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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]

Climate change impacts on hydrological processes should be simulated for river basins using validated models and multiple climate scenarios in order to provide reliable results for stakeholders. In the last 10-15 years climate impact assessment was performed for many river basins worldwide using different climate scenarios and models. Nevertheless, the results are hardly comparable and do not allow to create a full picture of impacts and uncertainties. Therefore, a systematic intercomparison of impacts is suggested, which should be done for representative regions using state-of-the-art models. Our study is intended as a step in this direction. The impact assessment presented here was performed for three river basins on three continents: Rhine in Europe, Upper Niger in Africa and Upper Yellow in Asia. For that, climate scenarios from five GCMs and three hydrological models: HBV, SWIM and VIC, were used. Four "Representative Concentration Pathways" (RCPs) covering a range of emissions and land-use change projections were included. The objectives were to analyze and compare climate impacts on future trends considering three runoff quantiles: Q90, Q50 and Q10 and on seasonal water discharge, and to evaluate uncertainties from different sources. The results allow drawing some robust conclusions, but uncertainties are large and shared differently between sources in the studied basins. The robust results in terms of trend direction and slope and changes in seasonal dynamics could be found for the Rhine basin regardless which hydrological model or forcing GCM is used. For the Niger River scenarios from climate models are the largest uncertainty source, providing large discrepancies in precipitation, and therefore clear projections are difficult to do. For the Upper Yellow basin, both the hydrological models and climate models contribute to uncertainty in the impacts, though an increase in high flows in future is a robust outcome assured by all three hydrological models. [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]

The overexploitation of water resources has a substantial influence on their sustainable utilization and the ecological environment in a river basin. Quantification of the development and utilization of water resources plays an important role in guiding the rational utilization of water resources. Based on this, this paper develops the concept of water resource utilization polarization (WRUP) in order to qualitatively analyze whether water resources are being overexploited in the process of utilization. An index model of WRUP was built to quantify the degree of water resources overexploitation. In addition, taking seven secondary basins of the Yellow River as examples, the available quantity, overdraft and polarization indexes of surface water and groundwater resources were calculated. The results show that there are 34.49×108 m3 of surface water available, which accounts for 56.21% of the total surface water volume. A total of 5.84×108 m3 of groundwater is available, which is 58.74% of the total groundwater resources. We also found that the water resources are heavily overexploited and that there is extensive polarization in the middle and lower reaches of the Yellow River. The highest polarization of water resources occurs from Lanzhou to Toudaoguai where the polarization index is 19.88 and from Longmen to Sanmenxia where it is 11.81. There is no polarization above Longyangxia or from Toudaoguai to Longmen. Overall, the polarization of water resources is 7.95 over the entire Yellow River area. These results provide a reference for the availability of water resources that can be used to determine the degree of overexploitation of the water resources in the Yellow River. [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]

The hydrological cycle over the Yellow River has been altered by the climate change and human interventions greatly during past decades, with a decadal drying trend mixed with a large variation of seasonal hydrological extremes. To provide support for the adaptation to a changing environment, an experimental seasonal hydrological forecasting system is established over the Yellow River basin. The system draws from a legacy of a global hydrological forecasting system that is able to make use of realtime seasonal climate predictions from North American Multimodel Ensemble (NMME) climate models through a statistical downscaling approach but with a higher resolution and a spatially disaggregated calibration procedure that is based on a newly compiled hydrological observation dataset with 5 decades of naturalized streamflow at 12 mainstream gauges and a newly released meteorological observation dataset including 324 meteorological stations over the Yellow River basin. While the evaluation of the NMME-based seasonal hydrological forecasting will be presented in a companion paper to explore the added values from climate forecast models, this paper investigates the role of initial hydrological conditions (ICs) by carrying out 6-month Ensemble Streamflow Prediction (ESP) and reverse ESP-type simulations for each calendar month during 1982-2010 with the hydrological models in the forecasting system, i.e., a large-scale land surface hydrological model and a global routing model that is regionalized over the Yellow River. In terms of streamflow predictability, the ICs outweigh the meteorological forcings up to 2-5 months during the cold and dry seasons, but the latter prevails over the former in the predictability after the first month during the warm and wet seasons. For the streamflow forecasts initialized at the end of the rainy season, the influence of ICs for lower reaches of the Yellow River can be 5 months longer than that for the upper reaches, while such a difference drops to 1 month during the rainy season. Based on an additional ESP-type simulation without the initialization of the river routing model, it is found that the initial surface water state is the main source of streamflow predictability during the first month, beyond which other sources of terrestrial memory become more important. During the dry/wet periods, the dominance of ICs on the streamflow predictability can be extended by a month even in the rainy season, suggesting the usefulness of the ESP forecasting approach after the onset of the hydrological extreme events. Similar results are found for the soil moisture predictability but with longer influences from ICs. And the simulations indicate that the soil moisture memory is longer over the middle reaches than those over the upper and lower reaches of the Yellow River. The naturalized hydrological predictability analysis in this study will provide a guideline for establishing an operational hydrological forecasting system as well as for managing the risks of hydrological extremes over the Yellow River basin. [ABSTRACT FROM AUTHOR]

As a result of climate change/variation and its aggravation by human activities over the past several decades, the hydrological conditions in the middle Yellow River in China have dramatically changed, which has led to a sharp decrease of streamflow and the drying up of certain tributaries. This paper simulated and analysed the impact of sediment-trapping dams (STDs, a type of large-sized check dam used to prevent sediment from entering the Yellow River main stem) on hydrological processes, and the study area was located in the 3246 km2 Huangfuchuan River basin. Changes in the hydrological processes were analysed, and periods of natural and disturbed states were defined. Subsequently, the number and distribution of the STDs were determined based on data collected from statistical reports and identified from remote sensing images, and the topological relationships between the STDs and high-resolution river reaches were established. A hydrological model, the digital Yellow River integrated model, was used to simulate the STD impact on the hydrological processes, and the maximum STD impact was evaluated through a comparison between the simulation results with and without the STDs, which revealed that the interception effect of the STDs contributed to the decrease of the streamflow by approximately 39%. This paper also analysed the relationship between the spatial distribution of the STDs and rainfall in the Huangfuchuan River basin and revealed that future soil and water conservation measures should focus on areas with a higher average annual rainfall and higher number of rainstorm hours. © 2015 The Authors Hydrological Processes Published by John Wiley & Sons Ltd. [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]

Ecological protection and high-quality development in the Yellow River Basin has become a major national strategy, and the coupling coordination of economic growth, industrial development and ecology in this area is becoming a research hot spot. This paper analyzed the coupling coordination mechanism of economic growth, industrial development and ecology in the Yellow River Basin and constructed an evaluation index system of coupling coordination degree. Using the coupling coordination model, the spatial autocorrelation model and grey relational model, this paper analyzed the space differences and time differences of the coupling coordination degree of 62 cities in the Yellow River Basin and their driving factors from 2012 to 2018, And the GM (1, 1) gray prediction method was used to predict the coupling coordination degree in the short term. The results showed that：① The overall level of economic growth, industrial development and ecology in the Yellow River Basin had shown a steady trend, and there were no significant differences in the speed of development. However, the coupling coordination of them was seriously out of coordination, and the coupling coordination of ecological protection and high-quality development in the Yellow River Basin had not yet reached a coordinated level,② The coupling coordination degree demonstrated significant global and local spatial autocorrelation features. The global spatial auto-correlation was positive and the convergence features were obvious. (3) The forecast results showed that the coupling coordination degree remained generally stable and coordination had not been reached during the forecast period in this area. The rate of improvement was relatively slow. Finally, a support system incorporating organizational guarantee, spatial governance, policy guarantee and institutional mechanism was established for economic growth and ecological protection in the Yellow River Basin. It is expected that this paper can provide a theoretical basis and lay a certain scientific decision-making foundation for the ecological protection and high-quality development in the Yellow River Basin, [ABSTRACT FROM AUTHOR]

Ice disaster is serious in Ning-Meng reach of Yellow River in China. Due to the complexity of ice disaster, it usually presents grey uncertainty. In order to evaluate the probability of ice disaster loss caused by the adverse events and reveal the development between ice regime data and ice disaster risk under grey information environment, this paper assesses and analyzes the ice disaster risk in Ning-Meng reach of Yellow River. Firstly, the index system of ice disaster risk is established based on the formation mechanism of ice disaster and the novel features of ice regime presented in recent years. Then, the two-phased intelligent model under grey information environment is proposed. The risk degree of ice disaster is assessed with grey interval relational clustering at the first phase, and the decision rules that reflect the development between ice regime information and ice disaster risk degree are extracted with grey dominance-based rough set approach at the second phase. The last empirical analysis of ice disaster risk in the year of 1996-2015 shows that the evaluated ice disaster risk degree of different years is consistent with the practical ice regime characteristics and the extracted decision rules could do as the intuitive criterion to estimate the ice disaster risk through ice regime data. [ABSTRACT FROM AUTHOR]

The potential nutrient stoichiometry changes caused by trout cage aquaculture is concerned especially in oligotrophic waters. Long-term total nitrogen (N), total phosphorus (P) and N:P ratio changes in 6 cascade reservoirs with rainbow trout cage aquaculture in the oligotrophic upstream Yellow River (UYR) were studied from 2013 to 2017 in this paper. The 5-year monitoring results showed that N, P and N:P ratio levels showed no obvious long-term changes in high-altitude oligotrophic waters with rainbow trout cage aquaculture. No obvious longitudinal N, P and N:P ratio level changes were observed in the 6 cascade reservoirs from upstream Longyangxia Reservoir (LYR) to downstream Jishixia Reservoir (JSR). The increased N and P resulting from the cage aquaculture accounted only for 1.74% and 5.2% of the natural N and P levels, respectively, with a fish production of 10,000 tonnes. The upstream Yellow River remained oligotrophic and phosphorus-limited. Results in this study proved that trout cage aquaculture do not necessarily cause nitrogen, phosphorus and N:P ratio changes even in oligotrophic waters. Phosphorus should be considered first when identifying priority nitrogen and phosphorus sources and the corresponding control measures in waters with high N:P ratio. [ABSTRACT FROM AUTHOR]

Reservoir sedimentation usually occurs in rivers that carry heavy amounts of silt. Setting reasonable schedules for drainage hole operations can balance the reservoir sediment levels and downstream river morphology. China's Yellow River is well known for its abundant sediment supply. The Xiaolangdi Reservoir is the key control project for the main stem of the Yellow River, and its sediment accumulation is especially serious. Preventing sedimentation before the gates is an important issue. The characteristics of the flow and sediment before the intake towers under scheduled drainage hole operations should be thoroughly researched. In this study, a three-dimensional numerical model was established based on MIKE 3. Variations of the flow structure, sediment concentration, and sedimentation elevation were the parameters studied under the scheduled operations. The results showed that the features of the bend flow are developed during the model phase. The velocity distribution in the vertical direction does not follow the general logarithmic distribution law of open channels. Scouring funnels appear during the development of the sedimentation surface before the intake towers. The sedimentation elevation is lower than the permissible value and has no influence on gate operations. This paper can provide a reference for similar research. [ABSTRACT FROM AUTHOR]

Fluid field can have significant effects on corrosion rates of steels. The objective of this paper is to investigate erosion-corrosion mechanisms of J55 steel and the effects of local hydrodynamic factors, in particular, the fluid flow velocity on J55 steel’s service life. A new experimental setup was developed to specifically simulate the actual hydrodynamic conditions of Huanghe (Yellow) River valley. Computational fluid dynamics (CFD) model was adopted to characterize the hydrodynamic factors, such as the flow rate, the turbulence kinetic energy and the shear stress, and their effects on the corrosion behavior of J55 steel. Corrosion morphology was analyzed. Results show that the erosion rate increased with the flow rate and the resulting corrosion pit became smaller and deeper. Through the research results of this paper, it could provide some technical supports for the scientific and rational exploitation of brine. [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]

The upper Yellow River basin is located in the new Silk Road economic belt. Fundamental to the healthy development of the Yellow River ecosystem and the security of water resources in the economic belt are the hydrological regime change that drives river ecosystem processes, or called ecological flow regimes (EFR). When developing a sustainable and ecofriendly Silk Road economic belt, the evaluation of the alteration of the EFR and an attribute analysis should receive great attention because they can provide decision makers with more information on ecological implications for balancing environmental and human water needs. The objective of this paper is to investigate the EFR variation at the Lanzhou gauge as the control section of the upper Yellow River basin. First, the paper addresses the macroscale EFR using ecoflow metrics (ecodeficit and ecosurplus), i.e., the multi-year trend of the annual and seasonal changes in ecological flow. Second, it evaluates microscale variations in EFR via the Yellow River ecohydrological index system and compares them with macroscale changes in EFR to verify their consistency. Third, it analyzes the attributes of EFR variation and determines the impact of the construction and operation of reservoirs on the variation. Results show that macro- and microscale EFR at the Lanzhou gauge have significant changes before and after the construction of reservoirs in the upper Yellow River basin, reaching a high degree of alteration. Reservoir construction and operation have been the major reason for the alteration of EFR in the past few decades, and the cascade reservoir regulation has more significantly affected the changes in EFR than has a single reservoir, placing the downstream fluvial ecological system under serious risk. This change should arouse considerable concern, particularly in the development of the new Silk Road economic belt. In addition, ecoflow metrics used for reflecting the macroscale change in this study are highly correlated with microscale indicators of EFR that are accepted in the upper Yellow River basin. This result implies that ecoflow metrics can mirror most ecological information from these microscale indicators and are suitable for the evaluation of alterations in hydrological processes at annual and seasonal timescales. [ABSTRACT FROM AUTHOR]

This is the second paper of a two-part series on introducing an experimental seasonal hydrological forecasting system over the Yellow River basin in northern China. While the natural hydrological predictability in terms of initial hydrological conditions (ICs) is investigated in a companion paper, the added value from eight North American Multimodel Ensemble (NMME) climate forecast models with a grand ensemble of 99 members is assessed in this paper, with an implicit consideration of human-induced uncertainty in the hydrological models through a post-processing procedure. The forecast skill in terms of anomaly correlation (AC) for 2m air temperature and precipitation does not necessarily decrease over leads but is dependent on the target month due to a strong seasonality for the climate over the Yellow River basin. As there is more diversity in the model performance for the temperature forecasts than the precipitation forecasts, the grand NMME ensemble mean forecast has consistently higher skill than the best single model up to 6 months for the temperature but up to 2 months for the precipitation. The NMME climate predictions are downscaled to drive the variable infiltration capacity (VIC) land surface hydrological model and a global routing model regionalized over the Yellow River basin to produce forecasts of soil moisture, runoff and streamflow. And the NMME/VIC forecasts are compared with the Ensemble Streamflow Prediction method (ESP/VIC) through 6-month hindcast experiments for each calendar month during 1982-2010. As verified by the VIC offline simulations, the NMME/VIC is comparable to the ESP/VIC for the soil moisture forecasts, and the former has higher skill than the latter only for the forecasts at long leads and for those initialized in the rainy season. The forecast skill for runoff is lower for both forecast approaches, but the added value from NMME/VIC is more obvious, with an increase of the average AC by 0.08-0.2. To compare with the observed streamflow, both the hindcasts from NMME/VIC and ESP/VIC are post-processed through a linear regression model fitted by using VIC offline-simulated streamflow. The post-processed NMME/VIC reduces the root mean squared error (RMSE) from the post-processed ESP/VIC by 5-15 %. And the reduction occurs mostly during the transition from wet to dry seasons. With the consideration of the uncertainty in the hydrological models, the added value from climate forecast models is decreased especially at short leads, suggesting the necessity of improving the large-scale hydrological models in human-intervened river basins. [ABSTRACT FROM AUTHOR]

Water is a major limiting factor of human survival and social economic development. Water security is also important for the ecological system. In this paper, the water security assessment index system of the Yellow River basin was developed based on three subsystems: the water resources subsystem, the water environment subsystem and the social economic subsystem. The integrated assessment of water security was developed based on the combination of set pair analysis (SPA) and fuzzy analytical hierarchy process (FAHP) as well as technique for order preference by similarity to ideal solution (TOPSIS), gray relational analysis (GRA), vague sets (VS) and matter element (ME) models. First, fuzzy cluster analysis method was used to check the consistency of all the models before and after implementing the integrated assessment. Secondly, the ranking values of four single assessment models (i.e., TOPSIS, GRA, VS and ME models) were analyzed by SPA method to get the consistency connection degree. Then FAHP was constructed to describe the relative importance of the four different single models when determining the weight coefficient in the integrated assessment model. And lastly, the integrated assessment model of water security was developed based on the ranking values and weight coefficients of the selected single assessment models. The conclusion of the developed integrated assessment model which was applied in the Yellow River basin showed that Sichuan province was at security level; Henan, Shandong, Qinghai and Shaanxi provinces were at the threshold security level; Shanxi, Gansu and Inner Mongolia provinces were at the relative insecurity level; Ningxia province was water no secure. The integrated assessment results showed that the improved integrated model presented in this paper had relatively better performance than single assessment models. The intention of this paper was to provide an integrated assessment model, propose potential countermeasures, and achieve sustainable water utilization in the Yellow River basin. [ABSTRACT FROM AUTHOR]

To improve the agricultural water-saving technology in the Yellow River Irrigation District. Methods: Establishing the CGE model based on Yellow River Irrigation District. The article introduces the water shortage of the Yellow River area, describes the water saving technology in the relevant irrigation district in detail, and constructs the CGE model of the Yellow River irrigation district by using the set of module functions. This paper studies the data base of CGE model, analyzes the experimental data by Gragg method, and finds that the more the magnitude of irrigation water reduces, the more the water price increases. The CGE model based on the Yellow River Irrigation District in this paper can promote the development of water-saving technology of the irrigation district. [ABSTRACT FROM AUTHOR]

Radioactive tracer techniques may be useful for assessing water transport and the overall effects of concurrent biogeochemical processes in river‐reservoir systems. In this study, we show that radium isotopes can assess the hydrodynamics and sediment/nutrient retention in the Xiaolangdi Reservoir, the largest impoundment along the Yellow River, China. Activity ratios of 224Ra/226Ra and 223Ra/226Ra were used for water mass age calculations in the riverine, transition, and lentic reaches of the reservoir. Water ages were combined with the length scale of three river‐reservoir zones to determine water transport rates of 3.6 ± 1.2, 1.3 ± 0.3, and 0.16 ± 0.14 km/day, respectively. Radium ages were also used to quantify the net retention of sediment and nutrients in different parts of the river‐reservoir system. Suspended sediment was removed at a rate of 1.4 ± 0.6 g/m3/day, mainly in the riverine zone. Nutrient dynamics were more complicated, with addition or removal at different rates within the three zones. Plain Language Summary: This paper should be of interest to fluvial aquatic scientists and resource managers. Typically, numerical models have been used to estimate reservoir hydrodynamics, and associated biogeochemical processes are investigated separately. Here for the first time, we explore the validity of using radium isotope tracers to assess water age distributions in the Xiaolangdi Reservoir, the largest impoundment along the Yellow River (China). Radium ages were then used to quantitatively evaluate the net retentions of suspended sediments and nutrients within the reservoir. The technique is easy to conduct at relatively low cost and allows one to assess the overall effect of synchronized biogeochemical processes. Key Points: Ra‐age technique is suitable for hydrodynamic assessments in river‐reservoir systems where model assumptions are metSediment and nutrient retentions may be quantified using Ra water agesNutrients are added and/or removed at different rates within three identified zones of the reservoir [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]

Risk evaluation for natural disasters is an important part of the emergency management, disaster prevention and mitigation. Because of the complexity and uncertainty of practical evaluation problems, the evaluation information available generally needs depiction of interval gray numbers instead of real numbers. This paper presents an evaluation method with three-parameter interval gray numbers which can deal with dynamic multiple indicators in order to evaluate efficiently the ice-jam disaster risk of Ningxia-Inner Mongolia reaches of the Yellow River in China. The gray range transformation is introduced into the process of model building to eliminate the incomparability of different dimensions. Moreover, model GM(1,1) is used to simulate and predict the development trend of risk vector. As the results show, while the ice-jam disaster risk of Ningxia-Inner Mongolia reaches of the Yellow River reveals certain wave characteristics, the overall trend remains smooth. The risk degree of ice-jam disaster with Bayangol and Toudaoguai is expected to decrease in the years between 2013 and 2015, while that with Sanhu River tends to increase. [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]

This paper investigates the effect of deficiencies in the tunnel crown thickness on pressure tunnels with the posttensioned concrete lining. Based on the lining parameters of the Yellow River Crossing Tunnel, the modeling approach of the posttensioned concrete lining is introduced in detail and a three-dimensional finite element model is established. The three-dimensional finite element model is validated by experimental results from the full-scale model experiment of the Yellow River Crossing Tunnel. Special attention is given to the changes in the deformation, radial displacement, and circumferential stress of the posttensioned concrete lining with gradual decreases in the tunnel crown thickness. The calculation results show that the influence scopes of deficiencies in the tunnel crown thickness are mainly concentrated in the crown and its adjacent parts. The posttensioned concrete lining can still maintain a satisfactory stress state when deficiencies in the tunnel crown thickness exist, and undesirable stress levels may be caused only when the tunnel crown thickness decreases below a certain threshold. Furthermore, cracks are most likely to occur at the external and internal surfaces of the crown and at the internal surface of the crown’s adjacent parts, which is useful for taking measurements regarding the lining tightness and stability. [ABSTRACT FROM AUTHOR]

For a pile foundation design, the value of proportional coefficient m to define the soil horizontal resist force is a significant parameter. However, different geological conditions and experimental environment have led to different m values. In this paper, an in situ test is firstly carried out on the horizontal bearing capacity of large-size precast square-piles. The piles deformation is then derived by using the optimization method from the measured data. Secondly a back analysis model is established to calculate the m value by using the simplex method, which reveals the evolution rule of the value of proportional coefficient m. Results show that the horizontal bearing characteristics of precast piles depend on the interaction force of piles and soils. The action mechanism of the soils around the piles is gradually developed with the increase in the concrete content. The horizontal critical load and the Eigenvalue of horizontal bearing capacity increased by 16.7% and 20%, respectively. It is also seen that the higher the content of the cement-soil around the piles and the longer the pile length, the bigger the m value obtained. The variation of the proportional coefficient m with the horizontal displacement of pile top is defined by three stages: rapid decaying stage, slow decaying stage, and balanced stage, respectively. The inverse analysis method on the proposed m value can accurately reflect the actual working state of piles and soils. In the depth of 3~18m in the west of Ji'nan, the range of m value is recommended as 4~6.58 MN·m-4. When Δ takes 12mm, the values of m are consistent with the result from the back analysis. In summary, the obtained m value can be effectively used to guide the design of enclosure structure in the super deep foundation pit in the Yellow River alluvial stratum. [ABSTRACT FROM AUTHOR]

The levels, spatial variation, congener profiles, impact factors, and ecological risk of polychlorinated biphenyls (PCBs) in the sediment from the Yellow River of Henan section, China, were investigated in this paper. Total concentration of 31 PCBs and seven indicator PCBs varied from ND to 1015 pg g−1 and ND to 423 pg g−1, respectively. Compared with other aquatic environments around China, PCB levels in the studied area were relatively low. Spatial variations revealed that tributaries possessed higher PCB levels, in comparison to mainstream, which acted as input sources of PCBs in the mainstream. The homolog profiles were dominated by lighter PCBs (Tri-PentaCBs), contributing above 70% of total PCBs. Correlation analysis between PCB concentrations and total organic carbon indicated that local input or atmospheric deposition was the primary controls of spatial variation of PCBs. According to simple sediment quality guidelines (SQG), the risks posed by PCBs in the sediments might be negligible. [ABSTRACT FROM AUTHOR]

The hydropower system in the Upper Yellow River (UYR), one of the largest hydropower bases in China, plays a vital role in the energy structure of the Qinghai Power Grid. Due to management difficulties, there is still considerable room for improvement in the joint operation of this system. This paper presents a general LINGO-based integrated framework to study the operation of the UYR hydropower system. The framework is easy to use for operators with little experience in mathematical modeling, takes full advantage of LINGO’s capabilities (such as its solving capacity and multi-threading ability), and packs its three layers (the user layer, the coordination layer, and the base layer) together into an integrated solution that is robust and efficient and represents an effective tool for data/scenario management and analysis. The framework is general and can be easily transferred to other hydropower systems with minimal effort, and it can be extended as the base layer is enriched. The multi-objective model that represents the trade-off between power quantity (i.e., maximum energy production) and power reliability (i.e., firm output) of hydropower operation has been formulated. With equivalent transformations, the optimization problem can be solved by the nonlinear programming (NLP) solvers embedded in the LINGO software, such as the General Solver, the Multi-start Solver, and the Global Solver. Both simulation and optimization are performed to verify the model’s accuracy and to evaluate the operation of the UYR hydropower system. A total of 13 hydropower plants currently in operation are involved, including two pivotal storage reservoirs on the Yellow River, which are the Longyangxia Reservoir and the Liujiaxia Reservoir. Historical hydrological data from multiple years (2000–2010) are provided as input to the model for analysis. The results are as follows. 1) Assuming that the reservoirs are all in operation (in fact, some reservoirs were not operational or did not collect all of the relevant data during the study period), the energy production is estimated as 267.7, 357.5, and 358.3×108 KWh for the Qinghai Power Grid during dry, normal, and wet years, respectively. 2) Assuming that the hydropower system is operated jointly, the firm output can reach 3110 MW (reliability of 100%) and 3510 MW (reliability of 90%). Moreover, a decrease in energy production from the Longyangxia Reservoir can bring about a very large increase in firm output from the hydropower system. 3) The maximum energy production can reach 297.7, 363.9, and 411.4×108 KWh during dry, normal, and wet years, respectively. The trade-off curve between maximum energy production and firm output is also provided for reference. [ABSTRACT FROM AUTHOR]

Medium- and long-term runoff forecasting is essential for hydropower generation and water resources coordinated regulation in the Yellow River headwaters region. Climate change has a great impact on runoff within basins, and incorporating different climate information into runoff forecasting can assist in creating longer lead-times in planning periods. In this paper, a multimodel approach was developed to further improve the accuracy and reliability of runoff forecasting fully considering of large-scale and local-scale climatic factors. First, with four large-scale atmospheric oscillations, sea surface temperature, precipitation, and temperature as the predictors, multiple linear regression (MLR), radial basis function neural network (RBFNN), and support vector regression (SVR) models were built. Next, a Bayesian model averaging (BMA)-based multimodel was developed using weighted MLR, RBFNN, and SVR models, and the performance of the BMA-based multimodel was compared to those of the MLR, RBFNN, and SVR models. Finally, the high-runoff performance of these four models was further analyzed to prove the effectiveness of each model. The BMA-based multimodel performed better than those of the other models, as well as high-runoff forecasting. The results also revealed that the performance of the forecasting models with multiple climatic factors were generally superior to that without climatic factors. The BMA-based multimodel with climatic factors not only provides a promising, reliable method for medium- and long-term runoff forecasting, but also facilitates uncertainty estimation under different confidence intervals. [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]

It has been the conventional assumption that wash load is supply limited and is only indirectly related to the hydraulics of a river. Hydraulic engineers also assumed that bed-material load concentration is independent of wash load concentration. This paper provides a detailed analysis of the Yellow River sediment transport data to determine whether the above assumptions are true and whether wash load concentration can be computed from the original unit stream power formula and the modified unit stream power formula for sediment-laden flows. A systematic and thorough analysis of 1,160 sets of data collected from 9 gauging stations along the Middle and Lower Yellow River confirmed that the method suggested by the conjunctive use of the two formulas can be used to compute wash load, bed-material load, and total load in the Yellow River with accuracy. [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]

A dominant form of integrated water resources management (IWRM) assumes that existing parochial path dependencies need to be overcome to transform fragmented, contested regimes into the integrative design of IWRM. This paper is an exploratory study of stakeholder perceptions around China's Yellow River, which has been hailed as a successful case of IWRM. We find that while water reforms have ostensibly achieved a programme that adheres to the formal discourse of IWRM, subjective perceptions of the stakeholders, as revealed by the Q methodology, still display elements of a localized, fragmented narrative, requiring constant negotiation. Primary elements of the discourse include the following positions: (1) localized, contextual approaches to governance persist; (2) market efficiency and environmental protection are seen as competing goals; and (3) technology creates new gains, but constant negotiation is needed to distribute them fairly. These narratives show that rather than 'overturning' old paths, the water reforms created a deliberatory arena in which old and new ideas meld into what we refer to as a 'thick' institutional narrative. Our work provides a new perspective on policy change, as well as the persistence of institutional life. [ABSTRACT FROM AUTHOR]

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Hair, water, and sediment samples (n= 69, 27, and 24, respectively) were collected at four locations (P1–P4) along the Yellow River Gan-Ning-Meng (GNM) reaches, China. Total elemental contents of Cd, Cr, Cu, Fe, Mn, Pb, and Zn were determined using inductively coupled plasma mass spectroscopy (ICP-MS) to investigate their distribution and exposure levels in the different media. Results showed that trace metals had widely spatial variability in water and hair samples. There were the highest levels of mean concentrations of Cd, Cu, Fe, Mn, Pb, and Zn (geometric mean, GM = 0.22, 17, 65, 3.0, 4.9, and 170 μg/g, respectively) in residents' hairs living at P2. Most of the hair donors in this study showed high concentrations of Cr when compared with the literature. Differences could be distinguished for Mn (p= 0.001) and Fe (p= 0.001) with gender, and for Cr (p= 0.021), Zn (p= 0.003), and Pb (p= 0.035) with age, respectively. The pollution assessments revealed an unpolluted degree in filtered water and a moderately polluted degree for Cd in sediments at P1–P4. Correlation analysis showed significant correlations between hair and sediment samples for Cr and Mn. This paper provides basic and useful information in facing public and environmental health challenges in the GNM sections of the Yellow River. [ABSTRACT FROM PUBLISHER]

Accurate mid- and long-term runoff forecasting is of great significance for rational development and utilization of water resources in “Yellow River Headwater” region, where runoff in the headwater region contributes to nearly 35% of the total amount of the Yellow River basin. In this paper, the monthly runoff data of Tangnaihai station in “Yellow River Headwater” region are analyzed as case studies. This paper presents support vector regression model for mid- and long-term runoff forecasting, and analyzes the influence of support vector regression model's parameters on the runoff forecasting accuracy, and finally compared with Auto Regressive model (AR) and Radial basis function neural network (RBFNN). The results indicate that SVR showed the best performance and is proved to be competitive with the AR and RBFNN models in both stations. SVR methods provide a promising reliable methods of mid- and long-term runoff forecasting. [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 heavy sediment load of the Yellow River makes it difficult to simulate sediment concentration using classic numerical models. In this paper, on the basis of the classic one-dimensional numerical model of open channel flow, a variational-based data assimilation method is introduced to improve the simulation accuracy of sediment concentration and to estimate parameters in sediment carrying capacity. In this method, a cost function is introduced first to determine the difference between the sediment concentration distributions and available field observations. A one-dimensional suspended sediment transport equation, assumed as a constraint, is integrated into the cost function. An adjoint equation of the data assimilation system is used to solve the minimum problem of the cost function. Field data observed from the Yellow River in 2013 are used to test the proposed method. When running the numerical model with the data assimilation method, errors between the calculations and the observations are analyzed. Results show that (1) the data assimilation system can improve the prediction accuracy of suspended sediment concentration; (2) the variational inverse data assimilation is an effective way to estimate the model parameters, which are poorly known in previous research; and (3) although the available observations are limited to two cross sections located in the central portion of the study reach, the variational-based data assimilation system has a positive effect on the simulated results in the portion of the model domain in which no observations are available. [ABSTRACT FROM AUTHOR]