Abstract:As an important engineering system for integrated allocation of water resources and hydroelectric energy development in river basins, cascade dam systems exhibit complex systematic characteristics characterized by the superposition, transmission and amplification of multi-source risks during operation. With China’s vigorous promotion of basin cascade development and the continuous strengthening of dam safety risk management system construction, risk management of cascade dam systems has become a research priority in the field of hydraulic engineering safety. Concentrated on the risk transmission effects within cascade dam systems, advances in the aspects of risk probability calculation, loss assessment, risk classification and coordinated regulation were reviewed. It is pointed out that future research should focus on the high-fidelity simulation of dam-break flood propagation in cascade systems, the coupling analysis of multi-source risks, the improvement of risk assessment frameworks, the formulation of multi-dimensional coordinated regulation strategies and the construction of intelligent river basin management platforms, with the aim of systematically enhancing the risk prevention and control capabilities as well as the regulation level of cascade dam systems.

Abstract:By early 2025, the number of completed and under-construction rock-filled concrete (RFC) dams had reached 200. Among them, the Zhouyuan RFC gravity dam with a height of 100 m had commenced construction. Concurrently, the Code for Design of Rock-Filled Concrete Dams (NB/T 10077-2024) was issued. These events indicate that RFC dam construction technology has achieved maturity after more than 20 years of development. The development process of RFC dam construction technology from its initial invention to gradual maturity was reviewed and divided into four key stages, the main technical problems and research achievements obtained in different stages were introduced, the main progress on fundamental research related to RFC was summarized, and the construction status of typical RFC dams as well as the continuous development and improvement process of the technical standard system for RFC dams were presented, so as to help readers better understand the evolution of RFC dams, point out the direction for future development, and promote the progress of RFC dam technology.

Abstract:The mechanisms of seepage failure in the reservoir-dam systems of the Yellow River Basin are increasingly complex, posing new challenges to safety prevention and control technologies against seepage failure. This paper reviews the research and practical progress on disaster-causing mechanisms and safety management of seepage failure in reservoir-dam systems of the Yellow River Basin, focusing on the following aspects: the evolution mechanism of seepage characteristics under seepage-stress coupling conditions in rock/soil masses, the dynamic behavior of seepage failure under coupled seepage-stress conditions in reservoir-dam systems, methods for seepage monitoring analysis and safety supervision, and risk assessment and mitigation technologies for seepage failure. Key issues urgently requiring resolution in current seepage safety research for the Yellow River Basin’s reservoir-dam systems have been identified. Future efforts should focus on developing visual experimental apparatus for studying rock/soil seepage-stress coupling, establishing a criterion system for judging seepage failure under multi-medium and multi-field coupling conditions, constructing mathematical models capable of characterizing environmental dynamics and uncertainties, and formulating a dynamic risk assessment and prevention/control framework that accounts for the variability of risk factors.

Abstract:Based on the disciplinary framework of soil and water conservation and its stage-wise development patterns, this paper reviews and summarizes the development process of soil and water conservation in the Yellow River Basin, analyzes the characteristics of different development stages, and synthesizes the progress achieved since the founding of the People’s Republic of China in terms of practice, theory, and technology. Based on years of investigation and research, it further examines key challenges and scientific issues hindering the high-quality development of soil and water conservation in the region. In addition, it identifies key scientific issues and critical technologies that need to be addressed, including the scientific connotation and disciplinary expansion of high-quality development of soil and water conservation, multi-dimensional service value assessment, landscape configuration and spatial zoning, carbon sink mechanisms and effectiveness evaluation, and the coordinated development of derivative industries. Finally, future directions for soil and water conservation in the Yellow River Basin are discussed.

Abstract:Given the frequent occurrence of landslide-induced river blockages in the alpine and canyon regions of southwestern China and based on the physical process of landslide-induced river blockage, this paper systematically reviews the research progress of continuum mechanics methods, discontinuum mechanics methods, and coupling methods in simulating landslide-induced river blockage processes, with a focus on analyzing the advantages and limitations of these methods in terms of computational accuracy, computational efficiency, and scope of application. The application of these methods in typical engineering cases is also discussed. Furthermore, the paper summarizes current key technical challenges in numerical simulation of landslide-induced river blockage processes, including high-performance computing, multi-scale modeling, parameter uncertainty handling, and coupling stability issues. Finally, future research directions are proposed, such as leveraging high-performance computing platforms, developing multi-scale coupled modeling techniques, advancing intelligent parameter inversion, and enhancing uncertainty quantification.

Abstract:Through a systematic review of research progress on mechanical test equipment for soil-structure interfaces, key influencing factors, numerical simulation methods, and constitutive models, the engineering applicability and technical limitations of current test equipment were analyzed, the response laws of interface mechanical properties under the influence of multiple factors were clarified, the key technologies and theoretical limitations in existing numerical simulations were summarized, and the applicable ranges and boundary conditions of commonly used constitutive models were classified. In light of the actual engineering needs and technological development trends, future research should focus on developing intelligent testing systems with integrated stress-seepage-temperature multi-field coupling functions, revealing the time-varying laws of interface mechanical properties under long-term complex environments and multi-field coupling, improving the numerical simulation method system based on the thin-layer element theory, and constructing intelligent constitutive models integrating machine learning algorithms and multi-source engineering data to enhance the accuracy and adaptability of interface mechanical behavior prediction under complex conditions.

Abstract:Due to the importance of accurate finite element models in assessing and analyzing the safety performance of hydraulic structures and on the basis of in-depth analysis of relevant research results at home and abroad, this paper systematically reviews the development and latest research progress of finite element model updating technology for hydraulic structures based on vibration response, with reference to both matrix-based and parameter-based updating approaches. Key issues of current finite element model updating technology for hydraulic structure are discussed and summarized. It is pointed out that future research can be carried out by combining artificial intelligence technology, from the aspects of high-efficiency sampling strategy and high-precision surrogate model development, multi-source information fusion and accurate extraction of vibration characteristics, and real-time dynamic model updating for the whole life cycle, so as to improve the practicability of vibration response-based finite element model updating technology and provide technical support for intelligent operation and maintenance of hydraulic structures.

Abstract:Given that the performance of hydraulic concrete directly affects the service function and operational safety of water conservancy and hydropower projects, this study reviews the progress in research of the laws and prediction methods concerning the influence of complex environments and complex components on the performance evolution of hydraulic concrete based on fundamental theories and new technologies for hydraulic concrete under complex conditions. The developments in new materials and technologies for hydraulic concrete are also introduced. In response to the current challenges in durability, as well as technical and economic performance of hydraulic concrete, key issues are put forward for further research, including multi-factor coupling effects, modern hydraulic concrete with complex components, and new technologies of the intelligent hydraulic concrete.

Abstract:To elucidate the coupling evolution mechanism of argillization and permeability in fault fracture zone filling materials driven by reservoir water seepage pressure, research progress on geological characteristics, experimental methods, and degradation mechanisms was systematically reviewed. Under in-situ high tectonic stress constraints, compressible faults exhibit a “fault core-failure zone” zonal structure. The low-permeability barrier within the core, which is rich in clay minerals, is susceptible to mineral softening and argillization under prolonged seepage pressure, resulting in an increase in permeability by three to five orders of magnitude. In-situ high-pressure water injection tests can capture the inhibitive effect of tectonic stress on fracture closure. In contrast, traditional laboratory tests often fail to accurately simulate realistic seepage pathways due to weakened cementation effects and stress release-induced distortions. The argillization of clay minerals leads to pore reconstruction, while fine particle content significantly increases the initiation pressure gradient through mechanisms such as flocculation cementation and “water film” effects. Seepage pressure-driven degradation follows a pattern wherein water seepage pressure promotes the penetration of seepage channels by propagating original fractures and accelerating particle migration and loss, ultimately leading to a notable reduction in the critical hydraulic gradient.

Abstract:Water control has always been a critical aspect of national governance and stability. China’s modern water control efforts have entered a new historical phase, requiring more advanced research. Summarizing the research progress on China’s modern water control and accurately identifying key future research tasks are crucial for advancing the water conservancy modernization. By outlining the main development of ancient and modern water control in China, the research progress on modern water control was summarized in terms of significant theories, key methods, and representative practices. Addressing future development needs in water control, this paper identifies key research frontiers for modern water control in China, including national macro water strategies, micro water scientific issues, integrated monitoring systems, smart simulation systems, intelligent service systems, water science research related to ecology, water disaster prevention and control, and efficient water utilization.

Abstract:From the perspective of risk transmission process of basin water resources security, this paper systematically analyzes fundamental concepts, including the water resources security system, water resources security risk system, and water resources security risk assessment. The conceptual framework for water resources security risk assessment is proposed, which is characterized by an Aristotelian syllogistic relational structure and encompasses five elements: the hazard of risk-inducing factors, the vulnerability of risk-bearing bodies, the risk-inducing potential of hazardous environment, the risk-resistance capacity of mitigation measures, and the water resources security loss risk. This paper reveals the transmission mechanism of water resources security risk elements, where under specific risk-incubating and risk-resisting conditions in a watershed, the hazard of risk-inducing factors serves as the system input, the vulnerability of risk-bearing bodies as the system transition, and the water resources security loss risk as the system output. This paper elaborates on methodology for water resources security risk assessment, consisting of water resources security risk assessment objects, evaluation indicators, evaluation indicator measurement methods, methods for quantifying qualitative indicators, single-indicator evaluation methods, methods for determining indicator weights, and methods for determining comprehensive evaluation indicators. The theoretical framework composed of the conceptual system, risk transmission mechanism, and risk assessment methodology forms a preliminary theoretical foundation for water resources security risk assessment. This theoretical framework also holds significant application value for risk assessment in other resources and environmental systems.

Abstract:Key hydrological factors such as water level, flow velocity, and discharge play a crucial role in regulating river and lake ecosystems. Based on extensive domestic and international research, and combining typical case studies, this paper systematically investigates the impacts of water level, flow velocity, flow rate, and hydrological connectivity on water environment and aquatic organisms. The regulation effects of these hydrological factors on ecological environment are analyzed. Water level influences the decomposition and transformation of pollutants in water and sediments, as well as the photosynthetic capacity of aquatic plants, by altering light intensity, redox conditions at the sediment-water interface, and the area of biological habitats. Changes in flow velocity and flow rate affect the suitability of biological habitats by modifying material transport capacity, sediment status, and the growth and reproductive needs of aquatic organisms, exhibiting significant threshold effects. Hydrological connectivity reflects the synergistic interactions and dynamic processes between hydrological elements, influencing the distribution of aquatic vegetation and the migratory and reproductive behaviors of fish. Finally, the paper introduces new technologies and methods used in related research and summarizes the current trends and developments in this field.

Abstract:Weakly mixed land-dominated estuaries are susceptible to the combined influences of fluvial water-sediment fluxes, marine dynamics, and anthropogenic activities, resulting in complex dynamic changes in hydrological connectivity. However, a systematic synthesis of hydrological connectivity in such estuaries is still lacking. Therefore, taking the Yellow River Delta, a representative weakly mixed land-dominated estuary in China, as an example, based on the classification of structural connectivity and functional connectivity, the spatiotemporal patterns, evolutionary trends, and driving factors of hydrological connectivity in tidal flat wetlands were analyzed, and the bidirectional feedback mechanisms between the hydrological connectivity and water-sediment dynamics were emphatically explored. It is pointed out that future research should focus on three directions, including integrating rivers, tidal creeks, and surface-groundwater systems to establish a multi-scale hydrological connectivity framework for entire tidal flat wetlands, enhancing synergistic analysis of field monitoring and numerical models to systematically analyze the feedback mechanisms between hydrological connectivity and water-sediment dynamics in weakly mixed estuaries, exploring nature-based and society-based solutions to improve hydrological connectivity, and establishing synergistic optimization strategies that concurrently enhance hydrological connectivity and restore wetland ecological function, thereby providing practical paradigms for integrated estuary management.

Abstract:Given the significant role of advancing comprehensive reform of agricultural water pricing in promoting the sound operation of farmland water conservancy projects, promoting agricultural water conservation, achieving efficient utilization of water resources, and ensuring national food and water security, this paper conducts a systematic analysis of reform policy documents and a thorough review of typical reform cases over the years. It provides an overall assessment of the general progress, institutional changes, mechanism development, typical practices, and notable achievements of China’s comprehensive reform of agricultural water pricing. In view of the prominent issues currently facing the reform, recommendations are proposed, such as further verifying the baseline data of the reform, carrying out extensive sampling surveys, establishing a follow-up mechanism, reimbursing operation and maintenance costs, and setting up a water price compensation mechanism.

Abstract:To address the insufficient quantitative characterization of the relationship between cropping systems, phenological information and irrigation water demand (IWD), this study utilized phenological data of staple crops in China from 2000 to 2019 to characterize cropping systems, growth stages and crop rotation patterns. Based on the normalized difference vegetation index, potential evapotranspiration and precipitation data, the IWD was estimated using the crop coefficient method, and its linkage with cropping systems was quantified. The results show that the IWD exhibited significant spatiotemporal heterogeneity, with interannual fluctuations ranging from 65.9 billion to 127.3 billion m³. High-IWD years were generally synchronized with drought events, and high-IWD regions were concentrated in high-intensity multiple-cropping regions, such as the Huang-Huai-Hai Plain and the middle-lower reaches of the Yangtze River. Due to the significant spatiotemporal mismatch between the peak crop growth periods and the peak precipitation period, the IWD showed distinct seasonal peaks from May to August. The mean unit-area IWD of the wheat-maize rotation system was consistently higher than those of other cropping systems from 2000 to 2019, making it the dominant factor influencing the spatial distribution of IWD.