Search

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]

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]

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]

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]

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]

Water shortages have become one of the most severe problems in semi-arid regions throughout the world. Although semi-arid regions have always been dry, human activities and climate change are acerbating the problem. In Chinese Yellow River basin, the river is the major source of freshwater for those living there, and they have long suffered from serious water shortages. However, increasing population and decreasing streamflow are making these shortages more acute. This study seeks to quantify changes in available water in the Yellow River basin over the last 100 years and attempts to determine causes for these changes. To do this, the study evaluated changing trends and regime shifts of streamflow using long term historical records at different hydrological stations in the Yellow River basin over the past century. The results show that annual streamflow has a significant decreasing trends (P < 0.01) in the mid-lower reaches of the basin. Streamflow decomposition by the breaks for additive seasonal and trend approach suggest that this trend can be decomposed into four distinct annual stages (1919-1933, 1934-1969, 1970-1986 and 1987-2011), while the seasonal component demonstrated an evident regime shift in 1986. This regime shift is mainly related to the construction of large reservoirs in the basin. The flow duration curves illustrate a decrease in the magnitude of streamflow over the last century with a relatively uniform flow regime at all stations. The reconstructed streamflow at Toudaoguai station suggests that agricultural irrigation is predominantly responsible for streamflow reductions between Lanzhou and Toudaoguai stations with approximately 9.1 km/a of water extracted between 1997 and 2006. Meanwhile, a decrease of incoming water from upper reaches and soil and water conservation measures were responsible for the significant decline in annual streamflow at mid-lower reaches station. The result of this paper should be of use for water resources planning, watershed management and climate adaptation as they demonstrate how natural and anthropogenic drivers influence water availability in semi-arid regions. [ABSTRACT FROM AUTHOR]

Spatial distribution of soil salinity can be estimated based on its environmental factors because soil salinity is strongly affected and indicated by environmental factors. Different with other properties such as soil texture, soil salinity varies with short-term time. Thus, how to choose powerful environmental predictors is especially important for soil salinity. This paper presents a similarity-based prediction approach to map soil salinity and detects powerful environmental predictors for the Huanghe (Yellow) River Delta area in China. The similarity-based approach predicts the soil salinities of unsampled locations based on the environmental similarity between unsampled and sampled locations. A dataset of 92 points with salt data at depth of 30-40 cm was divided into two subsets for prediction and validation. Topographical parameters, soil textures, distances to irrigation channels and to the coastline, land surface temperature from Moderate Resolution Imaging Spectroradiometer (MODIS), Normalized Difference Vegetation Indices (NDVIs) and land surface reflectance data from Landsat Thematic Mapper (TM) imagery were generated. The similarity-based prediction approach was applied on several combinations of different environmental factors. Based on three evaluation indices including the correlation coefficient (CC) between observed and predicted values, the mean absolute error and the root mean squared error we found that elevation, distance to irrigation channels, soil texture, night land surface temperature, NDVI, and land surface reflectance Band 5 are the optimal combination for mapping soil salinity at the 30-40 cm depth in the study area (with a CC value of 0.69 and a root mean squared error value of 0.38). Our results indicated that the similarity-based prediction approach could be a vital alternative to other methods for mapping soil salinity, especially for area with limited observation data and could be used to monitor soil salinity distributions in the future. [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]

Runoffs in the Yellow River and Yangtze River basins, China, have been changing constantly during the last half century. In this paper, data from eight river gauging stations and 529 meteorological stations, inside and adjacent to the study basins, were analyzed and compared to quantify the hydrological processes involved, and to evaluate the role of human activities in changing river discharges. The Inverse Distance Weighted (IDW) interpolation method was used to obtain climatic data coverage from station observations. According to the runoff coefficient equation, the effect of human activities and climate can be expressed by changes in runoff coefficients and changes in precipitation, respectively. Annual runoff coefficients were calculated for the period 1950-2008, according to the correlation between respective hydrological series and regional precipitation. Annual precipitation showed no obvious trend in the upper reaches of the Yellow River but a marked downward trend in the middle and downstream reaches, with declines of 8.8 and 9.8 mm/10 a, respectively. All annual runoff series for the Yellow River basin showed a significant downward trend. Runoff declined by about 7.8 mm/10 a at Sanmenxia and 10.8 mm/10 a at Lijin. The series results indicated that an abrupt change occurred in the late 1980s to early 1990s. The trend of correlations between annual runoff and precipitation decreased significantly at the Yellow River stations, with rates ranging from 0.013/10 a to 0.019/10 a. For the hydrologic series, all precipitation series showed a downward trend in the Yangtze River basin with declines ranging from about 24.7 mm/10 a at Cuntan to 18.2 mm/10 a at Datong. Annual runoff series for the upper reaches of the Yangtze River decreased significantly, at rates ranging from 9.9 to 7.2 mm/10 a. In the middle and lower reaches, the runoff series showed no significant trend, with rates of change ranging from 2.1 to 2.9 mm/10 a. Human activities had the greatest influence on changes in the hydrological series of runoff, regardless of whether the effect was negative or positive. During 1970-2008, human activities contributed to 83% of the reduction in runoff in the Yellow River basin, and to 71% of the increase in runoff in the Yangtze River basin. Moreover, the impacts of human activities across the entire basin increased over time. In the 2000s, the impact of human activities exceeded that of climate change and was responsible for 84% of the decrease and 73% of the increase in runoff in the Yellow River and Yangtze River basins, respectively. The average annual runoff from 1980 to 2008 fell by about 97%, 83%, 83%, and 91%, compared with 1951-1969, at the Yellow River stations Lanzhou, Sanmenxia, Huayuankou and Lijin, respectively. Most of the reduction in runoff was caused by human activities. Changes in precipitation also caused reductions in runoff of about 3%, 17%, 17%, and 9% at these four stations, respectively. Falling precipitation rates were the main explanation for runoff changes at the Yangtze River stations Cuntan, Yichang, Hankou, and Datong, causing reductions in runoff of 89%, 74%, 43%, and 35%, respectively. Underlying surface changes caused decreases in runoff in the Yellow River basin and increases in runoff in the Yangtze River basin. Runoff decreased in arid areas as a result of increased water usage, but increased in humid and sub-humid areas as a result of land reclamation and mass urbanization leading to decreases in evaporation and infiltration. [ABSTRACT FROM AUTHOR]

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]

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]

To identify problematic geological structures which would be encountered when driving tunnels in the high mountainous area of South West China, a joint geophysical and engineering geological study was made. The tunnels will form part of a project to divert water from the Yangtze to the Yellow Rivers. A controlled source audio-frequency magnetotelluric method (CSAMT) was carried out in 2004 between the Ma-ke and Jia-qu rivers in high, steep terrain. The paper discusses the method of data collection, processing, and analysis for the West route. The faults/fractures identified will need to be taken into account in the design and construction of the tunnel. [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]

Abstract  Morphological diversity has the potential to provide a very useful biodiversity metric in that it emphasizes essential aspects of diversity that are not picked up by taxonomic or phylogenetic metrics. While morphological diversity metrics are used increasingly in paleobiological studies, quantitative data on the spatial distribution of morphology in modern ecosystems are scarce. Comparison between different aspects of diversity is often essential in understanding the processes underlying observed biodiversity patterns. In this paper, the morphological traits of Suaeda salsa were characterized to explore the potentiality of morphological diversity and identify the unique diversity available at various water-salt soil assemblage ecosites. The newly created wetland of Huanghe River Delta is a nature laboratory for study of plant morphological diversity. Based on an extended general investigation, according to the variation of microphysiognomy of the newly formed Huanghe River Delta, we selected six plots as sample sites for the measurements of an individual’s traits and selected environmental factors and collection of genetic variability test samples. We performed descriptive statistics, ANOVA, correlation analysis, and cluster analysis to recognize the overall variation of S. salsa as a whole, within the sites, and among populations. The results show that a high level of variability was observed among the individuals in the field. We use sites as a categorical, independent variable that formed six interval-dependent variables for every five plant traits to perform ANOVA analysis, and the results show that all traits have a significant difference (p S. salsa show a significant correlation with the soil water content, soil salt content, and the combined index of salt to water. However, they did not show that the plants traits have a reliable relationship with the soil property. The cluster analysis result indicated that S. salsa can be classified into at least three ecotypes. Comparison of the genetic variation surveyed by starch gel electrophoresis to allozyme polymorphism indicated that morphological diversity is a good metric for quantifying spatial patterns of biodiversity. [ABSTRACT FROM AUTHOR]

The main-channel of the lower Yellow River is the main path of water and sediment transportation. In this paper, we put forth a suggestion that the bank-full discharge of the main-channel in the lower Yellow River should be no less than 4000 m³/s, which is based on the demand from effective sediment transportation (or riverbed scouring), the demand of flood control on morphology of the cross section of the main-channel, and the possible riverbed-forming force of future flood. The forming of the main-channel is the process for the flood force to overcome the resistance from the riverbed. The forming of the main-channel configuration comes from the competition between riverbed-forming force of flood and resistance from the riverbed. Regarding the flood with medium or less sediment content and without floodplain inundated, the main-channel forming mechanism can be simplified as the relationship between the change of cross section area and WαQβ. For forming same main-channel, the needed flood force W0.32Q0.37 is definite, i.e., when the discharge is large, the flood volume can be smaller; if some flood is able to scour the main-channel, its force W0.32Q0.37 should be larger than 41. Not all floods that inundate floodplain have the function of silting in floodplain and scouring main-channel. Regarding flood with medium or less sediment content, only when the flood discharge is over 1.5 times of the relevant bankfull discharge, obvious scouring effect can occur in the main-channel. [ABSTRACT FROM AUTHOR]

The evaluation of crustal stability in the lower Yellow River region (LYR) is vital to the engineering project of the Yellow River embankment and construction of the Huang-Huai-Hai plain. From three aspects of tectonic stability, surface stability and medium stability, this paper analyzes in detail the factors such as tectonic activity, tectonic stress, exogenic geologic disasters and ground material composition which affect crustal stability in the study area and the spatial distributions of subordinate degree of the evaluation factors. It then constructs the crustal stability evaluation model of fuzzy mathematics based on GIS by using AHP to find out the interrelations among the various factors, comprehensive evaluation of fuzzy mathematics and the functions of spatial overlay and spatial database of ArcGIS. Based upon this the crustal stability evaluation is carried out, the results show that the areas of stable and instable regions are basically the same, being 48.72% and 51.28% respectively. The area of moderate stable region takes a dominant position, being about 70.58%. The crust instable region presents zonal distribution and under the control of tectonic faulted belt. But the region where the LYR runs across is mostly instable with a total length of the river being 568.345 km, or 78.93% of all. The river reach where the crustal stability is relatively poor along the LYR is concentrated in the Lankao-Dongping section. [ABSTRACT FROM AUTHOR]

Great achievements have been gained in assuring the safety of the lower Yellow River through arduous work in the past fifty years. But the disadvantages of boundary for river-flow are obvious, such as topography, tectonic movement and crustal stability. The main conflicts of less water and more sand, and the speeding up of sedimentation still exist, causing continuous river shrinkage. However, all the existing methods cannot completely avoid flood catastrophe, so a new control method needs to be explored. The method of changing-route based on geographical theory has always been a focus of debate over whether there are other feasible routes for the current Yellow River. From geoscientific point of view, this paper investigates whether there is a best feasible reservation route in Huang-Huai-Hai plain. Under the actual condition that the conflict between water and sand cannot be eradicated, the selection of the best reservation route should be the overlaying area of the optimum boundary conditions and the less social and economic loss. By detailed analysis of topography, tectonic movement, crustal stability and social-economic progress in the region of the lower Yellow River, the best reservation route is obtained by using the distance weighted function and the minimum cost function. The analysis result indicates that the reservation route can get rid of the influence of the elevation in central western Shandong Province, and the whole route flows through the Hal-Huang rift valley, which is good for channel stability. As to the basic parameters of water and sand movements, the gradient increases 36.2%, the length shortens 15.4% and the curvature reduces 12.2%. Using the reservation route can comparatively reduce the flood risk of the Yellow River, except that it will induce such problems as resettlement and relocation of towns, infrastructure reconstruction, water shortage in the abandoned area of the present route, as well as the resultant ecological and environmental degradation. But in contrast to the huge accumulative input to the harnessing of the Yellow River by the state, the absolute input of dealing with the above-mentioned problems is still acceptable. In the construction of corresponding infrastructures, using the reservation route will promote the region's socio-economic development and offer a rare chance of burgeoning. [ABSTRACT FROM AUTHOR]