Yaohong Yang

Water source nodes within water network are subject to dual pressures: the propagation of failure risks and reverse feedback from fluctuations in user demand. As the connectivity of water network and the relationship between water supply and consumption become increasingly complex, there is an urgent need to elucidate the patterns of bidirectional risk transmission in complex water network and to effectively manage water source nodes. Taking the water network of Henan Province as a case study, improved forward and reverse cascade failure models were established respectively. The criticality of water source nodes in forward risk propagation and their sensitivity to pressure in reverse feedback were comprehensively identified. Spearman correlation analysis and K-means clustering were employed to classify water source nodes into ‘criticality+sensitivity’ two-dimensional clusters. The results indicate that forward risk transmission exhibits distinct head-concentration characteristics, with a small number of critical reservoir nodes dominating cascade failure. Spatially, risk first propagates through the structural layer before permeating to the functional endpoints.Temporally, it follows a non-linear evolution pattern, initially intensifying and subsequently attenuating. Reverse risk propagation exhibits characteristics of ‘source-proximity priority’ and hierarchical feedback: as the degree of demand deviation and the number of affected users increase, reservoirs closest to the source are the first to reach their pressure limits and transmit pressure to secondary reservoirs. The two-dimensional classification criteria combining the criticality and sensitivity of reservoir nodes more comprehensively reflect the characteristics of reservoir nodes within the water network, enabling more precise, differentiated management of these nodes. This study broadens the research perspective on risk propagation in complex water network and provides theoretical support and decision-making guidance for the precise management of water source nodes to enhance the water supply security of water network.

Connections between earth–rockfill and concrete dams are critical components of hybrid-dam seepage-control systems because material-stiffness contrasts and complex foundation conditions can create localized preferential seepage paths. Using HS Reservoir as a case study, this predictive design-stage assessment employed a full-domain three-dimensional model of the dam–foundation–abutment system and a local three-dimensional model of the cutoff-spur-wall connection. The seepage field, hydraulic gradients, and zonal seepage discharges were evaluated under the normal pool, design flood, and check flood levels, together with the responses of the connection interface and right-abutment grout curtain. Across the three baseline scenarios, the impervious core accounted for 82.2–83.6% of the total head difference at the maximum riverbed section, and the reported control-location gradients remained below the corresponding design values. At the check flood level, the modeled 178 and 179 m head contours passed above the local curtain crest at elevation 177.5 m, identifying an over-curtain seepage pathway. From the design flood level to the check flood level, right-abutment discharge increased from 259.86 to 544.49 m³/d (109.5%), while total discharge increased by 28.6%. Flow in the connection zone diverted around and beneath the cutoff spur wall, and the connection-surface gradients increased with reservoir level. These model predictions characterize the three-dimensional seepage response of the connection zone and right-abutment seepage-control system and can inform curtain-crest review, construction quality control, and post-impoundment monitoring.

To investigate the three-dimensional seepage response and safety implications of high concrete-face rockfill dams (CFRDs) under waterstop failure scenarios, this study establishes a refined three-dimensional finite element model for a high CFRD at the JD Hydropower Station using COMSOL (version 6.1) Multiphysics. A comparative analysis is conducted for six representative scenarios, including peripheral joint failure, single vertical joint failure, overall vertical joint failure, and combined failures. The seepage safety assessment is based on the phreatic surface, seepage discharge, hydraulic gradients in key zones, and left- and right-bank abutment bypass seepage. The results show that waterstop failure significantly changes the seepage field, phreatic surface, leakage discharge, and hydraulic gradients. Among the six scenarios, S5, representing overall vertical joint failure with an aperture of 0.5 mm for each of the 41 vertical joints, produces the most unfavorable leakage response, with the total seepage discharge reaching 3010.46 L/s and the water level behind the face slab reaching 3888.23 m. In contrast, peripheral joint failure mainly induces local hydraulic-gradient concentration in the special cushion zone. Under S1, the maximum hydraulic gradient in the special cushion zone reaches 2.72, exceeding the allowable value of 0.72. The results also reveal asymmetric bypass seepage around the dam abutments, with the right-bank foundation leakage being 90.4–137.7% higher than that on the left bank. These findings clarify the distinct seepage risk mechanisms of different waterstop failures and provide support for waterstop design, construction quality control, targeted monitoring, and operation-stage safety assessment of high CFRDs.

The implementation of the Yangtze-to-Hanjiang River Water Diversion Project has caused the water resources to be replaced in the middle and lower reaches of the Han River, bringing about the problem of "engineering intervention-type" water pollution control. The central government, which leads the national water network construction, bears the responsibility for coordinating water pollution control and, as a beneficiary, shares a certain proportion of pollution control costs for the water supply area, polluting enterprises, and water diversion enterprises in water pollution control. Considering differences in water quality and the central government-led nature of the national water network, this study employs differential game theory, with the dynamic change of pollutant elimination as the state variable and the pollution control effort levels of the three main stakeholders as the control variables, constructs a differential game model involving the central government, the water supply area, polluting enterprises, and water diversion enterprises. Numerical simulation results show that, compared to decentralized decision-making, the two-tier cost-sharing mechanism can increase total pollutant elimination by approximately 45% and overall governance benefits by 30%, outperforming the centralized control mode. The main conclusions include: (1) There is an interactive relationship between the cost-sharing mechanisms of the central government and the coordination mechanism within the basin, and the two-tier cost-sharing coordination mechanism can bring the highest governance benefits and the most efficient pollution treatment effect. (2) When the loss coefficient increases, the efforts of the WSA and PE are improved under the three modes of Decision C, Decision S, and Decision SR. (3) When the amount of pollutants eliminated per unit of pollution control effort increases, the efforts of the WSA and PE show an increasing trend under the four different modes, and the total amount of pollutants eliminated in the basin also shows an increasing trend. This study provides a dynamic mechanism design framework for national water network governance and offers timely policy references for the governance of large-scale inter-basin water transfer systems.

Soil erosion control is an important aspect of promoting ecological civilization and a key support mechanism for achieving the ‘dual-carbon’ goals. The successful implementation of PPP (Public–Private Partnership) projects for soil erosion control requires widespread participation from farmers. Therefore, it is necessary to study the evolutionary mechanisms of farmer participation behavior and the process of their state transformation, as well as exploring how to enhance farmers’ participation willingness. First, a dynamic group model of farmers’ participation behavior was constructed by dividing them into five states: unknown, observing, participating, rejecting, and immune. Then, the strategic interactions between the government, social capital, and farmers under the PPP model were considered, and this was coupled with the dynamic group model. Finally, Chongqing City was taken as a typical case for numerical simulation to analyze the evolutionary patterns of farmers participation behavior. The results indicate that: (1) synergistic effective government regulation and active enterprise governance can elevate the farmer participation rate to approximately 71% and facilitate the convergence of the system toward a stable high-participation equilibrium; (2) government subsidies need to be controlled within a reasonable range to ensure policy effectiveness; (3) improving government publicity and enhancing the social atmosphere can increase farmers’ participation rate to approximately 71% and 78%, respectively, significantly boosting their willingness to participate; (4) improving the social security system and reducing perceived risks can help increase farmers’ participation rate. The research conclusions can provide a valuable reference for local governments in China in formulating soil erosion control policies.

In the current soil erosion control efforts, the lack of collaboration among multiple stakeholders is a major problem that restricts governance performance. Based on carbon trading and the Public–Private Partnership model, this paper constructs a tripartite differential game model involving the government, enterprises, and farmers, focusing on the government subsidy and the enterprise–farmer benefit-sharing mechanism. It systematically analyzes the dynamic evolution process of multi-stakeholder collaborative governance behavior under the collaborative mechanism. Through numerical simulation, the impacts of key variables such as benefit-sharing ratio, synergy effect of measures, and unit carbon sequestration on the optimization of enterprise governance measures, effort level, government fiscal expenditure, and tripartite benefits were analyzed. The results indicate that (1) the benefit-sharing ratio has a significant bidirectional regulatory effect on the system, with both excessively high and excessively low ratios weakening the collaborative governance effect; (2) the synergistic effect between governance measures significantly enhances the enthusiasm of enterprise governance and promotes the allocation of resources towards measure with better carbon sequestration benefits; and (3) the unit carbon sequestration significantly affects governance structure and government subsidy strategies, with the government being more sensitive to carbon sink responses of afforestation measures. The research results provide a theoretical basis for optimizing the ecological governance system under the “dual carbon” goal and also provide policy references for promoting the transformation of governance model from “government-led” to “multi-stakeholder collaboration”.

Accurate prediction of jacking force is crucial for long-distance pipe jacking construction. This study establishes a theoretical jacking force model considering the soil pressure arch effect, where the Persson contact model and the hydrodynamic parallel plate model are incorporated to accurately characterize pipe–soil friction and lubrication resistance, resulting in more reliable friction force estimation as confirmed by field measurements. To enhance prediction accuracy, a Physics-Informed Domain Adversarial Training Neural Network (PIDANN) is proposed, integrating physical constraints into neural network training and expanding the dataset with theoretical values. A case study on the Zheng-Kai city water supply project demonstrates that (1) the theoretical model improves friction force predictions by incorporating the pressure arch effect; (2) PIDANN achieves superior prediction accuracy compared to models without adversarial training; (3) the two fusion methods of physical information integration reduce the mean squared error (MSE) by 36.9% and 20.2%, enhancing generalization and reducing overfitting risks. These findings provide valuable guidance for jacking force control in pipe jacking construction.

The construction of the national water network optimizes water resource allocation but also causes a redistribution of pollutants due to water quality differences, posing urgent challenges for water pollution management. Taking the South-to-North Water Diversion Project and Yangtze-to-Hanjiang River Water Diversion Project (YHRWDP) as an example and considering the pressure brought by the redistribution of pollutants to the polluting enterprises (PE) and water diversion enterprises (WDE) situated in areas where pollution is aggravated, a differential game model of pollution control among the central government, water-supply area (WSA), PE and WDE is constructed based on the cost-sharing mechanism. The results show that: (1) The pressure coefficient has an apparent negative correlation with the effort level of the affected subject. (2) An increase in the amount of pollution elimination per unit of pollution control effort of WSA and PE will lead to their own investment in more efforts to improve the ecology of the basin, thus benefiting all participants in the system. (3) The cost-sharing rate of the central government on the WSA of the YHRWDP, the PE, and the WDE is influenced by several factors, which shows a stable monotonically increasing or decreasing relation. The results are an useful supplement to the research on natural river pollution control, and can also provide a reference for designing pollution control mechanisms of national water network.

The green transformation of construction enterprises (GTCEs) is an important way to develop green buildings and realize the goal of “double carbon”. The GTCEs is not only influenced by the internal characteristics of the group but also influenced by the governmental orientation and the pull of the consumer groups. This paper simultaneously considers the heterogeneity of consumer groups and construction enterprise groups, coupling the improved SIR dissemination model, complex network model, and evolutionary game model to describe the dynamic interaction process between construction enterprise groups, government, and consumer groups and to explore the evolution law of GTCEs. The results show that (1) Appropriately increase in green R&D investment by construction enterprises for higher returns, the government’s subsidy and penalty policies and a higher carbon trading price have a positive effect on the GTCEs; (2) a positive social climate, along with the government’s publicity and education, the higher technology level of construction enterprises, and the higher green cognition and lower risk perception level of consumers will strongly promote the GTCEs; and (3) a steady development of the GTCEs is guaranteed by the enterprises’ own inputs and the government’s joint measures on both the supply and demand sides. The conclusions of this study can be used as a reference for the government to formulate policies and for the green transformation and development of construction enterprises.