In order to explore the influencing factors and spatial differences of the green development of agriculture (GDA) in the Yellow River Basin (YRB), and to provide theoretical support and decision-making basis for the high-quality development of agriculture in the YRB, an evaluation index system for the level of GDA was established, which included three dimensions of high efficiency of development, ecological friendliness and resources conservation. Based on the panel data of 68 prefecture-level cities in the YRB from 2011 to 2021, the global entropy method (GEM) was applied to assess the level of GDA in the YRB, and the Moran index was used to analyze the spatial and temporal patterns of its differentiation. On this basis, six indicators were set up in economic, social and natural aspects, including industrial structure, planting structure, industrialization level, urbanization level, topographic relief and annual precipitation, and a multi-scale geographically weighted regression (MGWR) model was used to empirically analyze the influencing factors of the GDA in the YRB and its spatial differences. The results show that a) the level of GDA in the YRB shows an upward trend from 2011 to 2021, but the overall level at the end of the study period is still low, with the level of GDA in the lower reaches significantly higher than that in the middle and upper reaches, the development of efficient dimensions in the upper reaches and lower reaches showing a clear upward trend, and the ecologically friendly and resources-saving dimensions showing a smaller increase in the study period. b) There is an obvious positive spatial correlation between the level of GDA in the YRB, with a relatively large number of H-H agglomeration and L-L agglomeration prefecture-level cities. c) The spatial heterogeneity of the factors influencing the GDA is significant and the intensity of influence is different, among which the spatial differences in the influence of industrial structure, planting structure, industrialization level and topographic relief are small and the spatial difference in the influence of urbanization and annual precipitation is large. Industrial structure, industrialization level and topographic relief have negative effects, while planting structure, urbanization level and annual precipitation have positive effects. The intensity of influence is topographic relief > industrialization level > urbanization level > industrial structure > planting structure > annual precipitation. Some suggestions are put forward, such as changing the concept of agricultural development, strengthening regional cooperation and implementing differentiated agricultural green development strategies.

In order to investigate the effect and mechanism of digital economic development on carbon emission in the Yellow River Basin, based on the panel data of 76 prefecture-level cities in the Yellow River Basin from 2011 to 2020, we measured the level of digital economic development, the total amount of carbon emission and the intensity of carbon emission in the Yellow River Basin, and built an individual and time two-way fixed-effects model to conduct empirical analysis, and conducted robustness tests on the results of the lagging effect of digital economic development, changing the sample capacity, and substitution variables. The empirical results are tested for robustness such as lagged effect of digital economic development, changing sample capacity, and substitution of variables, the mechanism of technological progress and industrial structure upgrading, and the heterogeneity of location and heterogeneity of resource endowment of carbon emission reduction effect of digital economic development. The results show that a) the digital economic development has a significant inhibitory effect on carbon emission intensity and total carbon emission in the Yellow River Basin. b) Technological progress and industrial structure upgrading are important mechanisms for digital economic development to promote carbon emission reduction in the Yellow River Basin. c) There is significant location heterogeneity and resources endowment heterogeneity in the inhibitory effect of digital economic development on carbon emission in the Yellow River Basin, and the inhibitory effect on carbon emission in the middle and upstream areas of the Yellow River is significantly better than that in the downstream areas, and the inhibitory effect on carbon emission in the middle and downstream areas is significantly worse. The inhibition effect on the total carbon emissions in the middle and upper reaches of the Yellow River is significantly better than that in the lower reaches, the inhibition effect on the carbon emission intensity in the upper reaches has not yet appeared, and the inhibition effect on the carbon emissions of non-resources cities is significantly greater than that of resources cities. Countermeasures and suggestions are put forward to coordinate the coordinated development of the digital economy in the Yellow River Basin, strengthen the promotion of green and low-carbon technological innovation, accelerate the transformation and upgrading of the industrial structure, implement differentiated digital economy development strategies, and effectively curb carbon emissions.

In order to address climate change and water resources pressures, and to achieve sustainable regional water resources utilization under the carbon neutrality target, the InVEST model was employed to assess carbon storage and water yield in the Qinhe River Basin from 2000 to 2020. The study also used geographical detectors to explore the driving factors and explanatory power, and spatial autocorrelation analysis to examine the spatial relationship between the two. The results show that: a) Water yield in the Qinhe River Basin has shown a fluctuating increasing trend, rising from 1.020 billion m³ in 2000 to 1.167 billion m³ in 2020. This change aligns with the trend in precipitation, with carbon storage and potential evapotranspiration being the main driving factors. b) Carbon storage decreases from 167.566 7 million tons in 2000 to 167.110 5 million tons in 2020, following a trend similar to soil carbon storage, with potential evapotranspiration and water yield being the primary driving factors. c) The global Moran’s index of water yield and carbon storage is -0.2, showing no significant spatial distribution overall. Spatially, there is a pattern of high water yield-low carbon storage and low water yield-high carbon storage.

Utilizing panel data from 2010 to 2020 pertaining to energy consumption and socio-economic dynamics within the energy-abundant region of the Yellow River basin, this research employed the Logarithmic Mean Divisia Index (LMDI) model in conjunction with the Tapio decoupling index to examine the decoupling relationship between economic growth and carbon emissions. Additionally, the study assessed the respective contributions of energy structure, energy consumption intensity, economic output, and population size to the variability in carbon emissions and the decoupling index. The findings indicate that: Over the course of the decade, carbon emissions in the energy-rich regions of the Yellow River Basin have experienced a marked upswing, with a fluctuating growth rate that has decreased by 8.83% compared to the initial period. Over the long term, the escalation of economic output levels emerges as the predominant factor contributing to the augmentation of regional carbon emissions. The predominance of coal in the energy mix constitutes the primary driver behind substantial carbon emission levels, although its impact on the incremental increase in carbon emissions is moderated by the entrenched nature of the energy structure, which is resistant to short-term transformation. The energy intensity effect reflects the combined impact of energy efficiency and energy consumption demand, and it is a significant factor in promoting carbon emission increases. Conversely, a contraction in population size exerts a mild inhibitory on the escalation of carbon emissions. The study region undergoes a triphasic transformation in its decoupling status, evolving from an undesirable condition predominantly marked by negative decoupling to a more desirable state predominantly characterized by positive decoupling, culminating in a regression to a less favorable condition of negative decoupling by the terminal period. Ascending energy intensity and economic output emerge as the predominant impediments to the realization of decoupling between regional carbon emissions. Of particular interest is the contrasting influence of population size reduction on carbon emissions and decoupling status, which demands further scholarly consideration. Population size is a critical determinant of a region's ability to achieve decoupling. In light of these findings, the study put forward several recommendations, including optimizing the energy structure, enhancing energy efficiency, fostering technological innovation, promoting sustainable industries, attracting talent, consolidating the population base, undertaking mining area rehabilitation efforts, and strengthening environmental regulations.

In order to solve the coordination problem between agricultural green development and ecological protection in the Yellow River Basin and identify the reasons behind the contradiction between agricultural production and ecological environment protection, the paper took the nine provinces (regions) in the Yellow River Basin as the research object to build an evaluation index system for agricultural green development and ecological protection was constructed. The entropy method was used to measure the agricultural green development index and ecological protection index of each province (region) from 2006 to 2020. The fusion coordination model was used to calculate the coupling coordination between agricultural green development and ecological protection, and the obstacle degree model and grey correlation degree model were used to diagnose and analyze the obstacles and driving factors of coupling coordination development. The results show that during the research period, the coupling coordination degree between agricultural green development and ecological protection in the Yellow River Basin shows an overall upward trend, with a spatial pattern of “upstream>downstream>midstream”. There is still a significant gap between each province (region) and high-quality coordinated development. The coordinated development of agricultural green development and ecological protection is mainly hindered by the dimensions of output efficiency and resources endowment. The internal driving factors that affect the degree of coupling and coordination between agricultural green development and ecological protection in the Yellow River Basin, in descending order of correlation, are the proportion of nature reserves area, the multiple cropping index of arable land, forest coverage, grain yield per unit area, per capita arable land area and fertilizer application intensity. Therefore, it is necessary to strengthen the overall coordination of agricultural industry development planning in the upper, middle, and lower reaches of the Yellow River Basin, accelerate the flow of factors such as technology, capital, and labor between regions, and formulate differentiated agricultural development and ecological civilization construction strategies.

The construction and management of flood retention areas are crucial for basin flood control safety, economic development and ecological construction. Based on an analysis of the current status and existing issues in the construction and management of flood retention areas in China, this study employed the PDCA cycle improvement strategy (Plan, Do, Check and Act) as its theoretical foundation. It focused on flood control, economic development and ecological construction to address issues such as lagging infrastructure development, inadequate compensation mechanisms and limited ecological construction in flood retention areas. Furthermore, considering the needs for coordinated development of flood retention areas, the study proposed improvement strategies for achieving coordinated flood control, economic and ecological development. Taking Dongdawei as a typical case, the current development status and challenges were analyzed. Based on the established evaluation index system for coordinated flood control, economic and ecological development levels in flood retention areas, the coordinated development level of Dongdawei after PDCA cycle improvements was assessed. Finally, comprehensive measures for ensuring the coordinated development of Dongdawei were proposed from the perspectives of flood control, economy and ecology.

In the formation and evolution of the Yellow River, long underestimated but extremely important records are the form and location of the river channel, as well as the interdependence between riparian geological bodies. The study shows that the Yellow River channel generally presents three extension styles of long line extension, short bend and zigzag swing. Regional tectonic evolution, faulting tectonism and other internal dynamic geological processes are the main controlling factors for the formation and evolution of the Yellow River channel. The Qinghai-Tibet Plateau, the margin of the Ordos block and the North China Plain are three unique tectono-geomorphic units formed by regional tectonic evolution, and the tectonic factors in the basin have respectively created three different geometric patterns of river channel combinations, namely, inverted Z-shaped, Ω-shaped and wide V-shaped. During the formation and evolution of the three types of river channel, their own unique issues in geology, engineering, development and protection are derived, according to which the development and management suggestions are put forward.

In order to provide theoretical reference and scientific basis for the high-quality development of digital agriculture in the Yellow River Basin, an evaluation index system for the development level of digital agriculture was constructed. Based on the panel data of nine provinces (regions) in the Yellow River Basin from 2015 to 2022, the entropy weight method was used to measure the development level of digital agriculture in the provinces (regions) in the Yellow River Basin. Theil index and Moran index were used to analyze the regional differences and spatial autocorrelation of digital agriculture development in the Yellow River Basin, and the key driving factors of digital agriculture development in the Yellow River basin were diagnosed by geographic detectors. The results show that: a)During the study period, the development level of digital agriculture shows a steady upward trend, but the regional gap is obvious. The development level of digital agriculture in the lower reaches of the Yellow River is much higher than that in the upper and middle reaches of the Yellow River, the lowest in the upper reaches, and the gap between provinces (regions) is large and the gap is increasing. b) The development level of digital agriculture in the Yellow River Basin shows obvious L-L and H-H agglomerations and mainly L-L agglomeration, the spatial agglomeration pattern is relatively stable during the research period. c)The level of scientific and technological innovation, rural infrastructure and the living standard of rural residents are the key driving factors for the development of digital agriculture in the Yellow River Basin, and the influence of each driving factor is significantly greater than that of a single factor. Therefore, the development of digital agriculture should give play to the synergistic effect of all driving factors, especially the synergistic effect of rural infrastructure and other factors. Suggestions: a)Strengthen regional cooperation to ensure the balanced development of digital agriculture in the Yellow River Basin. b)All regions in the basin should consolidate their advantages, make up for weaknesses, and explore new models of personalized development based on resource endowment and digital agriculture development foundation. c)Increase investment in digital agricultural infrastructure and digital agricultural science and technology innovation.

In order to study the impact of the operation of cascade reservoirs in the upper reaches of the Yellow River on the hydrological regime of the downstream section, the Longyangxia Reservoir to Liujiaxia Reservoir section was taken as the research area, the Mann-Kendall mutation test was used to examine the years of abrupt changes in the average annual flow of the inflow and outflow hydrological stations (Tangnaihai, Guide, Xunhua, and Xiaochuan hydrological stations) from 1952 to 2021, the hydrological change index method-hydrological change range method (IHA-RVA method) was used to quantitatively evaluate the hydrological change degree of the monthly average flow of the inflow and outflow hydrological stations, Pearson correlation analysis method was used to evaluate the correlation between annual runoff and annual sediment discharge at the inflow and outflow hydrological stations. The results show that the flow of hydrological stations entering and leaving the reservoir exhibits periodic changes and overall increases, while the annual average flow of the upper reaches of the Yellow River undergoes a sudden change after the operation of the cascade reservoirs. After the operation of the reservoir, the monthly average flow of hydrological stations located upstream of the reservoir shows moderate to low changes, while the monthly average flow of hydrological stations located downstream of the reservoir shows moderate to high changes. The monthly average flow change is related to the “flood storage and dry discharge” operation mode of the reservoir. The annual sediment discharge of the inflow and outflow hydrological stations shows a decreasing trend, with the Tangnaihai Hydrological Station in the upstream showing the smallest decrease in sediment discharge, and the Xiaochuan Hydrological Station in the downstream showing the largest decrease in sediment discharge. The annual runoff is significantly positively correlated with the annual sediment discharge.

The effects of UWB-Ⅱ flocculant and polycarboxylic acid superplasticizer on the fluidity and rheological properties of the slurry in underwater non-dispersible concrete were studied. The relationship between the fluidity and yield stress of the slurry was analyzed. The results show that a small amount of flocculant can increase the fluidity of slurry and reduce the yield stress and viscosity of slurry. The yield stress and viscosity of slurry are significantly increased with large dosage of flocculant. The addition of water reducing agent can slightly increase the fluidity of the slurry and reduce the yield stress and viscosity of the slurry, but the influence to the yield stress and viscosity of the slurry is weakened when the addition of water reducing agent is larger. When the dosage of flocculant is small, the slurry shows shear thickening, and when the dosage of flocculant is large, the slurry shows shear thinning. The addition of water reducing agent has no significant effect on the slurry shear thinning. There is a linear negative correlation between fluidity and yield stress.

Aiming at the pricing mechanism of water rights trading in cities along the South-to-North Water Diversion Project, this paper studied the pricing mechanism of water rights trading by using energy theory of ecological economics and game theory. Firstly, considering the ecological and economic losses of the seller and the ecological and economic benefits of the buyer, the quantitative system of the ecological and economic effects of water rights trading along the South-to-North Water Diversion Project was proposed by energy theory. Then the cooperative game model of water rights trading was constructed, and the Nash negotiation solution method was used to determine the game price of water rights trading. The calculation results of Pingdingshan-Xinmi City show that the game prices in 2016-2018, 2021 and 2030 are 0.50 yuan/m³, 0.54 yuan/m³, 0.74 yuan/m³, 1.04 yuan/m³ and 1.16 yuan/m³, respectively. Compared with the actual transaction price of 0.78 yuan/m³, the game price can better reflect the influence of water resources abundance and shortage on water rights trading price.

Taking 25 central cities in the Yellow River Basin as samples, this paper built an evaluation model of urban flood resilience in the Yellow River Basin based on PSR theoretical framework, calculated the level of flood resilience in the central cities in the Yellow River Basin, and analyzed the spatial-temporal evolution of the three-dimensional index of urban flood system by using Jenks’ natural discontinuity method. The results show that: a) During 2012-2020, the flood resilience of the central cities in the Yellow River Basin maintains an overall growth trend. b) From the perspective of three-dimensional degree of urban flood system, the pressure stimulation index of each urban system shows a fluctuating upward trend, the fluctuation of state sensitivity index is obvious, and the adaptability index of response dimension shows an upward trend year by year. c) The level of urban flood resilience is unevenly distributed in space, and the cities with high flood resilience are sporadically distributed. d) The spatial correlation degree of urban flood resilience mainly presents the three types of spatial correlation of H-H cluster, L-L cluster and H-L cluster.

Under the influence of climate change and human activities, the runoff of most rivers in Shanxi Province has been severely attenuated. Four typical watersheds in Shanxi province, including Fenhe, Qinhe, Zhanghe and Hutuo rivers, were taken as the research objects. The runoff evolution characteristics were analyzed. The hydrological processes were simulated by using the VIC model, based on which the contributions of climate change and human activities to runoff attenuation were analyzed. The results show that the annual runoff of typical watersheds shows a significant downward trend during 1956-2018, and all of which has an abrupt change around 1980. Compared with the baseline period (1960-1980), the average annual runoff (1981-2000) of Fenhe, Qinhe, Zhanghe and Hutuo rivers is decreased by 57.9%, 49.1%, 57.3% and 37.6%, and the contributions of human activities are 59.9%, 54.3%, 52.3% and 49.0% respectively. During 2001-2018, the attenuation is increased further, and the contribution of human activities increases to 74.8%, 73.1%, 72.4% and 57.7% respectively. Human activities such as surface and underground water extraction, coal mining, soil and water conservation measures and so on are the main driving factors of runoff attenuation.

In order to provide a reference for building the ecological compensation mechanism in the Yellow River Basin from the perspective of taxation, especially the horizontal ecological compensation tax mechanism, this paper analyzed the limitations of the existing ecological compensation schemes such as vertical ecological compensation from higher governments to lower governments, intra-provincial (regional) horizontal ecological compensation and inter-provincial (regional) horizontal ecological compensation in the Yellow River Basin, and put forward the idea of “fee to tax” for horizontal ecological compensation in the Yellow River Basin. From the perspective of tax regulation, the advantages of tax compensation in external governance, system design, vertical and horizontal complementarity and rebuilding of central-local relationship of ecological compensation were discussed. In terms of mechanism design, the corresponding analysis was made between water resources tax, environmental protection tax and ecological compensation tax and the key areas of ecological compensation, such as water conservation, cross-province (region) boundary water pollution, soil and water conservation and ecological compensation integrated management. Integrating the design of tax system into the ecological compensation mechanism could give full play to the regulating role of tax revenue, so that the horizontal ecological compensation mechanism can play a key role in the ecological function and economic and social development of the upper, middle and lower reaches of the Yellow River Basin.

In order to explore the possibility and impact of digital inclusive finance's intervention in agricultural green development in the Yellow River Basin, based on panel data from nine provinces (regions) in the Yellow River Basin from 2013 to 2021, the entropy method was employed to measure the level of agricultural green development. Fixed-effect and mediation-effect models were utilized to investigate the effect and mechanism of digital inclusive finance on agricultural green development. The results indicate that the comprehensive score of agricultural green development level exhibits a pattern of higher scores in Sichuan, Shandong and Henan. Digital inclusive finance and its three sub-dimensions significantly promote agricultural green development. Agricultural technology plays a bridging role between digital inclusive finance and agricultural green development. The development of digital inclusive finance in the Yellow River Basin is conducive to promoting the level of agricultural green development. Therefore, it is necessary to further strengthen the promotion of digital inclusive finance in the Yellow River Basin, fully leverage its role in enhancing agricultural technology, inject new vitality into agricultural green development, and promote ecological protection and high-quality development in the Yellow River Basin

In order to clarify the groundwater quality evolution characteristics and the sources of groundwater chemical components in the saline irrigation area in western Jilin, the groundwater quality monitoring data from 2012-2014 and 2019-2020 were selected, and mathematical statistics, graphical method, entropy-weighted Bayesian, factor analysis, and Absolute Factor Score-Multiple Linear Regression (APCS-MLR) model were used to carry out the research on groundwater chemical characteristics, water quality evaluation and hydrochemical components traceability analysis in western Jilin irrigation area. The results show that:Fe, F, Mn and tri-nitrogen compounds in the irrigation area and its surrounding areas are seriously exceeded. The water chemistry type is mainly weak alkaline water of the HCO^-₃-Na⁺-Ca²⁺ type, affected by the dissolution and filtration of rocks and evaporation-crystallization, and the long-term irrigation and drainage salt-washing improves salinization of the irrigation area and its surrounding areas. During the research period, the salinization of the irrigation area and its surrounding areas diving Ⅳ,Ⅴ water proportion increased by a total of 5.3 percentage points, Ⅳ,Ⅴ water proportion in the pressurized water decreased by a total of 4.0 percentage points. Dissolved filtration-secondary enrichment effect on groundwater quality is the most significant, so that the concentration of soluble ions in the water, TDS, total hardness and other components of the water increased. Saline and alkaline development of paddy field irrigation area leads to increased regional agricultural activities on the impact of the chemical components of groundwater.

Conventional models for sandy-river key water-control project often fail to accurately simulate actual project operations, resulting in various problems during and after project completion. This paper aimed to enhance the movable-bed model test of sandy-river key water-control project and optimized the design method of the reservoir sediment model. A sandy river reservoir was taken as a prototype, and the pseudo-scorched sand, chemically stable and moderate weight, was determined as the paramount model sand in the movable-bed model. The paper analyzed the similar motion conditions of suspended sand and nudging sand, and consulted relevant experimental results and calculation formulas for sinking speed and sand force with high accuracy. This study identified the scales of water movement, sediment movement and heterogeneous flow movement in the reservoir model, which provided a solid foundation for the validation and formal engineering program tests after the model had been built.

As a core link in the implementation of major hydropower projects under the EPC mode, procurement is crucial to the realization of design intent and the smooth implementation of the project. Under the relatively low level of standardization in the domestic construction market and the application level of EPC mode, there is an urgent need to carry out the adaptive innovation of procurement management in combination with the complex characteristics of major hydropower EPC projects. This study primarily analyzed the motivation of procurement management innovation in major hydropower EPC projects from the importance and complexity of the procurement task itself, and the issue of double entrustment agency of the procurement subject in the implementation process. On this basis, according to the general principle of implementing procurement by category and subject, the procurement goods of major hydropower projects were divided into four categories of leveraged goods, strategic goods, general goods and bottleneck goods based on Kraljic model. Based on the characteristics of the procurement of different categories of goods, the procurement management innovation path was proposed. The case studies of the two projects show that the differentiated procurement management mode is beneficial to the owner in controlling the quality and cost of the main equipment and materials, and improves the procurement efficiency while helping the project to be completed with high quality.

Facing the national strategic requirements of improving the ecological environment quality and high-quality development in the Yellow River Basin, in order to promote the conservation and intensive utilization of water resources, this paper constructed 15 evaluation indexes including water resources system, socio-economic system and ecological environment system. The entropy weight method was used to evaluate the water resources conservation and intensive utilization level of 50 cities in the upper and middle reaches of the Yellow River Basin from 2018 to 2021, and identified the main factors affecting the water resources conservation and intensive utilization level of cities in the study area by using obstacle model. The results show that the overall level of conservation and intensive utilization of water resources in the study area is on the rise, from 0.505 in 2018 to 0.553 in 2021. The utilization rate of reclaimed water, the proportion of agricultural water use and the sewage treatment rate are the main obstacle factors affecting the improvement of the level of conservation and intensive utilization of water resources in the study area. Based on this analysis, the countermeasures for the conservation and intensive utilization of water resources were put forward from four aspects of water saving, social and economic development, ecological environment protection and unconventional water resources utilization.

In order to study the characteristics of river regime change during Diaokou River flow and the influence of human activities to the flow path evolution after the flow stopped, based on the measured data analysis, the paper compared and analyzed the water and sediment conditions, the horizontal and vertical geometry of the Diaokou River and the changes of erosion and deposition in two different stages of the Diaokou River during the river running from 1964 to 1976 and after the river stopped running from 1976 to now. The results show that during Diaokou River flow, the evolution of the flow path is influenced by the factors of water and sediment conditions, channel morphology and tidal current dynamics, and the flow path evolution goes through three stages of the initial stage channel wandering and swinging, the middle stage channel being single and straight, and the final stage channel branching out. After the stop of the flow of the Diaokou River, it is affected by human activities, resulting in significant changes in the terrain of the river, the main channel shrank and the river beaches crisscrossed. In the future, the Diaokou River control should focus on prominent issues such as channel deposition and shrinkage, estuarine and coastal erosion, and human activities. Engineering measures such as dredging channel and optimizing ecological water supplement should be taken, and gradually restore ponds to rivers, reclaimed land to wetland and farmland to beach in an orderly manner.

There is independence and integration between water supply and sediment reduction in sediment-laden river reservoirs. How to maintain effective storage capacity and meet water supply requirements for a long time is one of the issues to be solved in the efficient operation of sediment-laden river reservoirs. In this paper, Dongzhuang Reservoir of Jinghe River was taken as the research object. Through the analysis of measured data and mathematical model calculation, the measured hydrological sediment and cross-section erosion and deposition in the lower reaches of Jinghe River and Weihe River were analyzed. The reservoir sediment discharge flow index which was beneficial to reduce the sediment deposition in the lower reaches of Weihe River and maintain the effective reservoir capacity for a long time was studied, and the joint regulation mode of reservoir runoff and sediment was put forward. The outcomes show that during the main flood season for the sediment interception period from July to September, when the inflow is greater than 600 m³/s and the sediment concentration is greater than 300 kg/m³, the Dongzhuang Reservoir is open for sediment discharge. As the normal operation period, during the main flood season from July to September, when the inflow exceeds 300 m³/s, the Dongzhuang Reservoir will open for sediment discharge. The reservoir cannot supply water during the sediment discharge period. The joint regulation of the Dongzhuang Reservoir and the surrounding four storage reservoirs can reduce the deposition of the lower reaches of the Weihe River by 11 million tons per year, increase the guarantee rate of agricultural irrigation from 30% to 50%, and increase the guarantee rate of industrial water supply from 57% to 95%.

The Yellow River runoff has unsteady and non-linear characteristics. In order to provide reference for ensuring water security in Henan Province, the non-flood season discharge of Sanmenxia Hydrology Station of the Yellow River was studied. The paper built non-flood season runoff prediction models by combining variational mode decomposition (VMD) with long short term memory (LSTM) and support vector regression (SVR). The sparrow search algorithm (SSA) was used to adjust the model parameters to improve the prediction accuracy. The runoff data was decomposed into multiple eigenmode functions (IMF) by the VMD algorithm, Euclidean distance between components was calculated based on K-Means clustering method and the reciprocal of Euclidean distance was used as the weight of each component. Finally, the results of each component were put into LSTM/SVR for model prediction, and the runoff results were obtained by weighted reconstruction of the predicted values of components. Comparing with before and after weighted VMD-SSA-LSTM and VMD-SSA-SVR model, the results show that the proposed K-Means weighted VMD-SSA-LSTM model predicts the average daily runoff of Sanmenxia Hydrology Station from January 2003 to May 2023 (non-flood season month), with the mean absolute error being 82.54 m³/s, the root-mean-square error being 106.64 m³/s and the fitted coefficient being 0.92, the trend of runoff can be predicted more effectively.

Using remote sensing technology to dynamically monitor the utilization type of the Yellow River embankment-line is helpful to understand the construction process of ecological corridor along the Yellow River. This paper took the middle reaches of the Yellow River as the research object, extracted embankment-line utilization information at intervals of 5 years based on Landsat-5 TM and Landsat-8 OLI images from 1993 to 2023, analyzed the spatial-temporal variation characteristics of embankment-line utilization after the implementation of the national strategy of ecological protection and high-quality development in the Yellow River Basin and preliminarily discussed the effectiveness of ecological protection of the Yellow River corridor. The results show that from 1993 to 2023, the proportion of living embankment-line in the middle reaches of the Yellow River is increased from 2.12% to 16.96%, and the proportion of ecological embankment-line shows a fluctuating upward trend, reaching 39.68% in 2023. The embankment-line utilization of three sections in the middle reaches of the Yellow River is quite different, among which, the ecological embankment-line is mainly used in the Jin-Shaan Valley section, the agricultural embankment-line is mainly used in the Fen-Wei Plain section, and the Sanmenxia-Taohuayu section has changed from an agricultural embankment-line to an ecological embankment-line. From 2018 to 2023, the increase of ecological embankment-line and living embankment-line and the decrease of agricultural embankment-line are the most significant, and the ecological embankment-line of each section shows positive changes.

In order to solve the issue of uneven subsidence of the channel, serious subsidence and slide of the concrete lining plate in the collapsible loess area, the reasons for subsidence of the No.10 main canal in Guhai extention irrigation in Ningxia were analyzed, and the foundation soil of the channel was ramped, and the bearing capacity of the foundation soil was increased. The channel subsidence is treated by arc bottom trapezoidal concrete section, composite geomembrae and benzene plate. The results show that the density of the channel reaches more than 1.78 g/cm³, the pore ratio of the base soil is greatly reduced, and the density is increased. The cast-in place arc bottom trapezoid section has good structural loading condition and uniform adjustment of frost heave force and uneven subsidence. The analysis of the effect after the reconstruction and treatment of the channel shows that the water content of the foundation soil, the frost heaving amount and the settlement amount of the concrete slab has been effectively controlled. Through the comprehensive treatment of collapsible channels, the theoretical design and methods for the treatment of collapsible channels and the collapse of concrete slabs are improved.

The formation and evolution of the wide V-shaped channel of the Yellow River depends not only on the boundary form of the tectonic belt around the North China Plain and its interaction, but also on the remote response of the NE-trending extrusion of the Qinghai-Tibet Plateau. From Sanmenxia to the estuary of Bohai Bay, the Yellow River channel takes Lankao as the inflection point due to the control of the regional major faults on the riverbank, and the flow direction of the front and rear sections of the river channel changes from NEE to NE, forming a wide V-shaped channel combination style. The extension style of the river channel in the area is mainly manifested as long linear extension, followed by oblique array swing and short broken line turning. The Yellow River in the Sanmenxia-Zhengzhou section is produced in the fault depression zones surrounded by the southern Taihang Mountains tectonic belt and the Qinling tectonic belt. The piedmont faults have been strongly active since the Quaternary, and the main river sections are produced in the fault zone. The North China Plain is an irregular hexagon-shaped depression plain on the plane bounded by four major tectonic belts. The long sides of the irregular hexagon are parallel to the Taihang Mountains tectonic belt and the Tai’an-Ji’nan tectonic belt, respectively. The main channel of the Yellow River is located in the hidden fault zone of Nanyang-Lankao-Pingyin-Kenli, with some of the NE trending long line tributaries parallel to and partially overlapping with the NE trending hidden fault zone in the area. The ancient diversion of the Yellow River in the verifiable historical period and the known abandoned Yellow River are all occurred in the hidden major fault zones. These hidden faults are the secondary faults of the two major tectonic belts along the river bank, and have mostly been significantly active since the Quaternary. The faults along the Yellow River and the hidden faults in the plain area are the main products of the formation and evolution of the orogenic belt, and also the main controlling factors for the generation, evolution, extension and turning of the river channels.

In order to explore the current development status of digital economy, green technology innovation and ecological protection in the Yellow River Basin, as well as the coupling, coordination and interaction relationship among the three, and provide useful reference for the promotion of ecological protection and high-quality development strategies in the Yellow River Basin, on the one hand, to theoretically deconstruct the coupling and coordination mechanism of the three systems of digital economy, green technology innovation and ecological protection in the Yellow River Basin and construct a theoretical framework, on the other hand, taking 77 prefecture level cities in the Yellow River Basin as research units and using 2012-2020 as the research period, this study empirically tested the current status of digital economy, green technology innovation and ecological protection development, and their coupled coordination level in the Yellow River Basin. The results show that a) from 2012 to 2020, the digital economy, green technology innovation and ecological protection index in the Yellow River Basin all show a steady upward trend. The ecological protection index shows a slight fluctuation and stable trend from 2012 to 2019, but shows a significant increase at the end of the research period in 2020. b) The coupling and coordination index of digital economy, green technology innovation and ecological protection in the Yellow River Basin has steadily increased during the research period. Through spatial evolution pattern analysis, it can be seen that cities along the basin have all crossed a serious imbalance state during the research period, and cities in a coordinated state have also gone through a process from scratch during the research period. Among them, Xi'an, Zhengzhou and Jinan have entered into the primary coordination stage. c) From the perspective of the spatial-temporal relationship of coupling coordination, on the one hand, there is a significant positive spatial clustering effect on the coupling coordination degree of digital economy, green technology innovation and ecological protection in various cities in the Yellow River Basin. On the other hand, the overall Gini coefficient of the coupling coordination degree shows a fluctuating downward trend, and the overall differences in the basin are gradually narrowing. However, specifically, the differences in the coupling coordination development between downstream and upstream regions are gradually expanding. Furthermore, according to the contribution rate of differences, it can be inferred that the development differences of coupling coordination mainly come from the development differences between watersheds.

Under the implementation of the major national strategy of ecological protection and high-quality development of the Yellow River Basin as well as the transportation power strategy, the construction of highways along the Yellow River is developing rapidly. The Yellow River silt is attracting attention for its potential as roadbed filler. Research on road performance and modified utilization of Yellow River silt becomes a hot issue. Chemical improvement, biomineralization reinforcement and polymer reinforcement techniques are considered to be effective in improving the engineering properties of Yellow River silt. Chemical improvement (e.g., alkali excitation technology) to reinforce the Yellow River silt is technically feasible. Still, the related research mostly focuses on the preparation of brick masonry by alkali excitation of Yellow River silt. Biomineralization technology is currently a research hotspot in the field of geotechnical engineering and the applicability of biomineralization technology to Yellow River silt has been confirmed by existing research. Compared with Microbial Induced Calcium Carbonate Precipitation (MICP) technology, Enzyme-Induced Calcium Carbonate Precipitation (EICP) technology has better applicability due to the small molecule size of free urease that is easier to pass through the pore throats of the Yellow River silt. The mechanical and durability performances of polymers reinforcing Yellow River silt indicate its application potentials are worth exploring. Based on this, the silt source and distribution data of the middle and lower reaches of the Yellow River Basin were integrated by this paper. The physical and chemical properties of Yellow River silt were summarized, and the research progress on road performance of Yellow River silt was systematically described. The feasibility of applying Yellow River silt to roadbed engineering had been preliminarily verified. The feasibility of Yellow River silt as roadbed filler will be further supported by green biomineralization reinforcement technology. Based on the continuous improvement of the existing engineering system and the deepening of multidisciplinary crossover, the utilization potential of Yellow River silt ecological resources will be fully developed and released.

Suspended sediment concentration (SSC) is a crucial water quality monitoring parameter. Taking the Wangtuan section of Qingshui River in Ningxia as the study area, an SSC inversion model suitable for waters with extremely high suspended sediment concentration was developed based on in-situ hyperspectral data and SSC measurements from August 26 to November 5, 2022. Four empirical models were selected for comparison, including single-band model, band difference model, band ratio model and binary linear model. The results indicate that for waters with extremely high suspended sediment concentrations, the single-band model performs poorly, with a coefficient of determination (R²) of less than 0.25. The band difference, band ratio and binary linear models are able to reduce the impact of noise and improve the model's R². Overall, the band difference model performs the best, with an R² greater than 0.40 for the model based on the reflectance difference between the 650-720 nm and 560-700 nm bands. Among which, the R687-R685 model achieves the highest R² value of 0.76.

In order to analyze the coupling relationship among energy, water and carbon in the Ω-shaped bend of the Yellow River urban agglomeration and to promote the green and low-carbon development of the region, this paper built an evaluation index system for the energy-water-carbon system of the urban agglomeration. This paper built energy-water-carbon evaluation index system of urban agglomeration of Ω-shaped bend of the Yellow River, used the entropy method and coupling coordination degree model to calculate the level of coupling coordination of energy, water and carbon in the urban agglomeration from 2005 to 2020, and built a random forest model to identify the main influencing factors. The results show that the coupling coordination degree of the energy-water-carbon system in the urban agglomeration of Ω-shaped bend of the Yellow River presents a fluctuating upward trend, but it has not reached a good coordination level in 2020. Environmental regulation, total factor productivity and proportion of built-up area are the main factors influencing the changes in this level. Based on these findings, suggestions are proposed to develop specialized environmental regulation policies, lead the energy revolution through technology, and promote the integration of environmental protection with economic development.

The Henan section of the Yangtze-to-Huaihe River Diversion Project supplies water from the Xifei River in Anhui Province to Henan Province, of which, the Qingshui River conveyance length is 47.46 km, and the conveyance channel has leakage and groundwater recharge problems. In this study, 15 groundwater level measuring points were set up around the Qingshui River to monitor the variation law of groundwater level after the water diversion experiment of the project in early December 2022. The results show that the rise of groundwater level at the measuring points near the river is earlier than that at the measuring points far away from the river, and the rise of water level is higher than that at the measuring points far away from the river. The change rate of groundwater level at different measuring points is generally a normal distribution of rising first and then falling at the initial stage after water diversion. The maximum change rate of water level at the measuring points close to the river channel is significantly higher than that at the measuring points far from the river channel. Different stratum conditions have a great influence to the groundwater recharge, which is manifested as that when there is a permeable layer with a large permeability coefficient or a thick permeable layer in the stratum, there is a large risk of leakage.

In order to investigate the variations in terrestrial water storage (TWS) and their driving factors in the West Liaohe River Basin, this study employed a Long Short-Term Memory (LSTM) model to reconstruct missing data between the GRACE and GRACE-FO satellite missions from April 2002 to December 2020. The water balance approach was utilized to analyze the spatiotemporal characteristics of TWS changes, and a quantitative assessment was conducted to evaluate the relative contributions of climate change and anthropogenic activities. The findings reveal that: a) The LSTM model effectively reconstructs the missing TWS data between the GRACE and GRACE-FO satellite records, demonstrating its applicability in hydrological studies. b) During the study period, GRACE-based observations indicate a significant decline in TWS in the West Liaohe River Basin at a rate of 0.41 mm/month, with pronounced spatial heterogeneity, particularly severe depletion in the southern region. c) Anthropogenic water consumption exerts a considerable influence on TWS variations, whereas the impact of reservoir storage is relatively limited; climate change emerges as a key determinant of TWS fluctuations.

In order to provide a basis for regional layout and development of new quality productivity according to local conditions, and formulate targeted policies for coordinated development of new quality productivity, a comprehensive index system reflecting the development level of new quality productivity was built based on the three dimensions of new types of workers, new types of labor materials and new types of labor objects. From the perspective of river basin, using the relevant data of 21 provinces (municipalities and autonomous regions) from 2015 to 2022, the entropy weight method, Dagum Gini coefficient and its decomposition method, and kernel density estimation method were used to empirically investigate the development level, regional differences and dynamic evolution trend of new quality productivity in the Yangtze River, Yellow River and Pearl River basins. The results show that a) in terms of spatial-temporal distribution, the development level of new quality productivity is on the rise as a whole, and the development level of new quality productivity and its components in the Yangtze River Basin is in the leading position, the Pearl River Basin is in the middle level and the Yellow River Basin is at the lowest level; b) In terms of regional differences, the internal differences of new quality productivity in the Yangtze River Basin are the smallest, the internal differences in the Pearl River Basin are the largest, and the differences between groups in the Yellow River basin and the Yangtze River basin are the largest, which is the main source of the overall differences of new quality productivity in the three major basins; c) In terms of dynamic evolution, the intra-regional gap of the development level of new quality productivity in the three major river basins shows a weakening trend, especially in the Yangtze River Basin, the unbalanced development of new quality productivity in the Pearl River Basin is more prominent, and the unbalanced development of the Yellow River Basin has shown a weakening trend, but the overall development level is at a relatively low level, and the task of developing new quality productivity is even more arduous.

The flood resistance ability of rock dam during the construction is insufficient, and the choice of flood control scheme directly affects the safety risk and cost risk of the project. However, there is relatively little research on the collaborative control of safety risk and cost risk of flood control scheme during the construction of earth-rock dam. At the same time, the evaluation index in multi-objective cooperative control involves many professional fields, and a single expert has different grasp of each evaluation index, so it is difficult to assign an accurate value. Therefore, a number of experts are used to assign values to evaluation indicators in the form of interval numbers, and an expert group opinion negotiation model is built by minimizing the distance of indicator values assigned among experts, and the value of interval numbers assigned by many experts is converted into a point that integrates all expert opinions, so as to establish a safety risk and cost risk evaluation model of flood control scheme during the construction period of earth-rock dam. Taking Qianping Reservoir as an example, a comprehensive evaluation of 7 flood schemes was carried out to guide the construction of Qianping Reservoir, and the collaborative control of safety risk and cost risk was realized.

In order to explore the synergistic relationship and evolutionary patterns between ecological resilience and high-quality economic development in the Yellow River Basin, we first conducted a theoretical analysis of their co-evolution. An evaluation index system for ecological resilience was built based on three dimensions of resistance, adaptability and recovery. Similarly, an evaluation index system for high-quality economic development was established based on four dimensions of economic scale, economic efficiency, economic structure and economic sustainability. Using the period from 2012 to 2022 as the study timeframe and the nine provinces (regions) of the Yellow River Basin as the calculation units, the entropy-weight TOPSIS method was employed to measure the annual ecological resilience and high-quality economic development capacity of each province (region). The Haken model was then used to calculate the annual synergy level between ecological resilience and high-quality economic development for each province (region). The results indicate that a) overall ecological resilience in the Yellow River Basin is higher than the capacity for high-quality economic development throughout the study period, showing a steady upward trend. The capacity for high-quality economic development is increased steadily from 2012 to 2019, with slight fluctuations from 2020 to 2022. b) The ecological resilience-high quality economic development composite system of the Yellow River Basin is still at a low-level orderly stage. In the process of their co-evolution, the capacity for high-quality economic development acts as the order parameter, guiding the path and direction of synergistic development and exerting a synergistic enhancement effect on ecological resilience. However, ecological resilience has a slightly inhibitory effect on high-quality economic development. c) The level of synergy between ecological resilience and high-quality economic development in the Yellow River Basin shows a steady upward trend during the study period, with a spatial pattern of higher levels in the east and lower levels in the west. The differences in synergy levels among the provinces (regions) are significant before 2018, and are narrowed after 2018.

In order to provide a reference for comprehensively promoting the high-quality development of the Yellow River Basin and realizing the goal of “dual carbon”, this paper took 2005-2022 as the study period, built an energy security index system, adopted the entropy method to measure the energy security level of provinces in the Yellow River Basin and adopted the Tapio model to measure the decoupling state of carbon emissions of provinces in the Yellow River Basin. The relationship between carbon decoupling and energy security was empirically analyzed by using the fixed effect model. The results show that a) the energy security level of all provinces in the Yellow River Basin shows an upward trend during the study period, but the energy security pressure is still large at the end of the study period and the difference between provinces is large. The energy security situation is not optimistic on the whole. b) The decoupling state of carbon emissions in the provinces of the Yellow River Basin shows a good development during the study period. Most provinces have a strong decoupling state, but the decoupling state is unstable, meaning that it is difficult to maintain the best state. c) The improvement of energy security has a promoting effect on the decoupling of carbon emissions in the Yellow River Basin, and this promoting effect is more significant after 2012. Some policy suggestions are put forward to systematically improve the level of energy security in the Yellow River Basin, accelerate the process of “carbon peaking” and accelerate the transformation of economic development mode.

In order to reasonably delineate the stages of water and sediment series in the Yellow River, the Mann-Kendall and Bayesian Model Averaging(BMA) were employed to analyze the trends and detect change points in the hydro-sediment sequences from six cross-sections of the Yellow River mainstream, namely Tangnaihai, Lanzhou, Toudaoguai, Tongguan, Huayuankou and Lijin from 1956 to 2022. The results indicate that the flow-sediment conditions in the Yellow River source region show no significant trend, while the other sections exhibit a decreasing trend. The abrupt points of runoff sequence are 1969, 1986 and 2018, which are closely related to the operation of water storage in key water control project and have regional influence. Most of the abrupt change points of sediment sequence in hydrological sections occur in the 1960s, and then show a significant downward trend, mainly due to the influence of soil and water conservation in the basin. It is recommended to divide the runoff series into four stages of before 1969, 1969-1985, 1986-2017 and from 2018 to the present, and the trend evaluation should be the main stage for sediment sequence analysis.

In order to investigate the spatial distribution characteristics and health risks of heavy metals in groundwater from abandoned mines, this study selected the abandoned mine in Houshan Town, Xuyong County, Luzhou City as the research area. Seven heavy metals (Fe, Cd, Cu, Pb, Zn, Mn, and Cr) in groundwater were measured and analyzed. The pollution characteristics, spatial distribution patterns, and health risks of heavy metals were systematically evaluated by using pollution index assessment, fuzzy comprehensive evaluation, and health risk assessment models. Monte Carlo simulation was employed for uncertainty analysis of health risk assessment. Results indicated that the mean concentrations of Fe, Pb, Mn, and Cd in groundwater exceeded Class Ⅲ water quality standards. The aggregate non-carcinogenic risk values from five heavy metals (Fe, Cu, Pb, Zn, and Mn) through drinking water exposure were 0.617 for adults and 0.145 for children, both below the threshold 1, with adults exhibiting higher susceptibility than children. Carcinogenic risks were identified for Cd and Cr through dual exposure pathways of ingestion and dermal contact. Monte Carlo simulations predicted carcinogenic risk ranges of 1.78×10^-4 to 6.33×10^-4 for adults and 2.29×10^-4 to 4.40×10^-4 for children, with mean values of 3.96×10^-4 and 3.33×10^-4 respectively. These findings demonstrate potential carcinogenic risks for adults and significant carcinogenic hazards for children from Cd and Cr exposure in the studied groundwater system.

The issue of groundwater pollution in the Fenhe River is becoming more and more serious and the water quality is deteriorating, resulting in the daily drinking water safety of residents in the Fenhe River Basin. In this paper, we selected groundwater in the Fenhe River Basin in the eastern part of the Loess Plateau as the research object, and comprehensively used mathematical statistics, graphical methods, correlation analysis, forward model, geographic detector and health risk assessment model to analyze the spatial-temporal evolution characteristics of groundwater chemistry, explore the formation mechanism of groundwater chemistry and quantify the contribution of different sources, identify the controlling factors of groundwater chemical evolution, and quantitatively evaluate the risks to human health through drinking water. The results show that the hydrochemical type of Fenhe River Basin evolves from HCO₃-Ca to HCO₃-Ca·Mg andSO₄ HCO₃-Ca·Mg; carbonate weathering and silicate weathering are the main sources of groundwater chemical composition. The main control factors of groundwater chemical evolution are elevation and ecosystem, and ecosystem and land use. The non-carcinogenic risk factor of nitrate to children through drinking water is greater than that of adults.

Xixiayuan Reservoir is a counter regulating reservoir of Xiaolangdi Reservoir, mainly used to counter regulate the unstable water flow discharged from Xiaolangdi Reservoir. This article systematically reviewed the operation mode, inflow water and sediment, flow path evolution and sediment deposition distribution characteristics of Xixiayuan Reservoir from 2007 to 2022. The results could provide technological support for optimizing and reducing sedimentation operation of Xixiayuan Reservoir. The results indicate that a) the average annual inflow volume of Xixiayuan Reservoir is about 30.555 billion cubic meters, and the average annual sediment volume is about 134 million tons. The continuous sedimentation of sediment in the reservoir area has caused significant changes in the flow path of the reservoir area. The section from the old bridge of Jiaozhi Railway to the dam front has gradually evolved from four flow paths in the initial stage to one flow path. b) As of August 2022, the sediment accumulation in Xixiayuan Reservoir is approximately 72.536 million cubic meters, of which the sediment deposition amount from the dam to xxy07 section is about 69.645 million cubic meters. The reservoir has a storage capacity of approximately 18.4 million cubic meters below the flood limit water level of 131.00 m, with sedimentation accounting for 76.71%. The reverse regulation of the reservoir water level between 131.00 m and 134.00 m has a storage capacity of approximately 56.7 million cubic meters, which has been encroached upon by 0.3 million cubic meters. c) The main chemical components of sediment in Xixiayuan Reservoir are SiO₂, Al₂O₃ and CaO, accounting for 80.14% of the total composition. The shape of sediment particles is elliptical or square, with an angular factor of less than or equal to 1.30. d) The current beach sedimentation elevation of Xixiayuan Reservoir, which is more than 5.8 km away from the dam, is more than 3 m higher than the designed beach elevation after sedimentation balance. It is recommended that Xixiayuan Reservoir operate when the water level in front of the dam drops below 132.00 m during the sediment discharge period of Xiaolangdi Reservoir to avoid the continuous elevation of the upstream beach surface from encroaching on the counter regulating storage capacity.

In order to solve the issue of data misjudgment caused by the inability to identify the trend and correlation between data when the isolated forest algorithm detected dam abnormal data, an anomaly detection algorithm based on smooth threshold and isolated forest was proposed. Firstly, the trend term of time series data was extracted by wavelet transform. Secondly, ARMA model was used to determine the dynamic threshold interval of the extracted trend item data. Finally, isolated forest algorithm was used to detect the outliers scattered outside the threshold interval. Taking the concrete faced rockfill dam of Jiayan Key Water Control Project in Bijie City, Guizhou Province as an example, the monitoring data of four parts of the dam foundation, dam body, peripheral joint and panel were tested respectively to verify the effectiveness of the algorithm. The results show that comparing with the traditional isolated forest algorithm, the algorithm based on smooth threshold and isolated forest reduces the misjudgment rates of pressure, observation room settlement, opening and closing degree, and stress have been reduced by 12.2, 13.4, 7.1, and 8.0 percentage points, respectively.