Abstract:In view of the tight construction schedule and heavy tasks of the tunnel project of the Yunxiao Pumped Storage Power Station in Fujian,as well as the technical characteristics of the loosened zone detection in the tunnel crown—namely the use of dry holes,a"one-transmit-two-receive"transducer,and the requirement of water injection coupling—which result in relatively low detection efficiency,this paper carries out an experimental study on shortening the detection time of the loosened zone of surrounding rock in the tunnel crown.By modifying the water injection device and installing pressure gauges,the reasonable water injection pressure under different testing heights and the pressure for water release during probe movement are determined,respectively.Comparative tests are also conducted by adopting measures such as shortening the length of the water injection pipeline.The results show that this technical approach can effectively improve the efficiency of dry-hole acoustic testing in this project.Engineering practice further verifies that the experimental results of water injection pressure parameters at different heights are scientifically sound and can provide effective guidance for subsequent dry-hole acoustic testing operations.

Abstract:River dike projects are characterized by long routes and complex geological conditions.Soft foundation problems are often encountered when crossing pits,ponds,and estuaries,and the effectiveness of their treatment directly impacts the safety of the dike project.Based on an overview of common soft foundation treatment methods,this paper focuses on analyzing the principles,applicable conditions,and technical points of the stone-throwing and silt-pressing technique.Taking the new dike construction in the Panjin section of the Liaohe River Flood Control and Improvement Project in Liaoning Province as an example,the design requirements for applying the stone-throwing and silt-pressing technique in foundation treatment are systematically elaborated.Combined with seepage analysis of the dike,anti-sliding stability calculations,and field test results,it is shown that after stone-throwing and silt-pressing treatment,the characteristic value of the foundation bearing capacity and the settlement difference before and after compaction meet the design requirements.The overall seepage stability and anti-sliding stability of the dike also meet the standards.The study shows that the stone-throwing and silt-pressing technique is safe and feasible for treating soft foundations in dike projects and can provide reference for similar projects.

Abstract:To address the inefficiencies of traditional water conservancy construction supervision models,including delayed information transmission and difficulties in multi-department coordination,an intelligent construction site platform was developed based on technologies such as artificial intelligence,geographic information systems,big data,and the Internet of Things.The platform includes core functional modules such as video surveillance,dust monitoring,personnel attendance,and inspection and testing.It enables intelligent recognition of construction activities,real-time monitoring of environmental parameters,dynamic management of on-site personnel,and full-process traceability of inspection and testing.Research shows that the application of the intelligent construction site platform has realized visual monitoring of the entire construction process,intelligent risk early warning,and dynamic multi-party coordination management,enhancing the ability to identify quality and safety hazards and effectively controlling construction schedule deviations.It provides intelligent and refined management methods for water conservancy project construction.

Abstract:In order to comprehensively understand the aquatic ecological condition of the Miyun Reservoir,this paper systematically analyzes the eutrophication level,phytoplankton,macrophytes,zooplankton,and benthic organisms based on the monitoring data from 2021 to 2023 in the reservoir area.The results show that,as of 2023,both the reservoir area and the incoming water bodies are at a moderate level of eutrophication.A total of 7 phyla and 79 genera of phytoplankton were identified in the reservoir,with dominant species in the year being Asterionella formosa,Synura petersenii,and Anabaena flos-aquae.A total of 54 species of macrophytes were found,with an increase in species diversity(18 additional species)and improved coverage.The disappearance or extinction phenomenon is gradually recovering.The total density of zooplankton increased,but species diversity decreased,with dominant species mainly belonging to the Phylum Rotifera,and the species density showed significant seasonal variation.Benthic organisms are primarily pollution-tolerant species,with higher numbers and species in relatively shallow areas compared to deep areas.However,the species composition is simple,and mollusks are rare.The study results provide theoretical support and data for the eutrophication control and aquatic ecological protection of the Miyun Reservoir.

Abstract:Kenli District is a region severely lacking in water resources.To effectively alleviate the water supply-demand contradiction in the district,the No.4 Reservoir is planned to be utilized for water storage and regulation,with an expansion of its capacity.The analysis and calculations cover aspects such as the water supply range,supply targets,water demand in the project area,available water supply,and water volume regulation,leading to the determination of the capacity expansion for the No.4 Reservoir.The total reservoir capacity is 4.07 million m3,with a dead storage capacity of 500,000 m3,a usable storage capacity of 3.56 million m3,and an outflow of 3.2 million m3.The research results provide a basis for the scale of the No.4 Reservoir capacity expansion project in Kenli District and offer a reference for similar capacity expansion projects in irrigation and water supply scale analysis.

Abstract:This paper systematically summarizes the main design points of the main water conveyance canal of the Xixiayuan Water Conservancy Hub,including the determination of channel cross-sectional form and dimensions,the arrangement of slope lining and jointing structures,and the determination of canal crest elevation based on hydraulic calculations.A typical unfavorable section is selected to carry out anti-sliding and anti-seepage stability analysis of the canal,so as to verify the rationality of the design scheme.On this basis,through anti-freezing design and protective measures for locally special canal sections,the service life and durability of the canal are further improved.The results show that the designed section meets relevant code requirements under different working conditions,which can provide assurance for the safe and stable operation of the project in the later stage.The research results are of great significance for improving regional water resources allocation efficiency,ensuring food security,and perfecting the modern water network system.

Abstract:As an important component of reservoir hubs,dams serve as a crucial physical barrier for regulating reservoir water levels.Due to their favorable economic efficiency and construction convenience,earth-rock dams are widely used.The structural design of earth-rock dams is constrained by various stability issues,among which seepage stability and anti-sliding stability are particularly prominent.During the structural design process of earth-rock dams,it is necessary to consider the operating conditions of the reservoir dam and carry out verification of seepage stability and anti-sliding stability through numerical simulation.Based on an actual engineering example,this paper conducts verification of seepage stability and anti-sliding stability of an earth-rock dam using the GeoStudio numerical simulation platform,which can provide reference for similar engineering verification.

Abstract:The secondary development of reservoirs is of great significance for improving economic benefits.Through technical improvements,the Central Guizhou Water Conservancy Hub Project adopted the approach of replacing the"ecological discharge facility cone valve"with an"ecological hydroelectric generator"(hereinafter referred to as"machine substitution for valve").This method fully utilized water resources for power generation,increasing the economic benefits of the project while replacing high-head energy dissipation measures.By employing a reasonable scheduling and operation method that alternated water discharge with the originally approved large units,the ecological water demand of downstream rivers was met.Following program demonstration,the technical and economic aspects were found to be reasonable and feasible.The modification was approved by relevant departments,and the system has been in operation for many years,generating considerable revenue.Operational practice confirmed that using the reservoir's ecological water energy for power generation through"machine substitution for valve"significantly increased economic benefits and enriched the avenues for secondary development of reservoirs,providing valuable experience for similar projects.

Abstract:Extreme rainfall events can lead to an increase in pollutant concentrations in semi-closed water bodies,thereby increasing the risk of eutrophication.This paper selected three intense rainfall events in the Phase Ⅱ of the Songzhuang Flood Retention Area in Beijing,where the rainfall intensity exceeded 120 mm/h during the summer of 2023-2025.The trends of water quality indicators such as ammonia nitrogen,total phosphorus,chemical oxygen demand,electrical conductivity,and turbidity were analyzed based on monitoring data.The results show that various water quality parameters changed to different extents before and after the intense rainfall events.Compared to the median values before the rainfall,the peak median values of water quality parameters during the three intense rainfall events showed the following changes:ammonia nitrogen concentration increased by 40％,total phosphorus concentration increased by 21％,chemical oxygen demand increased by 11％,electrical conductivity decreased by 10％,and turbidity increased by 452％.The study results indicate that intense rainfall has a significant impact on the water quality of semi-closed water bodies,providing valuable reference for pollution prevention and water quality management in semi-closed water bodies under extreme weather conditions.

Abstract:The flood diverting hub of Lugou Bridge on the Yongding River is located 982 meters upstream from Lugou Bridge,spanning the Yongding River.This hub was completed and put into operation in 1987 and has been in operation for nearly 40 years.It is a key part of the Yongding River flood control system and a national-level flood control priority project.During the process of reinforcing and eliminating hidden risks of the flood diversion hub,epoxy coatings were used as repair and anti-carbonation materials for the concrete structure.The treated hydraulic structures show good quality,effectively slowing down the carbonation rate of the concrete structure.This paper introduces the epoxy coating repair construction process and relevant technical parameters using the reinforcement and risk elimination project of the Lugou Bridge flood diversion hub on the Yongding River as a case study,which can serve as a reference for similar projects in the future.

Abstract:The Happy River and Lake Construction of Minghu Lake Project in Chuzhou,Anhui Province,is one of the first batch of Happy Rivers and Lakes construction projects initiated by the Ministry of Water Resources.The project practices the development philosophy of"lucid waters and lush mountains are invaluable assets".In response to the deficiencies in water environment quality,water ecological status,water resource allocation,water security assurance,and the inheritance of water culture in Minghu Lake,the project follows the principle of"overall planning and systematic governance"to carry out systematic and comprehensive governance of the Minghu Lake watershed.This paper analyzes and discusses the implementation plan for the Happy River and Lake construction of Minghu Lake from the perspectives of river-lake system governance,management and protection capability enhancement,and support for regional watershed development,aiming to provide ideas and references for promoting high-quality watershed water conservancy development,enhancing people's sense of gain and happiness,and enriching the connotation of river and lake water culture.

Abstract:Based on continuous 10-year precipitation monitoring data from 2014 to 2023 in Xinfu District,a systematic analysis of the composition characteristics,pollution types,and sources of water-soluble ions in the atmospheric precipitation of the region was carried out.The results show that the precipitation in Xinfu District is generally neutral,and the electrical conductivity(EC)is influenced by a variety of environmental factors.The dominant anions in the precipitation are SO42-and NO3 ⁻,while the dominant cations are Ca2+and Na+,indicating that Ca2+and Na+are the main ions neutralizing the acidic substances in the precipitation.The SO42-/NO3⁻ ratio in the precipitation over the years ranges from 5.1 to 17.3(much greater than 3),showing typical coal-burning(sulfuric)pollution characteristics.Ion correlation and source contribution analysis confirmed that K+and Ca2+are primarily influenced by terrestrial inputs,Mg2+is affected by both marine and terrestrial sources,and 98.2%of Cl ⁻ originates from the ocean.SO42-and NO3 ⁻ are mainly from anthropogenic sources(with SO42-also influenced to some extent by the ocean),and the contribution of anthropogenic sources to NO3⁻ is as high as 98.0%.

Abstract:To address the seepage issues observed at the downstream dam face and slopes of the Shuinianwan Reservoir dam in Guizhou Province after impoundment,the design team classified the seepages into three categories based on their locations and characteristics:joint-related seepage corresponding to upstream panel joints,local seepage at non-joint areas of the upstream panel,and foundation seepage.Based on field safety inspections and subsequent quality testing results of the upstream panels,a categorized treatment scheme was implemented:cracks in the upstream panels were repaired using coating methods,while consolidation grouting was performed to enhance the foundation curtain.Post-implementation monitoring confirmed satisfactory anti-seepage effectiveness,validating the feasibility of the"categorized treatment and precision-targeted measures"methodology.This approach provides valuable technical references for seepage control in similar masonry dams.

Abstract:To investigate the response of surface runoff in the Shahe River Basin to changes in climate and land use,based on the daily meteorological and hydrological data of the Shahe River Basin from 1960 to 2020,the trend of precipitation,temperature and runoff in the basin was analyzed by using moving average method,linear regression test method and m-k nonparametric test method.Combined with the land use data of Shahe River Basin,SWAT model of Shahe River Basin is established.Through calibration and verification,SWAT model has good applicability in runoff simulation of Shahe River Basin.On this basis,the impact of climate and land use change on runoff is quantitatively analyzed through scenario simulation.The results indicate:Over the past 61 years,the temperature of Shahe River Basin has a significant upward trend,the precipitation has not decreased significantly,but the measured runoff has a significant downward trend;Cultivated land,forest land and grassland are the main land use types in the basin,accounting for more than 90%of the area,and the area change range is small from 1980 to 2020;Climate and land use change will lead to runoff reduction in the study area.By comparing the contribution rate,the main factor leading to runoff reduction is climate change.

Abstract:In complex geological environments where there are both existing embankment protection structures and isolated stones,the construction of anti erosion walls into grooves faces many challenges.To this end,this article proposes a comprehensive construction technology that combines rotary drilling rig drilling,double wheel milling and grooving,and grooving machine grabbing by comparing various grooving processes.Taking the construction of the second section of the comprehensive upgrading project of the third section of Yongding River as an example,this paper analyzes in detail the selection of anti erosion wall trenching equipment and the research on trenching technology in complex geological environments.The results showed that the collaborative work of the three devices not only successfully overcame the construction challenges brought by complex geological environments,significantly improved construction efficiency,and ensured the quality of the trench.

Abstract:This paper conducts a non-stationary analysis of the maximum flood peak discharge of Wangkuai Reservoir in the Daqing River Basin,and calculates the reservoir flood return period under non-stationary conditions.It describes the influence of environmental changes and underlying surface conditions of the reservoir on the flood return period.The research method employed is the Generalized Additive Model for Location,Scale,and Shape(GAMLSS)based on the time-varying moment model.A non-stationary flood frequency analysis was performed on the maximum flood peak discharge of Wangkuai Reservoir.Model parameters were evaluated using the AIC criterion,and the optimal parameter model was selected to calculate the flood return period under non-stationary conditions.The results indicate that the maximum flood peak discharge of Wangkuai Reservoir shows a significant declining trend and change points,effectively reflecting the impact of continuously changing environmental and hydrological factors on flood risk assessment.

Abstract:The seepage control system of concrete face rockfill dams is crucial for the safe operation of the dam body.Some projects,due to geological conditions or construction cost limitations,cannot set up a downstream measuring weir and must rely on piezometers to monitor the seepage condition.However,because of high permeability in the foundation and rapid decline of the phreatic line,traditional piezometer layouts often lack monitoring sensitivity.This paper investigates the effectiveness of piezometer placement in monitoring the seepage condition of the concrete face through theoretical analysis and three-dimensional finite element seepage simulation,and establishes a piezometer monitoring model.Results indicate that the pore pressure at the foundation bottom increases with higher vertical joint permeability;piezometers placed at the foundation bottom near vertical joints are highly sensitive to deterioration in the lower part of the concrete face and along the full vertical joint,but respond relatively weakly to deterioration in the middle and upper parts.A further piezometer monitoring model considering water pressure,temperature,and time-dependent factors is established,and its predictions are generally consistent with field inspection results.The findings provide theoretical basis and technical support for piezometer layout and seepage condition assessment in projects without downstream measuring weirs.

Abstract:To meet the demand for water supply security,layered intakes are widely used in water conservancy engineering,and different types of intakes have their respective advantages and disadvantages.Taking the Meihuashan Reservoir Intake Project as a case study,this paper,based on the actual conditions of the region,innovated on the traditional tower-type layered intake and designed a new type of steel structure layered intake,which has been practically applied in Meihuashan Reservoir,Fujian Province.In the practical application of this intake project,analysis and summary were conducted on aspects such as layered height,well diameter selection,and wall thickness selection.Furthermore,the advantages and limitations of steel structure layered intakes were discussed,providing reference for the implementation of similar projects.

Abstract:Ensuring ecological flow in rivers and lakes is a key task for promoting ecological civilization construction in river basins and maintaining the health of rivers and lakes.To systematically guarantee the ecological flow(water volume)in the Lihe River Basin and strengthen the supervision of ecological flow,control sections for ecological flow were determined based on the characteristics of the Lihe River Basin.The average flow of the driest month over the past nearly ten years was used to analyze the natural runoff sequence at Chen'an Station from 2015 to 2024.At the same time,combined with approved ecological release flows from reservoirs and other relevant results,a reasonable and feasible ecological flow guarantee target was comprehensively determined.On this basis,schemes for scheduling,monitoring,early warning,and assessment were formulated to provide a basis for subsequent management of ecological flow in the Lihe River Basin and the implementation of water resource management mechanisms.

Abstract:To address issues such as insufficient ecological water for fish breeding periods and the flattening of hydrological processes during reservoir operation,a reservoir ecological operation model based on dynamic optimization strategy is developed.Key natural hydrological indicators are extracted using an iterative peak-seeking algorithm,and an"initial water level-operational water level-ecological response"elasticity relationship model is established.Under the premise of ensuring a water supply security rate of no less than 95％,the ecological pulse process is optimized.A case study is conducted for the Maiwan Reservoir on the Nandu River in Hainan Province.Results show that by regulating the ecological operating water level in June-July,the recurrence period of ecological pulses can be shortened from 2.5 years to 1 year,and the recurrence probability of ecological minor floods increases to 94.7％,effectively achieving coordination between water supply security and ecological needs.The study indicates that this method provides a technical pathway for reservoir ecological operation in river basins that balances hydrological process reconstruction with water resource security,offering favorable environmental benefits and engineering applicability.