Abstract:At present, industrial parks in Yangtze River Delta Region are facing multiple restrictions on water resources, water environment, water ecology and carbon emissions. The efficient utilization of water resources in the industrial parks is an important support for the high-quality development of the Yangtze River Delta Region, with the sewage resource utilization as a key way to achieve the goal. Based on the relevant research, practice and policy as well as the combination of the principles of comprehensive planning and systematic optimization, a strategy for the efficient utilization of water resources in the industrial parks was proposed with the five-level treatment and five-level reuse system as the core. Based on the “double carbon” strategy, a new idea for the efficient and low-carbon utilization of water resources in the industrial parks coupled with the sewage reuse, resource recovery, energy conservation and multi-energy complementary was proposed, which could promote the collaborative optimization of water conservation, pollution reduction and carbon reduction. It can also be found that the utilization of water resources in industrial parks in Yangtze River Delta Region should develop towards a low-carbon, regional, integrated and intelligent mode in the future.

Abstract:The Jiangsu section of the eastern route of the South-to-North Water Transfer (JE-SNWT) Project is prone to encounter the problem of spatiotemporal unbalanced water supply when transferring water to the water receiving area inside the province. In order to increase the comprehensive benefits of the project operation and improve the water supply balance of the project, this paper established a multi-objective optimization scheduling model with the minimum comprehensive water shortage rate in the water receiving area, the minimum total pumping volume of the pumping station, the minimum standard deviation of the water shortage rate in each period, and the minimum standard deviation of the water shortage rate in each water receiving area. The NSGA-Ⅲ algorithm was used to solve the optimization scheduling model, and the combination weighting approach based on the analytic hierarchy process and the TOPSIS method was used to optimize the scheme. The results showed that compared with the conventional scheduling scheme, the water supply rate of the water receiving area in Jiangsu section of the eastern route of the South-to-North Water Diversion Project in the optimized scheduling scheme was significantly improved. Under the 95%, 75% and 50% water frequency, the comprehensive water shortage rate decreased by 9.2%, 8.2% and 10.5%, respectively. The total pumping volume of the pumping station increased slightly by 21.6% and 15.4% at 95% and 75% inflow frequencies, and decreased significantly by 39.4% at 50% inflow frequency. The spatial and temporal balance of water supply in the water receiving area was obviously improved. The standard deviation of water shortage rate in each period and the standard deviation of water shortage rate in each water receiving area were significantly reduced under 95%, 75% and 50% water frequency. The distribution range of water shortage rate in different periods in different water receiving areas was more uniform and concentrated.

Abstract:To address the problem of calculating the combined design value of different regional flood under non-stationary conditions, this paper firstly constructs a varying-parameter Copula model based on the Copula function, which can consider the non-stationarity of the marginal distribution of different flood variables and the non-stationarity of their dependence structure. The non-stationary evolution characteristics of the joint distribution of floods in different regions over time are analyzed. Based on the equal reliability method and the conditional expectation combination method, a method for analyzing the regional composition of non-stationary design floods under changing environments is proposed, which can be used to calculate the design value combinations of different regional floods corresponding to a specified return period under non-stationary conditions. Based on the annual maximum 15-day flood volume (AM15FV) series at Cuntan and Yichang stations, the proposed method is used to analyze the change on design flood combinations among the Cuntan, Yichang and Cuntan-Yichang section. The results show that the AM15FV series at Cuntan and Yichang stations exhibits a decreasing trend, and their joint distribution of floods at Cuntan and Yichang stations varies with time. The design values of floods at Yichang station, Cuntan station and Cuntan-Yichang section corresponding to the specified return period tend to decrease with increasing design lifetime.

Abstract:The distributed hydrological model represented by the Grid Xin’anjiang model was used for flood simulation and forecasting in the Qinhuai River Basin. The spatiotemporal simulation is highly refined in the middle and upper reaches, but its application accuracy is limited in the downstream reaches. In this study, the Qianhancun (Qin) station is used as the node, the grid Xin’anjiang model is used to calculate the runoff in the upstream, the hydrodynamic model is used to simulate the water level of the tidal river section affected by the operation of the gate pump in the downstream, and the K -nearest neighbor ( K NN) algorithm and feedback method is adopted to correct the simulation results in real time. After the correction of the K NN method, the coefficient of certainty is 0.718-0.975, which meets the forecast accuracy requirements of Class B.

Abstract:In order to study the effect of wind fields during the water diversion period on the water transmission fields of Gaoyou Lake and Shaobo Lake in the inlet waterway of the Huaihe River, a two-dimensional wind flow numerical model of the study area was established by MIKE21 Flow Model, and the hydrodynamic changes and water quality renewal laws of the two lakes were analyzed under the action of prevailing wind fields. The results show that under the action of wind load, wind circulations of different structure are formed in Gaoyou Lake, and the flow direction and shape of the circulation are affected by the wind direction of the wind field; the upper and lower lakes of the Xinmintan control line are more significant areas of wind surge, and the higher the wind speed, the greater the water level variation, which may lead to a low design head of the pumping station project and insufficient water transfer power; the shear and drag effect of the wind field also has an impact on the renewal and replacement law of the water bodies in the lake area and the Yangtze River, and the renewal speed and degree of the water quality in the lake area are significantly improved under downwind conditions. Under headwind conditions, the degree of renewal of water quality in the lake area is decreased significantly.

Abstract:The purpose of this study is to quantitatively assess the influence of environmental factors on the spatial distribution of precipitation, to scientifically select the environmental factors for the statistical downscaling, and to address the problems of existing methods that cannot avoid the linearity assumption, ensure the immunity of multiple independent variables covariance and effectively explore the influence of factor interactions on the distribution of precipitation. By taking the Luanhe River basin as the research object, a quantitative analysis method based on GeoDetector is proposed and this study investigates the influence of environmental factors and their interactions on the spatial distribution of precipitation from three aspects: factor detection, interaction detection and ecological detection. Firstly, the factor detection results show that the influence of latitude, longitude, slope, slope direction, NDVI and elevation all exceed 1% in the annual, seasonal, monthly and tenday scales, and all these factors can directly affect the distribution of precipitation, among which latitude, longitude and elevation have the most significant influence on the distribution of precipitation. Secondly, the interaction detection results show that except for elevation-slope in February and NDVI-longitude in July, the other interactions are enhanced and the influences of all factors exceed 10%, which are more significant than that of single factor. Thirdly, the ecological detection results show that the influences of different environmental factors on the precipitation distribution are significantly different.

Abstract:The existing Technical Guidelines for Environmental Impact Assessment-Groundwater Environment (HJ 610-2016) is not clear enough in the identification of environmental impacts, current situation investigation and forecast evaluation in the groundwater environmental impact assessment of water conservancy and hydropower projects. Meanwhile, the prediction of the project’s impact on the groundwater flux and elevation is not covered by this guideline. Combined with the Dianzhong Water Diversion project, based on the characteristics analyzing of water conservancy projects, this paper elaborates the indicators to identify the impacts on groundwater environment in different project stages of water conservancy and hydropower projects, outlines the target types and work priorities of groundwater environment protection in different project stages, and summarizes the difficulties and main technologies of predicting the impacts on the groundwater environment. This paper indicates that the groundwater environmental protection should be carried out in combination with the scope of influence of on-site investigation, exploration, monitoring and engineering identification, and it is better to carry out numerical simulation research in areas with complex groundwater environments. Finally, the specific foothold of the groundwater environmental impact assessment for water conservancy and hydropower projects is given.

Abstract:To analyze the spatial and temporal variation of the leading edge of Ｓpartina alterniflora in Yancheng Wetland National Reserve, Jiangsu Province, an improved window of opportunity model based on Ｓpartina alterniflora reproduction mode and minimum disturbance-free time of remote sensing inversion was proposed, and the evolution pattern of Ｓpartina alterniflora leading edge and its driving mechanism were analyzed through the correlation analysis and mean absolute error to verify the accuracy of the model. The results showed that from 1998 to 2010, the front of Ｓpartina alterniflora advanced to the sea. From 2010 to 2020, the foreedge presents a W-shape trend of siltation-erosion-siltation-erosion-siltation from north to south. In 2020 and 2021, the Ｓpartina alterniflora front continued to erode and retreat in the north, remained relatively stable in the middle, and moved seaward in the south.

Abstract:Taking the eutrophic sediment as the research object, the indoor culture experiment was carried out. From the perspective of environmental micro-interface, the effects of common submerged plant Vallisneria natans on the migration and transformation of As(Ⅲ) and As(V) in interstitial water of sediment, the behavior of environmental micro-interface were explored, and the removal effect of Vallisneria natans on As in the sediment-water interface was accurately evaluated. The results showed that Vallisneria natans increased the penetration depth of dissolved oxygen in the sediment and decreased the pH, UV254, dissolved As, As(Ⅴ), As(Ⅲ),dissolved Fe(Ⅱ) and dissolved Mn; three forms of As (dissolved As, As(Ⅴ) and As(Ⅲ)) were significantly correlated with dissolved Mn and UV254, and were poorly correlated with dissolved Fe(Ⅱ); the removal effect of As(Ⅲ) (69.5%) was better than that of As(V) (64.6%). The research can provide a scientific basis for the control of heavy metal pollution in sediments and the water ecological restoration.

Abstract:In view of the research status and main problems of artificial island construction in the underwater tunnel engineering, this study collects typical engineering cases of artificial island in the underwater tunnel projects, and summarizes key construction technologies of foundation treatment, cofferdam construction and fill reinforcement of artificial islands. Two main problems in the construction process of underwater tunnel artificial islands were proposed: firstly, the combination of schemes and process optimization for the soft foundation treatment and the soil filling reinforcement; secondly, the utilization rate of dredged soil in the construction of artificial islands in China was relatively low. Based on the existing construction technology of artificial islands, the future development direction of artificial island construction is to achieve the green and rapid island building through prefabricated artificial island components.

Abstract:A multi-objective optimization function based on the schedule-cost-quality-carbon emission is constructed according to the improvement path of optimization of hydraulic tunnel construction machine fleet and carbon emission reduction under the constraint of carbon emission. A particle swarm optimization (PSO) after the improvement of simulated annealing (SA) is selected and the carbon emission per working unit of construction machines is calculated with the reference to the construction machine-working cost quota and IPCC guidelines. By incorporating the new mechanical configuration into carbon emission factors, an evaluation system with duration, cost, quality and carbon emission as the primary indicators and 14 secondary indicators is established and the optimization model of fleet configuration considering carbon emissions is built. The optimization of construction machine fleet configuration under multi-objective constraints was carried out in the No. 3 branch of Wanjia tunnel of the Dianzhong water diversion project. The results show that the established target preference weight evaluation system of hydraulic tunnel construction fleet configuration can comprehensively consider the impact of construction fleets on the environment. The main carbon emission sources of the construction machine fleet are tunnel multifunctional work cart and concrete mixing plant, and the carbon emission(CO2) reaches 1 000.kg/machine working unit. The improved particle algorithm can effectively enhance the search capability of global optimization and identify the key risk sources of carbon emission in the construction machinery. Finally, the model optimization results are consistent with the on-site construction situation, which verifies the feasibility of the model.

Abstract:In order to solve the problem that the optimal design of the gravity dam takes the section size as the only design variable and lacks consideration of the influence of material properties on the optimal design of the gravity dam, this paper studies the multi-objective optimization method of gravity dam comprehensively considering the economy and seismic safety. Firstly, the multi-factor evaluation system with comprehensive economy and safety indicators is put forward; secondly, based on the ABAQUS software, the static and dynamic model of the gravity dam are analyzed, and then the variable-weight efficiency coefficient method is used for the quantitative evaluation based on the calculation results of finite element analysis; finally, the XGBoost-PSO algorithm is used for optimum seeking to obtain the final optimization scheme. The validation results of real projects show that the economy and seismic safety indexes of the optimized scheme have been significantly improved compared with the initial scheme. Compared with the traditional single-objective optimization method, the economic and safety indexes of the multi-objective optimization is more suitable for gravity dam projects with high seismic safety requirements.

Abstract:In order to study the initiation law of consolidated cohesive sediments in Poyang Lake, the incipient velocity of cohesive fine sediment under different deposition duration and water depth was measured in a glass flume. Through a series of experiments on incipient motions after the deposition and consolidation, the variation laws of incipient velocity affected by the deposition duration and the water depth were found. According to the test data, the empirical formulas for the incipient motion, deposition duration and water depth of Poyang Lake sediment were obtained by fitting process, and the test results were compared with the calculation results of empirical formulas for the sediment incipient motion in the relevant literature. The results show that the consolidation degree of cohesive sediments in Poyang Lake went through four stages as the duration of sedimentation increases: the new sedimentation, the initial consolidation, the accelerated consolidation, and the stable consolidation. There was a positive correlation between the incipient velocity and the water depth. Meanwhile, the incipient velocity of sediment deposited for one-day was close to the result calculated by the empirical formula, the longer the deposition duration, the greater the difference between test results and empirical formula calculation results.

Abstract:In view of the fact that the sealing rubber is prone to edge warping under compression, which seriously affects the waterproof effect of segment joint, based on the grid mapping technology in ABAQUS/standard, the compression numerical model of hyperelastic rubber gasket is established, and the numerical simulation of axial compression is carried out for 7 kinds of gaskets with different opening shapes, opening rates and hole arrangement. The results show that in the whole process of compression simulation, the stress on the contact surface of elastic gasket meets the multi peak W distribution law of large at both ends and small in the middle; compared with other types of gasket, the maximum average contact stress of the gasket with closed hole of rounded triangle is increased by 86.8%; compared with other types of gaskets with different opening rate, the maximum average contact stress of the gasket with the opening rate of 0.294 increases by 92.6%; the maximum average contact stress of the gasket arranged with staggered holes is 25.2% higher than that of the gasket arranged with opposite holes; compared with the change of open hole configuration, the change of closed hole configuration is more sensitive to the contact stress. The maximum difference of average contact stress between two simulations under the same working condition is 85.2%.

Abstract:Consolidated drained triaxial shear tests, mercury injection tests and electron microscope scanning tests were conducted in this study to investigate the effects of the water content fluctuation on the mechanical properties of soil from the Gongming road and the meso-mechanism of deterioration. Based on the Duncan-Chang model, an empirical constitutive model of the subgrade soil was proposed to consider the effect of water content fluctuation. The results show that the development of pores, macropores and micro-cracks leads to the transformation of soil shear stress-strain relationship from the strain-softening to the strain-hardening, the improvement of soil shear shrinkage characteristics and the decrease of shear strength. With the increase of moisture content fluctuation, the shear shrinkage characteristics of the sample become more obvious, but the shear strength decreases. The calculation results of the proposed constitutive model for the subgrade soil are in good agreement with the test results, which proves the effectiveness and applicability of the model.

Abstract:Based on the FLAC3D finite difference software, the dynamic reliability of seismic liquefaction response of sandy soil foundation covered with clay layer was studied, and a plane-strain model of clay-sandy soil foundation was established. By simulating the spatial variability of soil shear modulus, the area of liquefaction zone, excess pore water pressure and surface displacement were evaluated using the Monte Carlo simulation method and the generated non-Gaussian random field. The influence of different coefficient of variation (COV) on the reliability of seismic dynamic liquefaction of foundation was studied. The results show that the larger the COV of shear modulus, the more difficult it is to reduce the liquefaction range and the more dispersed the distribution range of peak liquefaction range; the horizontal displacement and maximum differential settlement of the surface increase with the increase of COV of shear modulus.

Abstract:Based on the field test of horizontal loading characteristics of a single pile in an offshore wind farm, the load-displacement response, pile deflection and bending moment of a 2.4 m large-diameter steel-pipe pile in deep soft clay groundsill were studied. The applicability of m method, p-y curve and hyperbolic curve recommended by the API specification for soft clay foundation is discussed. Numerical models were established to analyze the contribution factors of horizontal bearing capacity of single pile foundations with different diameters. The results showed that the initial stiffness of pile and soil resistance in the shallow soil p-y curve from the API specification method and the hyperbolic is larger, and the hyperbolic under a certain depth can better predict the changing relationship of soil reaction force with displacement. The calculated horizontal displacement of m method and hyperbola is smaller than measured values, tending to be unsafe results, while the calculated results of the API specification method are larger compared with the measured values, more conservative. With the increase of pile diameter, the contribution of lateral friction and foundation resistance to the horizontal bearing capacity of single pile foundation will also increase, and the p-y curve method will seriously underestimate the horizontal bearing capacity of single pile.

Abstract:In order to study the unloading mechanical properties of rock under different seepage pressures, this paper selects the sandstone as the research object, conducts triaxial unloading tests under different seepage pressures and different stress paths, and compares the results with conventional triaxial tests. The rock strength characteristics under different stress paths are compared, and the effect of seepage pressure on the rock deformation and strength parameters is further analyzed. The test results show that the increase of seepage pressure will weaken the rock strength, the peak strength of rock decreases with the increase of seepage pressure, and the axial deformation increases with the increase of seepage pressure. Aiming at two different unloading stress paths, under the condition of constant axial pressure and unloading confining pressure, the cohesion of rock keeps decreasing and the internal friction angle increases; under the condition of increasing axial pressure and unloading confining pressure, the cohesion of rock keeps increasing and the internal friction angle decreases.

Abstract:This paper collected relevant research literatures on the smart water conservancy in the databases of China National Knowledge Infrastructure (CNKI) and Web of Science (WOS) from 2000 to 2021. By using the VOSviewer, CiteSpace and other software, this study built various knowledge maps for the time series distribution of literatures in the field of smart water conservancy, publishing institutions, and evolution of research hotspots, to analyze the current progress of smart water conservancy research. The results show that the literature amount of smart water conservancy is increasing year by year, but there is a significant gap between the CNKI database and the WOS database, and core research institutions have been formed in the field of smart water conservancy making important contributions to the frontier development. The CNKI database focuses on the construction of digital watershed and smart water conservancy framework by basin as a unit, while the WOS database focuses on researches from the perspective of geography and earth. Both of them build the platforms for smart water conservancy based on the Internet of Things and deep learning.

Abstract:By introducing the detection mode of UAV-mounted infrared and visible dual-light imaging, the non-destructive and fast detection technique of earth-rock embankment leakage is proposed for the more intuitive and efficient leakage detection of earth-rock embankments. The altitude setting of a UAV is discussed considering the imaging effect of the dual light equipment. The implementation procedure of using UAV-mounted infrared and visible dual-light imaging to detect the leakage of earth-rock embankment project is proposed, and the site detection tests of actual project are carried out under various weather conditions. The results of the tests reveal that this detection method can effectively discover the slope leakage and piping in the earth-rock embankment, and it is simple, efficient, and intuitive, with good performance at night. This detection method is excellent for the leakage inspection of large-volume and long-linear embankment projects. The limitations of this method in the practical engineering such as being affected by complex ground conditions, temperature changes, and surface sensing are also discussed.

Abstract:For realizing the intelligent and rapid identification of the parameters of temperature control of mass concrete during the construction, and improving the feedback and prediction accuracy of the model of intelligent temperature control system, a set of intelligent algorithms are developed to identify and transform the original data of various temperature control parameters collected based on the internet of things technology. As for key parameters for the concrete temperature control during the construction period, such as the concrete placement temperature, the start time, the maximum temperature, the temperature difference between the interior and exterior concrete, the start and end time of water cooling and the surface insulation, the judgment logic of the corresponding recognition task is given and the corresponding program is written combined with engineering experience. Then according to the data of several practical projects, the method and codes are validated, and the accuracy is analyzed. Results show that the proposed algorithms have a good performance for the identification, and can be used for practical projects, so as to benefit the automation, intelligentization, rapidity and accuracy of the collection of temperature control parameters.