To study the purification effect of artificial ecological pool on rice field drainage， this paper analyzes the purification effects of TN， NH₄ ⁺-N for paddy field drainage by two years’ rice field drainage artificial ecological pool purification test for emergent plants， floating plants and submerged plants. The artificial ecological pond has an obvious purification effect on TN and NH₄ ⁺-N in paddy field drainage. Different aquatic plants can reduce the pollutant concentration to the level before unsewage in the 6th to 7th day after purification. Among them， the removal of TN and NH₄ ⁺-N from Hydrilla verticillata is the best， and the removal effect is more than 90% after 4 days of purification. Artificial ecological pool can effectively purify rice field sewage and reduce agricultural non-point source pollution. Black algae have the best purification effect and are suitable for popularization in artificial ecological pools.

When the boat enters the drinking water source river from the waterway， it will pull the sewage into the drinking water source river. In order to improve the water quality of the drinking water source river and reduce the pollution of a certain drinking water source river， this paper optimizes the boundary of the drinking water source river branch. By using the Mike21FM hydrodynamic module， the two-dimensional hydrodynamic mathematical model of the drinking water source channel after the optimization of the current channel and the boundary of the branch stream is established. The mathematical model parameters are calibrated and verified through the physical model test， and the drinking water source under the current situation and the optimized scheme are simulated. The flow field of the river channel and the amount of sewage pulled into the drinking water source river channel by different boat speeds are calculated. The results show that optimizing the boundary of the drinking water source river branch can effectively improve the estuary of the drinking water source river branch flow field， the optimized scheme can greatly reduce the amount of sewage towed into the drinking water source river when the ship sails into the upper reaches of the drinking water source river at the same boat speed， and when the speed of the boat is 6 knots， the amount of sewage drawn into the optimized drinking water source river by the boat passing through the drinking water source river is the least. It is recommended that combined with the total benefit of project investment selection， optimizing the boundary of the drinking water source river branch to reduce the amount of sewage towed into the drinking water source river； boats slow down before entering the upper reaches of the drinking water source river， which can effectively reduce the amount of sewage pulled by the boat into the drinking water source river.

In view of the selection of rainwater harvesting tank materials in karst water shortage areas， experimental studies on water storage effects of four commonly used water tanks made of brick concrete， galvanized steel， high density polyethylene （HDPE） and linear low-density polyethylene （LLDPE） are carried out. Through the 294 - day field record， the correlation analysis of changes in water chemical indexes is carried out， and the dominant factors and causes of water quality changes are explored. The experimental results show that the water quality of brick mixing tank is affected by the reaction of lime and alkali aggregate in cement mortar， and there are phenomena of excessive pH and aluminum ions. The water quality of galvanized steel water tank will be affected by the electrochemical reaction of galvanized layer， resulting in the phenomenon of excessive zinc ions. The water quality of HDPE and LLDPE tanks is affected by planktonic algae. Among them， HDPE tank is prone to deformation and eutrophication， while LLDPE tank is mesotrophic. In the above four different materials of water tank， the water quality of rainwater in LLDPE water tank is the best， but there is still a phenomenon of medium nutrition. Taking light avoidance measures or using filtering devices are suggested to reduce the degree of water eutrophication. By studying the influence of tank material on water quality in karst water shortage area， this paper can provide a scientific basis for tank material selection and effective utilization of water resources.

Agricultural non-point source pollution has become one of the principle source of surface water pollution in China， and abundance of pollution control technologies spring up， aiming at prevention and control of agricultural non-point source pollution. Thus， how to select the technology with the highest comprehensive evaluation of environment， economy and society， is a decision problem. In this paper， an intuitionistic fuzzy-entropy weight-TOPSIS method is proposed by integrating intuitionistic fuzzy set theory and entropy weight method into Technique for Order Preference by Similarity to an Ideal Solution （TOPSIS） framework， and applied to an evaluation case of agricultural non-point source pollution control technology. The method has the advantages on transforming qualitative evaluation language into quantitative intuitionistic fuzzy number and obtain objective weights for index， simultaneously. The practical technology assessment case is carried out as validation， based on the typical agricultural non-point source pollution control technologies developed by Major Science and Technology Program for Water Pollution Control and Treatment Ministry of Ecology and Environment. According to the characteristics of the technologies， an index system is established， including the indices that can represent environmental benefit， economic benefit and technical performance of the technologies， in order to provide an evaluation basis for the method. The result shows that， technologies with high comprehensive evaluation can be selected by the proposed method from the source reduction technologies， the process interception technologies， the end treatment technologies and the whole process control technologies， respectively. Among 12 technologies in the source reduction category， Rotation Farmland and Citrus Orchard in Reservoir D ₄ gets the highest comprehensive evaluation， closely followed by Nitrogen and Phosphorus Reduction Technology Based on Slow and Controlled Release Fertilizer for Rice D ₇ and Integrated Technology of Rice Fertilization and Transplanting D ₈； Among 9 technologies in the process interception category， Compound Hedgerow Control Technology for Soil Nitrogen and Phosphorus Interception and Loss Control in Sloping Farmland D ₂₁ gets the highest comprehensive evaluation， closely followed by Pollution Control Technology of Farmland Receding Water D ₁₆ and Regulation Technology of Planting Structure and Fertilizer Structure on Sloping Land D ₁₉； Among 4 technologies in the end treatment category， the Ditch-canal-pond system purification technology D ₂₃ gets the highest comprehensive evaluation， closely followed by Collection and Re-reduction Technology of Non-point Source Pollution in Phosphorus-Rich Areas D ₂₂ and Low-cost comprehensive disposal technology of farmland waste D ₂₄； Among 9 technologies in the whole process control technologies category， the 4R Technology System of “Reduce-Retain-Reuse-Restore” D ₂₉ gets the highest comprehensive evaluation， closely followed by Agricultural Pollution Control Technology Based on Soil Nutrient Reservoir Expansion D ₃₂ and Large-area Contiguous and Multi-type Planting Mosaic of Farmland Non-point Source Pollution Control Technology D ₂₈. Further， analysis on advantages and disadvantages of the technologies are carried out from aspects of environment， economy and technical performance， thus some improvement recommendation technologies are proposed. This study is a new attempt to apply the intuitionistic fuzzy-entropy weight-TOPSIS method to agricultural non-point source pollution technology evaluation， which demonstrates that the method can also be applied to a wide scope of technology evaluation in other fields.

The excessive phosphate removal is a key factor that controls eutrophication. A series of measures have been adopted to remove phosphate in domestic sewage and industrial wastewater， such as upgrading and renovating sewage treatment plants. However， the removal of phosphorus from domestic sewage in rural areas is restricted by technological capabilities and financial investments. In order to achieve the integration of the rural domestic sewage treatment and sediments utilization， a series of experiments are conducted to verify thephosphate adsorption ability of three kinds of ceramsites， including Ceramsite A made of dredging sediments from Beijiang River in Qingyuan City， Guangdong Province， local wetland vegetation and iron salt； Ceramsite B made of the same raw material with Ceramsite A without iron salt； Ceramsite C is commercially available. The experimental results showed： ① Ceramstie A has rich honeycomb porous structures， which can provide an effective carrier for iron ions and act as channels and active sites for phosphate adsorption. Additionally， the nitrogen adsorption isotherms and BET surface area analysis shows that the Ceramsite C has a higher surface area and three kinds of ceramsites contain mainly mesopores （2 nm<d<50 nm）. ② The experimental data is inserted into Langmuir and Freundlich’s isotherms to undertake the mechanism and adsorption capacity of the test biosorbents. The adsorption isotherm models show that the adsorption results of Ceramsite A and Ceramsite B on total phosphorus （TP） are in better accordance with the Langmuir isotherm model （R ²>0.95）， while Freundlich isotherm model is used （R ²>0.82） is more suitable to describe the adsorption process of Ceramsite C. Moreover， the theoretical saturated adsorption capacity Q _max of Ceramsite A is far more than that of the other ceramsites， reaching 383.26 mg/kg. ③ The results of dynamic column experiments show that the maximum adsorption capacity q ₀ and half penetration time τ of Ceramsite A are more than that of Ceramsite B and Ceramsite C， reaching 7.058 mg/g， 458.80 min， respectively， indicating a better performance of Ceramsite A in phosphate absorption in flowing water. Simultaneously， the dynamic adsorption process of ceramsite can be described relatively well by both the Thomas Model and Yoon Nelson Model （R ²>0.86）. Overall， Ceramsite A has good adsorption ability for TP. The conclusions of the researches provide new ideas and methods for the resource utilization of dredging sediments and prove the feasibility of preparing ceramsite from sediments and then applying it as a matrix in a constructed wetland to absorb phosphate.

Nowadays， there is no clear and unified definition of ecological base flow of rivers， and there are many estimation methods. The appropriate calculation method should be selected according to the actual situation of the basin. In the implementation plan for ecological flow of Dongjiang River prepared by the Pearl River Water Resources Commission of the Ministry of Water Resources， eight hydrological methods for calculating ecological base flow are recommended， but their calculation results are very different. In this paper， two small basins in the upper reaches of the Dongjiang River is taken as the research object to find an ecological base flow calculation method which is most suitable for small basin of Dongjiang River. First， eight methods are used to calculate the corresponding ecological base flow based on the historical flow data of the monitored sections. Second， eight methods are given appropriate weights based on the comparation between subjective and objective weighting methods. Thus， the ideal scheme of ecological base flow can be obtained by comprehensively utilizing their calculation results. Finally， an optimal method is selected by analyzing the closeness between the results of eight methods and the ideal scheme respectively. The results indicate that： ① The monthly flow variation method is suitable for the calculation of ecological base flow in the small basin of Dongjiang River. ②The monthly flow variation method can give priority to the calculation of ecological base flow in small basin with abundant water in South China.

In order to improve the mechanical properties of the hydraulic gel material and increase the disposal rate of the sludge， materials such as diatomaceous earth are selected to temper the sludge， and the tempered sludge is naturally dried by using the abundant solar and wind energy in Zhangjiakou. The dried sludge is incinerated and ground to produce ash， and the volcanic ash activity of the tempered sludge ash is analyzed by means of a comparative gelling strength test and a volcanic ash activity test. The volcanic ash activity is tested by mixing the same quality of diatomaceous earth， fly ash， shale and zeolite with the tempered sludge ash， and the technical performance of the cement and the shrinkage of the cement sand are tested. The diatomaceous earth tempered sludge ash is tested for technical cement properties and sand shrinkage to analyze the performance of the cement as a hydraulic cementing material after it has been partially replaced. The test results show that the volcanic ash activity of the sludge ash first increases and then tends to level off with the increase in diatomaceous earth admixture， and the compressive strength ratio reaches a maximum of 87.3% when the admixture is 9%； the sludge admixture of 9% diatomaceous earth can obtain better drying effect and the best volcanic ash activity； the diatomaceous earth has higher volcanic ash activity than the sludge ash tempered with fly ash， shale and zeolite at the same admixture， and the modulated X-ray diffraction analysis shows that the uncalcined diatomaceous earth contains gypsum， quartz and muscovite crystals， while the gypsum diffraction peaks of the calcined diatomaceous earth disappear and the secondary diffraction peaks of quartz are weakened. When the diatomaceous earth is mixed with sludge and dried and calcined， the quartz crystals become weaker. The SEM analysis shows that the walls of the uncalcined diatomaceous earth are covered with well-arranged， uniformly sized micro-pores. After calcination， the surface becomes rough and the amorphous material covered with it becomes dispersed， which increases the contact area between diatomite and calcium hydroxide and facilitates its volcanic ash activity. The diatomaceous algae mixed with the sludge are more heavily damaged and are mostly seen as diatom fragments， allowing the volcanic ash activity to be fully exploited.

Affected by human factors， climate change and hydrological conditions， marshes in Naoli River Basin have deteriorated seriously in recent 40 years. Based on multi-period land use data and long-time series hydrological and meteorological data from 1980 to 2020， this paper analyzes the characteristics of marshes degradation in Naoli River Basin. Through linear fitting， correlation analysis and stepwise multiple regression analysis， the relationship between wetland degradation and hydrology， climate and human disturbance in Naoli River Basin is quantitatively discussed. In addition， this paper analyzes the comprehensive influence of various factors on marshes and calculates its contribution rate through RDA. The results show that from 1980 to 2020， the marsh area in Naoli River Basin decreased seriously and the landscape pattern was also significantly degraded. The Largest Patch Index （LPI）， Percentage of Landscape （PLAND） and Patch Cohesion Index （COHESION） of marsh showed a significant downward trend， the Patch Density （PD） and Landscape Shape Index （LSI） showed a trend of decrease - increase – decrease pattern， and Contagion Index （CONTAG） showed a fluctuating upward trend.Simpson's Diversity Index （SIDI） and Shannon's Diversity Index （SHDI） showed a downward trend. The runoff in Naoli River Basin generally showed a decreasing trend before 2019， the change rate of runoff coefficient was consistent with the change rate of marsh area， LPI and PLAND. Among the meteorological elements， temperature， relative humidity and sunshine hours are the main factors that affect the ecological landscape of marsh wetland. Temperature had significant effects on ecological indicators representing area， while relative humidity had significant effects on ecological indicators representing density and landscape shape； hemeroby was significantly negatively correlated with marsh area， LPI， PLAND and CONTAG. RDA1 and RDA2 accounted for 73.93% and 24.78% of the total variance of marshes landscape index change， and the contribution rate of hemeroby was 59.3%. After the establishment of the nature reserve， the influence of human factors on the marshes was weakened， and the influence of natural factors on the marshes was more prominent.This study has a high reference value for wetland protection and watershed ecological environment management in Northeast China.

In order to fundamentally eliminate the threat of flood control brought by the wandering channel， an artificial cutoff was implemented in the Shizuishan reach of the Upper Yellow River in 2018. After the artificial cutoff， the riverbed and river situation of the newly excavated diversion river changed significantly. Based on the measured data， the primary controlling factors of morphodynamics of diversion river after artificial cutoff is analyzed. The 3D hydrodynamic model of the diversion river based on the measured data and the MIKE3 hydrodynamic model is built. The effects of inlet flow on the flow field characteristics and longitudinal velocity distribution of the diversion river are studied. The study shows that the riverbed evolution of the diversion river changes with the change of water and sand after the artificial cutoff， including the erosion of the riverbed and the intensification of bank collapse. The recirculation zone appears at the entrance of the diversion river， which poses a greater threat to the cofferdam of the spur dike. With the increase in the inlet discharge of the diversion river， the beach on the left and right banks is submerged， and the submerged area of the left bank is more than that of the right bank. In order to ensure the success of artificial cutoff and prevent the phenomenon of backwater， bank protection measures should be carried out on the left bank of the middle and low reaches of the diversion river.

The beach area of the lower Yellow River is a complex reciprocal feeding system， the security and coordinated development of the system are related to the stability and sustainable development of a region. In order to scientifically evaluate the security development level and coordination degree of the social-economy-flood safety-ecological environment coupling system in the typical tidal flats of the lower Yellow River， and to clarify the main reasons affecting its development trend. According to the regional characteristics of Landong Beach Area in the lower reaches of the Yellow River， the influences of social economy， flood control safety and ecological environment on the development of beach area are comprehensively considered. Following many principles of index selection， the weight of index system is determined by combination weight method. This paper constructs the model of coupling coordination degree from 2001 to 2020 in the lower reaches of the Yellow River， and analyzes and predicts the change trend of coupling coordination degree. The results show that： ① The interaction of socio-economic， flood control safety-ecological environment coupling system is obvious in the Landong Tan Area of the lower Yellow River， but the overall coordination coupling development degree is not high， and there is still a certain gap to the quality coordination. ② The goodness of fit of the coupling degree and coupling coordination degree of the integrated system are good， both above 0.9，and their trend lines are close to the trend of flood control safety evaluation index， indicating that flood control safety has a great influence on the integrated system. ③ The index of flood control safety occupies a large proportion of the combined weight， followed by social economy， and finally ecological environment. The premise of the safe development and environmental friendliness of Landongtan is to ensure the most basic flood control safety.④ The safety evaluation index of the three subsystems has increased in different degrees in the past 20 years. The safety evaluation index of the social economic subsystem has increased steadily， and the growth rate is obviously higher than that of flood control and ecology， and the development of flood control safety and ecological environment subsystem is not balanced.

High-quality hydrometeorological observation data is the basic support for meteorological and hydrological disaster monitoring， forecasting and warning， and long-term climate change trend analysis. To solve the problem of low spatial resolution of existing integrated precipitation data at the watershed scale， this paper uses ensemble Kalman Filter （EnKF） fusion algorithm to merge precipitation data from 33 ground stations and TRMM and CMORPH satellite products at the daily scale in Qingjiang River Basin， yielding the 0.05°×0.05° fusion precipitation production of Qingjiang River Basin i.e.， MSAP. The Leave-One-Out Cross-Validation method is used to quantitatively analyze the satellite precipitation data， ground interpolation data and MSAP fused precipitation data. It is proved that the EnKF fusion algorithm can improve the precision of precipitation in Qingjiang River Basin from three aspects： correlation coefficient R， mean absolute error MAE and root mean square error RMSE. In addition， the fusion algorithm overcame the shortcomings of low accuracy of satellite data and ground data in part of the watershed boundary area， which shows that the EnKF fusion algorithm has application potential in precipitation data fusion. Furthermore， MSAP is compared with CMFD， ERA5 and MSWEP reanalysis data， and the spatial distribution of heavy precipitation events corresponding to the two largest flood peaks in Qingjiang River Basin and Yangtze River during the flood season in 1998 is analyzed. The results also show that the MSAP data has the highest R and the smallest MAE， RMSE in terms of the time scale. In terms of the spatial distribution of errors， the spatial difference of accuracy evaluation index of MSAP data in each site is the smallest， and the order of accuracy of the four kinds of reanalysis data from high to low is MSAP > CMFD > MSWEP > ERA5. CMFD， MSWEP and MSAP can reflect the center of rainstorm to some extent in the process of 5-day and 2-day heavy precipitation events. In terms of spatial distribution and precipitation amount， MSAP and CMFD are basically consistent.

In order to solve the problem of water conflict between ecological operation and power generation operation of reservoir， and low efficiency of comprehensive utilization of water resources， this paper proposes a comprehensive reservoir operation chart considering both ecology and power generation. By introducing the concepts of ecological control water level and ecological storage capacity in the dry season， the traditional power generation operation chart is divided into ecological operation period and power generation operation period， and the reservoir power generation and ecological comprehensive operation chart is constructed. On the basis of ensuring the demand of ecological operation， the operation chart can reduce the impact of ecological operation on power generation operation and improve the power generation efficiency of the reservoir as much as possible. At the same time， in order to solve the problem that it is difficult to effectively exert the benefits of reservoir engineering by using the operation chart drawn by typical runoff， a comprehensive operation chart optimization model with the goal of maximizing power generation is constructed. The model optimizes the scheduling line and uses the particle swarm algorithm to solve it. Taking Xiaozhongdian Reservoir located in Diqing Tibetan Autonomous Prefecture in Yunnan Province as an example， the comprehensive operation chart of Xiaozhongdian reservoir is drawn and optimized. The 55-year historical runoff is simulated and dispatched. Compared with the traditional power generation operation chart， the results of the comprehensive operation chart show that： ① The ecological flow satisfaction rate of Xiaozhongdian Reservoir has increased from 93% to 100%； ② The multi-year average power generation of Xiaozhongdian Reservoir and downstream cascade hydropower stations has increased by 1.64%， and the water utilization rate has increased by 1.11%. On the basis of ensuring the specific ecological flow demand of fish in the spawning period of Xiaozhongdian Reservoir， the comprehensive operation chart of Xiaozhongdian Reservoir has well coordinated the water use relationship between power generation operation and ecological operation， and the runoff compensation relationship between Xiaozhongdian Reservoir and downstream cascade hydropower stations. The research results can provide reference for reservoir operation with comprehensive utilization needs of ecology and power generation.

Because the optimal operation scheme is more effective than the conventional operation scheme in ensuring the safety of the reservoir， upstream and downstream and reducing flood losses， various optimization algorithms have been used to optimize flood control operations since the 1960s. Fruit fly optimization algorithm （FOA） has been widely used because of its simple principle， few parameters， small amount of calculation and easy to implement. However， it has been found that it has some problems such as premature convergence and easy to fall into a local optimization. Therefore， a fruit fly optimization algorithm coupled with simulated annealing algorithm （SA-FOA） is proposed to solve the reservoir flood control operation problem. By setting the search distance L， which gradually decreases with the number of iterations， the algorithm improves the convergence speed at the initial stage of iteration and avoids missing the optimal solution in the later stage of iteration. Meanwhile， the Metropolis acceptance rule of the simulated annealing algorithm （SA） is incorporated into the iterative process of the FOA， and the new individuals are selected according to probability， which avoids the disadvantage of FOA falling into a local optimal solution. Taking the maximum water level and the maximum flood peak reduction criterion as the objective function， an optimal reservoir dual-objective flood control operation model is established， and SA-FOA is used to solve the optimal discharge scheme set of two floods in Rizhao reservoir. The results show that： ①the two objective functions are approximately inversely proportional， this is due to the conflict between the two objectives； ②compared with the results obtained by using FOA， the objective function values obtained by using SA-FOA are better than those of FOA； ③compared with the measured discharges， it can be seen that the maximum water levels and the sums of square of discharge of the optimal schemes are less than those of the measured values， so the optimal operation schemes obtained by using SA-FOA are better than the measured values.

The phenomenon of water resources caused by unreasonable use of water resources is becoming more frequent，the demand for the optimization allocation of water resources is also increasing. The optimal allocation of water resources refers to the rational allocation of regional water resources by scientific and effective methods under the premise that the total amount of water resources is limited， comprehensively considering social and economic benefits. In this paper， the status of water resources in Jinzhong City is analyzed， the demand for optimizing the allocation of water resources in Jinzhong City is considered comprehensively， and a model of Jinzhong Water Resources Optimized Configuration Model with social benefits and economic benefits is established. Then an improved NSGA-II （INSGA-II） algorithm is proposed and INSGA-II algorithm is used to experiment with 6 multi-target test functions such as ZTD1， ZTD2 and ZTD3， the results show that an effective frontier of Pareto is obtained by the INSGA-II algorithm proposed in this paper， and the convergence and distribution are better than most of the multi-target optimization algorithms listed in this paper. Finally， the INSGA-II algorithm is applied to the optimized configuration model of the water resources of Jinzhong City and conducted instance analysis， at the same time， it is compared with the NSGA-II algorithm. Example analysis results show that the water resources optimization configuration based on the INSGA-II algorithm is less lacking and higher economic benefits than the NSGA-II algorithm optimization configuration solution based on the NSGA-II algorithm， and the feasibility of the optimization of water resources in Jinzhong City based on the INSGA-II algorithm is proved. Based on the different targets of decisionmakers for different goals， three optimized configuration solutions and three solutions are given， these configuration schemes also take into account social and economic benefits at the same time， which can effectively solve the problem of optimizing the configuration of water resources with many sub-regions， many water sources， many users and many constraints， and can provide a new way of thinking for water resources allocation and planning in Jinzhong City.

There are many parameterization schemes for the WRF （Weather Research and Forecast） model， and different parameterization schemes have a great influence on the rainfall simulation effect. In order to study the influence of the combination of cloud microphysics， land surface process and cumulus convection parameterization scheme in the WRF model on the rainfall simulation effect in the upper reaches of the Yangtze River， this paper takes the mainstream from Yibin to Yichang in the Yangtze River as the research area， selects five kinds of cloud microphysics parameterization schemes， two kinds of land surface process parameterization schemes and three kinds of cumulus convection parameterization schemes， a total of 30 kinds of scheme combinations are used to simulate the typical heavy rainfall processes in the four different rainfall centers in this area， and uses the measured site data and GPM （Global Precipitation Measurement） precipitation data product as a reference and uses TS score， empty alarm rate， misses alarm rate， accuracy rate， mean absolute error and root mean square error as evaluation indicators， fully considers the different influences of each index and uses the close relationship based on entropy weight. The numerical method is used to comprehensively evaluate the rainfall simulation results. The results show that the WRF-Single-Moment3 （WRF-Single-Moment3-class） scheme， the Noah （Noah Land Surface Model） scheme and the cumulus convection Grell-D （Grell-Devenyi Ensemble） scheme are parametric schemes in the WRF model. The combination has a good effect on the rainfall simulation in the upper reaches of the Yangtze River. Under this parameterization scheme combination， the simulation results of the average 24-h daily surface rainfall simulated by WRF are basically consistent with the measured data， and the simulated 24-h surface rainfall of four typical rainfalls The center and the distribution belt of rainfall magnitude are relatively close to the actual rainfall. The simulation error in most areas is less than 10 mm， and the simulation effect of light rain and moderate rain is better. In addition， the precision of WRF simulation rainfall will be affected by terrain changes， and the terrain is undulating. The aggravation will reduce the rainfall simulation accuracy， and the rainfall simulation accuracy in the southwestern mountainous areas is slightly lower than that in the northeastern plains. The research results serve as an important reference for the basin hydrological forecast.

The construction of intelligent water conservancy in the new era puts forward higher requirements for the simplicity， accuracy and continuity of flow measurement， and the traditional contact flow measurement method is gradually unable to meet the needs. In order to make full use of the advantages of modern video image recognition and artificial intelligence technology， so as to provide a new solution to river flow measurement， this paper takes the video non-contact flow measurement method as the research object， studies and establishes a video flow measurement calculation method based on space-time image velocimetry （STIV）， selects Qilijie Hydrological Station in Jianxi Basin of Minjiang River in Fujian Province as a demonstration application station for flow comparison test， and evaluates the accuracy and error analysis of the test results. The results show that the effect of establishing the velocity and discharge correlation of Qilijie Hydrological Station by means of the univariate linear alignment of water level segmentation is good. The actual effective comparison water level range is 89.41~100.43 m， the flow range is 69.31~9 122.57 m³/s， the maximum systematic error of the correlation line is 0.11%， the maximum uncertainty of the random machine is 7.80%， and the relative error is within ± 8%. Compared with the comparison results， the accuracy of various indicators meets the specification requirements， The water level discharge relation curve thus obtained can be used as the flow pushing scheme of Qilijie Hydrological Station. As a new non-contact instrument method， video flow measurement method has the advantages of fast measurement， safety and efficiency， full range monitoring， less affected by extreme conditions， low cost， high accuracy of flow measurement results， good safety， wide range of flow measurement， feasibility and strong potential for practical testing work， which can effectively improve the efficiency of flow measurement， reduce the intensity of field labor， and save human and material resources. The in-depth research， development and application of it can further promote the modernization and intelligent construction of hydrometry in China.

Urban flood disaster has become more frequent and serious due to the global climate change and rapid urbanization， which seriously affects the safety of people’s lives and the sustainable development of the society. Therefore， it is particularly important to study the assessment and disaster mechanism of urban flood disasters under the changing environment. There is still no widely accepted standard in flood hazard and risk assessment due to the varying perceptions and definitions of disasters by different researchers， and the flood hazard and risk assessment related indictors or methods are very uncertain and less objective. This study proposes a framework for analyzing flood disasters in Chikan District， Zhanjiang City， Guangdong Province by using k-means clustering and the Apriori algorithm. Firstly， k-means method is used to cluster each flood influencing factor. Secondly， association rule mining is used to identify the best precipitation index for evaluating flood disasters. Finally， environmental factors such as elevation， slope， impermeability and distance from the river are selected as flood influencing factors. They are combined with the best precipitation index and historical flood disaster data to extract association rules to investigate the forming mechanisms of different levels of flood disasters.Results show that flood hazards are frequent in this region， especially in urbanized areas with high impermeability， and gentle and low-lying areas are prone to more serious flood disasters. The accumulated 24-h rainfall is the most effective precipitation index in the Chikan District. When the inundation depth is 0.20~0.55 m for moderate waterlogging， the main hazard trigger is the distance from river （e.g.， less than 284.61 m）， and when the inundation depth is 0.55~1.00 m for severe waterlogging， the main trigger would be the slope （e.g.， less than 1.72°） and elevation （e.g.， -7~8 m）. In addition， as the most direct driving factor for the occurrence of moderate waterlogging events， the accumulated 24-h rainfall has decreased in the mechanism of severe waterlogging disasters， which indicates that the importance of environmental factors has increased in this case. These results would be helpful for providing procedures and solutions for urban flood risk management.

In order to flexibly use the prediction features of each independent model to perform high-precision coupled runoff forecasting in the study basin under the premise of considering the applicable conditions of each hydrological model， this paper constructs a multi-model runoff forecasting method library covering Xinanjiang model， Tank model and TOPMODEL model， and introduces least squares， ridge regression and extreme gradient boosting tree methods to couple each independent model for hydrological forecasting. A multi-evaluation metric system is proposed to analyze the prediction performance of each coupled method. The conclusions show that the extreme gradient boosting tree method has stable prediction performance and strong generalization ability compared with the other two methods in the runoff forecasting of the Yajiang-Jiju interval in the Yalong River Basin， which provides a new idea for the runoff forecasting of other areas in the basin.

It is of great significance to study the flood stage characteristics of reservoir basin and realize the reservoir stage control operation to improve the comprehensive utilization benefit on the premise of ensuring flood control safety. Taking the Xiajiang Reservoir located at Ganjiang River as the research object， this paper studies the flood staging law by using the genetic analysis method， hydrological characteristic value statistical method and change point analysis method， and a comparative analysis is conducted based on the data of daily average discharge and annual maximum flood peak discharge from 1957 to 2017 of the representative hydrological station （Xiajiang Hydrological Station）. The results show that the rainstorm and flood in the Ganjiang River basin are mainly concentrated between April and September， where the flood between April and June is formed by the frontal rain， and the flood between July and September is generally formed by the typhoon storm. The flood in the middle and lower reaches of the Ganjiang River has obvious seasonal variation， and can be regarded as the main flood season from April to June， and the post-flood season from July to September. The staging results of hydrological characteristic value statistical method and change point analysis method are basically consistent， and the staging results of flood season are reasonable and robust. The major floods in Xiajiang Hydrological Station are mainly concentrated in May and June， with frequencies of 24.59% and 39.34%， respectively. The probability of large magnitude floods in the first half of July （from July 1 to July 15） is still relatively large. The main flood season is considered from early April to early July， and as the post-flood season from mid-late July to late September. According to the analytic results of various approaches， the main flood season of Xiajiang Reservoir is from April 1 to July 15， and the post-flood season is from July 16 to September 30， from the perspective of partial safety and considering the convenience of management and habits. In the divided main flood season， the annual flood peak is encapsulated and the flood occurs most frequently， while the number and magnitude of floods in the post-flood period are relatively small. The research results can provide technical support for the stage control operation and flood management of Xiajiang Reservoir in Ganjiang.

Major water transfer projects are large-scale public works. The investment and construction of major water transfer projects play a great role in China′s economic and social development. Due to the characteristic of one-time and unique， the governance of major water transfer projects has attracted extensive attention from all walks of life. At present， problems such as project overruns， low investment efficiency and poor operation efficiency occur frequently， so it is urgent to adopt effective governance models and mechanisms. To solve the above problems of major water transfer projects in China， based on the network governance theory， a mathematical model of multi-subject joint governance is established. By studying the cooperation mechanism of the government， project legal person， and the public， the optimal control rights allocation and optimal input levels of the three-party are solved to optimize the governance benefits of major water transfer projects. The simulation analysis is carried out to verify the influence characteristics of the control rights allocation and input levels of the three-party on the benefits of network governance. The results show that there is an “inverted U-shaped” relationship between the control rights allocation of the project legal person and the network governance benefits of major water transfer projects. When the control rights allocation of the project legal person is within the valid range， the governance benefits are the greatest. The input levels of the government and the public have an “umbrella” relationship with the governance benefit. When the input levels exceed the critical value， it will lead to the decline of governance benefits.

In order to explore the water hammer protection measures of large floating ship pumping station with high head， taking a single-stage rocker-arm floating ship pumping station in Yunnan Province as an example， this paper simulates the water hammer protection measures numerically. Finally， the combined protection measures of setting fast closing check valve after pump + setting air tank on the bank + setting micro-injection exhaust valve in the back section are proposed. The quick closing check valve ensures that the pump group does not reverse， the air tank solves the pressure oscillation problem of the water pipe， and the micro-injection exhaust valve effectively protects the negative pressure section. This protection scheme provides a reference for the water hammer protection design of floating ship pumping station under the conditions of steep front and slow back complex terrain.

Taking soda saline-alkali soil as the research object， the effect of lignite containing humic acid on water holding characteristics of soda saline-alkali soil is studied by the indoor culture method， and the correlation and regression analysis of soil water holding characteristics are conducted. The results show that the soil saturated water holding capacity， capillary water holding capacity， field water holding capacity， capillary porosity， non- capillary porosity and total porosity of lignite treatment are significantly higher than those of CK treatment （P<0.05）， and all show an increasing trend with the increase in lignite dosage， but the non-capillary porosity does not change significantly when the lignite dosage is low （<25%）. Water holding capacity is positively correlated with porosity and negatively correlated with bulk density and compactness （P<0.01）. The correlation coefficients of saturated water holding capacity， capillary water holding capacity and field water holding capacity with capillary porosity are 0.972， 0.972 and 0.965 respectively， with non-capillary porosity are 0.697， 0.691 and 0.672 respectively， with bulk density are -0.948， -0.948 and -0.943 respectively， and with compactness are -0.693， -0.694 and -0.677 respectively. The regression trend lines between soil water holding capacity and bulk density， and between soil water holding capacity and compactness both conform to the power function linear relationship of y=ax^b （a and b were constants）， and the goodness of fit is good. In conclusion， the application of lignite containing humic acid can effectively improve the porosity of soda saline-alkali soil and improve soil water holding capacity. The corresponding water holding capacity can be estimated indirectly by using the fitting equation between soil water holding capacity and bulk density， and between soil water holding capacity and compactness.

By using the TANK-MIKE 11 coupling model， which is suitable for simulating rainfall-runoff processes in shrimp and rice co-cropping fields in plain irrigation area， this paper studies the effects of regional drainage and waterlogging on typical shrimp and rice co-cropping fields in Sihu Basin. Under different rainfall standards， the influences of the proportion of cultivated area in shrimp paddy fields and the upper drainage depth of shrimp paddy fields on runoff in Sixin Dikes are simulated. The main conclusions are as follows： Compared with 50% of the existing shrimp rice co-cropping area， the external displacement has increased by 6%~28% and decreased by 3%~18% when the shrimp rice paddy area was 10% and 90%， respectively. Under various designs， compared with the upper drainage depth of shrimp ditch at 1.2 m， the flood peak flow has decreased by 3.01%~5.62%. At 1.4 m， the flood peak flow has decreased by 5.79%~10.36%.

Hardening constitutive model （HS model） has been applied to the numerical simulation of the foundation pit because it can better simulate the loading， unloading， shear and compression hardening characteristics of soft soil. As the pit area is widely distributed with deep and highly sensitive soft soils， the value of the soft soil HS model parameters is crucial to the stability of the excavation process and the impact analysis of the adjacent metro tunnel. The value of HS model parameters of soft soil is very important to the stability of foundation pit excavation process and the impact analysis of adjacent metro tunnel. In order to obtain HS model parameters， sensitivity and thixotropic ratio of soft soil， the hardening constitutive model parameters c \text{'} \mathrm{、} \phi \text{'} \mathrm{、} E_{\mathrm{o}\mathrm{e}\mathrm{d}}^{\mathrm{r}\mathrm{e}\mathrm{f}} \mathrm{、} E_{\mathrm{50}}^{\mathrm{r}\mathrm{e}\mathrm{f}} \mathrm{、} E_{\mathrm{u}\mathrm{r}}^{\mathrm{r}\mathrm{e}\mathrm{f}} of different depth sand thixotropic ratio are obtained by conventional triaxial tester，standard consolidation instrument and miniature vane shearing instrument， and the relationship among parameters \text{?} E_{\mathrm{o}\mathrm{e}\mathrm{d}}^{\mathrm{r}\mathrm{e}\mathrm{f}}、 E_{\mathrm{50}}^{\mathrm{r}\mathrm{e}\mathrm{f}}、 E_{\mathrm{u}\mathrm{r}}^{\mathrm{r}\mathrm{e}\mathrm{f}} and E_{\mathrm{s}\mathrm{1}-\mathrm{2}} are studied. The HS model parameters of soft soil in other areas are compared and summarized. The soil hardening model parameters obtained from the test results can provide a reference for deep excavations numerical simulation in similar soft soil areas.

Canal ice disaster is a common operation safety problem in water conveyance projects in cold regions of northern China. The main form of water diversion project is open channel water conveyance. In winter， due to the influence of cold temperature， the river channels in the northern region are prone to form bank ice， ice flowers， ice sheets， etc.， which will change the hydraulic conditions of the channels， affect the normal operation of the channels， and easily cause ice disaster. This study intends to explore the method of using the bottom layer warm water of offline reservoir to improve the water temperature of the main canal and prevent secondary disasters such as ice slush and ice jam， which is of great engineering significance for improving the water conveyance efficiency of the water transfer project in winter and ensuring the safe operation of the project in winter. The confluence of trunk and tributaries is a common hydraulic phenomenon in natural river networks and artificial channel networks. At the junction of open channels， the flow structure is complex and the hydraulic characteristics are unique，so the non isothermal mixing at the confluence is affected by its complex hydraulic characteristics. Taking a large water transfer project and its reservoirs along the line as the research object， this paper establishes a three-dimensional hydrodynamic thermodynamic coupling transport model by using the fluid simulation software Fluent to explore the non isothermal mixing law of reservoir canal intersection and the effect of reservoir warm water on the water temperature of the main canal when the mixing ratio and channel intersection angle are different. The simulation results show that： ① the hydraulic water temperature mixing in the downstream of the intersection has obvious three-dimensional distribution characteristics， and there are obvious low speed reflux separation areas and cross section secondary circulation areas in the downstream， and the average water temperature in the cross section is basically unchanged after 500m downstream of the intersection； ② The greater the mixing ratio is， the more turbulent the flow is， the larger the diffusion range of water temperature on the cross section is， and the greater the temperature rise value after the flow is evenly mixed， the maximum rise value is 1.25 ℃； ③ The larger the intersection angle is， the stronger the cross section circulation is， and the faster the mixing uniform rate is； The temperature difference is different after the water is mixed evenly under different intersection angle conditions. In order to ensure the mixing rate of water flow and the effect of water temperature rise， it is recommended to select the channel 60° intersection angle. The research results can provide ideas and data support for the active regulation of channel water temperature in winter and the improvement of water conveyance capacity.

Air vessel is a common water hammer protection measure in long-distance water transmission projects. In order to explore the effect of a variety of factors， based on the characteristic line method， combined with an actual project on the water pipeline for hydraulic transition process analysis， nine different combinations of parameters model is established to study the volume of the vessel， the vessel air-liquid ratio and vessel height diameter ratio on the effect of water hammer protection. The results show that the water hammer protection ability of the vessel increases with the increase in volume and gas-liquid ratio， and the decrease in height-diameter ratio， and the optimal parameters of the vessel are obtained from the perspective of economic efficiency and safety： volume 50.49 m3， height-diameter ratio 0.5， and gas-liquid ratio 1.2. In addition， through the comparison of twelve different groups of valve closing law schemes， it is found that the reasonable setting of the end valve closing time can not only reduce the size of the one-way tower， but also further improve the air vessel protection at the restricted water hammer.

Soil water and heat environment has an important impact on crop growth. In order to determine the characteristics of soil water and heat change and its meteorological impact factors in the Dongfeng Canal Irrigation Area， the soil temperature and moisture data in the irrigation area were observed for one year. The soil water and heat data in the irrigation area were processed and analyzed by using the coefficient of variation Cv and Pearson correlation method. The results show that： ① the soil temperature is higher in summer. Soil temperature of each layer is： surface soil > deep soil， which is low in winter. The soil temperature of each layer is： surface soil < deep soil. In the rainy season， the soil moisture fluctuates greatly and is relatively high， which reflects the water holding capacity of each layer of soil： 40 cm > 20 cm > 60 cm>10 cm. ② The fluctuation of soil temperature in sunny days is generally greater than that in rainy days， but when effective precipitation occurs in rainy days， the soil moisture fluctuates. ③ In non-rainy days， air temperature has the best correlation with soil temperature （positive correlation） and soil moisture （negative correlation）. In rainy days， the correlation between soil temperature and relative humidity is the best （positive correlation）， and the correlation between soil moisture and air temperature is the best （positive correlation）. The impact of meteorological factors on soil moisture and heat decreases gradually with the increase in soil depth. The research results are of great significance for improving the theory of soil water and heat change in irrigation areas and for soil water and heat management in agricultural production activities in irrigation areas.

The aim of this paper is to improve the understanding of water conservancy industry management and technical personnel on the revision of agricultural quota of irrigation water in Gansu Province， rationally allocate water resource， and improve the efficiency and benefit of agricultural irrigation water utilization. Based on the “Industrial Water Quota in Gansu Province （2022 Edition）”， this paper standardizes the industry code of agricultural quota of irrigation water， clarifies and supplemented the terms and definitions of agricultural quota of irrigation water， and redivided the original 5 agricultural irrigation subdivisions in Gansu Province into 12 by considering the level of agricultural economic development in the province， the trend of agricultural industrial structure adjustment， as well as regulations and requirements to meet the current and future demand of water resources. The analysis is based on the climatic resources， water resources， topography and crop planting layout of Gansu Province by using data measured from irrigation experimental stations and weather monitoring stations. This paper calculates the scientific research experimental platform of agricultural in the irrigation area， with the help of a series of meteorological， hydrological， soil and crop data， the adjustment coefficient of water source type and the conversion coefficient between the general value and the advanced value is determined， the irrigation system of the main crops under the condition of different designs of irrigation water supply guarantee rate is analyzed， at the same time the quota of irrigation water of 55 main crops in Gansu Province has been given. And we compared and analyzed the latest revision results of the state and neighboring provinces to modify it again. The results show that the coverage， rational， advanced and progressive of the conclusion is improved obviously. However， it is still necessary to revise the result at the right moment because of the dynamic， certain， different， mandatory and other characteristics of agricultural quota of irrigation water and the current limitation and transformation of the layout of agriculture.

In order to understand the role and effect of biochar on improving coastal saline soil under brackish water irrigation， two types of coastal saline soil （silty sand loam and sandy loam） are taken as research objects， and biochar treatment with different particle sizes （1~2 mm，<1 mm） and dosage （0， 2.5%， 5%） is set up to carry out corn pot experiment irrigated with 3 g/L brackish water. The results show that： ① Under brackish water irrigation， biochar decreases soil Na+concentration， electrical conductivity and bulk density. Soil bulk density， electrical conductivity and Na+mass concentration decreases by 4.7%~14.4%， 3.0%~14.3% and 4.1%~14.1% respectively. ② Biochar reduces the salt stress and oxidative stress of brackish water and saline soil on maize， and improves the photosynthetic capacity of maize. Chlorophyll mass fraction， net photosynthetic rate and stomatal conductance increases by 3.6%~11.7%， 3.5%~11.9% and 3.5%~11.7% respectively， and abscisic acid mass ratio， hydrogen peroxide and malondialdehyde concentration decreases by 1.7%~7.9%， 1.8%~8.7% and 1.6%~8.7% respectively. ③ Under the brackish water irrigation alone， the growth of corn is inhibited， and the yield decreases by 9.0%~9.9%. In the silt loam and sandy loam， the maximum yield increase in corn treated with biochar is 7.6% and 5.2%， respectively， compared with the brackish water treatment alone， while that of corn treated with fresh water is 3.1% and 4.6%， respectively. The appropriate application amount of biochar for the improvement of silty sand soil and sandy soil texture saline soil is 5% biochar with a grain size of 1~2 mm， and 5% biochar with a grain size of<1mm， which can effectively promote salt leaching and increase the yield of corn in saline soil.

Aiming at the problems of complex installation pipeline， low automation degree and low fertilizer utilization efficiency of the existing water and fertilizer integrated system， this study analyzed the working principle of the bypass fertilizer machine， designed the water and fertilizer ratio pipeline， electrical control component layout structure and dynamic display interface， and got a bypass fertilizer machine. The bypass fertilizer applicator has a high degree of automation and can adjust the precision of water and fertilizer. Combined with the field experiment results in Tongliao City， Inner Mongolia in 2015 and 2016， the practical application of the bypass fertilizer machine was verified. Compared with the differential pressure fertilization tank and rain-fed fertilization， the application of the bypass fertilizer machine in 2015 increased the yield by 12% and 69%， respectively. In 2016， the increase was 9% and 47%， respectively， and the water productivity of maize fertilized by the bypass fertilizer machine was the highest in two years， which were 1.87 and 1.81 kg/m3， respectively， showing significant economic benefits. The bypass fertilizer applicator has certain application significance in the field of high efficient water saving irrigation in modern agriculture.

Southwest China is rich in hydropower resources， but the extremely high and steep environmental slope in the dam site area has a height of hundreds of meters or even kilometers， and the slope is more than 50°~60°. The above hazard sources seriously threaten the construction and operation safety of hydropower projects， and are the key technical problems restricting the construction of hydropower projects. Focusing on the difficulties of investigation， prevention and control of ultra-high and steep environmental slopes， this paper carries out a systematic and in-depth research. Key technologies such as rapid and accurate investigation， systematic and efficient prevention and control and efficient integrated control have been developed and successfully applied in the prevention and control of ultra-high and steep environmental slopes of Wudongde Hydropower Station.

To improve the dynamic quality of hydropower units during the startup process， this paper proposes a multi-objective optimization method based on nonlinear model of hydropower turbine governing system （ HTGS）. A nonlinear model of the governing system is established in order to accurately describe the hydraulic and mechanical dynamic characteristics of the system. When the optimization targets are selected， the suppression of hydraulic pressure fluctuation and mechanical vibration is also considered comprehensively in addition to the requirement of fast and stable speed rise， so three objectives are selected： absolute value integral of relative error of speed， absolute value integral of relative error of water pressure at the inlet of voluteand relative value of maximum axial water thrust. Then the multi-objective particle swarm optimization （MOPSO） algorithm is used to optimize the opening law of the guide vane， and Pareto optimal solution sets are obtained， four solutions are selected in a weighted way for simulation experiment. The results show that the multi-objective optimization method can effectively suppress hydraulic pressure fluctuation and mechanical vibration while ensuring the steady rise of rotational speed， and achieve good control quality， it can provide decision-making support for the safe and stable operation of hydropower units.

Ascertaining slope disturbance deterioration mechanism of the reservoir slope in high seismic region under earthquake， reservoir water and human engineering activities actions is the key point of stability estimation and premise of scientific reasonable countermeasures done. Relying on a reservoir collapse-slide slope， its main disaster-causing factor， slope body disturbance and stability deterioration mechanism are discussed with surface survey and numerical computing combined on the basis of survey and design services， water storage and landslide bulletins of Three Gorges Immigration Bureau， correspondence of participating units and historical earthquake recording. And feasibility of engineering disposal is comprehensively estimated， too. Main conclusions are as follows. ① Engineering construction exerts little effect on the reservoir slope’s body disturbance and stability. Yongshan earthquake and Ludian earthquake both affect the slope. But Ludian earthquake with 1 339 times aftershock does more harm to slope body and remarkable loosening effect produced. High water level enhances shock loosening rock mass saturated softening. The whole slope stability is basic-to-not stable， front local stability being not-to-losing stable. ② Deformation traces on slope top and surface are historical ones， which don’t expand. ③To meet 1.30 safety standardization needs strength force being 20 015~197 421 kN/m， reinforcement depth being 60~180 m and reinforcement scope being 350~980 m. It is difficult to meet reinforcement aim by engineering measures. ④The reservoir slope is estimated comprehensively. Because it is hard to reinforce by regular engineering measures， giving up the bridge under construction is suggested.

The dam seepage flow directly reflects the safety condition in the dam structure， so the accuracy， long-term stability and reliability of seepage monitoring data are very important for dam safety. According to the problems in the application of the low-flow seepage meter developed in the earlier period of the investigation and research， the optimal design is carried out. The separation of measurement and drainage is realized by the design of the rotating measuring vessel， which not only simplifies the structure of the instrument and reduces the cost of the instrument， but also solves such problems as unreliable volumetric methods under the influence of water erosion and seepage. By adding the design of wave-proof pipes and spillway boards， and optimizing the design of liquid level switches， the measuring precision of the instrument is improved， and the more accurate data basis is provided for dam seepage monitoring， the problem that the instrument cannot continue to measure after recharging increases the reliability of the instrument and has wider adaptability. The device adopts zero-valve design， which solves the problem that the valve is jammed or cannot be completely closed due to the silt entering the valve， and the measurement is abnormal or cannot be measured， and improves the long-term stability and poor reliability of the instrument， the self-cleaning device is increased， the maintenance workload of the instrument is reduced， and the adaptability of the instrument is enhanced. Through a performance test in the factory and practical application in four hydropower stations， it is proved that the optimized instrument has advantages like high measuring precision， good reliability and long-term stability， simple structure and convenient field installation， and provides reliable guarantee for dam seepage monitoring.

Baihetan Hydropower Station started water storage on April 6， 2021， and the water level reached a maximum of 816.51m on September 30， 2021， after which the water level began to fall back to about 790 m at the end of February 2022. Based on the seepage monitoring data during stage impoundment， the engineering and geological conditions of the dam site area and the seepage control arrangement scheme， the seepage state of the dam foundation of Baihetan Hydropower Station is analyzed and the possible seepage channels of the dam foundation are speculated. The analysis results show that the seepage volume of the riverbed foundation is influenced by the upstream water level. The water storage， the maximum seepage volume of the riverbed foundation reaches 1 226.37 L/min， which is 784.78 L/min higher than that before the water storage. Besides， the increase mainly concentrated in 15^# and 16^# dam sections.Nevertheless， the seepage volumes of the left and right bank foundations are relatively small， and are affected by the upstream water level and rainfall. At 816.51 m water level， the reduction coefficients of the lifting pressure before the curtain are 0.73~0.97， after curtain are 0.07~0.30， and at the main drainage curtain are 0~0.07. The uplift pressure at the foundation of the dam is effectively reduced because of the presence of the seepage control system. It is presumed that the leakage water flows downstream through the weak part of the impermeable curtain， with strata P₂β₃ ^2-2 and P₂β₃ ^2-1 as the main water-conducting stratum. Combined with the weak structure developed in the stratum， the leakage water flows toward the drainage holes located in the dam foundation， resulting in a significantly higher seepage volume in some dam sections than in others. In general， the seepage state of the dam foundation is stable during the stage impoundment. Besides， the seepage control arrangement scheme of the dam is reasonable and the seepage control effect is good.

The post-relocation support funds for large and medium-sized reservoirs are related to the immediate interests of the immigrant， and are of great significance to the social stability of the resettlement areas and the reservoir areas. Based on the use and implementation effects of the post-support funds in 13 sample counties （cities， districts） in the GX Autonomous Region in 2021， this paper uses the DEA model to measure the efficiency of post-support funds and analyze related factors. The research results show that the pure technical efficiency value of the post-support funds in each county is good， the overall efficiency is mainly affected by the scale efficiency， and the allocation scale needs to be further optimized to improve the redundancy problem in capital investment. The calculation result of the slack variable matches the actual situation， which can be used as an effective basis for adjusting the direction of capital use. From the data analysis， it can be seen that the key points to improve the use efficiency of post-support funds are： to explore the blocking points in the use of post-support funds based on the efficiency evaluation results， to adjust and optimize the distribution scale and usage direction of post-support funds， and to make a reasonable layout based on the actual needs of immigrants.

Soil-rock mixture is a kind of discontinuous medium with different particle sizes， complex material composition and irregular structure distribution. Its mechanical properties are affected by a variety of factors. In this paper， discrete element simulation program PFC2D is used to establish discrete element model for direct shear test of soil-rock mixture. The direct shear test is carried out to simulate the mixture with different stone content， different gravel - soil particle size ratio and different bond strength， and to study its influence on shear strength and failure characteristics of soil-rock mixture. The results show that the discrete element simulation is similar to the laboratory experiment， which proves that the discrete element shear model is highly reliable. When the stone content increases， dilatancy and strain hardening are more obvious. The shear stress peak of the sample with particle size ratio of 10 times is the largest. The peak shear stress is positively correlated with the change of bond force， while the residual strength is less affected by the cohesive force. The research results are helpful to further reveal the shear strength and deformation characteristics of soil-rock mixture.

Under the new power system， intermittent new energy sources such as wind power and photovoltaics are connected to the power grid on a large scale， which puts forward higher requirements for the Automatic Generation Control （AGC） of hydropower plants that undertake the task of peak regulation. The new demand for AGC for hydropower plants under the background of the development of new power systems are analyzed， an improved AGC system architecture for hydropower plants is proposed， and key technologies such as data flow optimization design， on-site installation implementation， parallel computing system and scenario applicability improvement are studied. The improved AGC devices for hydropower plants have been applied to projects such as Gutianxi Hydropower Plant.， and the research result indicates that the new device can effectively improve the response rate of AGC of hydropower plants， which helps to improve the operational stability of the power grid.

Aiming at the problem of energy utilization of low-velocity turbines in irrigation canals， this paper proposes a fishtail vertical shaft impeller with dual-drive design， and uses the method of combining CFD numerical simulation with physical model test to analyze the hydrodynamic properties and power of the impeller. The results show that for the micro-water flow turbine equipped with the deflector cover， the dual-drive design can increase the energy utilization rate； the imitation fishtail can optimize the rotation performance of the impeller； the imitation fishtail double-drive vertical axis impeller has better energy utilization and hydrodynamic performance than the ordinary horizontal impeller at the low flow rate of the micro-water head.

The satisfaction degree of reservoir resettlement is an important basis for measuring the level of resettlement work and improving the focus of resettlement work. In order to reasonably evaluate the satisfaction of reservoir resettlement， this paper， starting from the perspective of resettlement， combined with the characteristics and content of resettlement work， establishes a satisfaction evaluation index system， and comprehensively evaluates the index through an improved matter-element extension model based on asymmetric proximity， and takes the QP reservoir in HN province as an example to verify the applicability and rationality of the model. Finally， a Logistic regression model is established to further analyze the impact of migrant families' own factors on resettlement satisfaction. It is concluded that the per capita disposable income and the understanding of resettlement policies are the most significant influencing factors， and corresponding suggestions are put forward to improve the resettlement satisfaction of migrants according to the results of satisfaction evaluation and analysis of influencing factors.

In the reservoir resettlement， resettlement willingness is very important to the subsequent development and stability of immigrants. This paper extends it according to the planned behavior theory， constructs a more systematic interpretation framework for the choice of resettlement methods of immigrant families， and uses the structural equation model to analyze the influencing factors and influencing paths of resettlement willingness based on the resettlement data of CSD reservoir in HN Province， which has been completed and obtained high satisfaction. The results show that the psychological expectation， learning and cognitive ability， recovery and adaptability of immigrants are important factors affecting resettlement willingness. At the same time， the external conditions also indirectly affect their resettlement willingness through the migration attitude. In addition， the observation variables corresponding to each potential variable have a positive or negative impact on the choice of resettlement methods. Finally， combined with the analysis results， aiming at the possible conflicts and problems in the process of resettlement， this paper puts forward some suggestions， such as guiding the selection of resettlement methods， reducing the living costs and relocation risks of urban resettlement immigrants， and allowing immigrants to choose a variety of resettlement methods.