Abstract:Taking the Wenyu River as an example,this paper analyzes and determines the goals of river habitat restoration based on multiple aspects,such as historical changes of the river,ecological baseline survey results,and planning positioning.The habitat restoration strategies are discussed from the perspectives of improving the connectivity of river ecological corridors,increasing deep pool habitats,constructing river island habitats,enriching shallow beach habitats,diversifying water flow patterns,restoring farmland habitats,and optimizing plant communities.Based on the characteristics of biological growth and reproduction,as well as the laws of ecosystem development and evolution,operational and management suggestions are provided.The strategies aim to enhance biological diversity in river ecological governance projects and improve the self-maintenance ability of aquatic ecosystems.

Abstract:In order to analyze the impact of return flows generated after the operation of the Pagu Reservoir Project on the surrounding water environment,a one-dimensional hydrodynamic and water quality coupled model of the reservoir drawdown area is established based on the hydrodynamic and water quality modules of MIKE11,and the variation of river water quality in the drawdown area is predicted and analyzed.Based on the MIKE11 water quality model,this paper predicts and analyzes the longitudinal variation of water quality along the Nimumaqu River downstream of the dam site under a P=95%hydrological year,as well as the intra-annual variation of water quality at key water source sections downstream of the dam site.According to the prediction results,in a P=95%hydrological year,with the inflow of downstream point sources and agricultural non-point sources,the concentration of pollutants in the river increases.The pollutant concentrations along the Nimumaqu River and at key water source sections are slightly higher than the current levels,but still meet the Class Ⅲ standard,indicating that the impact on the water quality of the Nimumaqu River and key water sources is relatively small.

Abstract:Affected by harsh climate,complex terrain conditions,and insufficient communication coverage,hydrological monitoring and reporting for hydropower projects in alpine regions face common technical bottlenecks.Taking the Suki Kinari(SK)Hydropower Project in Pakistan as the research object,this paper constructs a hydrological automatic monitoring and reporting system with BeiDou satellite communication as the core.Combined with the hydrometeorological characteristics of the Kunhar River Basin and engineering requirements,rainfall stations,hydrological stations,water level stations,and meteorological stations are scientifically arranged to form a three-dimensional monitoring network covering the basin scale.A scheme is proposed in which BeiDou satellite communication serves as the primary communication channel in areas without public network coverage,increasing the data transmission arrival rate of hydrological information to over 95%.Meanwhile,in response to river measurement requirements during the ice period,corresponding measurement schemes are proposed,and power supply and lightning protection strategies are developed to ensure the stable operation of monitoring equipment under extreme environmental conditions.The research results can provide technical reference for the construction and operation of hydrological automatic monitoring and reporting systems for hydropower projects in similar alpine and complex regions in China.

Abstract:Taking five watersheds in Langfang City—Sanhe,Xiluocun,Beichang,Gengsheng,and Jingezhuang—as the research objects,this paper first applies the principal component analysis(PCA)method to reduce the dimensionality of ten topographic and geomorphologic characteristic indices of the watersheds,including watershed area,channel slope,total river network length,river network density,main channel length,watershed length,form factor,average watershed slope,average elevation difference,and average watershed elevation,and extracts two principal components that can comprehensively reflect the original characteristics.Then,an objective weighting method is used to assign weights to the principal components,quantifying the similarity among watersheds.As a result,two pairs of similar watersheds—Sanhe-Xiluocun and Beichang-Gengsheng—are identified,for which parameter transfer can be carried out.The research results provide a basis for identifying reference watersheds for hydrological forecasting in ungauged regions in the future.

Abstract:Hydraulic tunnels are buried underground,where they not only bear significant surrounding rock pressure but are also subjected to the combined effects of external and internal water pressures.As the permanent support structure of hydraulic tunnels,the lining plays a critical role in ensuring the long-term safe operation of the tunnel;therefore,conducting lining quality inspection is of great significance.Taking a water conservancy hub project in Xinjiang as an example,this paper employs integrated geophysical methods,including ground penetrating radar and ultrasonic shear wave reflection three-dimensional imaging,to carry out non-destructive testing of the tunnel lining quality.The detection results are analyzed and compared with borehole verification for evaluation.The results indicate that the integrated geophysical methods have good effectiveness and feasibility in tunnel lining quality inspection,and can provide reference for the inspection and evaluation of lining quality in similar projects.

Abstract:The Tonghui River is a key river in the central urban area of Beijing,playing an important role in the city's operation.With urban development,people's demands for ecological livability are increasing,and the construction around rivers is constantly being updated.In sections of the Tonghui River with long straight walls,the green space on both sides is narrow,and the landscaping techniques are simple.Conflicts often arise between landscape construction and the daily management of hydraulic facilities,so further improvement in the landscape of the Tonghui River is necessary.In recent years,vertical greening technology has been widely used in urban landscapes.When applied reasonably,it can make up for the lack of flat greening area and has characteristics such as strong plasticity and small spatial requirements.The attempt to use vertical greening techniques in the landscape construction of the Tonghui River can further alleviate the shortcomings of landscape construction on both sides of the river,improve the urban ecological environment,and has broad application prospects.

Abstract:The magnitude of radial tensile force of rubber dam bags is a critical factor affecting the overall stability and safety of the dam structure.Three different working conditions during the use of rubber dams were compared to identify the most unfavorable condition for dam bags.Subsequently,utilizing relevant mechanical knowledge,a theoretical derivation for the solution method of the dam bag's radial tension was performed.The results indicate that the formula for calculating the radial tensile force under the most unfavorable working condition,obtained through theoretical deduction,accurately reflected the maximum radial tensile force during operation after vertification and analysis.This finding holds guiding significance and reference value for the selection of dam bag materials in future engineering designs.

Abstract:Under the combined influence of cold and warm air masses and Typhoon Doksuri,from July 27 to August 1,2023,Baoding City in Hebei Province experienced a historically rare"23·7"heavy rainfall event.This paper aims to systematically analyze this extreme rainfall event by reviewing the preceding rainfall background and focusing on the spatial and temporal distribution,movement path,intensity characteristics,and frequency of the heavy rain,while comparing it with historically typical heavy rainfall events.In terms of research methodology,meteorological observation data were comprehensively used to statistically evaluate and analyze the causes and impacts of the extreme rainfall.The research results indicate that the"23·7"heavy rainfall had a long duration,a wide area of impact,and extreme local rainfall intensities.The return period of precipitation at some stations exceeded 100 years,demonstrating its extremity and typicality.The findings provide a reference for disaster prevention and reduction work in Baoding.

Abstract:To evaluate the impact of impervious walls on the seepage characteristics of a small(Type 2)reservoir dam,this paper employs numerical simulation based on Autobank software to compare and analyze the seepage characteristics and downstream slope stability of the dam body under two conditions:with and without an impervious core wall.Five typical operating conditions are selected for the study,and key parameters such as the exit point slope,horizontal segment slope,exit point elevation,seepage flow rate,and slope safety factor are quantitatively calculated.The research results show that after the installation of the impervious wall,the exit point slope,horizontal segment slope,exit point elevation,and seepage flow rate of the dam body are significantly reduced,and the dam slope safety factor is improved.The impervious core wall ensures the seepage stability of the dam body and plays an important role in the safe operation of the dam.

Abstract:The safety and sustainable operation of the reservoir is of great significance to the economic benefits of the surrounding areas.The study employs piezometric tests and finite element analysis methods to evaluate the seepage stability of the dam foundation and dam slopes,respectively.The results show that a total of 81 sections were inspected in the piezometric tests,with the highest permeability rate found in the horizontal toe plate hole J-2,section 2 of the bedrock,which was 2.91 Lu,meeting the anti-seepage standard of 3 Lu.The AutoBank finite element simulation software was used to calculate the dam slope stability under five possible conditions,and the safety factors under each condition met the regulatory requirements.It is concluded that under the action of seepage,the dam foundation and slopes are basically stable,and there is no risk of reservoir leakage.

Abstract:The Longhekou Water Diversion Project pipeline adopts a pipe jacking scheme plan to cross the national highway,and the overlying strata are gravel layers with high groundwater levels.Currently,there are few cases of pipe jacking implementation in such environments,making the project implementation difficult.The engineering design adopts various solutions such as the transformation of the pipe jacking machine cutterhead,the improvement of the grouting system,the pre-reinforcement of the jacking stratum,and the monitoring technology of road surface settlement.The design scheme has been verified to be reasonable and effective through construction,and can provide reference for future pipe jacking design and construction under similar conditions.

Abstract:To advance renewable energy development tailored to local conditions,explore a new mode combining photovoltaic development and hydraulic engineering construction,effectively promote the development and consumption of new energy,and serve the implementation of the dual carbon strategy;Using current policies and regulations as a foundation,this paper took the South-to-North Water Diversion Middle Route Project as an example and proposed a method for photovoltaic construction using various water resources of the long-distance water transmission line in the Hebei section,such as the outer slope of the main canal,the drainage channel,the muck disposal sites,the inverted siphon,and the gate chamber roofs;and assessed the feasibility of establishing a"photovoltaic corridor for ecologically-optimized water diversion"along this route.The construction of photovoltaic corridors can make full use of existing water project resources,adapt renewble energy development to local contexts,and set a replicabe paradigm for green transition of major infrastructure,which proves highly scalability.

Abstract:Currently,the evaluation indicators for the maintenance of the urban river and lake water environment in Beijing are rather singular and significantly influenced by subjective factors.In order to conduct a scientific and objective benefit evaluation and quantify the management effectiveness,the Analytic Hierarchy Process(AHP)was employed.Eleven evaluation indicators were established from three dimensions:water quality,maintenance and management,and social benefits.The weights of each indicator were determined based on expert opinions,and an evaluation system tailored for the benefits of urban river and lake water environment maintenance was constructed.Taking the urban river and lake water environment maintenance work in 2023 as a case study,a benefit evaluation was performed,and the evaluation result was rated as"good".Furthermore,suggestions were proposed to further enhance the benefits of water environment maintenance.

Abstract:Dikes are a critical component of the flood control system in the middle and lower reaches of the Wei River.Studying the simulation of dike-break flood propagation is of great significance for flood prevention and disaster mitigation.This study collected data from the"21·7"flood event in the Wei River and employed a MIKE 1D-2D coupled model to simulate the Pengcun dike breach along the main channel.The simulation analyzed the breach discharge hydrograph,flood propagation process,and variations in disaster-inducing factors such as inundation depth and flow velocity after the breach.The results indicate that:For the Wuling hydrological station,the correlation coefficients between simulated and observed water levels and discharges are 0.94 and 0.92,respectively,both close to 1,demonstrating a high level of agreement.The simulated peak discharge/timing lags 0.5 hours behind the observed peak,but the overall simulation meets the required accuracy criteria.The dike breach module was reasonably configured,and the breach discharge process effectively reflected the actual conditions.The inundation extent in severely affected areas aligned well with actual emergency response records,and the maximum inundation depth in Yuanzhuang Village showed a 6.09%deviation from field survey data.The findings of this study provide technical support for dike-break flood simulation and risk assessment,contributing to improved flood management strategies.

Abstract:In hydraulic engineering construction,pipe jacking is an important method for crossing underground tunnels.The MJS technology can reinforce the soil during the jacking process,increase its bearing capacity,and reduce the impact of construction-induced foundation settlement on surface structures.This paper focuses on the application of pipe jacking technology in special operation scenarios under railway mainlines,aiming to explore the impact of MJS pipe jacking technology on railway foundation settlement and deformation under different working conditions,providing a reference for similar projects.The underpass construction of the Li Xi Canal and the Baiyun Airport Second Expressway North Drainage Canal beneath the New Bai Guang Intercity Railway is analyzed using the finite element method to study the impact of foundation pit and pipe jacking construction on railway foundation settlement and deformation under various working conditions.The calculation results show that the maximum horizontal displacement and vertical settlement of the intercity railway box culvert and track structure are minimal,with the maximum settlement difference in the deformation joint tunnel being 0.287 mm.The displacement and settlement values meet the engineering expectations.Therefore,the MJS method can effectively control the settlement of railway foundations under various working conditions.

Abstract:To ensure the structural safety of the lining during the repair of the channel in the Middle Route of the South-to-North Water Diversion Project,this study develops a refined three-dimensional(3D)numerical model based on the concrete damaged plasticity(CDP)theory,leveraging a dry-land repair scheme with an expandable cofferdam.The model is used to investigate the stress,displacement response,and damage evolution of the channel slope lining slab under various load distribution ratios between the track system and the waterstop structure.The results indicate that:During the cofferdam lowering stage,the lining slab remains within the elastic range,and the structure is safe.After dewatering the cofferdam's interior,the stress in the lining slab increases significantly,with the upper surface primarily subjected to compressive stress and the lower surface to tensile stress.When the load distribution ratio between the track system and the waterstop structure is 5:5,the stress distribution in the lining slab is uniform,the total displacement is minimized,and no compressive or tensile damage occurs,indicating that the structure is in an optimal elastic working state.The findings of this research can provide a theoretical basis for the optimal design of the expandable cofferdam and for ensuring construction safety.

Abstract:Nutrients and heavy metals are important sources of river and lake pollution.This study takes a certain section of the river as the object,analyzes the pollution of nutrients and heavy metals in the sediment of the river,explores the scope of ecological dredging and evaluates the implementation effect of ecological dredging projects.The results showed that the ecological dredging project had significant effects in removing nutrients and heavy metals from sediment.The dredging project reduced the nutrient content in river sediment from the"lowest level"to the"safe level",and the ecological risk index level of heavy metals decreased from"medium risk"to"low risk".Ecological dredging effectively reduces the accumulation of nutrients and heavy metals in river sediment,with significant benefits.

Abstract:Aiming at the adverse effects of backfilling on the installation and structural safety of the immersed tunnel foundation at the connection section of the east artificial island of the Hong Kong-Zhuhai-Macau Bridge,caused by bank flow and the"island head effect",this paper adopts a source-level backfill control method using steel plate covers to carry out stability design and stress characteristic analysis of the scour-prevention structure.Based on the 100-year and 20-year return period wave conditions,two calculation models,namely vertical and sloped revetments,are established.The combined effects of wave action and hydrodynamic forces on the stability of the toe-protection components are systematically considered,and the optimal ballast parameters for the scour-prevention steel plate are ultimately determined.The results indicate that the steel plate cover source-level backfill control technology can effectively mitigate the adverse impacts of continuous backfilling on the installation accuracy and structural safety of the immersed tunnel.The analysis method and ballast calculation approach can provide a reference for the design of scour-prevention structures and determination of ballast parameters in similar large-scale projects.

Abstract:Climate change and human activities have affected surface runoff in the Dongbing River Basin,the main inflow river of Dongfeng Reservoir,resulting in a gradual decrease in inflow and posing a threat to the water supply security of downtown Yuxi City.To analyze the quantitative impacts of climate change and human activities on runoff in the Dongbing River Basin,this paper is based on observed runoff data from Dayizi Hydrological Station and precipitation data from Anhua and Dayizi rain gauge stations from 1980 to 2024.Methods including water balance,statistical analysis,and separation evaluation were applied to analyze the evolution characteristics of rainfall-runoff in the basin and to quantify the contribution of climate change and human activities to runoff variations.The main results are as follows:The multi-year average natural runoff of the Dongbing River Basin is 31.88 million m³,with a coefficient of variation(Cv)of 0.35.The multi-year average total water consumption shows an increasing trend,dominated by agricultural water use;The basin's multi-year average precipitation is 942 mm,with a Cv of 0.15.The runoff coefficient is positively correlated with precipitation,indicating that rainfall is an important factor affecting runoff in the Dongbing River Basin.However,the intra-annual distribution of rainfall and runoff is highly uneven,and runoff peaks lag behind precipitation peaks;Both precipitation and runoff exhibit significant decreasing trends,with abrupt change points around 2008 and 2003,respectively;Climate change and human activities jointly contributed to the reduction of runoff in the Dongbing River Basin,with contribution rates of 53.0％and 47.0％,respectively.The results of this study provide scientific reference for the protection of the Dongfeng Reservoir water source and for scheduling water supply security in downtown Yuxi City.

Abstract:The Yongding River Water Diversion Project is the main source of production and domestic water supply for Beijing.Its headwater,the Sanjiadian Water Conservancy Hub,is the first controlling water conservancy project connecting the Guanting Gorge section and the plain section of the Yongding River,playing a key role in providing water for urban development in Beijing and the construction of river and lake ecological environments.This paper analyzes the history of water resources dispatching and current development status of the Sanjiadian Water Conservancy Hub over more than 60 years,summarizes the achievements in water resources,water ecology,and water economy,and identifies existing problems.With the construction of the Hexi branch and West Storage Project,as well as the continuous updating of water management concepts in the new era,relevant measures and suggestions are proposed for the dispatching operation of the Sanjiadian Water Conservancy Hub under new conditions,which are of great significance for further improving regional water resources dispatching and management.