Under the condition of large water level variation in inland rivers， the realization of adaptive water level rise and fall of floating facilities without external drive is still an unsolved technical challenge. In view of the steep rise and fall of mountain rivers， this paper proposes a new type of inland river floating facility equipped with self-driven mutual coupling tensioning mooring device. Based on the principle of static equilibrium， this paper established a mechanical model， deduced the principle of driving force application in the lifting process of floating facilities， and analyzed the main factors affecting the stable lifting of the floating body. A 1∶40 scale physical model of the new inland floating facility was designed， and an automatic lifting test system of the floating facility was constructed. Four groups of water level lifting and lowering conditions with different rates were carried out， and test parameters such as water level height， vertical displacement of the platform， bollard force， and horizontal offset of the platform were tested. The results show that： ① During the lifting and lowering process of the floating facility， the floating body is affected by the change of vertical bollard force， and the vertical displacement and water level change cannot be completely synchronized， but the sensitivity k of following the water level variation is greater than 0.96， reflecting the excellent adaptive lifting characteristics of the floating facility. ② The increase of the water level lifting rate leads to an increase in the variance of the bollard force， but the mean value of the bollard force under different rates of rising and falling conditions is basically the same， with the rising mean value of about 3 370 kN and the falling mean value of about 1 850 kN， which indicates the high efficiency of the self-propelled and mutual-coupled tensioning mooring device in the adjustment of the cable force. ③ The maximum horizontal deflection of the floating body under different rates of lifting and lowering does not exceed 2% of the amplitude of the variable water level， which proves that the mooring device has a high positioning accuracy. The study shows that the proposed self-driven mutual coupling tensioning mooring device can effectively realize the autonomous lifting and lowering of floating facilities without external driving force， and maintain good positioning effect and stability.

While reservoir dams have made significant contributions to flood control， power generation， navigation， and other areas， they also pose potential safety hazards， such as the risk of dam failure. With the increasing frequency of extreme weather events， the risk of dam failure has grown， making dam breach flood analysis especially important. The simulation of flood evolution in the event of a dam breach is a critical method for risk analysis. Previous studies have generally used the broad-crested weir formula for simulating breach flow， which does not account for the influence of factors such as downstream water depth and the development process of the breach. To fully consider these factors， this study proposes a two-dimensional dam breach flood evolution coupled breach model based on the summary of prior research results. This model conceptualizes the development process of the breach shape and integrates reservoir water balance analysis with two-dimensional hydrodynamic computations to simulate both the breach formation process and the downstream flood evolution. It enables the automatic calculation of breach flow and real-time exchange of data with the downstream flood evolution. The model is validated using empirical formulas and experimental data， with the simulation results showing good agreement with both the empirical formulas and experimental observations， confirming the reliability of the model. The model is then applied to simulate the dam break flood of a specific reservoir. Based on the simulation results， the processes of flood flow variation， reservoir water level changes， flood inundation， and the evolution of the flood at key points and typical cross-sections are analyzed. The results demonstrate that the simulated outcomes of the proposed model are reasonable， consistent with the actual physical processes， and suitable for application in dam break flood studies.

Geological disasters such as landslides and mudslides occur frequently in southwestern mountainous areas in China under heavy rainfall， and geological disasters in the early stage is always accompanied by sediment transport and hydraulic erosion， and soil and water erosion problems have always occupied an important position in the field of geology and disaster research. This paper adopts the method of artificial simulation of natural rainfall， conducts rainfall erosion test for different slopes and subsurface conditions under heavy rainfall conditions， and analyzes the change of measured sand transport in the rainfall erosion process. It then compares the result of sand transport with the amount of sand production obtained by the camera capturing the surface morphology， analyzes the change of erosion mode in the process of rainfall erosion， as well as the influence of the subsurface conditions on the characteristics of rainfall erosion， and investigates the mechanism of sediment erosion of slopes， laying a foundation for subsequent research， and providing reference for the prevention and control of soil erosion and geologic disasters. The main conclusions obtained in this paper are： ① The development of slope erosion mode is jointly influenced by the gradation of underlayment and slope. As the percentage of fine sand in the underlayment decreases and the slope increases， the time required for slope flow production decreases， and the slope has a greater influence on the shortening of the time for flow production than the gradation. ② In terms of sand transport intensity， the slope has less influence than gradation of underlayment. Under the same slope condition， the peak difference of sand transport affected by gradation is 60 g/min， and under the same gradation condition， the peak difference of sand transport affected by slope is 40 g/min. The intensity of sand transport on the slope surface shows a gradual decrease in the overall trend， and the change of sand transport over time on slopes of more than 15° under the current experimental condition is less influenced by the slope. ③ The sediment transport capacity of the slope surface under the present experimental conditions is strong， and the sediment transport ratio SDR of the slope surface under different sub-bedding conditions are all between 86.6% and 94.32%， and the slope surface is weak in the ability of sediment interception and deposition. The magnitude of the sediment delivery ratio is more related to whether the slope surface generates slope flow or not. The sediment delivery ratio is larger when the slope surface generates obvious slope flow， and the sediment delivery ratio increases with the increase of the slope gradient. The effect of grade on sediment transport ratio is reflected in the fact that in the case of increasing the proportion of fine sand component， the sediment transport ratio will show a corresponding trend of increasing.

The bed scour of natural branched channels can change according to the density and distribution of vegetation， flow， and the shape and location of the center beach， which in turn can lead to changes in the flow characteristics and diversion of the branched channel. In order to investigate the influence of vegetation on the flow characteristics of branched channels， a dynamic bed test of straight asymmetric branched flume was designed to simulate the growth of vegetation in natural branched channels by taking the vegetation coverage and flow rate as test variables， and the water surface line， flow rate and diversion ratio of straight branched channels were investigated. The results showed that the water surface line of the main branch decreased when vegetation grew in the branch， and the degree of decrease was positively correlated with the vegetation coverage compared with the no-vegetation condition. The water surface line of the branch was affected by both flow rate and vegetation coverage rate. At low flow rate， the water surface line of the branch was similar to that of the main branch； at high flow rate， the presence of vegetation enhanced the water surface line of the upstream of the branch， and the magnitude of the enhancement increased slightly with the increase of vegetation cover； on the other hand， in the downstream of the branch， the vegetation caused the water surface line to decrease. In terms of flow velocity， vegetation in the branch caused a small increase in flow velocity in the main branch and a significant decrease in flow velocity in the branch， but flow velocity in both branches increased with increasing vegetation coverage. For changes in diversion ratios， vegetation deployment in the branch caused a decrease in the diversion ratio of the branch and an increase in the diversion ratio of the main branch， but the magnitude of vegetation cover had little effect on the diversion ratios of the two branch channels.

The morphology of river channels is crucial in the management and conservation of river systems. A thorough understanding of the evolutionary processes of river morphology significantly enhances the ability to manage and protect these vital watercourses. This study focuses on the morphological characteristics of the channel between Yichang and Datong in the middle and lower reaches of the Yangtze River， using Landsat remote sensing imagery from 1988 to 2023. Key morphological indicators， including the area of river islands， average water surface width， meander ratio， and bifurcation coefficient， were assessed. By incorporating coefficients of variation， change rates， and recovery rates， the study analyzed the sensitivity and recoverability of the river's morphological adjustments in response to changing environmental conditions. The results indicate several important trends in the morphological evolution of the Yangtze River： ① From 1988 to 2002， the water and sediment conditions in the middle and lower reaches of the Yangtze River were relatively balanced， with a notable 11% increase in river island area and an 8% decrease in average water surface width. However， following the operation of the Three Gorges Reservoir and upstream cascade reservoirs after 2003， substantial changes in water and sediment conditions occurred. As a result， the area of river islands decreased by 9%， while the average river width increased by 6%， with minor changes in sinuosity and bifurcation coefficient. ② The river island area was the most sensitive morphological indicator during the study period. Significant differences were found in the sensitivity of morphological indicators before and after the construction of the Three Gorges Reservoir， indicating its substantial impact on river morphology. ③ Under the regulation of the Three Gorges Reservoir， the average annual rate of morphological change decreased from 1% before the construction of the reservoir to 0.33% afterward. The rate of channel morphological evolution decelerated， reflecting the long-term impact of the reservoir on the river system. From 2003 to 2005， the rate of morphological change was 12%， largely due to the continuous erosion of the river channel. However， as erosion stabilized， the recovery rate declined from 52% in 2005 to 34% by 2023. In summary， the evolution of river morphology in the middle and lower reaches of the Yangtze River has been profoundly influenced by human activities， including the construction of the Three Gorges Reservoir and upstream cascade reservoirs， riverbank protection works， and sand mining.

To investigate the effect of solidified soil protection range on scour characteristics of monopile foundation， this study used Flow-3D software to construct two models： a solidified soil prevention model and a solidified soil repair model， considering the presence or absence of scour pits around the pile.Under various conditions of prevention and repair ranges， a series of calculations and analyses were conducted to examine the changes in the protective effects of solidified soil.The results show that solidified soil protection can greatly reduce the sediment scour depth and scour pit area around the pile. It can also change the scour morphology and location， thus improving local scour conditions. The protection effect increases non-linearly with the expansion of the range.It’s recommended that the optimal solidified soil protection range for monopile foundations be twice the pile diameter.

Developing a realistic and feasible water allocation solution is the key to resolving water competition conflicts of the trans-administrative rivers under water scarcity. The demand ratio method has been widely used in water management practice due to its simple calculation principle， transparent water distribution ratio， and easily operational solution. However， this method only considers regional water demand as the sole influencing factor for water allocation， without paying attention to the influence of other characteristic factors， and may result in a certain degree of one-sidedness in the allocation results. In response to the limitations of the demand ratio allocation method in resolving water allocation conflicts of the trans-administrative rivers， this study proposed a water allocation index system considering principles such as water contribution， social equity， respect for current situation， water use efficiency， and ecological environment sustainability. And an asymmetric demand proportion model for inter-administrative river water allocation was proposed by combining the information entropy-CRITIC method and bankruptcy game theory. Subsequently， taking the Hanjiang River Basin of Hubei Province as the practical case， it conducted study on trans-administrative river water allocation under two supply and demand scenarios using the basic data including distributable water volume， water demand， average annual runoff， water user population size， current water consumption， GDP， ecological environment flow， and sewage discharge as model inputs. The results showed that compared with the demand ratio allocation method， because the proposed model comprehensively considered the differences in water contribution， water use population， water demand， water use efficiency， and ecological environment among agents， the water allocation satisfactions of Shiyan and Xiangyang cities with higher water demand and larger weight coefficients both increased by 2.39% in dry year， while that of Suizhou and Qianjiang cities with lower water demand and smaller weight coefficients decreased by 47.25% and 33.54%， respectively； In the extremely dry year， the water allocation satisfaction obtained by Shiyan and Xiangyang cities raised by 32.09% and 23.10% respectively， whereas Suizhou and Qianjiang cities decreased by 46.71% and 40.94% respectively. The proposed model can highlight the differences in various influencing factors of the agents in water allocation， and ensure that the principle of individual rationality is not undermined. It has high application value in solving water allocation conflicts of the trans-administrative rivers.

Accurate water quantity estimation is the foundation for the rational development and utilization of water resources in a watershed. It is mainly based on the main stream runoff data and uses the fitting line method for hydrological frequency analysis. To ensure the accuracy and rationality of the calculation of the design value of available water supply， it is generally necessary to consider different distribution curves and fitting line rules. At the same time， to consider the differences in water demand in different regions， the regional composition of available water supply cannot be ignored. This article establishes a watershed available water supply calculation model based on genetic algorithm and Copula function. The model selects three different distribution lines， namely Gamma， P-III， and log normal， with two parameters. Based on the minimum sum of squares of relative deviations criterion and the minimum root mean square error criterion， the genetic algorithm is used to optimize and solve the optimal distribution line of water supply for each tributary in the watershed. Based on this， a joint distribution function of available water supply for downstream design sections of the watershed is constructed using GH Copula function， which can reflect the regional composition of water supply while calculating available water supply. The model is applied to the Liuxi River Basin， to obtain the optimal distribution lines of each tributary under different scenarios， and to calculate the range of available water supply for the downstream control section of the Liuxi River Basin under different assurance rates. In the optimization and fitting results of water volume in various tributaries of the watershed， the optimization and fitting based on the minimum sum of squared deviations criterion has a good fitting effect on the low water points of the sample， while the optimization and fitting based on the minimum root mean square error criterion has a good fitting effect on the overall sample data. Based on this result， using GH Copula function to construct a joint distribution function for the available water supply of the watershed design section to solve the available water supply of the watershed can better reflect its regional composition and has higher accuracy than traditional available water supply estimation methods.

In the numerical modeling of groundwater seepage field at the site scale with a single geological structure， the unclear boundary conditions often lead to the difficulty of fitting the model results to the actual situation. To address this problem， the article proposes a new method to optimize the boundary conditions of model wells with evenly distributed virtual pumping wells， and constructs an optimization model with the amount of pumping as the decision variable， and the absolute error between the simulated head and the real head of the actual observation wells as the objective function. The Keplerian optimization algorithm （KOA） is used to solve the model， and a site on the left bank of the lower reaches of the Ganjiang River is used as an example to explore the influence of the number of evenly distributed virtual wells on the optimization model. The results show that： under the basic conditions of the optimization algorithm with an initial population of 10 and an iteration number of 100， the upper limit of pumping volume of 6、 10、 15 and 27 virtual wells is set to 8、 9、 9 and 10 m³/d， respectively， and the optimization model adaptability achieves the optimal value； The method of evenly distributed virtual pumping wells can be used to optimize the groundwater seepage model after combining with the KOA algorithm， and 15 virtual wells can balance the complexity of the algorithm and the influence of the wells on the model to achieve the best fit between the simulated flow field and the actual flow field； The relative optimization degree of 6 or 10 wells is limited， and 27 wells will increase the dimensionality of the decision variables and make the optimization more difficult； The absolute error （MAE） and the root-mean-square error （RMSE） between the simulated and the real heads of the observation wells are used to quantify the optimization effect of the groundwater seepage field simulation. Compared with the pre-optimization， the MAE of the optimization scheme for the 6、 10、 15 and 27 virtual wells decreased by 54.58%、56.91%、 61.67% and 59.29%， respectively， and the RMSE decreased by 46.36、 44.79%、 53.76% and 53.05%， respectively. The method of optimizing well boundary conditions based on KOA can provide a reference for the optimization of groundwater seepage field simulation at the site and improve the model fitting accuracy.

The spatial-temporal characteristics of precipitation in the Miju River are of great significance to the water resources scheduling of Erhai Lake and the study of droughts and floods in the basin. Based on the monthly precipitation data from 1979 to 2023， this papar analyzes the characteristics of spatio-temporal variation of precipitation concentration degree and precipitation concentration period in the Miju River Basin， using trend analysis， spatial interpolation， Morlet wavelet and other methods. The results show that： ①The annual precipitation shows a decreasing trend， with a reduction rate of 11.8 mm/10 a， and the spatial distribution shows a decreasing trend from upstream to downstream， and the coefficient of variation of precipitation shows a reverse relationship with precipitation. ②Precipitation concentration degree shows a fluctuating upward trend， with an increase rate of 0.01/10 a， and precipitation concentration degree has increased by 0.04 from the 1980s to the past 15 years. Precipitation concentration degree of the eastern region is above 0.70，while precipitation concentration degree of the western region is below 0.60， showing a trend of high in the east and low in the west， high in the south and low in the north， and precipitation concentration degree is higher in the downstream region. Precipitation concentration period shows a fluctuating downward trend， with a decreaserate of 16.3°/10 a，and there is a time difference of “earlier in the south branch Fengyu River and the rest later”. Precipitation concentration period mainly occurs in July， precipitation concentration period of Fengyu River spans within seven 10 days （from mid-June to mid-August）， and precipitation concentration period in other regions spans within five 10 days （late June to early August or early July to mid-August）. ③ The PCD values in the upper reaches of the Mici River have remained relatively stable over the years， and the precipitation concentration degree and precipitation concentration period of in other regions showed a trend of decreasing at first and then increasing in different decade. Precipitation is more concentrated in the upper reaches of the Mici River in high rainfall years， and there is little difference in other regions， and the precipitation concentration period appears slightly earlier in high rainfall years. ④The main cycle of annual precipitation， precipitation concentration degree and precipitation concentration period in the basin is 18 years， and it has experienced two concussion processes in 45 years. From the perspective of wavelet coefficients， 2023 is at the end stage of the high-frequency. In the coming period of time， the Miju River basin will enter a period of less precipitation， relatively uniform precipitation concentration degree， and early precipitation concentration period.

The anisotropy of karst media leads to the complex and variable dynamics of karst water， and studying the response mechanisms of karst water systems is of great significance for the protection of springs. This paper takes the karst water system in Jinan as an example， and uses methods such as time series， correlation analysis， and sliding window analysis to study the dynamic characteristics of karst water， clarify the grading and development patterns of the groundwater flow system in the karst water system， and reveal the response of groundwater levels in different hierarchical groundwater flow systems of karst spring domains to atmospheric precipitation. The results show： ① The groundwater level response within the spring domain has a high degree of seasonal and cyclical variation characteristics， with different groundwater dynamics in different hierarchical flow systems， where local flow systems exhibit drastic and large-amplitude changes in groundwater dynamics， while regional flow systems show stable and small-amplitude changes. ② The groundwater dynamic response lag time of different hierarchical flow systems is different， which is characterized by regional features. It is mainly controlled by topography， geological structure， lithology， and the intensity of fracture karst development. Fault structures and fracture karst shorten the response lag time of groundwater dynamics， and local flow systems transform groundwater into regional flow systems， extending the gushing time of karst springs. ③ There is a lag in the initial response time of groundwater levels in different hierarchical flow systems to subsequent precipitation， with local flow systems having a response lag time of 0.75 to 2.32 days， and regional flow systems having a response lag time of 30.79 to 33.35 days. The degree of karst development， lithology of strata， geological structure， and the extent of fracture karst development are important factors for the differences in response lag times. The research results are expected to enrich the theoretical research of multi-level groundwater flow systems in the Jinan spring domain and provide technical support for the protection of springs， water supply， and ecological replenishment in the Jinan spring domain.

Groundwater level is a critical indicator for assessing the sustainable use of groundwater resources and serves as a key basis for groundwater management. Accurate prediction of groundwater levels is essential. Traditional numerical models， such as MODFLOW， are complex to construct and require numerous parameters， while data-driven neural network models often lack interpretability and generalization capabilities. In this papar， a Groundwater Physics-Informed Neural Network （GWPINN） model is developed to solve the groundwater flow equation by integrating Physics-Informed Neural Networks （PINNs） with the governing equation of groundwater flow. The model employs fully connected neural networks， using spatial-temporal coordinates as inputs and groundwater head as outputs. It incorporates the groundwater flow equation， initial conditions， and boundary conditions as physical constraints， and combines the measurement data to construct a loss function to solve the groundwater flow equation. To evaluate the effectiveness and accuracy of the algorithm， we applies the GWPINN model to single pumping well of the confined aquifer. The simulation results are compared with those of the traditional numerical model， MODFLOW. The findings show that when relying solely on physical constraints without any data， the GWPINN solver achieves a Mean Absolute Error （MAE） of 0.063 m and a Relative Root Mean Square Error （RRMSE） of 0.083%. When combining physical constraints with data-driven approaches， the MAE is 0.069 m， and the RRMSE is 0.079%. These results demonstrate that the algorithm can effectively solve groundwater flow equations， especially for those with source of wells. Additionally， the impact of spatial and temporal sampling frequency on the solution results is investigated. The study reveals that a denser spatial sampling interval of 100 meters near the well source is required to capture the rapid changes in groundwater head. On a temporal scale， an increased sampling frequency with an interval of 0.3 days is necessary at the start of pumping to capture the rapid changes in water head near the well. However， in regions farther from the pumping well or after 1 day of pumping， the spatial and temporal sampling frequency can be appropriately reduced to intervals of 200 meters and 5 days， respectively.

Drought is one of the most widespread natural disasters in the world， causing the largest agricultural losses. Exploring the effects of climate and land use change on the driving mechanism and transmission of drought is of great significance for drought monitoring and early warning. We constructed a SWAT （Soil and Water Assessment Tool） hydrological model to identify hydrological and agricultural drought in the Fuhe River basin based on standardized runoff index （SRI） and standardized soil moisture index （SSMI）. The influencing factor separation method and Pearson correlation analysis method were used to quantitatively analyze the driving mechanism of climate and land use change on hydrological and agricultural drought transmission and the influencing mechanism of hydrological and agricultural drought transmission in the watershed. The results showed that： ① SWAT model was suitable for the simulation of water cycle process in the Fuhe River Basin. The coefficients of determination （R ²） of runoff at the Liaojiawan Hydrological Station were 0.94 and 0.91， the Nash efficiency coefficients （Ens） were 0.93 and 0.91， and the relative errors （Re） were -4.7% and 2.5%， respectively. At the Loujiacun hydrological station， the R ² of runoff in the rate period and the verification period were 0.96 and 0.93， the Ens were 0.95 and 0.92， and the Re were -8.6% and 8.92%， respectively， with high accuracy. ② Climate and land use change had aggravating effects on hydrology and agricultural drought in the basin， and the effect of climate change was stronger than that of land use change. Climate change had the greatest impact on hydrology and agricultural drought duration， while land use change had the greatest impact on hydrology and agricultural drought frequency. ③ Climate and land use change accelerated the transfer process of hydrological drought to agricultural drought in the watershed. The transfer time in summer was 9 months in the base period， and 3 months in the impact period of climate and land use change. The transfer time in autumn was 3 months in the base period and 1 month in the impact period. The results can provide scientific reference for drought monitoring and defense.

The “canals joining reservoirs” type irrigation system is widely distributed in hilly regions of southern China， and is a complex water conservancy engineering system composed of canals， ponds and reservoirs. Current allocation strategies predominantly treat reservoir cluster regulation and canal water distribution as independent issues， lacking research on multi-level reservoir-canal coordinated operations， making it difficult to maximize overall system efficiency in practical implementations. Therefore， the study of how to build a set of water resources optimization mechanism under the conditions of joint use of reservoirs and canals has an important practical application value. Based on the multilevel hierarchical control structure of “total regulation—sub-regulation—self-regulation”， this study organically combines the scheduling of reservoir groups with the coordinated scheduling of cross-basin canal transmission and distribution， and constructs an optimized water resources regulation and control model that takes into account the multilevel structure of the irrigation district and the joint use of reservoirs and canals. The model employs the NSGA-II multi-objective intelligent optimization algorithm for solution generation and Projection Pursuit method for selecting optimal allocation schemes， and takes the Quanmutang Reservoir Irrigation Project as an application example. The results show that： ① Through the joint deployment of reservoirs and canals， the three optimal deployment schemes significantly reduce the water shortage rates of urban and rural and irrigation water users. Except for Shaodong City， Jiugongqiao Branch Canal Irrigation Area， Huangjiaba Sanhe Irrigation Area， and Sandu Baotian Irrigation Area， the urban and rural water users and irrigation water users are all kept below 7% and 5% respectively. ② Economic costs of the three schemes decrease by 1.261 3 million yuan， 8.776 5 million yuan， and 5.371 1 million yuan respectively compared to traditional methods， with an average reduction of 5.136 3 million yuan. ③ The storage and regulation capacity of the reservoir is enhanced. The water filling volume of the canal system during the dry season accounts for about 50% of the annual discharge flow of the reservoir， which enhances the reservoir’s storage capacity in the dry season and guarantees the stability of the water supply. Overall， the research findings can enrich the theoretical system of systematic water resources allocation under the condition of joint utilization of reservoirs and canals， and provide a scientific basis for the water resources allocation of the “canals joining reservoirs" type irrigation districts.

The high energy efficiency of hydraulic machinery has always been the direction pursued by many scholars. Centrifugal pump is a kind of widely used hydraulic machinery， and its efficiency is generally between 70% and 80%. The method of optimizing centrifugal pump and improving its efficiency is worth discussing. In this paper， a vertical single-stage single-suction volute centrifugal pump is used to calculate and analyze the simulated fluid. Based on RNG turbulence model， the fluid simulation calculation of centrifugal pump under seven different flow inlet conditions of 0.5Q_d ~1.3Q_d was carried out， and the hydraulic performance of centrifugal pump under large and small flow conditions was obtained. The main performance was low efficiency and high head under low flow conditions. The opposite was true for large large flow conditions， with high efficiency and low head. After that， the impeller of centrifugal pump was optimized by Bezier spline curve， which mainly shows the change of bending degree of edge profile of blade inlet. Five schemes including the initial model were established. The simulation numerical calculation of different schemes was carried out under rated working conditions， and the changes of efficiency and head with the bending of blade inlet edge profile were analyzed. The difference of blade pressure， velocity vector and outlet pipe flow pattern under different schemes was compared. Finally， the optimal scheme was obtained， with the efficiency slightly increased to 91.2% and the head became closer to the design head.

In order to improve hydraulic performance and and operation stability of the mixed flow pump device at the first station in Qinglongshan irrigation district， an optimization hydraulic design of the inlet conduit and outlet conduit is completed based on three-dimensional turbulent flow numerical simulation. The experimental research on the hydrodynamic characteristics of optimized pump system model is carried out. The research results show that the flow in the optimized inlet and outlet conduits run orderly， the velocity changes uniformly， and the hydraulic loss of conduits is small. The optimal efficiency of the pump system reaches 83.71%， and the hydraulic performance is excellent. The occurrence of cavitation in a mixed flow pump syetem first is the initial cavitation of the gap， followed by the initial cavitation of the blade；When the efficiency of the pump device decreases by 1%， the cavitation on the blade surface is already severe. The maximum pressure pulsation amplitude of the pump system occurs in the oulet of the impeller， followed by the outlet of the guide vane， and the minimum amplitude occurs in the inlet of the impeller.

The vibration issues associated with pump station facilities have long posed challenges for the industry. Accurately obtaining the inherent vibration characteristics of the pump house structure and the metal structure of the flow channel is a fundamental prerequisite for avoiding resonance and anti-vibration optimization design. This paper， based on a large-scale underground pump station project in China， establishes a three-dimensional dynamic coupling model of the pump house structure， the flow channel metal structure， and the water body within the flow channel， exploring the dynamic characteristics of both the pump room structure and the flow channel metal structure. The results indicate that for the first 20 vibration modes of the pump room structure， the vibrations are predominantly associated with the upper beam-column structure， while the dynamic interaction between the lower flow channel metal structure and the upper beam-column structure is relatively weak. Therefore， it is not necessary to consider the influence of the water body within the flow channel when extracting the inherent vibration characteristics of the pump room structure. Considering the impact of the water body will significantly reduce the inherent frequency of the flow channel metal structure， which fundamentally affects the conclusions regarding resonance checks. Furthermore， the additional mass method simulating the water body results in a frequency reduction that is markedly greater than that produced by the fluid-structure coupling method. It is recommended to employ the fluid-structure coupling approach to analyze the inherent vibration characteristics of the flow channel metal structure.

Aiming at the problem that Stacked Denoising Auto-Encoders （SDAE） are highly influenced by network parameters in fault diagnosis， a new hybrid intelligent algorithm is proposed to adaptively extract SDAE network parameters to improve fault diagnosis accuracy. Firstly， an improved Harris Hawks Optimization （HHO） algorithm is proposed， that is， Sin chaotic mapping and Levy flight strategy are introduced to accelerate the convergence rate of HHO algorithm and improve the global search effect. Then， an improved Sand Cat Swarm Optimization （SCSO） algorithm is proposed， which combines reverse learning and Cauchy mutation strategies to make up for the shortage of SCSO algorithm easily falling into local optimal solutions. Finally， a switching quasi test is proposed， which fuses the improved HHO algorithm and the improved SCSO algorithm into the HHO-SCSO hybrid intelligent algorithm， so as to realize the advantages of the two algorithms to complement each other and make up for their shortcomings. Taking the bearing fault diagnosis of hydro-generator set as an example， the bearing friction experimental data set provided by Xi’an Jiaotong University is used to validate the algorithm. The experimental results show that the proposed method has an average fault diagnosis accuracy of 98.21%， which is 8.19% higher than that of the non-optimized SDAE network. Compared with other fault diagnosis methods， the proposed method has better robustness and higher fault diagnosis accuracy.

The simulation of the transient processes of large pumping stations is usually based on the flow and torque characteristic curves provided by the manufacturer. For a giant pumping station， the transient process simulation cannot be continued because the working point is missing. The reason or this is that a negative head occurs due to lower water level in the surge tank， and the working point exceeds the normal characteristic range. To handle this special situation， a method to extend and complete the manufacturer's characteristic curves and convert them to the Suter characteristics is proposed. By calculating the transient processes of a pump station with an overflow surge tank in the Pearl River Delta water resource management project， the feasibility of the method is verified， and the parameter fluctuations of the main operating conditions are analyzed， which is valuable for engineering design.

Ultra-low head axial flow hydraulic turbine is a hydraulic turbine device specifically designed for power generation under ultra-low head water resource conditions， and the axial spacing between the guide vanes and the rotor significantly influences its hydraulic performance. This paper focuses on a particular type of ultra-low head axial hydraulic turbine as the research object， and analyzes the energy conversion characteristics， internal flow dynamics， and vortex structures at different axial spacings. The results indicate that the axial spacing between the guide vanes and the rotor under design flow conditions has a minimal effect on the turbine′s head， power， and efficiency. However， the turbine′s efficiency is significantly impacted when operating outside the design flow conditions. When the axial spacing 60.2 mm， turbulent energy dissipation is small， and the flow channel effectively suppresses channel vortices and leakage vortices at the top of the impeller. This research provides some theoretical basis and reference for the design and optimization of ultra-low head axial hydraulic turbines.

In order to improve the operational efficiency and stability of impeller machinery， based on the "nodule effect" of the leading edge of the pectoral fin of the humpback whale， the leading edge nodule are applied to the NACA0012 airfoil for bionic design， which transforms the optimization of the blade design into an airfoil optimization design problem， so as to improve the hydrodynamic performance of the blade. The NACA0012 airfoil is taken as the basic airfoil， and nine leading edge nodular bionic airfoils with different structural parameters are designed. Numerical simulation is used to study the flow characteristics of the leading edge nodal bionic airfoil under the working conditions of inlet velocity u=3.6 m/s and Reynolds number Re=2.0×10⁵. The change rule of lift resistance coefficient of bionic airfoil under different structural parameters from 0° to 30° angle of attack is analyzed， and the key factors affecting the hydrodynamic performance of the airfoil are obtained. It is found that the hydrodynamic performance of the bionic airfoil is better than that of the basic airfoil at large angles of attack， in which the hydrodynamic performance of the airfoil with amplitude A=0.1c and wavelength W=0.2c improves the most obviously， and the average lift-resistance ratio increases by 15.7% at large angles of attack.

In order to optimize the landslide disaster control scheme scientifically and effectively， a landslide control decision system is constructed in this paper from the aspects of economy， technology and environment， synthetically integrating comprehensive influence factors such as “Man-Machine-Environment-Disaster mechanism”. Moreover considering the superiority of interval normal distribution of decision index weight attribute compared with uniform distribution， an interval fuzzy VIKOR method for optimization of landslide treatment scheme is proposed based on the principle of maximum group utility and minimum individual loss. Firstly， the original decision interval matrix of landslide treatment is normalized. Then the linear programming model is optimized by lingo 9.0 software， and the decision-making group utility value and individual regret degree of each governance scheme are obtained. Finally， the decision analysis of control schemes can be achieved by different psychological situations， which guarantees that the decision maker under limited rational mentality can obtain acceptable compromise probability solution， and the landslide management plans are ranked optimally. The research shows that this method can effectively reduce the interference of subjective preference and uncertain factors， and has strong practicability and rationality， which provide reference for optimal decision-making of landslide disaster control.

Steel fiber reinforced concrete has been widely used in engineering practice due to its superior mechanical properties. However， unlike other fibers， steel fibers are susceptible to corrosion in corrosive environments. This paper systematically reviews the research progress and key findings on the corrosion of steel fiber concrete at home and abroad， including the corrosion mechanism， as well as the effects of corrosion on the mechanical and durability properties of concrete. Previous studies have shown that the corrosion resistance of steel fibers is influenced by several main factors， such as the water-cement ratio， fiber type， concrete cracks， and the erosion environment. Besides， steel fibers corrode only within approximately 5 mm of the surface layer in uncracked concrete. The strength of the steel fibers gradually decreases as corrosion advances， while the corrosion products play dominant roles in the filling and compression of pores at different stages. These processes affect the bonding performance between the steel fibers and the cement matrix， thereby altering the mechanical properties of the concrete. Consequently， the mechanical properties of the concrete are closely related to the corrosion degree of steel fibers. Most existing studies have not considered the impact of the corrosion degree on the strength of steel fiber concrete， and the quantitative relationship between the corrosion degree of steel fibers and the degradation of concrete mechanical property has not been established. Finally， this paper discusses the challenges in steel fiber corrosion research and suggests future research trend.

Aiming at the problems of rapid deterioration of durability and reduction of service life due to the coupling of multiple salt ions erosion and freeze-thaw damage on hydraulic buildings in cold and arid irrigation areas， based on the indoor freeze-thaw test， we designed four kinds of basalt fibers volumetric admixture and four kinds of fiber lengths， and researched the change of concrete durability performance with clear water and 5%Na₂SO₄+3%NaCl composite salt solution as the medium in the process of freezing and thawing， and at the same time， established a Weibull probability distribution-based damage model. Based on the freeze-thaw damage model of Weibull probability distribution， the damage degree of relative dynamic elastic modulus of concrete under different freeze-thaw media was analyzed， and the life span of concrete was predicted under each working condition. The results show that： the loss of concrete mass， compressive strength and relative dynamic elastic modulus damage in clear water is much lower than that in composite salt solution， and the incorporation of fibre can effectively reduce the degree of damage to the test block due to salt freezing， in which the volume mixing amount of 0.15% and the fibre length of 25 mm are optimal for the improvement of the performance of the test block； According to the Weibull prediction model， the values of the fitted parameters A and B and the fitted correlation coefficient R2 are all above 0.9， and the predicted results of the model life are consistent with the results of the durability tests of the concrete test blocks under various working conditions. The results of the research can provide theoretical basis and reference for the research on the durability and service life of the concrete in cold and arid regions.

A three-dimensional finite element seepage numerical analysis model is established based on a long distance water supply tunnel project， considering the dynamic characteristics of tunnel excavation and support， and the evolution law of pore water pressure during tunnel construction period is studied. The temporal and spatial evolution curve of pore pressure during tunnel excavation can be divided into three stages： slowly changing stage， rapidly changing stage and stabilizing stage. Based on the temporal and spatial evolution characteristics of pore pressure in the process of tunnel face excavation and segmental lining installation （including pea gravel backfilling and grouting， etc.）， the disturbance range of pore pressure during tunnel excavation is discussed. The results show that the pore pressure will change before the tunnel is excavated to the monitoring section， and the pore pressure begins to change dramatically within about 5πD （D is the diameter of tunnel） near the monitoring section， while the influence range of segmental lining installation is slightly smaller， about 3πD. And the effects of lining on the pore pressure present a law of time-delaying. The plane model based on the transient seepage calculation can provide the calculation results of the corresponding stable time obtained after the completion of a certain construction link （excavation or support） in the three-dimensional calculation model， but it can not simulate the temporal-spatial evolution of pore pressure.

In order to reveal the mechanism of hydration temperature rise of Rock-filled concrete， adiabatic temperature rise experiments of rock-filled concrete（RFC） with different rockfill rates， different storage temperatures and different rockfill gradations were carried out by using the thermal physical parameter tester. The variation law of adiabatic temperature rise and temperature rise rate of rock-filled concrete was studied， and the hydration temperature rise process and hydration reaction kinetic parameters were obtained by using Krstulovic-Dabic hydration kinetic method， and the hydration temperature rise process and influence mechanism of rock-filled concrete were analyzed. The results show that the hydration temperature rise process of rock-filled concrete can be divided into four stages： induction period， acceleration period， deceleration period and recession period. With the increase of rockfill ratio， the adiabatic temperature rise decreases， and the decrease range is consistent with the increase of rockfill ratio. For every 1% increase in rockfill rate， the peak temperature rise rate decreases by 1.6%. The peak temperature rise rate increases by 2.9% for every 1 ℃ increase in the storage temperature. The rockfill gradation has no significant effect on the adiabatic temperature rise and temperature rise rate. The entry temperature has a great influence on the hydration temperature rise process. The hydration process at the entry temperature of 25 ℃ goes directly from the crystallization nucleation and crystal growth （NG） stage to the diffusion （D） stage. The hydration process at the entry temperature of 5 ℃ and 15 ℃ goes from the crystallization nucleation and crystal growth（NG） stage to the phase boundary reaction（I） stage and then to the diffusion（D） stage. The rockfill rate， entry temperature and rockfill gradation have a great influence on the hydration rate of NG in the hydration stage. As a composite material， the equivalent hydration rate of rock-filled concrete is 1/6~1/20 of that of ordinary concrete.

The thermal parameters of concrete are crucial to the calculation results due to the complex and changeable construction environment. Therefore， this paper proposes a thermal parameter inversion method for mass concrete based on the Parrot Optimization Algorithm（PO）， aiming to solve the limitation that there are differences between the thermal parameters obtained from specifications or experiments and those under actual working conditions. Due to the particularity of the search method of PO， its search efficiency is slightly insufficient. To address this issue， a random stay strategy is introduced to improve PO. The global search capability and solution efficiency of the algorithm are significantly enhanced by the introduction of triangular wandering and Levy flight strategy. Through 12 benchmark test functions from IEEE CEC 2022， a comparison was made between the improved PO and three traditional algorithms， revealing significantly superior performance of the former. The improved algorithm was applied to a concrete arch dam in the lower reaches of the Jinsha River， achieving efficient inversion of final adiabatic temperature rise， surface heat release coefficient， and temperature rise pattern parameters. The results demonstrate that compared to traditional methods， the proposed approach in this paper can more effectively reduce the deviation between simulated and measured temperatures， enhancing the inversion accuracy. This provides robust technical support and practical reference for thermal performance analysis and optimization of related engineering structures.

Aiming at the problems of distortion of evaluation results caused by strong subjectivity in traditional evaluation methods and uncertainty in monitoring data， a monitoring model of measuring points was established based on the measured data of earth-rock dam， and the safety level intervals were divided based on the residual of each measuring point. The cloud model was combined to extract the cloud characteristic value and calculate the cloud similarity， and the local safety evaluation of a single measuring point was realized. The evaluation result of cloud model was taken as the basic probability distribution of D-S evidence theory to solve the subjective problem caused by the need for subjective construction. Considering the continuity of the dam evaluation grade， Wasserstein distance was used to measure the conflict among the evidence， and the availability of the evidence was analyzed by combining the information entropy theory， which overcame the high conflict and uncertainty in the fusion of multiple evidence and enhances the reliability of the evaluation results. The coupling model of cloud model and improved D-S evidence theory was applied to the operation safety evaluation of the earth-rock dam of Liujiagou Reservoir in Ningxia. The results show that the operation safety evaluation grade of the earth-rock dam of Liujiagou Reservoir is “normal” from April to June 2024， which is consistent with the evaluation results of other improved D-S evidence theories， and the constructed model has the highest support for “normal”. The applicability and superiority of the model are confirmed， and the study can provide reference for the seepage pressure safety evaluation of earth-rock dams.

In order to clarify the influence of uneven step length on the energy dissipation characteristics of stepped spillways， computational fluid dynamics （CFD） method is used to numerically simulate the two-phase flow on stepped spillways， including concave， convex， random， and semi-uniform step length approaches. The main conclusions of this paper are as follows： Compared with the conventional uniform stepped spillway， the energy dissipation rate of concave and convex stepped spillways is reduced by 5.3% and 16.1%， and there is no significant change in the energy dissipation rate of random stepped spillways. In the combination of a short step length followed by an adequately long step length， the swirling vortexes above the two steps will collide and connect into a large swirling vortex area， which will further expand the length of the vortex area and dissipate more water energy. Taking the formation of the connected swirling vortex area as the original intention， a semi-uniform stepped spillway is designed by alternately advancing steps with short and long step lengths. It is found that a connected swirling vortex area is formed above each group of short and long steps， and the energy dissipation rate is greatly improved， with a maximum increase of 11.6%.

In the context of international communication of academic achievements， English abstracts serve as critical academic credentials for scientific papers， directly influencing the inclusion efficiency in mainstream international index databases and the global visibility of research outcomes. The study， based on a corpus analysis of English abstracts of 393 articles to be accepted by the journal of China Rural Water and Hydropower during 2024-2025， identifies five prevalent problems in authors′ English abstract composition practices： ① inconsistency between the content of Chinese and English abstracts； ② inaccurate professional terminology； ③ syntactic errors； ④ misuse of words and collocational inappropriateness， and ⑤ misspelling and misuse of punctuation. The main causes include authors′ insufficient attention to English abstracts， inadequate academic writing training in English， overreliance on machine translation and lack of post-editing， structural imbalances between disciplinary literacy and language proficiency， and inappropriate reference selection. To address these challenges and enhance the international academic discourse power of the water resources and hydropower sector， this study proposes four strategic recommendations： ① establishing a dynamic standardization system for English abstracts； ② elevating authors′ awareness of abstract quality； ③ fostering cross-journal collaborative mechanisms， and ④ engaging experts who are proficient in English for targeted guidance. This study provides critical inspiration for breaking through linguistic barriers and enhancing the international communication effectiveness of China′s water resources and hydropower research achievements.