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Super-large-diameter caissons, serving as working wells for trenchless pipe jacking technology, are being extensively constructed alongside the increasing adoption of trenchless technology in urban areas. However, being regarded merely as ancillary structures, the structural stability of a caisson during both construction and operation phases are often neglected. This study, centered on the super-large-diameter caissons within the Jinshui River flood control project in Zhengzhou, China, systematically monitored the mechanical behavior of caisson structures and surface settlement during construction and operational phases. Utilizing a validated FE method, the influence of groundwater fluctuations on the structural stability of caissons during operational phases was examined. Furthermore, potential occurrences of loose soil, voids, and caisson tilting were considered. Subsequently, the applicability of permeable polymer, foam polymer, and anchor rod reinforcement techniques were evaluated, followed by an analysis of the structural stability of the caissons post reinforcement during long-term operations. The findings demonstrate the minimal horizontal displacement of and stress variation in caissons under seasonal groundwater fluctuations, without significant structural alterations. Nevertheless, the presence of loose soil, voids, and caisson inclinations may decline the caisson's support force and bearing capacity. With the increase in non-compactness, void size, and inclination, the structural stability of caissons notably diminishes. Reinforcing loose soil with permeable polymers, filling voids with foam polymers, and utilizing anchor rods are all effective methods for strengthening caisson structures and enhancing their stability. [ABSTRACT FROM AUTHOR]

The contradiction between increasing energy demand, decreasing water availability, and deteriorating ecological environment indicates the urgent necessity for an energy-water-climate nexus management (EWCM) system. The contribution of this paper is to propose a posterior probability-based multi-stage cooperative game and type-2-fuzzy interval-stochastic programming model of the EWCM (PMCTFSP-EWCM) to determine the optimal solutions for sustainable development under ambiguities and uncertainties. The type-2-fuzzy sets and multi-stage interval-stochastic programming are combined to deal with objective and subjective uncertainties of partial parameters with flexible constraints. Moreover, multi-stage cooperative game was adopted to reflect the cooperation and competition between energy subsystem and water resources subsystem. Then, the model was applied to a case study to investigate the EWCM in the Yellow River Basin (YRB), China. Improving water availability satisfaction and feasibility degree can reduce external energy dependence costs from 84.9 , 126.4 × 10 9 $ to 12.7 , 14.3 × 10 9 $ . Furthermore, when considering the objective function of cost, target revenue functions, and corresponding constraints of the EWCM mutual feedback relationship, the proportion of fossil energy supply in the YRB was reduced to 63.28%-71.79%. These measures could reduce the generation of negative values, which has long-term significance for the healthy and sustainable development of EWCM. [ABSTRACT FROM AUTHOR]

Environmental pollution control and greenhouse gas emissions reduction have become the main ecological protection issues. The digital transformation of the financial sector provides a vital opportunity to holistically promote environmental governance. This article incorporates the synergistic reduction of pollution and carbon emissions into the environmental governance system of digital financial development. Using panel data from 280 cities in China between 2011 and 2018, we examine the impact of digital financial development on the synergistic reduction of pollution and carbon emissions. We find that (1) digital finance development can significantly improve the synergistic reduction of pollution and carbon emissions, effectively lowering carbon emissions while reducing pollution. External environmental concerns can further unleash the potential for digital finance development to enhance its synergistic reduction of pollution and carbon emissions. (2) The key transmission mechanism lies in the dual guidance of digital finance development toward biased technical change, i.e., toward energy-saving elements on the input side and toward reduced pollution output on the output side, thereby inducing the synergistic reduction of pollution and carbon emissions. (3) The synergistic effect of digital finance development on pollution and carbon reduction depends on the necessary regional development endowment, such as strong green technology innovation capabilities, lower traditional financial accessibility, and carbon sink reserves. This study expands the understanding of the environmental effects of digital finance development and offers crucial insights for exploring the optimal development path under green strategies. [ABSTRACT FROM AUTHOR]

The growing concern surrounding climate change has gradually drawn attention to the influence of climate factors on drought occurrence. In order to effectively prevent the occurrence of drought and reasonably utilize water resources, the vegetation health index (VHI) was used to characterize drought in North China Plain (NCP) in this study. Furthermore, six climate factors: air temperature (AT), precipitation (P), evapotranspiration (ET), specific humidity (SH), soil moisture (SM), and soil temperature (ST) were selected. The pole symmetric mode decomposition (PSMD) and improved gridded trend test (IGT) were used to analyze the spatial–temporal characteristics of drought and climate factors in NCP from 1982 to 2020. By calculating the cumulative climatic factors of 0 months, 1 month, 2 months, and 3 months, the correlation between drought and the climatic factors with different cumulative scales was analyzed. The results showed that: (1) from 1982 to 2020, the drought in NCP showed a downward trend and the climate factors showed an upward trend; (2) with the increase in AT, P, ET, SH, SM, and ST, VHI showed an upward trend, and SM showed the strongest correlation with VHI; (3) the optimal cumulative lag time (CLT) for AT, P, ET, SH, SM, and ST were 1.67 months, 1.48 months, 1.95 months, 1.69 months, 0.89 months, and 1.81 months, respectively; and (4) AT was the main driving factor of drought in NCP. This study contributes to the early warning and prediction of drought events, providing a scientific basis for water management authorities in drought management and decision making, and mitigating the negative impacts of drought on socio-economic aspects. [ABSTRACT FROM AUTHOR]

In the article, on the basis of quantifying the emergy water ecological footprint, a sustainability evaluation system for the overall water ecological economic system of the basin and each province (region) was proposed. And using the subjective and objective combination of the Analytic Hierarchy Process (AHP) and Entropy Weight Method (EWM) to determine the weight of the indicator system, a TOPSIS model for sustainability evaluation was constructed. And taking the Yellow River Basin as an example, the results indicate that (1) Throughout the entire basin, the sustainability of the water ecological economic system showed a fluctuating upward trend year by year during the study period, from 0.37 to 0.51. (2) In each province (region), the sustainability of the water ecological economic system had gathered in space. The overall sustainability level of the upstream Sichuan, Qinghai and Gansu provinces is high, always at level (I). The overall sustainability level of the midstream Ningxia and Neimenggu was low, always at level (IV). The overall sustainability level of the downstream Shaanxi, Shanxi, Henan and Shandong provinces is high, rising gradually over time, from level (III) to level (II) or (I). Against the backdrop of the rapid development of the economy and society, the contradiction between economic and social development, ecological environment protection, and sustainable utilization of water resources is becoming increasingly severe, which has become a key factor restricting the sustainable development of the ecological economic system in Yellow River Basin. Multidimensional comprehensive evaluation of the sustainability level of the regional water ecological economic system is a prerequisite for identifying sustainable development issues in the Yellow River Basin, and also the basis for formulating targeted policies for sustainable utilization of regional water resources and high-quality economic development. [ABSTRACT FROM AUTHOR]

The vegetation drought phenomenon will reduce the amount of water available to the vegetation system, change the ecological and hydrological cycles of plants, and affect the aquatic and terrestrial ecosystem in various forms. Therefore, research on the dynamic variation and driving mechanism of vegetation drought will help us recognize and predict the response of vegetation under drought stress conditions, implement appropriate policy measures to deal with the drought crisis, and provide technical support for implementing vegetation protection and alleviating the increasing risk of vegetation drought. However, the dynamic variation of vegetation drought and its dynamic propagation mechanism are still undefined across China. In this study, the spatio-temporal evolutions and pixel-scaled trends of vegetation drought were analyzed during the period between 1999 and 2020. Additionally, the propagation features were investigated between vegetation drought and meteorological drought. Finally, the relationships between vegetation drought and atmospheric teleconnection were explicitly clarified using multivariate cross wavelet transform technology. The results highlighted five key findings: (1) the vegetation drought presented an overall decreasing trend across China in 1999–2020; (2) the most serious vegetation drought occurred in the year 2000, with the average vegetation condition index (VCI) values ranging from 0.36 to 0.46; (3) vegetation droughts were alleviating at the pixel scale for each season; (4) the propagation time from meteorological drought to vegetation drought was shorter in summer (1.26 months) and longer in winter (2.26 months); and (5) the three-factors combination of Pacific North American (PNA), El Niño-Southern Oscillation (ENSO), and Trans Polar Index (TPI) can satisfactorily explain the variations of vegetation drought. This study sheds new viewpoints into the identification of vegetation drought variation across China, which can also be applied in other areas. [ABSTRACT FROM AUTHOR]

To quantify and analyze the human demand for water resources and the available supply of water resource systems, this study combined emergy analysis and spatial autocorrelation analysis to establish a quantification and analysis system for water ecological footprint (WEF). First, the emergy theory of ecological economics and WEF were combined to propose an emergy quantification method for WEF and water ecological carrying capacity (WEC). Based on the spatial autocorrelation method, three-dimensional ecological footprint indicators (footprint size and depth) were introduced to analyze the spatial correlation and spatial aggregation of capital flow occupation and capital stock consumption in the water resource system. Using the Yellow River Basin (YRB) as the study area to verify the applicability of the WEF quantification and analysis system based on the emergy-spatial autocorrelation method, the following results were obtained. (1) From 2003 to 2018, the per capita WEF of the YRB generally showed a slow growth trend. (2) Compared to the upper and lower reaches of the YRB, the middle reaches had a higher WEF, and the WEC of the YRB was generally high in the west and low in the east. (3) Utilization of the water resources capital in the basin was generally unsustainable. It is necessary to take measures to promote rational allocation and efficient utilization of water resources for the coordinated development of society, the economy, and the environment in the YRB. (4) The emergy-spatial autocorrelation method is applied to basin/region water sustainability studies for decision makers. [ABSTRACT FROM AUTHOR]

It is important to manage water resources via emergy theory and its implementation mechanism for water dispatching while considering both economic development and environmental needs. The contribution of this paper is to propose a multi-objective dynamic differential game that can determine the optimal tax rate (OTR), optimal trading quantity of water (OTQW) in each province, and optimal bargain price (OBP) to balance resource consumption, economic development and environmental protection. Considering the sustainability of the ecological environment, the quantification of negative sewage value and net carbon emission constraints are introduced into the water allocation. To maximize the target revenue functions, minimize the net carbon emission constraints and obtain sustainable equilibrium solutions in this triple-level game, the costate function, Hamiltonian, and Lagrangian multiplier method are introduced. Then, a water dispatching structure is constructed for error correction between the predicted and actual runoff of the YRB. Taking the Yellow River Basin as an example, the validity of the proposed framework and solution method were verified under different hydrological years, with 6.5% ~ 9.1% higher economic benefits than other schemes and 4.3% ~ 5.9% lower net carbon emissions than other schemes. Compared to previous studies, this scheme can better meet the requirements of sustainable development and environmental protection. [ABSTRACT FROM AUTHOR]

Effective supply of environmental public services (EPS) is important to guarantee the mitigation of residential pollution exposure risk. This study analyzes the impact of the supply efficiency of EPS on residential health through the sample of 289 cities in China by fixed-effect model and threshold regression model. The results show that: (1) Improving the efficiency of EPS can significantly increase the efficiency of pollution control, and improve the environmental quality and health level of residents. (2) Improving the efficiency of EPS can have a greater positive effect on residents' health in areas with high-level population aging, poor medical condition, and low population density. (3) Environmental decentralization weakens the positive effect of EPS on residential health. Giving more power of environmental management to local governments may be detrimental to pollution control. Therefore, differentiated strategies of EPS should be developed to realize the equalization of basic public services with healthcare and environmental protection. It is necessary to strengthen central environmental supervision and establish resident offices for environmental supervision. [ABSTRACT FROM AUTHOR]

It is an important content of environment management to accurately identify the time change and spatial distribution of net anthropogenic nitrogen inputs (NANI) in the river basin. In order to develop a unified management and diverse control strategy that fits the characteristics of the basin, this study establishes the NANI-S model combining the NANI model with the spatial autocorrelation analysis method, which is a quantification-analysis-control process, and takes the 70 prefecture-cities in the Yellow River Basin (YRB) as the study area. The result shows that (1) the NANI of YRB increased first and then decreased with an average NANI value of 6787.59 kg/(km2·a), showing that the overall N pollution situation of the YRB shows a trend of improvement in nitrogen (N) fertilizer input as the main source, and the average contribution rate was 47.45%. (2) There were obvious spatial differences in the NANI in the YRB because the global Moran's I fluctuated between 0.67 and 0.78. Cities with high NANI clustered in the middle and lower reaches, while low NANI clustered in the upper reaches. (3) Improving fertilizer utilization rate and industrial and domestic sewage treatment capacity was the key point of N control. Based on the results, practical policy recommendations for water pollution management were constructed, which provides a scientific basis for pollution prevention and high-quality development in the basin. In addition, this analysis method can also be applied to other basin N management studies. [ABSTRACT FROM AUTHOR]

Environmental regulation is an important tool for local governments to intervene in environmental governance. Based on 2008–2017 panel data on 289 cities in China, this paper analyzes the impact of environmental regulation on the supply efficiency of environmental public services and explores whether environmental decentralization changes the effect of environmental regulation. The results show that environmental regulation can significantly improve the supply efficiency of environmental public services, and this finding still holds after a series of robustness tests. The main reason is the improvement in green technology innovation capabilities caused by environmental regulation. Environmental regulation has a more significant positive effect on the supply efficiency of environmental public services in regions with a higher local government governance capacity, lower levels of fiscal decentralization, and a higher pollutant emission intensity. A moderate level of environmental decentralization helps to better promote the supply efficiency of environmental public services through environmental regulation. When the level of environmental decentralization lies between 0.362 and 1.353, environmental regulation effectively improves the supply efficiency of environmental public services. [ABSTRACT FROM AUTHOR]

The evaluation of the benefits of urban water resource utilization, which include supporting life and industrial and agricultural production, is important for decision-making and policy formulation in urban water management. However, since life cannot be quantified in terms of economic value, it is difficult for traditional economic analysis methods to comprehensively evaluate the benefits of urban water resource utilization. Output per unit water and the proportion of water to resource inputs were proposed to evaluate these benefits. An evaluation index system was established based on catastrophe theory, which evaluates the system under the condition that the relative importance of indices is determined and the exact weights are unknown. Emergy theory, which reflects the process of energy conversion, was introduced to analyze various benefits of urban water resource utilization. By applying these methods to evaluate these benefits in Zhengzhou, China, the author verified the rationality of the proposed methods, providing new ideas to evaluate these benefits. [ABSTRACT FROM AUTHOR]

The increase in water demand due to industrial development and agricultural expansion and the need for ecosystem improvement call for the efficient, equitable and sustainable management of water resources. This is particularly essential in basins where water management authorities are the distributor of the initial water allocation and where incentives are lacking for improving water use efficiency. The purpose of this paper is to present an administrative and market-based game model for solving the problem of water rights transactions in a basin. To accomplish this, a double-layer dynamic differential game model is developed based on the water reallocation in the basin. In this model, the water management authorities of the basin and surrounding regions seek to maximize their own comprehensive value of the water resource/target revenue function. To obtain the optimal trading quantity of water in each region and the bargain price, the Hamiltonian and Lagrangian are introduced. A case study is presented in the Yellow River basin to demonstrate the applicability and efficiency of this method. The proposed dynamic differential game and pricing game show good performance for determining the optimal trading quantity of water in each region and the bargain price with optimal results of ¥ 204.3384 billion per half year and ¥ 409.4115 billion per year, outperforming other methodologies. [ABSTRACT FROM AUTHOR]

Jinci Spring is one of the most famous karst spring in Northern China and is the main drinking and irrigation water source of Taiyuan city, Shanxi Province. It has special significance in terms of humanities and water resources. Because of the continuous over-exploitation of groundwater, the water level of groundwater has been decreased significantly. The flow of Jinci Spring has decreased year by year since the 1970s, and in 1994 it cut off completely. The flow cutoff has brought huge losses to the local economy and negatively impacted the ecological environment. From the hydrogeological conditions of Jinci Spring area to study, the dynamic change in karst groundwater level will provide a basis for the protection and rational exploitation of karst water in the spring area. The previous research on Jinci Spring area was limited to the spring flow and water level changes, lack of analysis to the overall spring area and the decay process of spring flow. This paper takes the overall spring area as research object. According to groundwater level data over 1961–2012, the period is divided into two phases of decline and recovery. Human activities in the region and corresponding groundwater evolution at various stages were systematically analyzed, and the reservoir capacity was calculated for each period of decline. The results show that the average reservoir capacity decreased from 920 (1954–1960) to 116 (1961–1977) to 31 (1978–1994) million m3. The important effect of "Water Resumption" project on groundwater in the area during the remediation period was also analyzed. In the light of observed increases in groundwater level during this stage, the project has a notably positive effect. [ABSTRACT FROM AUTHOR]

Value accounting of water in the Yellow River Basin is a key issue in managing local water resources in an efficient, equitable, and sustainable way. In view of the dubious current theories of water resource value, the value transfer of water resources, based on energy flow, is discussed from the perspective of eco-economics. An emergy analysis method is introduced to quantify both the sediment transportation value and social value, and a quantitative system of eco-economic value indicators is constructed. The water resource values of 66 cities in the Basin were calculated, and the GIS atlas was used to describe their spatial distribution. Eight typical cities were selected for the key analysis. The results show that: (1) Among the sub-items, the social value of water per unit is the largest, reaching 30.67 Chinese Yuan/m³, and the difference between the maximum and minimum is only 0.04%, which reflects the social equity of water resources. (2) The eco-environmental value inside the river is generally higher than that of industry, and it is verified that industrial water should not intrude the eco-environmental water in the river. (3) The unit agricultural value of water is the lowest among the sub-items, and the construction of water-saving agriculture should be carried out. [ABSTRACT FROM AUTHOR]