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The cooperative operation of cascade reservoir systems is an efficient way to regulate water resources. However, noncooperation among various reservoir stakeholders is often observed in practice; this produces an interesting dilemma in the game of water resource management. Considering the upper Yellow River cascade reservoir system as a case study, in this paper we model and analyze the cooperation dilemma in a cascade reservoir system. In our game theoretical analysis, we find that, except for the most upstream reservoir, all reservoirs have free-ride strategies. The free-ride strategy indicates that a reservoir obtains free gain from the cooperation of other reservoirs due to spatial connections, and this fact changes the cooperative game in terms of equilibrium and benefit allocation. The results show that the regulation capacity of the free rider directly affects the equilibrium and benefit allocation of the game. A midstream reservoir with a small or medium regulation capacity tends to employ a free-ride strategy. A midstream reservoir with a large regulation capacity can entirely interrupt the cooperation between upstream and downstream reservoirs, interestingly, which can lead to the disappearance of the free-ride strategy for the midstream reservoir. However, the downstream reservoir may employ a free-ride strategy when the midstream reservoir chooses to cooperate. This implies that grand cooperation is not stable when considering free-ride, whereas partial coalitions are more likely to form. In this paper, we derive equilibrium in the cooperative game of cascade reservoirs, providing theoretical interpretation of the noncooperation phenomenon in the operation of cascade reservoirs. [ABSTRACT FROM AUTHOR]

Accurately identifying the matching relationships between territorial space evolution and the resources and environment carrying capacity will directly guide the sustainable use of territorial space. Based on the evaluation of the territorial space dynamics of the lower Yellow River, this paper evaluates the suitability of territorial space development by focusing on ecological protection, agricultural development, and urban construction. Specifically, the resources and environment carrying capacity is estimated by identifying and mediating potential conflicts in the development of territorial space. The matching relationship between the evolution of territorial space and the resources and environment carrying capacity is identified using the matching degree model. The results demonstrated that: (1) Between 2000 and 2020, the agricultural space of the lower Yellow River was relatively stable, while the ecological space was generally shrinking, and the urban space continued to increase; (2) The characteristics of suitability for the agricultural development and urban construction of the lower Yellow River are characterized by landform and land-sea differentiation. The carrying scale of resources and the environment is based on agricultural space and is increasing yearly, followed by ecological space, which is gradually decreasing, and urban space, which first increased and then decreased; (3) Between 2000 and 2020, the matching index of the ecological and agricultural space evolution and the resource and environmental carrying capacity in the lower Yellow River exhibited a downward trend, while the regional difference increased. Furthermore, the matching index of urban space and the resources and environment carrying capacity indicated an upward trend, while the regional difference decreased. [ABSTRACT FROM AUTHOR]

Accurate and reliable monthly streamflow prediction plays a crucial role in the scientific allocation and efficient utilization of water resources. In this paper, we proposed a prediction framework that integrates the input variable selection method and Long Short-Term Memory (LSTM). The input selection methods, including autocorrelation function (ACF), partial autocorrelation function (PACF), and time lag cross-correlation (TLCC), were used to analyze the lagged time between variables. Then, the performance of the LSTM model was compared with three other traditional methods. The framework was used to predict monthly streamflow at the Jimai, Maqu, and Tangnaihai stations in the source area of the Yellow River. The results indicated that grid search and cross-validation can improve the efficiency of determining model parameters. The models incorporating ACF, PACF, and TLCC with lagged time are evidently superior to the models using the current variable as the model inputs. Furthermore, the LSTM model, which considers the lagged time, demonstrated better performance in predicting monthly streamflow. The coefficient of determination (R2) improved by an average of 17.46%, 33.94%, and 15.29% for each station, respectively. The integrated framework shows promise in enhancing the accuracy of monthly streamflow prediction, thereby aiding in strategic decision-making for water resources management. [ABSTRACT FROM AUTHOR]

China has implemented many green transition policies to reach its carbon peak target, some of which do not consider the actual carbon reduction pressures that localities can afford, thus lowering the living standards of residents and economic growth, which makes the green transition process unsustainable. The Yellow River Basin plays an important role in China's energy, food, manufacturing, and ecological sectors. Thus, the design of green transition policies in the region needs to be modest and efficient. Based on the data of 100 prefecture-level cities in the Yellow River Basin from 2006 to 2017, this paper uses the K-means clustering to divide the carbon reduction potential of cities into four types. Most cities' carbon reduction potentials are low or medium, unsuitable for adopting a rapid green transition. Based on the logarithmic mean Divisia index (LMDI) decomposition results and the carbon reduction potential, we designed different carbon-control pathways: Shandong and Henan should focus on increasing investment in green technology, especially oxy-combustion technology; Gansu, Ningxia, and Qinghai could partially offset carbon emissions through land use, land-use change and forestry (LULUCF) activities; Sichuan and Inner Mongolia should increase their energy-use efficiency; Shaanxi and Shanxi could use green finance to complete the upgrading of local industries. The above emission-reduction strategies can be actively pursued in cities with high emission reduction potential and should be implemented with caution in cities with low emission reduction potential. This paper provides a new and cost-effective perspective on carbon emission control in the Yellow River Basin. [ABSTRACT FROM AUTHOR]

The governance and development history of the Yellow River is an important part of Chinese history. Many historical documents and archives have been produced around the governance and development of the Yellow River as well as modern information resources such as databases and pictures, which together constitute a special collection of cultural heritage resources of the Yellow River Governance Landscape. In this paper, a literature search was conducted and unique resources collected for the construction of the Yellow River Governance Landscape, including the main literature, archives, pictures, databases, and other resources. Experts identified the concept and relevant resources of the Yellow River Governance Landscape, and librarians constructed the special collection. The future direction of digitization and database construction for the Yellow River Governance Landscape resources are also discussed. The special resources of the Yellow River Governance Landscape will help to increase the discipline collections and special collections of university libraries, provide resources for multidisciplinary teaching and research, and help to digitize and build databases of Yellow River Governance Landscape resources in the future as well as provide the content basis for open access and sharing of digital resources. [ABSTRACT FROM AUTHOR]

Many rivers are tightly coupled and intersected with aeolian sand dunes, whose geomorphological evolution involves not only fluvial processes but also aeolian processes that pose a new challenge to fluvial geomorphological studies. However, due to few field studies, our overall understanding of the desert channel geomorphic process is limited. In this paper, we present an outstanding example of desert river channel evolution regulated by aeolian–fluvial interactions in the Ulan Buh Desert of the Yellow River, based on a long time series data set (1966–2019) of channel cross-sections. The results indicate that the lateral addition of aeolian sand, the water–sediment relationship and human interference have a significant role at different periods of channel evolution. Before 1986, higher discharge, lower sediment content and greater intensity of aeolian activity caused aeolian–fluvial interactions and a relative scouring and silting balance in the channel, with little human activity. From 1986 to 2000, an increase in large reservoir operation, vegetation coverage and floodplain farming, coupled with water–sediment relationship variation, caused rapid deposition and shrinkage of the river channel. From 2000 to 2014, the channel kept a slight scouring state. With Haibowan reservoir operation beginning in 2014, the talweg experienced rapid scouring and undercut rebound. However, an expanding and stable floodplain accelerated sedimentation on the floodplain and weakened river lateral erosion, indicating that the channel has shown a shrinkage trend. Meanwhile, wavelet analysis results indicate that human interferences and aeolian activities have no significant role in the periodical characteristics of the channel's longitudinal erosion and deposition. Therefore, on the whole, increasing human interferences and decreasing wind dynamics have driven this desert wandering channel to be stable, and to gradually form a new balance between erosion and sedimentation. [ABSTRACT FROM AUTHOR]

Sediment erosion through synergetic effects between free surface vortex (FSV) and particle erosion in silt-laden flow seriously affects the safe operations of pump. The purpose of this paper is to study the influence of free surface vortex entrainment on the erosion inner the pump impeller, aimed at the FSV and sediment erosion in sediment laden flow in a pump station of Yellow River, a new Eulerian-Lagrange approach was applied to simulate the sediment-laden flow by combining the Lagrange particle tracking approach and Volume of Fluid (VOF) method, followed by the application of Tabakoff model to estimate the erosion. Volume of fluid method was used to simulate the continuous flow FSV, and Lagrange method the particle trajectory. The theoretical model and filed results on site were used to verify the reliability of the proposed approach. Free surface vortex on particle motion and microscopic interactions between air and erosion were reviewed and discussed. Combined with the theoretical analysis and calculation results, the particle impact angle in the impeller was analyzed, and the erosion types were defined. Air entrainment by FSV does not directly erode the impeller components, but mainly changes the position, the local velocity and the concentration of the particles, which aggravates the sediment erosion in the impeller. Interestingly, air entrainment can reduce the surface erosion at some instantaneous moments. The present work may provide important engineering insights to resolve the erosion. [ABSTRACT FROM AUTHOR]

In 2020, Yellow River runoff was more than twice as much as past years, and the proportion of strong winds was also higher than that in past years, which will inevitably lead to a change in salinity plume distribution in the Yellow River Estuary and Laizhou Bay. Based on FVCOM numerical modelling, this paper presents the spatial salinity distribution and dispersion of the Yellow River Estuary and Laizhou Bay during the wet and dry seasons in 2020. We used data from six tidal and current stations and two salinity stations to verify the model, and the results showed that the model can simulate the local hydrodynamic and salinity distribution well. The influence of river discharge and wind speed on salinity diffusion was then investigated. The simulation results showed that under the action of residual currents, fresh water from the Yellow River spread to Laizhou Bay, and the low salinity area of Laizhou Bay was mainly distributed in the northwest. The envelope area of 27 psu isohaline can account for about one-quarter of Laizhou Bay in the wet season, while the low-salinity area was only concentrated near the estuary of Yellow River in the dry season. River discharge mainly affects the diffusion area and depth of fresh water, and wind can change the diffusion structure and direction. In the wet season, with the increase in wind speed, the surface area of the plume decreased gradually, and the direction of the fresh water plume changed counterclockwise from south to north. During the dry season, the plume spread to the northwest along the nearshore. The increase in wind speed in the early stage increased the surface plume area, and the plume area decreased above a wind speed of 10 m/s due to the change in the turbulence structure. The model developed and the results from this study provide valuable information for establishing robust water resource regulations for the Yellow River. This is particularly important to ensure that the areas with low salinity in the Yellow River Estuary will not decrease and affect the reproduction of fish species. [ABSTRACT FROM AUTHOR]

This is a paper about the speed and intensity with which new and intensive human land use in a semi-arid environment can bring about large-scale environmental change. In particular, this paper pinpoints how and why it was that the Yellow River shifted from a long-term condition of relative stability to a later state of frequent floods and course changes in the eleventh century. It is possible to trace the environmental history of this dramatic and sudden change of state with precision and confidence. Historical sources that record the dates and characteristics of flood events downstream align well with those that note the locations and dates of human activity upstream. More important, each aligns well not only with one another, but also with information from environmental science: sediment cores that preserve soil and pollen evidence for the timing and processes of systematic change. [ABSTRACT FROM AUTHOR]

The ongoing transition from fossil fuel-based electricity generation toward green energy relying on the intermittent renewable energy sources indispensably requires development of novel energy conversion and storage methods. Depending on a particular location and local resources, pumped storage, lithium- or sodium-ion batteries, compressed air energy storage, as well as the so called power-to-gas (P2G) technologies may be applied. Taking into account the abundant solar energy resources available in the northwestern China, such as Ningxia hui autonomous region, and local water resources coming from the Yellow River, a power-to-hydrogen (P2H2) distributed energy conversion system is proposed in this paper, which is based on a high-efficiency reversible Solid Oxide Cell (rSOC). The conducted studies comprise tests with simulated current based on the actual photovoltaic power station data, and with usage of the as-obtained Yellow River water for the electrolysis mode without any pretreatment. It is documented that the reversible operation is beneficial, and the tested cell can operate for a prolonged time. Of importance, Na, Ca, Mg, and Si elements remain in an evaporator, and do not contaminate the cell, while higher than the initial boron concentration can be found in the condensed exhaust gases. The respective operational parameters of the system correspond to an electrolysis current density loading up 433.3 mA cm−2 for 4 h, as well as fuel cell operation mode with a current density of 8.3 mA cm−2 for 12 h. It is found that the average voltage losses in the electrolysis cell and fuel cell mode are 0.27 %/cycle and 0.886 %/cycle, respectively, indicating that the lifetime of the cells can be more than 800 h. The reported studies demonstrate validity of applying rSOC-based P2H2 system, especially if abundant photovoltaic power and water resources are available. [Display omitted] • The Yellow River water was utilized by rSOC for the first time. • The designed test current was modeled with local photovoltaics. • The P2H2 nearby consumption system can reversibly operate for over 800 h. • The degradation rates in SOFC mode are lower than those in SOEC mode. • The Yellow River water has no significant effect on the degradation rate. [ABSTRACT FROM AUTHOR]

In recent years, ecological problems in the middle and lower reaches of the Yellow River have been frequent. Therefore, exploring its core influences can advance the implementation of "Ecological Protection and High-quality Development of the Yellow River Basin". This paper constructs an indicator system based on PSR guidelines, evaluates the ecological protection level of 55 cities in the middle and lower reaches of the Yellow River from 2009 to 2019, and uses correlation analysis with geographically and temporally weighted regression (GTWR) model to explore the spatial distribution characteristics of influencing factors, such as intensity of fertilizer application, amount of agricultural film applied, afforestation area per capita, and green technology innovation level on the ecological protection level. It is found that the overall level of ecological protection has shown a steady increase, but the spatial distribution varies widely. The ecological level increased from 0.2218 to 0.3357, showing a decreasing distribution trend from coastal to inland. Furthermore, it is found that the ecological protection level has a significant positive spatial correlation, mainly for similar clustering. The Global Moran's I for ecological protection level is greater than 0, and the Moran scatter plot has a high number of cities distributed in the first and third quadrants. There is a heterogeneity in the spatial and temporal distribution of factors influencing the level of ecological protection. Fertilizer application, the agricultural film uses, and afforestation area per capita are mainly negatively affected, while green innovation level has a strong positive effect, and agricultural film use, afforestation area per capita, and green innovation level become the core influencing factor of different regions. Therefore, in the middle and lower reaches of the Yellow River, the ecological protection level should be improved by implementing a regional differentiated development strategy, realizing cross-regional linkages between cities and focusing on differences in core driving factors. [ABSTRACT FROM AUTHOR]

Key ecological function areas are not only recognized as the critical subject for national and global ecosystem protection, but also the crucial hinterland for maintaining the livelihood of local residents. Studies on livelihood resilience contribute to better understand the adaptation strategies and development needs of poor and highly vulnerable groups in key ecological function zones, which is crucial to promoting the long run sustainability. Based on the survey data of 575 households, this paper constructs the livelihood resilience evaluation index system from three dimensions of buffer capacity, self-organization ability and learning ability. The method of weighted sum is used to evaluate the livelihood resilience of farmers, and the influencing factors are analyzed by multiple regression model. The results show that the overall level of livelihood resilience of farmers is weak, and the self-organization ability of farmers is significantly higher than their buffering ability and learning ability. We found that ecological policy, age of head of household, diversity of livelihoods, family size, and environmental dependence are the key factors that affect the resilience of farmers' livelihoods. We argued that, new methods such as establishing a technical training system for farmers, promoting livelihood diversity, improving and implementing active ecological policies, and building long-term and effective risk warning, emergency response, and poverty alleviation mechanisms should be considered and implemented. [ABSTRACT FROM AUTHOR]

Hyperconcentrated turbidity currents typically display non-Newtonian characteristics that influence sediment transport and morphological evolution in alluvial rivers. However, hydro-sediment-morphological processes involving hyperconcentrated turbidity currents are poorly understood, with little known about the effect of the non-Newtonian rheology. The current paper extends a recent two-dimensional double layer-averaged model to incorporate non-Newtonian constitutive relations. The extended model is benchmarked against experimental and numerical data for cases including subaerial mud flow, subaqueous debris flow, and reservoir turbidity currents. The computational results agree well with observations for the subaerial mud flow and independent numerical simulations of subaqueous debris flow. Differences between the non-Newtonian and Newtonian model results become more pronounced in terms of propagation distance and sediment transport rate as sediment concentration increases. The model is then applied to turbidity currents in the Guxian Reservoir planned for middle Yellow River, China, which connects to a tributary featuring hyperconcentrated sediment-laden flow. The non-Newtonian model predicts slower propagation of turbidity currents and more significant bed aggradation at the confluence between the tributary Wuding River and the Yellow River in the reservoir than its Newtonian counterpart. This difference in model performance could be of considerable importance when optimizing reservoir operation schemes. [ABSTRACT FROM AUTHOR]

This paper presents numerical simulations regarding the transport characteristics of soil salt. It has been recognized in recent years that the growth and output of crops in the irrigation area of the lower reaches of the Yellow River are affected by the decreased fertility of soil as a result of the transport of soil salt, due to the long-term farming, fertilization of farmland which contains a high proportion of sands. Accordingly, numerical simulations by Hydrus are carried out, in which, based on the similarity principle, two-dimensional convection-diffusion partial-differential governing equations of unsteady flow in saturated-unsaturated porous media are applied to depict the motion parameters' spatial variability of soil water in the irrigation area. And the van Genuchten equation is adopted to express the relationship between volumetric water content and soil hydraulic conductivity and negative soil water pressure. The irrigation basin of the People's Victory Canal, which is downstream of the Yellow River, is investigated in detail as an example. The findings revealed that soil salt in the irrigation region is transferred by water diffusion, with irrigation and fertilization being the primary causes of downward migration and salt accumulation. It benefits the soil in irrigation areas and protects groundwater. [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]

Spatially detailed characterization of the distribution amount and timing of river ice are important for identifying and predicting potential ice hazards. In this paper, we present an asynchronous river ice extraction and change detection method using multi-temporal SAR image and multi-spectral image. River channel information is a strong prior knowledge for ice detection and analysis. Therefore a river channel extraction algorithm on multi-spectral image based on sparse reconstruction is proposed and adopted in our method. The extracted river channel is used as prior information to effectively eliminate most interference regions on the shore. Then an adaptive threshold segmentation method is adopted to accurately detect river ice regions in SAR image. Fuzzy C-means clustering is used to segment river ice using the infrared bands of multi-spectral image, considering temperature can provide significant information to discriminate ice, water and shore. Finally, change analysis is done based on the ice extractions results of two kinds of images. The proposed method is applied on the Yellow River ice monitoring and experiments demonstrated that this straightforward approach works well with both SAR image and multi-spectral image. [ABSTRACT FROM AUTHOR]

The changes of runoff in the middle reaches of the Yellow River basin of China have received considerable attention owing to their sharply decline during recent decades. In this paper, the impacts of rainfall characteristics and land use and cover change on water yields in the Jingle sub-basin of the middle reaches of the Yellow River basin were investigated using a combination of statistical analysis and hydrological simulations. The Levenberg Marquardt and Analysis of Variance methods were used to construct multivariate, nonlinear, model equations between runoff coefficient and rainfall intensity and vegetation coverage. The land use changes from 1971 to 2017 were ascertained using transition matrix analysis. The impact of land use on water yields was estimated using the M-EIES hydrological model. The results show that the runoff during flood season (July to September) decreased significantly after 2000, whereas slightly decreasing trend was detected for precipitation. Furthermore, there were increase in short, intense, rainfall events after 2000 and this rainfall events were more conducive to flood generation. The "Grain for Green" project was carried out in 1999, and the land use in the middle reaches of the Yellow River improved significantly, which make the vegetation coverage (Vc) of the Jingle sub-basin increased by 13%. When Vc approaches 48%, the runoff coefficient decreased to the lowest, and the vegetation conditions have the greatest effect on reducing runoff. Both land use and climate can change the water yield in the basin, but for areas where land use has significantly improved, the impact of land use change on water yield plays a dominant role. The results acquired in this study provide a useful reference for water resources planning and soil and water conservation in the erodible areas of the middle reaches of the Yellow River basin. [ABSTRACT FROM AUTHOR]

The source region of the Yellow River, located in the north-eastern edge of the Qinghai-Tibet Plateau, is an important water conservation region and ecological barrier of the Yellow River. In this paper, based on remote sensing technology, multi-period Landsat remote sensing images in the source region were taken as the main information source. With the assistance of field investigation, we monitored the spatial and temporal changes of desertification in the source region from 2000 to 2019. The results show that the area of desertification in the source region has accounted for 9.36% of the total area, of which the light desertification land is the major portion. The desertification is mainly distributed between the southern margin of Madoi Valley basin and the northern margin of Heihe Valley basin, and is distributed on the river valleys, lakesides, ancient rivers and piedmont proluvial fan, showing the form of patches, sheets and belts. The growth rate of desertification in the source region was 87.47% from 2000 to 2010. With a high growth rate, the process of desertification was represented by the rapid spread of desertification. From 2010 to 2019, the growth rate of desertification was 37.32%, which was relatively slow. But the moderate desertification land maintained a straight linear growth trend, showing an increasing trend of desertification degree. Through the analysis of the driving factors of desertification in the source region of the Yellow River, this paper argues that the special geographical location, climatic factors, rodent damages and human activities are the main causes of desertification. [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]

Based on the observed runoff and sediment data from Lijin hydrological station during the period of 1950–2018, this paper addressed the long-term change characteristics of runoff and sediment fluxes into the sea from the Yellow River. The Mann-Kendall test was adopt to estimate the long-term trends in the runoff and sediment time series. The Mann-Whitney-Pettitt (MWP) test were used to determine the change points of runoff and sediment time series. It could be concluded that the annual runoff and the sediment fluxes decreased significantly at the rates of −6.17×109 m³/a and −0.213×109 t/a, respectively. The changes during the flood season were more dramatic than in the dry season, especially for the sediment flux. Different significant change points are detected in the runoff and sediment time series. The changing point for the runoff occurred in 1968, 1985, and 2002 and those of sediment flux in 1968, 1985, and 1996, respectively. The negative long-term change trend and the occurrence of change points are highly associated to natural variation and human activities in the Yellow River basin. The occurrence time of some change points accords even with man-made events. [ABSTRACT FROM AUTHOR]

During the ice flood period of the Yellow River, the fracture and destruction of river ice can easily lead to the formation of ice jams and ice dams in the curved and narrow reaches. However, the occurrence and development mechanism of river ice fracture remain incompletely understood in the Yellow River. Therefore, based on the three-point bending physical test of the Yellow River ice, a three-point bending fracture numerical model of the Yellow River ice was constructed. The fracture failure process of the Yellow River ice under three-point bending was simulated, and the effects of the crack-to-height ratio and ice grain size on the fracture properties of the river ice were analyzed. By comparing the results with those of physical tests on river ice, it is evident that the fracture model can effectively simulate the cracking process of river ice. Within the confines of the simulated sample size spectrum, as the crack-to-height ratio varies from 0.2 to 0.8, the fracture toughness value of the Yellow River ice spans a range from 115.01 to 143.37 KPa·m1/2. Correspondingly, within the simulated calculation values ranging from 5.38 mm to 24.07 mm for ice crystal size, the fracture toughness value of the Yellow River ice exhibits a range from 116.89 to 143.37 KPa·m1/2. The findings reveal that an increase in the crack-to-depth ratio leads to a decrement in the fracture toughness of river ice. Within the scale range encompassed by the model calculations, as the average size of the ice crystal grains augments, the fracture toughness of the river ice exhibits a gradual ascending trend. The research results provide a parameter basis for studying the fracture performance of the Yellow River ice using a numerical simulation method and lays a foundation for investigating the cracking process of river ice from macro and micro multi-scales. [ABSTRACT FROM AUTHOR]

The different shapes of bridge piers across rivers have a great influence on the river water movement, and the study of the influence of pier morphology changes on the water movement characteristics is of great value for bridge design and river flooding. The hydrodynamic model can effectively simulate and predict the changes of river flow patterns, which can provide scientific data support for river management. This paper constructs a hydrodynamic model based on MIKE21 and applies it to the numerical simulation of river hydrodynamics in the lower reaches of the Yellow River, taking elliptical piers as an example, and simulates the effect of the change of pier morphology on the flow velocity, water level and flow field of the river. The results show that the effect of elliptical pier morphology on the flow characteristics of the river channel is significant; under the same flow rate, the congestion value of the pier at the maximum axis ratio is 1.65 times the minimum axis ratio, and the larger the axis ratio, the more serious the congestion; the difference in flow velocity at the maximum axis ratio can reach 2.33 times the minimum axis ratio. HIGHLIGHTS This paper uses MIKE21 numerical simulation to analyze and study the changes in river congestion and flow patterns caused by bridge construction, and to provide more practical simulation data for the construction of cross-river bridges.; The Nash efficiency coefficient of 0.94 is highly accurate in the model validation and evaluation.;

Soil conservation on the Loess Plateau is important not only for local residents but also for reducing sediment downstream in the Yellow River. In this paper, we report a decrease in soil erosion from 2000 to 2010 as a result of the 'Grain for Green' (GFG) Project. By using the Revised Universal Soil Loss Equation and data on land cover, climate and sediment yield, we found that soil erosion decreased from 6579.55tkm–2yr–1 in 2000 to 1986.66tkm–2yr–1 in 2010. During this period, there was a major land cover change from farmland to grassland in response to the GFG. The area of low vegetation coverage with severe erosion decreased dramatically, whereas the area of high vegetation coverage with slight erosion increased. Our study demonstrates that the reduction in soil erosion on the Loess Plateau contributed to the decrease in the sediment concentration in the Yellow River. [ABSTRACT FROM AUTHOR]

• A framework is proposed to improve real-time reservoir flood control operation. • An optimization model is proposed to get updated water release. • The proposed model can decrease the flood risk of the water system. A flood hazard is one of the most common and destructive natural disasters. Flood risk reduction with non-engineering measures has become the primary goal for flood management. This paper proposes an approach to improve the flood control operation for cascade reservoirs by minimizing flood control risk. A framework of reservoir flood control operation coupled with risk assessment (RFCORA) and the corresponding RFCORA model are proposed to reduce risk. The model contains three sub-modules. A real-time reservoir flood control operation simulation module is developed, in which a flood discharge control chart is used to determine the flood magnitude, and flood release is obtained by operation rules. Entropy-weighted fuzzy comprehensive evaluation method is applied to assess the risk level in the flood risk assessment module. Finally, the flood release is updated according to the developed outflow adjustment optimization module aimed at minimizing flood control risk by combing future inflow information. In addition, another model without outflow adjustment optimization is set to be a comparative experiment. The water system of the Upper Yellow River is selected as a case study to verify the model. The results show that the framework and RFCORA model developed in this paper can decrease the time duration in the highest risk level without increasing the maximum water level and maximum outflow of reservoirs. The approach proposed in this paper based on flood control operation and flood risk assessment can be extended to flood mitigation in other water systems in similar situations. [ABSTRACT FROM AUTHOR]

The Yellow River Basin is a closed basin under serious stress with dense population, intensive agriculture, and excess water withdrawals. Low water use efficiency and groundwater overexploitation are threatening the sustainable development of the basin. This paper describes a coupled modeling approach to analyze sustainable management strategies in surface-groundwater conjunctive use irrigation districts in the lower Yellow River Basin. An appropriate irrigation schedule and an optimal range of groundwater levels are first established using the soil water atmosphere plant (SWAP) model with data from an irrigation experiment station. The integrated surface water and groundwater model was then set up using modified soil and water assessment tool (SWAT2000) and modular three-dimensional groundwater flow model (MODFLOW) models. The two models were connected through standardized simulation grids and calibrated using field measurements. Five scenarios that were designed according to different well-canal irrigation supply ratios and the irrigation schedule determined by SWAP were tested using the integrated modeling approach. It is proved that conjunctive management strategies of canal diversions and tube-well pumps can effectively reduce phreatic evaporation losses, increase water use efficiency, and sustain groundwater levels while maintaining crop yields at current levels. [ABSTRACT FROM AUTHOR]

While geoarchaeology as a practice within archaeology grew out of many historical roots, a major role has been the explication of site formation processes and site-level contextual analysis. In recent years, geoarchaeological research has branched out to encompass larger geographic scales, and to play a greater role in environmental archaeological investigations. This paper argues that geoarchaeology has a great deal to contribute to the understanding of human history and to archaeological theory through the application of multiscalar approaches that place human behavior in a physical, environmental and ecological context and by creating linkages between physical processes and human responses. We use geoarchaeological data from the Yellow River valley to show that drainage/irrigation canal and bank/levee building had commenced in the lower reaches by ca. 2900-2700 cal B.P. The emphasis on flood plain flood control infrastructure was a result of long-term increases in sedimentation caused by large populations farming with increasingly efficient technologies in the fragile environments of the Loess Plateau. Ever increasing sedimentation set in motion a cycle of further investment in flood control works eventually leading to a massive flood catastrophe in the first 20 years of the first millennium A.D. as the Yellow River exceeded natural and human geomorphic thresholds that constrained it in its previous course. These floods arguably triggered the social and political events that brought down the Western Han Dynasty but the root causes are clearly more complex. Geoarchaeology thus contributes to an understanding of the multiple causes and consequences of large-scale social and political collapse. [ABSTRACT FROM AUTHOR]

In the context of global climate change and ecological restoration projects, significant changes have been observed in the fractional vegetation cover (FVC) in the Yellow River basin. The increased vegetation growth accelerates water consumption, exacerbating drought and water scarcity issues, thereby heightening regional water resource shortage risks. This study targets the Yellow River basin in China, employing a pixel-based model to convert NDVI into FVC datasets. We establish a pixel-wise mathematical model for annual runoff and environmental factors based on residual analysis and methods like multiple linear regression. Using climate model data from CMIP6 as independent variables, in conjunction with the statistical model, we elucidate the spatiotemporal characteristics of annual runoff in the Yellow River basin under future climate scenarios. Our results indicate that, under four different climate scenarios, the average annual runoff in the Yellow River basin is projected to increase. The increases are quantified as 0.008 mm/a, 0.065 mm/a, 0.25 mm/a, and 0.24 mm/a for SSP126, SSP245, SSP370, and SSP585 scenarios, respectively. From 2022 to 2040, the spatial distribution of the runoff change rates under the SSP245 and SSP370 scenarios show an increasing trend in upstream areas such as the Qinhe and Longmen regions, with rates ranging from 6.00 to 8.61 mm/a. During the period from 2041 to 2060, all four climate scenarios indicate minimal changes in the runoff depth in the northern part of the Yellow River basin. From 2061 to 2080, under the SSP126 and SSP245 scenarios, the spatial distribution of the runoff shows significant increases in the river source area and a decreasing trend in the middle reaches, with rates ranging from 4.52 to 11.39 mm/a. For the period from 2081 to 2100, the runoff change rates vary significantly under the four climate scenarios. These findings provide a detailed understanding of how future climate scenarios could impact water resource distribution in the Yellow River basin, offering critical insights for regional water management and policy making to mitigate potential water scarcity challenges. [ABSTRACT FROM AUTHOR]

This study utilizes meteorological and leaf area index (LAI) data for three shared socioeconomic pathways (SSP1–2.6, SSP2–4.5, and SSP5–8.5) from four general circulation models (GCMs) of the sixth climate model intercomparison project (CMIP6) spanning from 2015 to 2099. Employing calibrated data and incorporating future land use data under three SSPs, the distributed hydrology soil vegetation model (DHSVM) is employed to simulate streamflow in the source region of the Yellow River (SRYR). The research aims to elucidate variations in streamflow across different future scenarios and to estimate extreme streamflow events and temporal distribution changes under future land use and cover change (LUCC) and climate change scenarios. The main conclusions are as follows: The grassland status in the SRYR will significantly improve from 2020 to 2099, with noticeable increases in temperature, precipitation, and longwave radiation, alongside a pronounced decrease in wind speed. The probability of flooding events increases in the future, although the magnitude of the increase diminishes over time. Both LUCC and climate change contribute to an increase in the multi-year average streamflow in the region, with respective increments of 48.8%, 24.5%, and 18.9% under SSP1–2.6, SSP2–4.5, and SSP5–8.5. Notably, the fluctuation in streamflow is most pronounced under SSP5–8.5. In SSP1–2.6, the increase in streamflow during the near future (2020–2059) exceeds that of the distant future (2059–2099). Seasonal variations in streamflow intensify across most scenarios, leading to a more uneven distribution of streamflow throughout the year and an extension of the flood season. [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]

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]

Through active involvement in UNESCO's ICH (Intangible Cultural Heritage) programme, China has developed its own framework to support traditional making practices. To examine the 'characteristics' of heritage crafts preservation in China, we undertook empirical research in the Yellow River basin. Our research involved in-depth observations and key informant interviews with a range of highly accomplished craftspeople who have inherited their particular expertise from their family and have been officially designated ICH Inheritors. Through our qualitative research with inheritors, a businessperson and a government official, we identified various support mechanisms employed by the Chinese government that aim to protect traditional culture while also recognising outstanding individuals. We also found that ICH Inheritors play an important role in raising cultural awareness and enhancing cultural confidence through their creative activities and making practices, craft businesses and transfer of expertise. Based on the findings, potential areas where designers may collaborate with inheritors were identified. [ABSTRACT FROM AUTHOR]

The source area of the Yellow River (SAYR) in China is an important water yield and water-conservation area in the Yellow River. Understanding the variability in rainfall and flood over the SAYR region and the related mechanism of flood-causing rainfall is of great importance for the utilization of flood water resources through the optimal operation of cascade reservoirs over the upper Yellow River such as Longyangxia and Liujiaxia, and even for the prevention of flood and drought disasters for the entire Yellow River. Based on the flow data of Tangnaihai hydrological station, the rainfall data of the SAYR region and NCEP-NCAR reanalysis data from 1961 to 2020, three meteorological conceptual models of flood-causing rainfall—namely westerly trough type, low vortex shear type, and subtropical high southwest flow type—are established by using the weather-type method. The mechanism of flood-causing rainfall and the corresponding flood characteristics of each weather type were investigated. The results show that during the process of flood-causing rainfall, in the westerly trough type, the mid- and high-latitude circulation is flat and fluctuating. In the low vortex shear type, the high pressures over the Ural Mountains and the Okhotsk Sea are stronger compared to other types in the same period, and a low vortex shear line is formed in the west of the SAYR region at the low level. The rain is formed during the eastward movement of the shear line. In the subtropical high southwest flow type, the low trough of Lake Balkhash and the subtropical high are stronger compared to other types in the same period. Flood-causing rainfall generally occurs in areas with low-level convergence, high-level negative vorticity, low-level positive vorticity, convergence of water vapor flux, a certain amount of atmospheric precipitable water, and low-level cold advection. In terms of flood peak increment and the maximum accumulated flood volume, the westerly trough type has a long duration and small flood volume, and the low vortex shear type and the subtropical high southwest flow type have a short duration and large flood volume. [ABSTRACT FROM AUTHOR]

The vast rural drinking water sources along the Yellow River basin in Henan Province mainly come from the local high-salinity groundwater, which cannot be directly drunk. Zeolitic imidazolate framework-71/polyvinylidene fluoride hollow fiber composite membrane was applied to treat rural groundwater through membrane distillation technology. The variations of water quality parameters from 12 different rural regions after membrane distillation treatment were well analyzed and compared. Membrane separation performance for water samples from different regions during the membrane distillation process was investigated, including water flux and salt rejection. During a continuous 24-h membrane distillation process for the treatment of these water samples, hollow fiber membrane exhibits high solute retention rates (>99%) for salt ions, suspended solids and total dissolved solids, which are within the limits of national standards (GB 5749-2006), meanwhile membrane permeation water flux can remain stable. After the acid-cleaning for 180 min, all hollow fiber membranes can recover water flux well with a flux recovery rate above 98%. Even if the concentration ratio continued to increase, the water production rate of membrane distillation was basically maintained between 50% and 60%, which was obviously higher than the 30% of the reverse osmosis process. The economic analysis confirmed that the water production cost varied between US$0.45 and US$0.29/m3. With the extension of membrane service life, the specific membrane cost decreased rapidly in the first 6 years and then leveled off. The proposed vacuum membrane distillation process proved to be a promising water purification method for treating rural high-salinity groundwater. [ABSTRACT FROM AUTHOR]

The abrupt reduction of the water discharge and sediment load in the Yellow River has attracted much attention during the past several decades. This paper investigates the temporal and spatial changes of annual sediment load and water discharge in the Weihe River basin, the largest tributary of the Yellow River, which contributes 40 % of the sediment and 26 % of the water to the Yellow River. The results suggest that sediment load and water discharge in the Weihe River basin from both mainstream and tributaries show significant decreasing trends (significance level of 0.05). The trends show the following three distinct stages: the fluctuating stage (1956–1969), the slowly decreasing stage (1970–1979) and the accelerated decreasing stage (1980–2010). Additionally, the water discharge decreases more quickly than sediment. Spatially, the greatest reduction in water discharge and sediment load occurs upstream of the river. Additionally, the decrease in water discharge and sediment load in the main stream is greater than in the tributary. The focal years of water discharge and sediment changes are the same for each station except for the Zhuangtou Station, which were approximately 1970 and during the 1990s. Human activities contribute much more to changes in the hydrological series, and the percentage of human activity impacts on the water discharge are much larger than the sediment load for most of the periods. The relationship between the average monthly water discharge and the sediment load shows a clockwise loop curve. The change points for the annual water discharge and the sediment load relationship occurred mainly in 1983 for most stations. The reduction in the water discharge and sediment load is caused mainly by human activities, especially soil and water conservation projects (such as afforestation, terraces, reservoirs and dams). In summary, the results in this study provide further evidence of the need for river basin management. [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]

In this paper, we use geoarchaeological and paleoenvironmental data from three localities in the Yellow River Valley, China – Taosi, Sanyangzhuang, and the Yiluo Valley – to argue that human activity in the mid- to late-Holocene contributed to large-scale changes in the behavior of the Yellow River and that these changes were of sufficient magnitude to bend the arc of China’s history. Massive anthropogenic landscape transformation from the later Neolithic into the early Dynastic periods, especially in the Chinese Loess Plateau, increased sedimentation in the Yellow River requiring intensive investment in flood control features to protect an ever-growing population. As the Yellow River channel aggraded, channel gradients became increasingly steep, and avulsions occurred with greater frequency and consequence. Flooding reached an apogee in the first decades of the Common Era when a massive avulsion of the Yellow River ca. 14–17 CE caused the river to shift to the south and east of its former channel. This avulsion and the catastrophic flooding that followed triggered the collapse of the Western Han dynasty. The Yellow River – known as ‘China’s Tribulation’ – has been seen as a natural scourge that afflicts the inhabitants of the fertile North China Plain. However, when viewed in an Anthropocene perspective, it is evident that China’s Tribulation largely is the result of human manipulation of the environment. [ABSTRACT FROM AUTHOR]

Bisphenols (BPs), which act as endocrine disruptors, are extensively used in epoxy resin and polycarbonate plastic production and are found in various environmental media. This study investigated the occurrence and distribution of seven BPs in water and sediment samples from the Lanzhou section of the Yellow River, China. Previous studies have focused on the southern and more developed regions in China. Paired water and sediments were collected in the Yellow River from August 2016 to March 2017. Bisphenol A (BPA), bisphenol AF (BPAF) and bisphenol S (BPS) were measured in the study samples. Mean concentrations of BPs were 88 and 61.2 ng/L in the rainy and dry seasons, respectively, in water samples. The concentrations were 40.4 and 29.9 ng/g in the rainy and dry seasons, respectively, in sediment samples. BPA accounted for the largest proportion in ∑BPs, followed by BPAF and BPS, which indicates that BPA and BPAF have been widely used and discharged in this region. 17β-estradiol equivalents for BP analogues were 21.57–203.83 pg/L and 13.06–185.30 pg/L in the dry and rainy seasons, respectively, in water samples. BPAF had the highest mean estrogenic activity (> 80%) amongst the study samples. The concentration of ∑BPs was lower than those in previous studies; however, the concentration of BPAF was high. The present study also surveyed the estrogenicity of BPs from the samples, and BPAF contributed the highest mean estrogenic activity. The results of this study demonstrate that BP pollution exists to some degree, and the use and discharge of BPAF should be monitored. [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]