the carbon balance in these agro-ecosystems are fundamental for the management of carbon sequestration. This paper simulated the long-term variability of the carbon balance in a typical irrigated area along the lower Yellow River from 1984 to 2006, using a process-based ecosystem model called the Simple Biosphere Model, version 2. The mean annual gross primary production (GPP), mean annual net assimilation rate (NAR), mean annual soil respiration ( R), and mean annual net ecosystem exchange (NEE) were 1733, 1642, 1304, and −338 g C m a, respectively. A significant increasing trend in the seasonal total NAR during the wheat growing season, and a significant decreasing trend in the seasonal total NAR during the maize growing season were detected. However, no significant trend was found in the annual NAR, R, and NEE. The average carbon sequestration was 1.93 Tg C a when the grain harvest was not taken into account, and the carbon sequestration amount during the maize season was higher than that during the wheat season. However, the agro-ecosystem was a weak carbon source with a value of 0.23 Tg C a, when the carbon in the grain was assumed emitted into the atmosphere. [ABSTRACT FROM AUTHOR]

The major obstacles to simulating flood flow in the Yellow River are its high sediment concentration, complex compound cross section, and rapid change in channel planform. This paper presents an improved one-dimensional numerical model that takes into account the effect of sediment concentration and bed change on mass and momentum conservation of flood flow in the Yellow River. The model is calibrated and then validated by simulating three individual flood events. Results show that an increase in sediment concentration leads to a reduction in flood wave celerity and peak discharge. The generalized likelihood uncertainty estimation (GLUE) method is used to evaluate the uncertainty of modeling results. A sensitivity index, analogous to the Nash-Sutcliffe efficiency factor, is adopted to quantify the sensitivity of calibration parameters. The modeling results are sensitive to the choice of Manning's roughness coefficient and the empirical recovery coefficient for suspended sediment transport at reaches of transitional channel planform. [ABSTRACT FROM AUTHOR]

For decades, the Chinese government has been searching for solutions to cope with the increasing imbalance between the supply and demand of water in the Yellow River Basin. This paper aims at a better understanding of the development of the water allocation regime in the Yellow River Basin between 1950 and 2009, introducing a fresh perspective based on the notion of 'regime transition'. Accordingly, we investigated 1) whether so-called 'Windows of Opportunity for Transition (WOPTs)' emerged, triggering a transition, and whether WOPT(s) resulted in a stable transition towards the new regime; 2) how informal learning processes and epistemic communities have contributed to the regime change. We adapted Kingdon's 'multiple stream model' and identified four WOPTs from the 1950s, analyzing the reconfiguration process of the regime after the onset of the transition. Our examples of two types of informal learning processes demonstrate their contribution to the creation of WOPTs and the reconfiguration of the regime. Furthermore, this study indicates, in a qualitative manner, how epistemic communities contribute to the knowledge base of the regime, and thus to its development. Finally, we have provided a general insight into the further development of the water allocation regime and highlighted potential avenues for further studies. [ABSTRACT FROM AUTHOR]

Understanding the factors affecting irrigation management performance is crucial for sustainable resource use, especially with the decentralized management mode of irrigation systems being implemented in rural China. This paper contributes to the research field by incorporating different categories of social trust and perceived organization support (POS) into the analysis of irrigation management performance, by linking multiple elements that are based on the Institutional Analysis and Development (IAD) framework. We employed principal component analysis (PCA) and ordered probit regression to analyze a database covering 785 households in the upstream of the Yellow River basin. The results suggested that social trust and POS positively affected the irrigation management performance, and social trust strengthened the positive effect of POS on the performance. Furthermore, the results indicated that personal trust and institutional trust, as well as perceived emotional support and physical support, positively affected the performance. In addition, we also found that household characteristics, household cognition, group characteristics, physical conditions, and rules-in-use also had significant impact on the performance. This paper can be used to inform the government that social trust and POS need to be considered in the common-pool resources (CPRs) management. [ABSTRACT FROM AUTHOR]

The paper reviews some representative etymologies so far suggested for Hé 'the Yellow River'. It pays particular attention to the methodologies involved in etymological enquiries. There are basically two of them. One is the comparative method as developed in the Indo-European languages and applied to the Sino-Tibetan and Tibeto-Burman languages. Another one is a traditional method based on the evidence available in Chinese itself. It has roots in Sòng times (ca. 13th c). Known widely as Chinese word-family studies the first systematic work is by a Japanese scholar Tōdō Akiyasu (1914-1985) in his D. Lit. thesis entitled Jōko Kango no tango kazoku no kenkyû (Tokyo University, 1962). Its revised and enlarged version (1965) and other notable works are critically discussed. There is no doubt that Chinese language was used before the emergence of oracle-bone inscriptions (abbreviated hereinafter as OBI) ca. 1230 B.C. (lasting to ca. 1046 B.C.), but the phonological and morphological reconstructions we have for Old Chinese cannot be considered to precede the date of the emergence of OBI. We have thus redefined etymology: it studies the earliest attested meanings of words, of their relationship to those in different languages thought of the same origin, and in the case of many words, but not all of them, be considered in terms of the interface of palaeography and etymology. This paper thus attempts to bridge the two disciplines. Even though the Shāng scribes may not have been the creators of the graphs themselves, they must have continued the traditions of the original graph makers. The Shäng scribes lived more than a thousand years earlier than the users of the clerical script of Hàn time. Many bone and bronze graphs reflect the words they were writing, often subtly mirroring their meanings. How this last aspect has bearing on the etymology of Hé is the major theme of this paper. Not only linguistic but also palaeographical and archaeological analyses in this paper have led to a conclusion that the etymology of Hé is related to both the phonetic and shape of an adze handle, kē/*khâi. This in and of itself is not new, but other details are novel including a finer analysis of the predecessors of written like and as well as that of such Zhōuyuán graphs as and. The former graph consists of the water element and a standing human figure with its head turning backward and carrying a pole with some load. The latter one consists of the water element and a similar human figure, but the carrying pole and the load are abbreviated. The DT of the former is the latter. These forms reflect a scribal tradition different from the predecessors of, and the word represented by these forms is hé/*gâiB 'to carry on the shoulder' and because the sound was close to hé/*gâi, actually closer than kē/*khâi was to it, the graph was loaned to express the Yellow River, Hé. [ABSTRACT FROM AUTHOR]

The Xiaolangdi Dam, completed in 2000, is second in scale in China to the Three Gorges Project. It has generated remarkable economic and social benefits but with profound impacts to the riverine and regional environments. This paper reports field monitoring of riparian groundwater in the Kouma section of the Yellow River to illustrate the interactions between dam-regulated river flow and riparian groundwater. The results show that the hydrological condition in riparian zones downstream from the dam has changed from a typical wet-dry cycle to a condition of semi-permanent dryness, resulting in degradation of the typical attributes and functions of the wetland ecosystem. Hydrological processes in the riparian zone have changed from a complex multiple flooding regime to a simple regime of dominant groundwater drainage towards the river, which only reverses temporarily during the water and sediment regulation period of the dam. Data on groundwater level and groundwater quality show that there are two key points, at ca 200 and 400 m from the river bank, which distinguish zones with different sensitivity to changes of river flow and indicate different interactions between river water and groundwater. The shallow groundwater quality also is negatively affected by the intensive agricultural development that has occurred since the dam was completed. Ecological restoration needs to be carried out to construct a protective natural riparian zone within ca 200 m from the river, this being an ecotone, which is key to the protection of both riparian groundwater and the river. The riparian zone from 200 to 400 m also should be treated as a transitional zone. In addition, ecologically sensitive agriculture and ecotourism organized by local communities would be beneficial in the area beyond 400 m. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Reliable projections of extremes at finer spatial scales are important in assessing the potential impacts of climate change on societal and natural systems, particularly for elevated and cold regions in the Tibetan Plateau. This paper presents future projections of extremes of daily precipitation and temperature, under different future scenarios in the headwater catchment of Yellow River basin over the 21st century, using the statistical downscaling model (SDSM). The results indicate that: (1) although the mean temperature was simulated perfectly, followed by monthly pan evaporation, the skill scores in simulating extreme indices of precipitation are inadequate; (2) The inter-annual variabilities for most extreme indices were underestimated, although the model could reproduce the extreme temperatures well. In fact, the simulation of extreme indices for precipitation and evaporation were not satisfactory in many cases. (3) In future period from 2011 to 2100, increases in the temperature and evaporation indices are projected under a range of climate scenarios, although decreasing mean and maximum precipitation are found in summer during 2020s. The findings of this work will contribute toward a better understanding of future climate changes for this unique region. [ABSTRACT FROM AUTHOR]

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Vegetation significantly influences human health in the Yellow River basin and the plant cover is vulnerable to people. Typical types of erosion in the Yellow River basin include that caused by water, wind and freeze-thaw. In this paper, vegetation cover change from 1982 to 2006 was studied for a number of different erosion regions. The Global Inventory Monitoring and Modeling Studies Normalized Difference Vegetation Index (GIMMS NDVI) data were employed, while climatic data were also used for analysis of other influencing factors. It was shown that: (1) generally the vegetation cover in different erosion regions displayed similar increasing trends; (2) spatially the vegetation cover was highest in the water erosion region, the second highest was in the freeze-thaw region and the lowest in the wind erosion region; and (3) vegetation cover in the Yellow River basin is influenced by climate factors, especially by temperature. In water erosion regions, the temporal change of vegetation cover seemed complicated by comprehensive climatic and human influences. In wind erosion regions, the vegetation cover had close relations to precipitation. In freeze-thaw erosion regions, the vegetation cover was primarily altered by temperature. In all the three erosion regions, significant change of the vegetation cover occurred from 2000 just after the 'Grain for Green' (GFG) programme was implemented throughout China. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: In this paper, the trends of the annual streamflow and precipitation and cross correlations between them were analyzed in nine large river basins of China during 1956–2005. The results indicate that: (1) the annual mean streamflow decreases in arid and semi-arid regions of north China; however, increasing trends occur in south and Southwest China; (2) the annual streamflow and precipitation exhibit reasonable correlation in nine large river basins except those located in inland areas. The annual streamflow over most areas of China is fed by precipitation; however, the decline in streamflow is faster than the decreases of precipitation since 1970s in the arid and semi-arid regions of north China. The relationship between the annual precipitation and streamflow presents a non-stationary state in north China. This non-stationary relationship is strongly influenced by both human activities and precipitation changes; (3) a significant increase of water use might be the major factor responsible for the steeper decline in streamflow than in precipitation in Haihe River, Yellow River and Songliao River basins in north China. In inland river areas, increase of water use and actual evapotranspiration might result in decline in streamflow although precipitation has an increase tendency. This paper sheds light on the non-stationary relationship between annual precipitation and streamflow and possible underlying causes, which will be helpful for a better understanding of the changes of precipitation and streamflow in China at large scale and in other regions of the world. [Copyright &y& Elsevier]

This paper studies the relationship between net primary productivity (NPP) and annual average air temperature (GT) at 0cm above ground in permafrost regions by using revised Chikugo NPP model, cubic spline interpolating functions, and nonlinear regression methods. The source regions of the Yangtze and Yellow Rivers were selected as the research areas. Results illustrate that: (1) There is significant non-linear relationship between NPP and GT in various typical years; (2) The maximum value of NPP is 6.17, 5.87, 7.73, and 5.41 DM·t·hm·a respectively, and the corresponding GT is 7.1, 10.0, 21.2, and 8.9°C respectively in 1980, 1990, 2000 and 2007; (3) In 1980, the sensitivity of NPP to GT is higher than in 1990, 2000 and 2007. This tendency shows that the NPP presents change from fluctuation to an adaptation process over time; (4) During 1980∼2007, the accumulated NPP was reduced to 8.05, and the corresponding carrying capacity of theoretical livestock reduced by 11%; (5) The shape of the demonstration region of ecological compensation system, livelihood support system, and science appraisal system in the source regions of Yangtze and Yellow Rivers are an important research for increasing the adaptation capacity and balancing protection and development. [ABSTRACT FROM AUTHOR]

The high sediment load of the Yellow River results in rapid infilling of its reservoirs when sediment is not regularly flushed. Simultaneously, the downstream reaches of the Yellow River experience extremely high siltation rates, which are reduced when sediment is retained in its reservoirs. To minimize siltation in the reservoirs and the downstream river bed, water and sediment are released from the reservoir in a controlled way through flushing experiments. In this paper, we analyze the effect of such a flushing event on the downstream river bed through data analysis and numerical modeling. Sedimentation may be minimized by relating the amount of sediment released from the reservoir to the sediment available for release through operational monitoring and by releasing relatively clear water after turbid water. Despite this flushing of sediment, the reservoir will eventually fill up, and more sediment released again into the lower Yellow River. The change in discharge magnitude and frequency brought about by the reservoir will then probably result in increased siltation rates in the lower Yellow River compared to the predam situation. [ABSTRACT FROM AUTHOR]

The changes in streamflow and sediment discharge in the middle reaches of the Yellow River are a focus. In this paper, based on the precipitation, streamflow and sediment discharge series data (1950-2008), the streamflow and sediment discharge variation and its impact on precipitation/response to human activities have been analysis. The results show that significant decreasing trends in annual streamflow and sediment discharge have existed since the late 1950s in the middle reaches of the Yellow River (P = 0.01). Change-point analyses further revealed that transition years existed and that abrupt decline in streamflow and sediment discharge began in 1985 and 1981, respectively, in the middle reaches of the Yellow River (P = 0.05). Adoption of conservation measures in the 1980s and 1990s corroborates the identified transition years. Double-mass curves of precipitation vs. streamflow (sediment) for the periods before and after the transition year show remarkable decreases in proportionality of streamflow (sediment) generation. Compared with the period before the transition year, cumulative streamflow and cumulative sediment discharge reduced respectively by 17.8% and 28% during 1985-2008, which was caused by human intervention, in the middle reaches of the Yellow River. It is, therefore, concluded that human activities occupied a dominant position and played a major role in the streamflow and sediment discharge reduction in the middle reaches of the Yellow River. [ABSTRACT FROM AUTHOR]

This paper presents the mechanical behavior of two innovative prestressed composite linings in shield tunnels for water conveyance. The Yellow River Crossing Tunnel of the Middle Route Project of the South-to-North Water Division Project (SNWD) is adopted in this study as a case. Three-dimensional finite element models are established to analyse the stress distribution and deformation feature of the prestressed composite lining when the tunnel is under the completed segment assembly condition (CSAC), the completed cable tension condition (CCTC) and the design water pressure condition (DWPC). The calculation and analysis results reveal that the prestressed composite lining with rebars (Model R) has an obviously combined bearing capacity, and the rebar is the key factor influencing the capacity. The prestressed composite lining with membranes (Model M) has a relatively separated bearing capacity, because the membrane can play a significant role in preventing stress transmission between the segmental ling and the secondary lining. Full circular compression can be realized for the secondary linings of both Model R and Model M when the tunnel is under the DWPC. However, the load bearing mechanism of Model M is more concise than that of Model R, the secondary lining of Model M is more secure than that of Model R because of the full use of prestresses and materials, and the membrane is beneficial to anti-seepage. By contrast, Model M is more suitable for the Yellow River Crossing Tunnel. [ABSTRACT FROM AUTHOR]

Zhang, J., Lu, H., Wu, N., Li, F., Yang, X., Wang, W., Ma, M. & Zhang, X. 2010: Phytolith evidence for rice cultivation and spread in Mid-Late Neolithic archaeological sites in central North China. Boreas, Vol. 39, pp. 592–602. 10.1111/j.1502-3885.2010.00145.x. ISSN 0300-9483. The history of rice ( Oryza sativa) cultivation in North China is ambiguous owing to a lack of evidence from rice remains with precise ages in archaeological sites. In this paper, we present rice phytolith evidence from six archaeological sites in the Guanzhong Basin, central North China, dating from c. 5500 to 2100 cal. a BP (calibrated/calendar ages) based on 19 AMS-dates. The phytoliths found in the three archaeological sites located on the second river terrace (Quanhu, Yangguanzhai and Anban) include three types of phytoliths from rice, namely bulliform, parallel-bilobe and double-peaked. These findings suggest that the earliest cultivated rice in central North China occurred not later than c. 5690 cal. a BP. After c. 5500 cal. a BP, the farming pattern in the Guanzhong Basin was characterized by dominant dry crops (e.g. millets) and locally cultivated rice. A likely spread route of rice from the lower reaches of the Huanghe (Yellow) River towards the Guanzhong Basin in central North China is speculated to have happened at c. 5690 cal. a BP. The findings of this study help us to understand the farming pattern in the area and how rice spread across the semi-arid regions of East Asia. [ABSTRACT FROM AUTHOR]

Abstract: The magnitude of bankfull discharge is an important indicator of the discharging capacity of the Lower Yellow River (LYR), and bankfull discharges at key sections need to be accurately estimated before each experiment of regulating water and sediment in the Yellow River. In this paper, a definition of bankfull stage is first proposed for complicated cross sections in the LYR, including the identification of the main-channel zone and corresponding bankfull elevation, and the geometrical characteristics of typical cross-sectional profiles are investigated during different periods. Four different approaches are listed herein to determine the magnitude of bankfull discharge in the LYR, including a method using the mean daily stage–discharge relation, a method using the instantaneous stage–discharge relation, a method using the stage–velocity relation, and a method using the simulated stage–discharge relation from a one-dimensional hydrodynamic model. The advantages, disadvantages, and applicability of these approaches are pointed out. Finally, the Huayuankou section in the braided reach of the LYR is selected as a study section, and the bankfull discharges at this section during different periods are estimated using these four methods. In addition, the predicted water levels from these approaches are compared with the observed values for the corresponding maximum discharges occurring in the next year. Calculated results show that existing approaches determining the magnitude of bankfull discharge are usually only applicable to specified hydrometric sections with negligible morphological changes during flood seasons, and the fourth method proposed in this paper has higher prediction accuracy than the other methods. [Copyright &y& Elsevier]

This paper analyses the contents and species distributions of rare earth elements (REEs) in the water-suspended particulate-sediment system of the Baotou section of the Yellow River, China, with known anthropogenic REE input from industrial discharges. The major forms of REEs were suspended and dissolved in the mainstream and the tributaries of the Baotou section, respectively. The concentrations of the dissolved and suspended REEs had the same trends in the overlying water along the mainstream, which increased from the Seqi section (site A) to the mouth of the Sidaosha River (site D), reaching a maximum value at site D, and tending to decrease thereafter. The contents of REEs in sediment cores showed enrichment with light rare earth elements (LREEs). The bound to carbonates and to Fe–Mn oxides are the major forms of REE in the secondary phase and the REE exhibited LREE enrichment pattern and moderate Eu depletion in suspended particulates and surface sediments. The contents and species distributions of REEs in the water-suspended particulate-sediment system of the Baotou section suggest that the anthropogenic source of REEs from Baotou city have enhanced REE accumulation to the Baotou section. This information is important for predicting possible pollution resulting from anthropogenic REE input into rivers. [ABSTRACT FROM AUTHOR]

Abstract  The paper analyzes the characteristics and stability of the Jishixia landslide on the Yellow River in Qinghai Province, China, based on field investigations and various exploratory data. The current stability of the landslide was calculated and the future potential stability was assessed assuming a peak ground acceleration of 0.11g due to an earthquake, and the moisture created by flood discharge from the hydropower station. The results indicate that at present the overall landslide is stable, but further movement could be triggered by an earthquake event and/or significant wetting. [ABSTRACT FROM AUTHOR]