Abstract:Bends of flood channels and areas near diversion projects are prone to varying degrees of erosion and siltation after floods.The state has invested massive funds to support post-disaster reconstruction.Analysis of post-disaster channel erosion and siltation reveals that some river sections show inner bank erosion and outer bank deposition,some sections experience channel bending deformation and elevated flood water levels due to erosion and bank collapse,and some sections form vortices and scour pits due to sudden flow changes,even causing uneven inlet gate flow distribution.This paper considers that the sudden changes in flow velocity and direction caused by deflected flow in the channel,along with changes in river sediment concentration,are the main influencing factors for the formation of erosion and siltation phenomena in flood channels.On this basis,countermeasures and suggestions for preventing erosion and siltation disasters in flood channels and control projects from the source are proposed.

Abstract:With the intelligent transformation of water resources management,the scientific determination and precise monitoring of ecological flow have become crucial to ensuring river and lake ecological security.Taking Huangcaoba Reservoir in Yunnan Province as the research object,this paper systematically investigates ecological flow determination and monitoring informatization application,with comprehensive consideration of aquatic ecosystem stability,water environment quality,and downstream domestic and production water demands.Through multiple-scheme comparison and envelope calculation using the Tennant method,R2-Cross method,ecological hydraulic method,and 7Q10 method,the results indicate that,to meet hydraulic habitat standards in different periods,the recommended ecological flow is 1.58 m³/s for the wet season(June-November,accounting for 30%of the multi-year average flow at the dam site)and 0.79 m³/s for the dry season(December-May of the following year,accounting for 15%of the multi-year average flow at the dam site).Aiming at the difficulty of precise reservoir dispatching according to natural inflow,a monitoring system covering information perception,communication network,and application management platform is established.This system integrates technologies including radar velocimeter online monitoring,Beidou satellite communication,and video surveillance,realizing real-time monitoring,compliance analysis,and abnormal alarm functions for discharged flow.The research findings not only establish scientific discharge standards,but also achieve closed-loop control of discharged flow through informatization means,providing strong support for scientific management of basin ecological flow and optimal reservoir dispatching.

Abstract:Sand and gravel materials are one of the main materials for water conservancy projects,and their accurate unit price calculation is key to investment control in project budget preparation.To study the pricing of sand and gravel materials in hub projects,this paper takes a reservoir project in Hunan Province as a practical case and conducts a systematic calculation study on the comprehensive unit price of sand and gravel materials.Strictly following the quota pricing specifications for water conservancy projects,and combining with actual working conditions of on-site extraction,processing,transportation,and loss of the project,the unit price of sand and gravel materials is explicitly broken down into cost components including overburden removal,raw material extraction and transportation,crushing,and finished product transportation.Through the process unit price method,the unit price calculation of sand and gravel materials for this reservoir project is calculated.Finally,the calculated unit price of manually self-extracted sand and gravel is compared with the direct purchase price from material yards to better control project investment.The calculation method and results of this case study can serve as a reference for the unit price calculation of sand and gravel materials and project cost control in similar water conservancy hub projects.

Abstract:During the excavation of the spillway slope at Yazhai Reservoir,deformation occurred in the high slope on the left side.Combined with the site excavation exposure and engineering investigation data,the slope was identified as a deep overburden soil slope developed in a"U"-shaped ancient gully.Through comprehensive analysis of the causes of slope deformation,this paper proposes the use of anti-slide piles for treatment.After project implementation,slope deformation was controlled and safety hazards were addressed,thereby ensuring smooth construction progress and safe operation after completion.

Abstract:At the project proposal and feasibility study stages,reasonably predicting project financial benefits according to market demand,formulating project financing schemes,calculating the loan amount the project can bear and the required capital,and recommending project water price,can provide basis for decision-making by the state,local governments,and relevant investors through scientific and reasonable financial feasibility evaluation.Taking the Jiabai Reservoir Project in Guizhou Province as an example,this paper conducted engineering financial cost estimation and allocation,analyzed the current water price,cost water price,and affordable water price in the water-receiving area,formulated loan schemes,calculated the loan capacity of each scheme,and preliminarily proposed a water price suitable for the sound operation of Jiabai Reservoir,aiming to provide reference for loan capacity calculation of similar reservoir projects.

Abstract:Reconstruction projects of irrigation-drainage dual-purpose pumping stations usually involve dike-crossing construction,which will adversely affect dike safety and river flood discharge.To systematically identify key technical points for flood control assessment of such projects,this paper takes the Chaodong Pumping Station Renovation and Reconstruction Project on the left dike of Chaobai New River as an example.Under the 50-year flood control standard,the design water level is calculated using the steady non-uniform flow method,local scour depth under drainage and flood discharge conditions are computed using the Zhang Ruijin formula,and dike seepage and slope stability analyses are carried out.Meanwhile,the compliance of the project with relevant planning and risks including dike breaking during construction period,foundation pit excavation,and flood emergency rescue are assessed.The results indicate that no scour occurs in the approach channel under drainage conditions,while the scour depth on the floodplain under flood discharge conditions is 1.08 m,requiring rigid protection measures.Dike stability meets code requirements of relevant specifications.With the implementation of special construction schemes,deformation monitoring,and dewatering control measures,the impact of the project on dike and flood emergency rescue is controllable.This analysis case can provide technical references for flood control assessment of similar irrigation-drainage pumping station projects involving river construction.

Abstract:Concrete erosion deterioration under high sulfate environments is relatively severe.This paper explores the effects of different addition methods of polyester fiber(PF),basalt fiber(BF),and U-type expansive agent(UEA)on the sulfate erosion resistance of concrete by designing indoor sulfate immersion-wet-dry cycle tests.The changes in concrete specimen appearance,mass loss,and pore structure parameters are analyzed,and the sulfate erosion resistance characteristics of different specimens under different erosion cycles are evaluated to reveal the deterioration laws under wet-dry cycle conditions.The erosion mechanism of sulfate on crack-resistant concrete is analyzed from both macro and micro perspectives,and the mechanism by which fiber-UEA co-mixing improves the sulfate erosion resistance of concrete is elucidated.The results show that both single fiber addition and co-mixing of fiber with expansive agent can improve the macro and micro performance of concrete under sulfate wet-dry cycle conditions.Concrete under sulfate wet-dry cycle action is mainly subjected to two types of damage:physical erosion and chemical erosion.Co-mixing of fiber and UEA can significantly improve the erosion resistance of concrete,and its sulfate erosion resistance is superior to that of plain concrete and single-fiber concrete.

Abstract:Flash floods are the leading cause of fatal natural disasters in Zhejiang Province,China.Traditional monitoring devices and warning methods have deficiencies both on feedback mechanisms and efficiency of information transmission.Based on the practical needs of flash flood prevention in Zhejiang,this study develops multiple warning approaches,including public alerts,emergency radio broadcasting,and linked warning on upstream-downstream from on-site equipment,building upon the existing multi-stage warning system.Furthermore,a closed-loop management mechanism has been developed through Zhejiang DingTalk platform,telephone calls,and household alarm devices.These integrated warning approaches and management mechanism are design to deliver warning information rapidly and effectively to the affected populations.This study can provide practical suggestions for flash flood disaster prevention on improving warning efficiency and promoting the safety of lives and property.

Abstract:In 2023-2024,Shandong Province completed a review of province-wide river and lake list,sort out the list of rivers and lakes in the water census list,as well as the list of rivers with a watershed area of less than 50km2 and lakes with a surface area of less than 1km2 that have management tasks.This paper comprehensively summarizes the results of Shandong Province's river and lake review,briefly explains the criteria of Shandong Province's river and lake review,and refines the issues of river source,estuary,stem-branch relationship,and classification of water bodies,and conducts exploratory reflections on the existing problems and deficiencies from the perspectives of data acquisition,experience,and introduction of the standard.

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:At the preliminary planning and design stage of irrigation district,optimizing construction schemes from social,economic,environmental,and technical perspectives and reasonably determining project layout can better avoid investment risks and increase investment benefits.Taking the newly constructed Wenyangtian Irrigation District in Shandong Province as an example,this paper analyzed the scope and area of the irrigation district,summarized existing problems in current irrigation,and used water from the Dawen River,Caohe River,and reservoirs within the irrigation district as water sources to formulate three project layout schemes.Comparative analysis was conducted from aspects of land occupation and investment,and a reasonable project layout was proposed.The results indicate that areas with groundwater well depths above 80 m should be taken as the irrigation scope;meanwhile,considering irrigation economy,the irrigation elevation should not exceed 130 m;the designed irrigation area of the district is 6,680 hm2;the scheme with dispersed water intake and the Bian'an Pumping Station located in the middle of the irrigation area occupies less land,has the minimum total investment,and the lowest annual operation cost,and can be recommended as the preferred scheme.The research findings can lay a foundation for determining the construction content of the irrigation district,and simultaneously provide important guidance for newly constructed irrigation districts currently being developed in China.

Abstract:The reservoir in the Yellow River Diversion Plain in Binzhou City is an important drinking water source,and the rate of total nitrogen exceeding the standard has remained high for many years.The phosphorus-containing substances in the Yellow River diversion water are rich and absorbed in sediment,and the total phosphorus content in the overlying water of the reservoir is low,which effectively curbed the eutrophication process of the reservoir to some extent.However,in recent years,there have been a large number of regional algae blooms in reservoirs in summer.Through the analogy analysis of similar reservoirs in the province,this paper concludes that there are ecological risks such as accelerated eutrophication,abnormal algae reproduction and unhealthy development of water ecosystem in severe siltation,low water level operation and hot summer,which further affect the water supply quality and should be paid great attention to.

Abstract:The slope at the exit of No.1 tunnel of the main canal in Niululing Irrigation District Project in Hainan Province is characterized by steep gradient and significant differences in weathering degree of rock and soil mass,and its stability directly affects the operation safety of the tunnel and the overall benefits of the irrigation district project.To clarify the stability state of this slope and formulate a reasonable reinforcement scheme,this paper takes the typical 1-1 section at the exit of No.1 tunnel as the research object,and employs GeoStudio software to comparatively analyze the safety factors of the slope under unsupported and supported conditions.The results indicate that the safety factor of the unsupported slope under normal operating conditions is only 0.867,which does not meet the code requirements;after reinforcement with the combined support of steel pipe piles,frame beams,and anchor cables,the safety factor under normal operating conditions reaches 1.236,and that under abnormal operating conditions is 1.126,both meeting the relevant code requirements.The research findings can provide theoretical basis and technical support for the engineering design,construction,and long-term safe operation of tunnel exit slopes.

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: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:Under the background of global climate change and urbanization,combined sewer overflow pollution and waterlogging during flood seasons have become critical bottlenecks constraining urban resilience enhancement.The central urban area of Tianjin,as a northern coastal urban area located at the confluence of nine rivers,retains 21.88 km² of combined sewer system areas,with existing facilities having insufficient storage capacity and pollution not being fundamentally resolved.Taking the Tianjin Nanjing Road Storage Tank Project as a case study,this paper examined the issue from three perspectives of hydrology,environment,and urban development,analyzed the synergy among four dimensions of infrastructure,policy,space,and system,clarified that key measures can amplify effects and form virtuous cycles,highlighted the core role of large-scale drainage storage tanks in enhancing urban flood resilience,provided replicable resilience enhancement paths for similar cities with high combined sewer system proportions,land scarcity,and complex hydrological conditions,and enriched the theory and practice paradigms of resilient city construction.

Abstract:To address the incompatibility between the original characteristic water levels and the current flood control system in the Dongdian,Wen'anwa,and Jiakouwa flood storage and detention areas within the Daqing River basin,this paper re-evaluates the current terrain,hydrological boundaries,and tailrace discharge capacities.A one-and two-dimensional coupled flood routing model for the middle and lower reaches of the Daqing River system is established.Under the control condition of a 100-year return period flood,adjustments to the characteristic water levels of the Xisanwa flood storage and detention areas are investigated.The results indicate that the controlled operational water level at Diliupu of Dongdian should be adjusted from 6.44 m to 5.9 m,and the characteristic water levels in Wen'anwa and Jiakouwa should be uniformly adjusted from 5.94 m to 5.5 m.Following these adjustments,the designed detention storage capacity of the Xisanwa flood storage and detention areas is 6.26 billion m³,which still exceeds the original planned storage capacity of 6.066 billion m³ after excluding safety zones and protected areas.The adjustment of characteristic water levels ensures that the functions of the flood storage and detention areas remain unchanged and their storage capacities are not reduced.The findings of this paper have been applied in the flood control planning of the Haihe River basin.

Abstract:From July 28 to August 1,2023,a heavy rainfall process occurred in the entire Haihe River Basin,with a cumulative surface rainfall of 155.3mm and a total rainfall of 49.4 billion cubic meters,exceeding the"August 96"watershed flood of the Haihe River and the strongest rainfall in the Haihe River Basin since 1963.This article takes typical sections of the Dashi River,Juma River,and Yongding River in Beijing that have been severely affected by floods as representatives.Based on preliminary investigations of flood disasters,the problems in river and lake management are analyzed,and suggestions for further strengthening river and lake management are proposed.

Abstract:To better plan the construction of the digital twin water conservancy system for the Zhangwei River and accelerate the beneficial application of construction achievements,the Zhangweinan Canal Administration Bureau,starting from the intrinsic demands of its own business development,sorted out management pain points of core businesses including river basin flood control and water withdrawal management.Based on the existing overall framework of the digital twin Zhangwei River platform,through multi-source heterogeneous water conservancy data fusion and global business situation perception on one screen,intelligent water regime threshold diagnosis and multi-level early warning linkage,intelligent statistics and analysis of water conservancy monitoring data,high-performance vector map rendering,and other collaborative technological innovations,the administration developed and deployed the intelligent collaborative platform—the digital twin Zhangwei River business panorama,empowering various river basin water conservancy comprehensive governance and management businesses with digital intelligence.

Abstract:The concrete construction volume of the Shizhen Reservoir gravity dam is large,the project is of great importance,and the requirements concrete pouring construction are high.In order to ensure the quality of concrete construction,the temperature control measures for concrete pouring construction are analyzed.The numerical simulation method is used analyze the temperature control effect under different cold water pipe arrangement spacing,and the temperature control effect of each scheme is as follows:0.5 m spacing>1 m spacing>2 m spacing>no water,but the 0.5 m spacing causes a large tensile stress on the concrete surface,which may lead cracks on the concrete surface,so it is recommended to use 1 m spacing to arrange the cold water pipe during the construction process.