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 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 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.

The Xiaolangdi Reservoir is a key project for controlling water and sediment of the Yellow River. Studying its sediment discharge law and regulation indicators is of great significance for maintaining effective storage capacity in the long term. Based on the analysis of measured data and the practice of water and sediment regulation, 34 sediment discharge processes in the Xiaolangdi Reservoir from 2010 to 2023 were selected, and the reservoir sediment discharge law and its influencing factors were analyzed, in the meantime the regulation indicators which were useful to reducing reservoir silt were proposed. The results show that, during water and sediment regulation in pre-flood season, sediment discharge is mainly caused by flushing of clear water discharged by the Sanmenxia Reservoir. The sediment discharge amount is positively linear correlated with the inflow volume and negatively linear correlated with the storage volume of the Xiaolangdi Reservoir. During water and sediment regulation in flood season, the sediment discharge ratio is negatively correlated with the degree of reservoir damming and the ratio of inflow and outflow flow, which is a power function relationship. The quantitative expressions of sediment discharge amount during water and sediment regulation in pre-flood season and sediment discharge ratio during water and sediment regulation in flood season are established, and the water level of the reservoir can be reduced and then maintained to 215 m and 223 m respectively during water and sediment regulation in pre-flood and flood season are proposed, in which the annual sediment discharge ratio can reach 125%.

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 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.

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%.

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.

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.

he formation and evolution of the Ω-shaped channel of the Yellow River depend on the boundary morphology and interactions of the tectonic belts around the Ordos block. The collision, subduction, compression, strike-slip and whirl effects of the peripheral tectonic belt on the block have made the Yinchuan Graben, Hetao Graben, Jin-Shaan Gorge and other tectonic landforms through the Yellow River. The highly developed fault zone, cataclastic rock zone and dense joint zone in graben and canyon have strictly controlled the extension and bend of the channel. In Neoid period, the extrusion of the Indian Plate in NE-trending and the Pacific Plate in NW-trending has compounded new activities of the peripheral major fault, which has controlled and constrained the Ω-shaped channel of the Yellow River.

In order to calculate the maximum population scale and economic scale that the urban water resources in Qingdao City can support, and to formulate the urban development model for urbanization and sustainable utilization of water resources, the entropy weight method was used to measure the water resources carrying capacity and urbanization level of Qingdao City from 2015 to 2022. A system dynamics model was built from both water resources and social economy aspects, and the water supply and demand situations of four development models (natural development, rapid development, water conservation priority, and comprehensive development) from 2023 to 2030 were simulated. The results show that the water resources carrying capacity of the urban area of Qingdao City shows a fluctuating upward trend from 2015 to 2022, and the urbanization level is steadily increased. The comprehensive development is the optimal mode of the urbanization development in Qingdao City, which can ensure that there is still a surplus water resources after meeting the needs of residents' life and economic development.

In order to investigate the influence of land use change to the basin flood process, the Fenhe River Basin was chosen as the study area. The SWAT model and the extreme land use scenario analysis method were employed to analyze the effects of land use type changes on the flood process in different periods and scenarios. The results show that a) the mean value of Nash-Sutcliffe Efficiency(E_NS) is greater than 0.70 and the mean value of determination coefficient (R²) is greater than 0.65 during the calibrated and validated period, indicating that the SWAT model has good applicability in the Fenhe River Basin. b) Between 2000 and 2020, there is a reduction in the area of cultivated land, grassland, water bodies and unused land, while the area of forested land and built-up land is increased. c) Under the land use in 2000, 2010 and 2020, each peak flow and the total flood volume show a slight upward trend. d) Under the arable land scenario, there is an increasing trend in each peak flow and its total flood volume; while under both the woodland and grassland scenarios, there is a decreasing trend. In terms of magnitude of impact, land use type change has a smaller impact on larger flood processes and a larger impact on small and medium flood processes. Therefore, it is necessary to increase the area of forest and grass and vegetation coverage, promote water-appropriate planting, and avoid high-water-consuming vegetation in areas with high incidence of flood disasters and serious soil erosion, so as to improve the ability of flood control, flood resistance, disaster prevention and mitigation in Fenhe River Basin, and promote ecological restoration and high-quality development in Fenhe River Basin.

General Secretary Xi Jinping proposed to adhere to the principle of “defining city, land, population and production by water”(referred to as “Four Waters and Four Determinations”), at the symposium on ecological protection and high-quality development in the Yellow River Basin in China. In order to provide theoretical guidance and reference for ecological protection and high-quality development in Gansu Province, the Yellow River Basin, and even the water-scarce areas in the northern China, as well as to implement the “Four Waters and Four Determinations” policy, taking the Yellow River Basin in Gansu Province as a representative of water-scarce areas in northern China, this paper analyzed the characteristics and main water issues of the region, as well as the new situation and strategic position it faced. The current situation of water resources management in the Yellow River Basin in Gansu Province was analyzed, and strategic countermeasures for innovative management of the “Four Waters and Four Determinations” policy in the Yellow River Basin of Gansu Province under the new situation were proposed, including carrying out top-level design, strengthening rigid constraints on water resources, promoting key technology research and development and engineering construction, establishing a sound management system and mechanism, and promoting pilot projects. The core of implementing the “Four Waters and Four Determinations” in water-scarce areas of northern China is to use water resources as a rigid constraint, optimize the development pattern of ecology, energy and food, make the scale of population, urban, irrigation, and industrial development coordinated with water resources conditions, enhance the compatibility of water with city, land, population and production development, and fundamentally promote the harmonious development of human and water resources.

In order to coordinate the relationship between water resources and economic and social development in the Yellow River Basin, based on the current water consumption data of the Yellow River Basin in Shandong Province from 2008 to 2022, the evolution characteristics and spatial distribution law of water consumption structure in the Yellow River Basin in Shandong Province were analyzed by using the methods of information entropy and equilibrium degree, Lorenz curve and Gini coefficient. The results show that the agricultural water use in the Yellow River Basin in Shandong Province no longer has a single absolute advantage, and the water resources allocation is transforming into multi-objective. The information entropy and equilibrium degree show a synchronous upward trend, indicating that the distribution of various types of water consumption is developing towards uniformity. From 2008 to 2022, the spatial equilibrium degree of agricultural water use in the Yellow River Basin of Shandong Provinceis is decreased obviously, the spatial equilibrium degree of industrial water use is increased slightly, the spatial equilibrium state of domestic water use does not change greatly, and the spatial equilibrium degree of ecological water use is increased obviously. From 2008 to 2022, the spatial distribution of agricultural water use in the Yellow River Basin in Shandong Province changs from an obvious equilibrium state to a relatively balanced state, while the spatial distribution of industrial and domestic water use has always been relatively balanced, and the spatial distribution of ecological water use has changed from a poor equilibrium state to a relatively balanced state. The proportion of agricultural water in Dezhou is the highest, the proportion of industrial water in Zibo is obviously higher than that in other regions, and the proportion of domestic water in Jinan is the highest and slowly rising. In 2018, the proportion of ecological water in Jinan is the highest, and the proportion of ecological water is the lowest in Dezhou.

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.

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.

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.

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.

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 explore the evaluation method of carbon sequestration capacity for comprehensive management of small watersheds in the Loess Plateau region, the Nanxiaohegou watershed in the gullied rolling loess area was taken as the research object. The soil and water conservation comprehensive test site established in the watershed in 1952 was used as the accounting scenario, and the untreated comparative observation ditch Dongzhuanggou small watershed was used as the baseline scenario. The land use situation in the study area was obtained through remote sensing image interpretation, unmanned aerial vehicle aerial survey and field investigation. The artificial forest land was divided into 10 carbon layers and sample areas were set up for vegetation and soil sample collection and physical and chemical index measurement. The carbon sequestration capacity of three main approaches, namely, greening and sink enhancement of artificial forest land, vegetation measures and soil retention and carbon fixation of warping dams, and erosion reduction and emission reduction of watershed comprehensive management were evaluated. The results show that the afforestation and sink enhancement capacity of artificial forest land is 6.40 t/(hm²·a), with vegetation carbon pool and soil carbon pool carbon sink capacities of 5.85 and 0.55 t/(hm²·a) respectively. The soil conservation and carbon sequestration capacity of plant measures is 0.92 t/(hm²·a), and the soil conservation and carbon sequestration capacity of warping dams (dammed land) is 30.84 t/(hm²·a). The comprehensive management and erosion reduction capacity of the watershed is 0.14 t/(hm²·a). The warping dam has the greatest ability to retain soil and fix carbon, but its land area is relatively small. The ability of artificial forest land to increase greenery and carbon sequestration is relatively small but its area is large compared to warping dams. Erosion reduction and emission reduction are important links in slowing down the rise of atmospheric carbon dioxide concentration through optimizing land management measures. The three complement each other and cannot be neglected. It is recommended to vigorously build warping dams according to local conditions, strengthen the management and renewal of soil and water conservation forests, coordinate various control measures, better play the carbon sequestration role of comprehensive soil and water conservation management and improve the carbon sequestration capacity of regional soil and water conservation.

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.

In order to explore the evolution characteristics of runoff in the Yellow River basin, this paper analyzed the natural runoff data of Huayuankou Hydrological Station from 1919 to 2016 for nearly 100 years. The order of clustering analysis, MannKendall mutation test and sliding taverage method were used to analyze the mutation points of the runoff sequence in Huayuankou Hydrological Station. Linear trend regression test, MannKendall trend test and Spearmann rank correlation test were used to analyze the trend of the runoff series before and after the mutation point. The results show that the runoff mutations in the Yellow River basin were relatively obvious at 1933-1934 and 1989-1990. The mutation of the former is mainly caused by largescale changes in natural factors (such as temperature, precipitation), and the latter is mainly caused by changes in the basin scale of artificial factors (water use increasing and the bottom surface changing). In 1919-1933, the trend of runoff change is relatively significant, passed 0.10 of the significant level test, showing a downward trend. In 1934-1989 and 1990-2016, the trends of runoff changed are more smoothly.

山西省万家寨引黄工程泵站压力隧洞(竖井)建成后,砼裂缝较为密集,部分隧洞充水后发生明显漏水.经反复处理后情况虽有所改善,但仍未完全奏效.经分析,裂缝与水泥用量较大、不设伸缩缝、隧洞超挖以及施工质量控制不严等因素有关,建议采取合理分缝、降低水泥用量、改进泵送砼施工工艺以及加强缺陷处理等措施.在内水压力较高的情况下,钢衬仍不失为最安全可靠的设计方案.

The study of the spatial-temporal heterogeneity characteristics of flash flood disasters is an important basis for formulating policies and measures for flash flood disaster prevention and control. In order to strengthen the pertinence of flash flood prevention and control in Shaanxi Province, this paper used standard deviation ellipse and gravity model to analyze the spatial and temporal distribution characteristics of flash flood disasters, and used geographic detectors to quantitatively evaluate the driving factors and interactions of flash flood disasters in northern Shaanxi, Guanzhong and southern Shaanxi. The results show that the high incidence period of flash floods in northern Shaanxi has been advanced from August to July. The center of gravity of flash flood disaster is gradually moved from Guanzhong to southeastern Shaanxi. The driving factors of the strongest rainfall in northern Shaanxi, Guanzhong and southern Shaanxi are rainstorm, heavy rain and moderate rain, respectively, and decision-makers should consider the differences in the driving forces of flash flood disasters among different regions and formulate flood control measures according to local conditions.

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 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 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.

Based on the theoretical of eigenvalue buckling analysis method and considering the material utilization efficiency of chord member structures, this study employed numerical simulation method to conduct stability calculations for gate arms without chord member, with single chord member, and with double chord members. The influence of chord member positioning, quantity, and cross-sectional properties on the structural stability of steel gate arms was analyzed. An optimized chord-layout scheme was proposed, and on this basis, finite element analysis was conducted on the overall stability of the steel gate support arm. The results indicate that for single chord member gate arms, the optimal ratio of the distance between the chord and the hinged support to the total arm length (l/m) ranges from 0.60 to 0.75, achieving the highest load-bearing capacity per unit mass. Arranging double chord members away from the hinge end can improve the unit mass bearing capacity of the support arm, but the spacing between chord members should not be too large. Dimensional analysis of the chord member structure reveals that when the width-to-height ratio of the chord is 1.4, the overall stability of the gate arm is favorable. The thickness ratio of the flange to the web (t₃/t₄) has minimal effect on the load-bearing capacity per unit mass, with the primary design consideration being to ensure local stability of the gate arm. Adding chord members improves gate stiffness and enhances the stress state, primarily by reducing the maximum equivalent stress in the steel gate arm. Compared to gate arms without chord member, single chord member arms reduce the maximum equivalent stress by 8.44%, while double chord member arms achieve a reduction of 12.99%.

万家寨引黄一期工程南干隧洞总长达100km,洞段的防渗设计尤为重要.由于采用了全断面双护盾掘进机施工,因而管片衬砌结构自身特点决定了其接缝防渗构造的特殊性.隧洞的防渗设计包括管片衬砌防渗止水系统和接缝止水密封垫两部分.

万家寨引黄工程调度控制和运行系统是一个复杂的自动化监控系统,分为6个单元:①万家寨水库-申同嘴水库;②申同嘴水库-分水闸;③南干一级、二级泵站-头马营隧洞出口;④汾河河道和汾河水库;⑤北干运行单元;⑥供电系统.包括系统的安全运行,稳定运行,经济运行,设备的安全运行,系统的集中、统一控制及调度5个部分.

山西省万家寨引黄一期工程是一项跨流域的工程.工程引水线路长,泵站扬程高,PCCP管径大,地质条件复杂,运行管理自动化科技含量高.工程建设引进世界银行贷款,设备采购和工程施工采用国际竞争性招标,因而工程管理任务相当艰巨.在引黄一期工程建设过程中,探索并实践了国内工程国际管理的做法,通过建立目标激励、思想融通、利益驱动等机制实现了工程的安全稳定运行.

Taking the Yellow River Basin in Shandong Province as the research object, six categories of indicators were proposed, and the AHP-TOPSIS method was used to allocate the water rights of the nine cities along the Yellow River Basin in Shandong Province in 2025. On this basis, the quota method was used to analyze the water resources carrying threshold of each city in 2025, and the current carrying state was analyzed. The results shows that a) the water use rights of agriculture, industry, living and ecological industries in 9 cities along the Yellow River are 9.828 billion m³,2.515 billion m³, 2.752 billion m³ and 1.477 billion m³, respectively. b) The carrying threshold of population size in 9 cities is 45.195 5-59.562 0 million, among which Jinan has the largest upper limit of carrying threshold. The threshold of industrial added value is 1 654.037-1 935.323 billion yuan, with an overall increase of 15%-35 %; the carrying threshold of irrigated cultivated land area is 2.285 5-3.795 4 million hectares, and only Heze and Dongying exceed the upper limit of the threshold. The threshold of urban construction land is 384.2-625.5 thousand hectares. The current value of Binzhou exceeds the upper limit of the threshold, and Zibo is close to the upper limit. c) The population size and irrigated cultivated land area carrying status of 9 cities are the weakest in the southwest of Shandong Province. Compared with the current situation, the industrial added value has increased by different degrees, all of which are in a loadable state. The carrying capacity of urban construction land in southwest Shandong is the best, and the carrying capacity of Binzhou and Zibo is the worst.

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.

The Loess Plateau in the East Gansu is characterized by loose soil and uneven spatial and temporal distribution of rainfall. The soil erosion is very serious with continuous advance of ditches and shrinkage of plateau surface year by year, which have caused serious harm to the local agriculture and economic development. In order to provide technical reference for the construction of Gully Consolidation and Highland Protection Project in the Loess Plateau area, a field investigation was conducted on the governance of Dongzhi plateau, a typical loess plateau area. The governance modes in the implementation scheme of Gully Consolidation and Highland Protection Project were systematically summarized and the effects of Huoxiang gully governance works were evaluated through remote sensing image interpretation. At present, there are four kinds of governance modes of gully consolidation and highland protection in the northwest plateau: simple landfill, drainage + landfill, drainage + landfill + slope protection, drainage + landfill + ecological slope protection, among which drainage + landfill + ecological slope protection has the most obvious effect. After the simple landfill method was adopted to treat the Huoxiang gully in 2000, although the shortterm effect is obvious, the gully head is still eroding in the long run. Therefore, the simple landfill project should coordinate with the runoff control and other measures to comprehensively prevent the erosion of the gully and prevent the gully head from advancing. It suggested that to clarify the causes of disasters, find out “the right medicine” for the main control factors and formulate a scientific and systematic control system, so as to achieve the goal of “water can be held by tableland, no slope collapse and no gully development”.