According to the characteristics of the Zongyang nature-like fishway and the requirements of fish passing， a three-dimensional generalized turbulent numerical model of fishway pools under the continuous bend arrangement is established. And the optimization idea of the flow conditions is put forward. Through the gradual improvement of five schemes， the flow conditions in the fishway pools are optimized， and the structural layout parameters of pools are obtained. The results show that under the comprehensive influence of various factors， the flow pattern in the fishway pools is extremely complex. By adopting some measures such as increasing the offset distance of the vertical slot and prolonging the main flow path， reducing the width of the vertical slot and increasing the local resistance， shortening the length of fishway pools and increasing the resistance， the flow velocity in the fishway pools can be reduced. At the same time， the curvature of the main stream should be controlled and the excessive deviation from the center line of the adjacent vertical slot should be avoided to cause flow disorder. Under the recommended fishway layout， the maximum velocity in the vertical slot area can be basically controlled at 0.7~0.9 m/s， the main flow in pools is clear， and the flow pattern is good， which can basically satisfy the fish passing requirements. The relevant research methods can provide a reference for similar projects.

After the implementation of the river （lake） chief system， the shoreline boundary and protection scope of Yunnan Province have not been delimited， which brings many difficulties to the control of lake shoreline space. Taking Qilu Lake as an example， the characteristics of periodicity and equilibrium of lake water level change are analyzed by wavelet function and the Gini coefficient， and the ecological water level， water boundary and outer boundary are determined by the method of water level guarantee rate， flood regulation and development. ① The water level of Qilu Lake has oscillation periods of 10， 15 and 25 years， with 25 years as the first main period， showing an insignificant upward trend. There are two abrupt changes in 1969 and 2009， with the most prominent one in 2009. The characteristics of water level change revealed by the Gini coefficient and precipitation fluctuation index are consistent with the results of wavelet analysis. ② The minimum ecological water level ranges from 1 793.72 to 1 794.90 m， reaching the lowest in May and June while reaching the highest in December. The suitable ecological water level varies between 1 794.35 and 1 795.39 m， and the optimal ecological water level varies between 1 795.22 and 1 796.21 m. ③ The boundary of the water is 1 793.92 m when lake water ecological restoration， basin water resources allocation planning and water supply security are considered. The optimal ecological water level of lake water ecological restoration and the factors of promoting flood control are taken into account， the outer boundary of the lake bank is 1 796.62 m. The results indicate that the operating water level stipulated by the Lake Protection Regulations can meet the requirements of shoreline demarcation and control. ④ Based on a spatial superposition analysis of the GF-3 satellite images， the shoreline space is designated as a protected area. This paper analyzes problems in shoreline management from the perspectives of responsibility transmission， supported means and social participation， and formulates the basic rules and requirements of shoreline management and control.

In order to study the improvement of highland barley fiber on the mechanical properties of ecological concrete， NaOH， NaOH+H₂O₂， or glacial acetic acid + NaClO₂ are used to modify the surface of highland barley fibers. The optimum modification method is sought through the orthogonal test. Meanwhile， with the assistance of modern material testing methods like XRD， FTIR， SEM etc.， modification effects are evaluated from different perspectives. The highland barley fiber before and after modification is then mixed into ecological concrete， measuring its compressive， splitting tensile and flexural strength respectively to analyze modification effect and its influence on the mechanical properties of the ecological concrete. The results show that the pretreatment of highland barley fiber with 6%NaOH+10%H₂O₂ solution at 40~50 ℃ has a superior surface modification effect. In addition， the incorporation of fibers has decreased the pore contents inside the ecological concrete. The compressive strength of fiber ecological concrete is lower than that of ordinary ecological concrete， while its tensile and bending resistance are significantly enhanced. Compared to unmodified fiber concrete， the 28 d compressive， flexural， and splitting tensile strengths of modified fiber concrete has increased by 4.3%， 16.5% and 20.3% respectively. Hence， cellulose in highland barley fiber is effectively purified， which greatly improves the integrity and toughness of the ecological concrete structure.

Domestic waste water is an important source of natural water pollution. The treated domestic waste water is discharged into natural water bodies through the pipe network， which has a serious impact on the quality of the receiving water body. The water quality monitoring data from Taihu Lake and the plant-resolved and actual operation data of 212 waste water treatment plants in Taihu Lake from 2007 to 2015 are collected and analyzed in order to accurately predict the total nitrogen in Taihu Lake. The Pearson correlation coefficient is used to calculate the relationship between Taihu Lake water quality and the WWTP effluent indexes. For the top five items with high correlation， three machine learning models， K-Nearest Neighbors （KNN）， Decision Tree， and AdaBoost are used to predict the monthly average TN in Taihu Lake. In general， AdaBoost has higher precision and better accuracy， with a goodness-of-fit index of 0.84 and a root mean square error less than 14.08%， which establishes a good mathematical model for predicting of TN concentration of Taihu Lake. Meanwhile， the model finds that NO₃-N， NH₄-N， TP in Taihu Lake and NH₄-N in effluent of WWTP can cause an important impact on the TN concentration of Taihu Lake.

To solve the water treatment engineering of biological filter bed gravel drive technology in the process of application of filter bed scale parameters and different size， different boundary conditions to determine the filter bed with different regional conditions， different degree of pollution of river pollution treatment effect simulation prediction problem， this paper is used as an example in Hanzhong water system based on water quality QUAL2k model to generalize the experimental monitoring results combining the indoor small simulations under different working conditions of gravel filter bed of river water quality purification effect. The results show that the maximum removal rates of NH₄ ⁺-N， PO₄ ^3--P and COD of the filter bed at 200 m in summer are 51.5%， 54.3% and 54.1%， respectively， which can improve the PO₄ ^3--P and COD of the controlled cut water to the Class Ⅲ water standard and NH₄ ⁺-N to the Class Ⅳ water standard. In winter， the removal rates of NH₄ ⁺-N， PO₄ ^3--P and COD of the 400 m filter bed are 68.6%， 57.5% and 51.1%， respectively， realizing the water quality goal of COD reaching Class Ⅲ water and PO₄ ^3--P approaching Class Ⅳ water.

The microbial-dominated denitrification process is the main way to absorb the loss of non-point source nitrogen in flooded sediments. At present， there are plentiful researches on the influence of environmental factors on the denitrification process， but the law of denitrification under the influence of periphyton is still unclear. Through the submerged sediment culture experiment， the nitrogen denitrification rate， and total of 17 indicators of the overlying water-peripheral organisms-sediment system influencing denitrification process are measured， and the PLSR model is used to explore the influence of various factors on the denitrification and absorption of non-point source nitrogen in the sediment， and to find out the main control factor and avoid the problem of collinearity between factors. The results show that the pH， NH⁴⁺-N， NO^3--N， DOC in the overlying water and the CHI in the periphyton are the main influencing factors in the denitrification process of the sediment. More attention is paid to the research on periphyton. The water-soil interface can demonstrate the mechanism of nitrogen denitrification loss process and provide a theoretical basis for non-point source pollution control.

Limited by the shoreline planning， Yalan wharf only chooses site in the branch between Ruxi shoal and upper shoal at Jiepai reach， which is accompanied by dredging of harbor basin and approach channel. As a kind of special wharf embedded in the shoal， the downstream is often close to the shoal regulation buildings， such as spur dikes， and the riverbed evolution and channel conditions of the reach are complex. In order to study the influence of the wharf pile group and large-scale dredging on the channel conditions， this paper adopts the physical model test of Jiepai reach to determine the scope and degree of influence， including the changes of water level， velocity， branch diversion ratio and riverbed erosion and deposition before and after the implementation of the engineering are analyzed. The results show that the engineering construction has little impact on the navigation flow conditions of the main shipping channel of the Yangtze River. However， due to the combined action of wharf piles and dredging of approach channel， the left edge of upper shoal head is scoured. To a certain extent， scouring affects the shoal protection function of spur dike， and compensation engineering needs to be implemented to mitigate this adverse impact.

Due to limited monitoring points and insufficient pollution source data， the water quality simulated by traditional mathematical models has low accuracy. In this study， the Xiangxi River in the Three Gorges， where water blooms have frequently occurred in recent years， was used as the research area. A method was proposed to simulate water quality， using water quality remote sensing results as the initial conditions of the Environmental Fluid Dynamics Code （EFDC）. The multiple linear regression model was selected for remote sensing inversion， and the multiple correlation coefficients of the simulated and measured values of chlorophyll a （Chl-a）， total nitrogen （TN） and total phosphorus （TP） reached 0.983， 0.848 and 0.736， respectively. The results show that the proposed technology combining remote sensing with mathematical model can improve the effect of model simulation. Compared with using only limited in-situ data， this technology decreased the average error of the simulation of Chl-a from 3.96% to 3.84%， that of TN from 44.57% to 39.27%， and that of TP from 22.17% to 19.44%. The study shows that the technology coupling remote sensing with EFDC model has high practical value for the water quality simulations of rivers lacking observational data.

In view of the problems affecting the operation safety of the water flow characteristics of the lateral inflow inverted siphon， such as the flow characteristics are affected by the inflow and boundary conditions， the flow conditions of the pool are complex， which is easy to produce suction vortex. We took the Dali inverted siphon project of Dali Section II of the Yunnan-Dianzhong Water Delivery Project as an example. The gravity similarity and similar vortex were considered， and the physical model test method with a geometric scale of 1∶20 was used to study the flow pattern and vortex characteristic parameters of the lateral inlet inverted siphon. Research shows that： by adjusting the shape of the right side wall of the inlet pool， extending the diversion pier， adding integrated vortex board and trapezoidal vertical beam vortex elimination measures， the backflow and vortex of the inlet pool can be effectively eliminated to improve the flow pattern of the inverted siphon inlet and eliminate the suction before the inlet. The proposed vortex elimination measures applicable to the side-injection inverted siphon into the pool can stabilize the lateral flow， destroy the conditions for the vertical shaft vortex， and can better solve the flow pattern of the inverted siphon. The study can be used as a reference for the improvement of the bad flow pattern of lateral inflow.

It is easy to form large-scale sedimentation under the tide gate， which may have a serious impact on the operation of the project. As a new type of gate， the double-layer tide gate has been applied to many projects in Zhejiang Province， but its scouring and silting effect has not been systematically studied. Combined with the tidal gate project at the outlet of a large pump station， a 1∶25 physical model is established， and the hydraulic scouring and silting characteristics of different gates are studied with the scouring and silting effect and scouring and silting efficiency as indicators. The research shows that the hydraulic scouring and silting can be solved by running a pump station unit （20 m³/s） and opening the upper gate within the range of 1~2 m. The effective scouring and silting time under the gate under different working conditions is short， and gully stability time is generally less than 15 min. The lower the water level under the gate， the more favorable it is for sand flushing. Open the one-hole gate for operation， and the scouring and silting flow is relatively concentrated. The apron under the gate can be flushed out within 10 min. If the two-hole gate is opened for operation， the discharge per unit width of the gate can be reduced， which can effectively scour and silt in the initial stage， with high efficiency， but the apron cannot be flushed out completely， and the scouring and silting effect cannot be fully met. When the sedimentation under the sluice is high and the sediment is abundant， the flushing efficiency is relatively high. The double-layer tide gate has good scouring and silting efficiency and effect. The relevant results can be used as a reference for design and operation management

In order to investigate the degree of coupling， the level of coordinated development and its main constraints between the development and utilization of water resources and the sustainable development of socio-economy and eco-environment in northern China， this paper builds a coupling coordination evaluation model and quantitatively analyzed the development of water resources， socio-economy， eco-environment subsystems and the coupled systems from 2005 to 2019 on the scale of areas （Northeast， Northwest and North China） and administrative units （provinces and municipalities）. As shown by results， in the past 15 years， the development level of the three subsystems has all been continuously improved. Among them， the socio-economy subsystem has developed fastest， while the water resources subsystem has developed slowly. In addition， the coupling degree of the three subsystems has always been at a high-quality coupling level， indicating that these subsystems have a significant impact on each other. Although， the coupling coordinated development level of this composite system consists of water resources， socio-economy， and eco-environment has been continuously improved， it remains in the primary stage. That is to say， the coordinated development among the three subsystems is strengthening， while the unbalanced and discordant factors still exist. Relatively speaking， North China has been making up for the shortage of natural endowment of water resources by strengthening regional water resources management and optimizing water resource utilization efficiency and water use structure. Hence， the degree of coupling and coordination in North China is at the best level among the three northern regions， but seems to be relatively poor in Northeast and Northwest， where improving the structure and efficiency of water resources utilization further is needed.

Due to the limitations of a single drought index in evaluating drought， a new comprehensive drought index （ P C A_{\mathrm{p}\mathrm{r}\mathrm{s}}） is constructed to provide theoretical support for drought monitoring and defense in the Qinhe River Basin. Based on the hydrological and meteorological elements of the Qinhe River Basin simulated by the SWAT model， this paper calculates three drought indices in the Qinhe River Basin： Standardized Precipitation Evapotranspiration Index（SPEI）， Standardized Runoff Index（SRI）， Standardized Soil Moisture Index（SSI）. The combination of three drought indexes through Principal Component Analysis （PCA） methods constructs the Qinhe River Basin’s short-term， medium-term and long-term P C A_{\mathrm{p}\mathrm{r}\mathrm{s}}； the results show that： ① The constructed P C A_{\mathrm{p}\mathrm{r}\mathrm{s}} reflects the drought monitoring results that are consistent with actual drought events. Compared with a single drought index， \mathrm{P} \mathrm{C} {\mathrm{A}}_{\mathrm{p}\mathrm{r}\mathrm{s}} integrates precipitation， evapotranspiration， soil moisture and runoff and other factors， the description of the drought in the Qinhe River Basin is more realistic； the evaluation of the drought in the Qin River Basin is more comprehensive； ② P C A_{\mathrm{p}\mathrm{r}\mathrm{s}} of different time scales is more targeted for identifying drought events of different duration； ③ The short-term P C A_{\mathrm{p}\mathrm{r}\mathrm{s}} and the mid-term P C A_{\mathrm{p}\mathrm{r}\mathrm{s}} can be used to monitor the real-time changes of drought in the study area； and the long-term P C A_{\mathrm{p}\mathrm{r}\mathrm{s}} is more suitable for describing the long-term drought development trend. It shows that P C A_{\mathrm{p}\mathrm{r}\mathrm{s}} can be used for drought monitoring in the Qinhe River Basin， and provides a new reference for drought resistance research in this region.

Taking Tieshan Harbor Area as an example， based on the function superiority evaluation method， P-III type and generalized Pareto distribution are selected as the edge distribution models of rainfall and corresponding tide level respectively. Based on the graphic evaluation method， GH copula function is selected to construct the joint distribution of rain and tide level， the return period is designed by considering the combination of rain and tide， and the concept of secondary return period is introduced. By comparing the differences between the traditional return period and the secondary return period under different combinations of rain and tide， it is obtained that the range of rain and tide dangerous events defined by the secondary return period is wider and safer than that defined by the traditional return period， and the occurrence risk rate and conditional risk rate under different combinations of rain and tide levels are analyzed so as to provide a scientific basis for the flood control planning of Tieshan Harbor.

Water resources are the lifeblood of social and economic development in oases. In areas where water resources are scarce， water resources utilization efficiency is the key to the improvement of the regional water resources carrying capacity. Based on the water resources utilization data of Shule River Basin from 2005 to 2018， the factors affecting the water consumption of the basin are decomposed into economic effect， population effect， quota effect and industrial structure effect by using the logarithmic mean Di decomposition method （LMDI）， and the effects of different factors on the change of water consumption are analyzed. The decoupling elasticity index is introduced to further analyze the relative relationship between the economic effect with the largest cumulative effect and water consumption. The results show that ① In Shule River Basin， economic effect and population effect play a pulling effect on the change of water resources utilization. Industrial structure effect and quota effect are inhibitory effects. ② The comprehensive effect of basin water resources utilization is negative on the whole， which can be divided into two stages with 2010 as the boundary. In the first stage， the comprehensive effect of basin water resources utilization shows an upward trend. In the second stage， the comprehensive effect of water resources utilization shows a fluctuating downward trend. ③The decoupling state of water resources utilization and economic growth has experienced a process of strong decoupling， strong negative decoupling and recession decoupling. There are differences in the decoupling state of various industries， among which the decoupling state of the primary industry is the best.

Water price is an important tool for water demand management. At this stage， there is a huge potential for water conservation in China's residential water consumption， while urban residents' income also has an impact on water consumption. Therefore， under different urban conditions， how to effective use water price to guide residents to use water wisely is one of the most pressing challenges in water conservation. Using the VAR model with impulse response functions and variance decomposition， the study analyzed the impact of water price and income on residents’ water demand and their dynamics in eight typical cities across China， grouped in pairs according to water abundance， per capita disposable income and current water price levels. The results show that higher water prices can effectively suppress water demand， but the suppression effect decreases over time， while long-term lower water prices cannot effectively reflect water scarcity， making it difficult for residents to accurately understand the extent of water scarcity， and thus cannot effectively suppress water demand. The average contribution of water price to residential water demand in water-deficient cities is concentrated between 12.14% and 26.41%， generally higher than the 2.72% to 10.10% in water-rich cities； In the selected cities， the impact of water price on residential water demand is generally higher than that of income， while the pulling effect of income growth on water demand is relatively insignificant. On the contrary， higher-income can have a certain inhibitory effect on water demand. The water price should be adjusted according to local conditions in different cities， giving full play to the feedback effect of water price on the scarcity of water resources， specifying the periodicity of water price adjustment or setting the conditions for starting water price adjustment， timely and effectively transmit water conservation signals to residents， to reasonably control the water consumption of residents， and strictly control the unreasonable increase in the total amount of urban residents' water consumption.

The SWMM low-impact development module can simulate the hydrological effects of LID facilities under rainstorm scenarios， and is widely used in urban stormwater management in China. Taking the Xinqiao River Catchment in Bao’an District， Shenzhen as an example， this paper analyzes the sensitivity of multiple output variables of the SWMM model to the typical LID facilities. The output variables of the model include evaporation， rainwater infiltration， surface runoff and peak flow. LID facilities include vegetative swales， green roofs， bio-retention cells and permeable pavements. It also compares the consistency of the results of the three global sensitivity analysis methods （Morris Method， Sobol Method and EFAST Method）. The results show that the conductivity of bio-retention cells has the most significant impact on evaporation， rainwater infiltration and surface runoff， while the vegetation-volume fraction and conductivity of bio-retention cells have the most significant influence on the peak flow. The parameter sensitivities calculated by Morris Method， Sobol Method and EFAST Method are highly consistent. The comparative analysis of the three methods can effectively improve the reliability and accuracy of the sensitivity analysis of LID facility parameters， so as to provide technical support for the optimal design of a sponge city.

Based on the monthly precipitation data of rainfall stations in Jinzhong Area from 1958 to 2020， based on the flood records in historical documents， the occurrence law， frequency and the chain of floods are analyzed by using the methods of linear regression， Z-index and wavelet analysis. In the past 2382 years， the occurrence frequencies of flood disaster years， major flood disaster years and especially major flood disaster years in Jinzhong Area are 13.6%， 2.7% and 0.9% . The frequency of flood is accelerating， and the phenomenon of flood chain is very significant. From 1958 to 2020， the precipitation showed a downward trend， with the largest decline in summer， arranged in a U-shape on the whole， and precipitation was the most in 1960s. The frequency of continuous waterlogging is 17.5% in spring and summer， 25.4% in summer and autumn， and 4.8% in spring， summer and autumn. The main precipitation cycles are interannual 26 a， spring 24 a， summer 4 a and autumn 8 a.The rainstorm mainly occurs in July and August. The highest rainstorm frequency is Yushe， with an average annual frequency of 0.89 times. The rainstorm frequency in the trumpet mouth topographic area is significantly increased. Finally， the causes of rainstorm and flood are analyzed from the characteristics of underlying surface， landform， rainstorm characteristics， atmospheric circulation， Pacific temperature anomaly and Earth Day relationship in Jinzhong Area so as to provide reference basis for regional disaster prevention and reduction and water resources utilization.

Extreme events such as floods have brought serious ecological impacts and huge economic losses to our society， but the mechanism of these extreme events has not been fully understood. This paper takes the Yangtze River basin as the research area， and selects discharge data from 224 hydrological stations， and meteorological data measured at 247 meteorological stations in the Yangtze River Basin. Extreme precipitation and soil water storage are taken as flood driving forces. Our results show that both extreme rainfall events and floods occur from May to August， and the occurrence time of extreme events in different watersheds is related to latitude. For the dominant mechanism of floods， there are different dominant drivers in different regions， and there is a certain correlation between the dominant factors and the basin area.

Flood disaster is one of the most common natural disasters in China. The research on the risk assessment of regional flood disaster has become a hot topic in the field of disaster science and regional planning. In view of the flood disaster in Jingzhou City， Hubei Province in July 2020， the random forest model is used to complete the measurement of flood impact factor contribution rate and the construction of disaster risk assessment system in Jingzhou City， and then based on XGBoost model， regional flood risk assessment and regionalization are carried out. The results show that： ①The three indexes contributing most to the risk of flood disaster in Jingzhou City are the buffer zone of river system， flood storage area and night light intensity. Extreme daily rainfall， soil moisture， soil texture， proportion of cultivated land area and rainstorm days in recent 5 years also contributes significantly to flood disaster risk assessment.②The performance and prediction accuracy of the risk assessment model reaches the highest after the four indexes of land use type，slope aspect，vegetation coverage and distance from main roads decrease. ③The area of high risk area of flood disaster in Jingzhou is 15.30%， and the area of high risk area of flood disaster is distributed significantly along Honghu Lake， mainstream of Yangtze River and its subordinate tributaries. Therefore， Jingzhou is very important for the detection of water level of Yangtze River and the planning of the flood dike. Honghu City， eastern Jianli City， Gong’an County and Shishou City are the most vulnerable to the flood disaster in Jingzhou. Relevant management personnel should take timely measures to prevent and reduce disasters.

Actually， for the flood routing， one of the most common hydraulic methods is the discrete method for the simplified form of the Saint-Venant equations. However， this method has some problems such as numerical instability and slow calculation speed. It is also a challenge for the description of fluid motion by the macroscopic method. The Lattice Boltzmann Method takes the distribution function as the research object. In solving nonlinear partial differential equations，there is a need for transforming it into the Lattice Boltzmann Evolution Equation which is a simple linear equation for solving the slow calculation speed of the macroscopic method. In this paper， the linear diffusion wave equation is used to describe the flood wave motion in the river channel. Instead of using the space coordinate， it adopts the multi-scale expansion method with five time scales to establish the D1Q5 model of Lattice Boltzmann Method for the linear diffusion wave equation and then to inquire into the inference of the flood process of downstream. The Muskingum Method， analytical solution method and the D1Q5 model of Lattice Boltzmann Method applied in flood computation at the Longjie-Qiaojia upper reaches of the Changjiang River and Jiangnan-Fuxi downstream reaches of one hydropower station in Hunan Province. The simulation results of the flood peak relative error， peak appearance time and deterministic coefficient of the three methods are similar， which verifies the accuracy of Lattice Boltzmann Method. In addition， the influences of step length and relaxation time on calculation accuracy are also analyzed. The results show that the Lattice Boltzmann Method can effectively predict the flood process. And compared with the macroscopic method， the computational efficiency is greatly improved. The selection of space step value has a greater influence on calculation accuracy than the time step value. The appropriate space step should be selected， combined with the upstream and downstream section length. The value of the relaxation time is appropriate within the range of ［1.5，3］.

Henan is an important grain production base in China， but frequent drought has greatly hindered social and economic development. As an important index to reflect drought， the research on the dynamic change of soil moisture and its relationship with meteorological factors can provide a basis for scientifically understanding the occurrence and development law of drought and formulating control measures. Based on MODIS enhanced vegetation index （EVI） and corrected land surface temperature （LST） data to build a double parabola EVI-LST space， according to the characteristic space to calculate TVDI. ①The TVDI shows a significant negative correlation with 0~10 cm soil relative humidity in the same period （P<0.05），which can effectively reflect the soil moisture in Henan Province and can be used for soil moisture monitoring in this area. ② In the past 20 years， the main types of soil moisture in Henan Province changes from humid to normal， the turning point is 2012， and drought occurs every year， among which the drought occurs most frequently in the canyon areas from Sanmenxia， Luoyang to Pingdingshan. ③ The soil moisture has obvious regional differentiation in space， Eastern Henan Plains， Southern Henan Mountainous and Funiu Mountains in western Henan are relatively damp， while central and Northern Henan Mountains and Western Henan hills are arid. During the study period， the drought area expands to the southeast， and the soil moisture shows a slow drying trend as a whole. The areas with wetting trend and drought trend accounts for 29.71% and 60.27% respectively. ④ In meteorological factors， the increase in precipitation leads to the increase in soil moisture， while the increase in temperature leads to the decrease in soil moisture. In both， the influence of temperature on soil moisture is greater.

Water rights market is an important way to promote the optimal allocation of water resources. The evaluation of the performance of water right market （WRM） is vital to the improvement of the market. A performance evaluation index system is established from the aspects of equity， efficiency and sustainability. The TF-IDF algorithm is improved and used to calculate the index weight. Based on the questionnaire survey and statistical data， the performance of WRM in a well-irrigation district and an irrigation district dominated by surface water in Shiyang River Basin is evaluated. The performance of WRM in the two irrigation districts is evaluated to be moderate. The WRMs performs best in sustainability and worst inequity. The WRM in the well-irrigation district performs better than that in the irrigation district dominated by surface water. The performance of WRM in the irrigation district dominated by surface water shows a downward trend from 2008 to 2012. The performance difference of WRM between the irrigation districts is caused by water rights trading level， water rights monitoring mode， irrigation water source reliability and irrigation organization mode. Water rights trading policy has an important influence on the performance of WRM. Appropriate water rights policies should be adopted according to the temporal and spatial differences of the WRM. The improved TF-IDF algorithm can determine the index weight through quantitative analysis of the views of officials and scholars， which can provide new ideas for calculating the index weight.

In order to promote the use of unconventional water and relieve the pressure of agricultural water， the alleviating effect of biochar on the adverse effect of brackish water irrigation is explored. Through the experiment of barrel planting corn in rain shelter， three biochar application gradients of 0%， 2% and 5% and the salinity of fresh water， 4， 5 and 6 g/L irrigation water are set to determine the soil electrical conductivity （EC）， the contents of major salt ions （Na⁺， Ca²⁺， Mg²⁺， K⁺， Cl^-） and the distribution of soil particle size in different treatment stages. The effects of biochar and brackish water irrigation and their coupling on soil salt content and aggregate structure are systematically studied. The results show that： ① Brackish water irrigation will cause soil salt accumulation， and the application of biochar can effectively reduce the soil EC value， among which 2% biochar has the best effect. ② The changes in major salt ions in soil during the whole growth period of maize are basically the same under brackish water irrigation. Applying biochar in soil can reduce the content of soil main salt ions， but biochar cannot play an effective mitigation role when the salinity of irrigation water is high（6 g/L）. ③ Brackish water irrigation will destroy soil aggregate structure， and the greater the salinity of irrigation water， the greater the impact. The application of biochar can increase the number of soil water stable aggregates and alleviate the damage of brackish water irrigation to soil aggregate structure， and the application amount of 5% biochar has the best improvement effect. In general， 2% and 5% biochar can effectively improve the soil environment under 4g/L brackish water irrigation， which serves as a reference for the development and utilization of brackish water resources.

The objective is to improve the ability and level of agricultural drought early warning， this paper takes Baihe Irrigation District as the research area. The meteorological drought index SPI（Standardized Precipitation Index）is used and the agricultural drought index SSI（Standardized Storage Index）， the response relationship between the intensity and duration of two types droughts in Baihe irrigation area from 1990 to 2016 is analyzed. The results show that： ① The duration and intensity of agricultural drought are related not only to the duration and intensity of meteorological drought， but also to the process of crop water use in irrigation area. ② The duration and intensity of agricultural drought on the time scale of one month have the best response to the duration and intensity of meteorological drought of three months. ③ Compared with five different response relationships， and combined with the response degree of agricultural drought to meteorological drought on a one month time scale， the exponential model is the best response model of one month time scale agricultural drought to three months meteorological drought.The relationship between drought intensity and diachronic response are： y = 2.211 5 e^{0.101 7} x、y = 2.790 5 e^{0.078 2} x.

In order to clarify the effects of irrigation schedules and varieties on winter wheat yield traits and water use efficiency， 4 varieties （Heng 4399， Heng 4444， Hengmai 28 and Shimai 22） are selected from 2020 to 2021， and 5 are set in the field. Water treatment （non-irrigated control treatment-CK， 1 water-W1， 2 water-W2， 3 water-W3， 4 water-W4）， each irrigation quota is 75 mm， the ear traits， biomass， yield， components and water use efficiency of winter wheat are studied. The results of the study show that the ear length of winter wheat increases with the increase in irrigation times. The number of fruiting spikelets is the largest in W3 treatment， and the number of infertile spikelets is the smallest in W2 treatment. The proportion of stem biomass to total biomass increases with the increase in irrigation times. The biomass of Heng 4444， Hengmai 28 and Shimai 22 are significantly higher than Heng 4399. The number of ears per unit area of ??winter wheat increases with the increase in irrigation frequency， which is significantly affected by the irrigation system. In W3 treatment， the 1000-grain weight of Heng 4444， Hengmai 28 and Shimai 22 is the largest in W3 treatment， and Heng 4399 reaches the maximum in W4 treatment. The grain yield of W1， W2， W3， and W4 increases by 68.15% and 98.68 compared with CK treatment. %， 120.76% and 136.85%， Hengmai 28 increases by 12.53%， 6.33% and 6.55% compared with Heng 4399， Heng 4444 and Shimai 22 grain yield. Heng 4399 reaches the maximum water use efficiency of 2.39 kg/m³ in W3 treatment， Hengmai 28 Mai 28， Heng 4444 and Shi Mai 22 reaches the maximum 2.49， 2.48 and 2.43 kg/m³ in W2 treatment. In summary， Hengmai 28 combined with W2 irrigation treatment can achieve higher grain yield and water use efficiency.

Taking two kinds of typical coastal saline-alkali soil （silt loam and sandy loam） as the research object， different particle sizes （1~2 mm， <1 mm） and different addition amounts of biochar （0，2.5%， 5%） are applied. Then the pot experiment of tomato is carried out to determine the physical and chemical characteristics of soil and the yield and quality of tomatoes so as to understand the function and effect of biochar on improving coastal saline-alkali soil.The results show that： ① In addition to the 2.5% addition treatment in sandy loam， biochar significantly reduces soil bulk density， improves the three-phase ratio of soil， reduces conductivity and sodium adsorption ratio， increases soil nutrient content. And the soil physical and chemical properties of 5% biochar treatment are better than that of 2.5% biochar treatment. The effect of 1~2 mm biochar on reducing bulk density and conductivity is better， and the effect of < 1mm biochar on increasing part of nutrient content is better. ② Tomato yield is the highest in silty loam with 5% application of 1~2 mm particle size biochar， which is 20.6% higher than the control. Tomato yield is the highest in the sandy loam with 5% application of <1mm particle size biochar， which is 19.8% higher than the control. The mass concentrations of soluble solids， soluble sugar， vitamin C and titratable acid in tomato increases with the application of biochar， but there is no significant correlation with the particle size of biochar.

The structural characteristics of large vertical submersible pumps are different from vertical pumps. A series of excellent axial and mixed flow pump models has been developed in the construction of South-to-North Water Diversion Project and many large-scale pump stations in China. There is no hydraulic model for the development of vertical submersible pumps. This paper takes a large vertical submersible pumping station in China as an example. The existing hydraulic model is used for the similarity conversion of pump section characteristics， and the CFD is used to match the guide vanes that meet the structural requirements for device model test verification. The results show that the selection flow of vertical submersible pump is about 5.8% smaller and the device efficiency is about 2.66% lower by using the conventional hydraulic model. The variation trend of flow head efficiency predicted by CFD calculation is accurate. Without considering the influence of tip clearance and surface roughness， the flow rate is about two blade angles compared with the device model test， and the highest efficiency is about 3.5%. At the same time， for the large-scale development of submersible pumps， the idea of standardized vertical submersible pump section model test is proposed. The research idea of this paper provides a reference for the selection design and hydraulic model development of large vertical submersible pumps in the future.

In order to further optimize the pump station multi-unit combined operation mode and to reduce the pump station energy consumption， a dispatching model is established to minimize the daily power consumption of the pump station in our study. Aiming at the local convergence problem of genetic algorithm， a nonlinear fitness function based on genetic individual order is designed from the perspective of improved fitness function of genetic algorithm. Through the practical application in pumping stations， it is found that the improved fitness genetic algorithm （FFGA） is obviously better than the traditional genetic algorithm SGA in algorithm stability. The daily power consumption of optimal dispatching scheme of pumping stations by using the FFGA method is 1.77% and 8.07% lower than the SGA method and the practical method， respectively. The results can be useful to practical engineering.

Shaoguan is rich in hydropower resources. Most of them supply mountainous areas with power in the form of distributed small hydropower， and the grid structure in the power supply area is weak. When the main power supply line fails， the mode of splitting small hydropower units is often adopted， resulting in a waste of hydropower resources and reducing the power supply quality of residents in mountainous areas. In order to improve the operation efficiency of small hydropower stations and ensure the power supply reliability of residents in mountainous areas， a frequency modulation strategy of small hydropower microgrid considering parallel off grid mode switching is proposed in this paper. Fourier algorithm is used to analyze the signal flow， accurately obtain the unit frequency， realize and identify the off-grid state through frequency criterion， and adjust the working mode of hydropower unit in time. Discrete PID control algorithm is used to improve the stability of unit output frequency during off-grid operation. The application research on Ru-yuan 10 kV dong-xia-shan branch line verifies the effectiveness of the proposed strategy for the frequency modulation control of small hydropower microgrid， and has good application and popularization value for power grid in multi-hydropower mountainous areas.

Based on the questionnaire targeted at 324 sample farmers from 6 migrant villages in the monitoring and evaluation work of late migration support in Henan Province in 2020， this paper analyzes the influence mechanism of industrial development and social adaptation integration on the employment of rural relocation migrants through OLS and quantile regression. The results show that the development of eco-tourism industry， e-commerce industry， supply chain industry and promotion of livable and beautiful homeland construction have a significant positive effect on the improvement of the employment quality of rural migrants， while the return to agricultural production of migrants， post-stage support policy guarantee and employment skills training have no significant effect on the improvement of the employment quality of rural migrants. It is suggested that the development of non-agricultural employment industries be encouraged in resettled areas， the construction of beautiful homes for migrants be speeded up， the living standards of migrants be improved， and the integration of resettlement areas and reservoir areas be realized with high-quality social adaptation.

The computer supervision and control systems （CSCS） for the pumped storage power stations supplied by suppliers abroad， face problems such as equipment aging， insufficient system functions， spare parts， after-sale service， etc. This paper introduces the current technology status of the domestic pumped storage power station CSCS， describing and researching domestic modification schemes for CSCS of Pumped Storage Power Station. The paper analyses three ways of domestic modification for hydropower plants CSCS， then discusses those ways of domestic modification for pumped storage power station CSCS， summarizing two models： with middle transformation instruments added and with nothing added. The characteristics of those typical cases with middle transformation instruments added are discussed which are Zhanghewan Pumped Storage Power Station， Guangzhou B Pumped Storage Power Station， Guangzhou A Pumped Storage Power Station. This paper researches those problems in modification schemes for those cases which the LCU main computer is IPC with nonstandard communication protocol in it， Henan Baoquan Pumped Storage Power Station， Hubei Bailianhe Pumped Storage Power Station， Guangzhou Huizhou Pumped Storage Power Station. Based on the project of domestic modification for computer supervision and control system of Baoquan Pumped Storage Hydropower Station， studies its domestic modification schemes for computer supervision and control systems without any transformation instrument.

In order to clarify the hydration characteristics of the composite cementitious system in high performance concrete and boost the application of high performance concrete in water conservancy construction， the cement-slag-fly ash composite cementitious material is used as the research object， and assume the gradient structure low water-cement ratio to be 0.2， 0.25 and 0.3， the mortar strength test， chemical combined water method and scanning electron microscope observation， the effects of low water-cement ratio on the mechanical properties， hydration degree and microscopic morphology of high performance concrete cementing system are investigated by using the cement strength test， chemically bound water method and scanning electron microscope observation. The results of the study verifies that， the increase in water-cement ratio causes a linear decrease in the mechanical properties of the system， but the increase in water-cement ratio can significantly mitigate the mechanical loss when the fly ash-slag compounding amount is 40%~50%.The addition of fly ash slag increases the rate of hydration degree in the later stage of the composite system， and the positive hydration effect of pozzolanic reaction is more significant in the system with high water-gel ratio. When the water-binder ratio is 0.2 and 0.25， the growth rate of chemically bonded water and strength is similar. When the water-binder ratio is 0.3， the growth rate of chemically bonded water in the early stage of hydration is higher than that of the strength， but the growth rate of the strength in the late stage is higher than that of the bonded water. When the water-binder ratio is 0.2， the C-S-H morphology is spherically extruded together. When the water-binder ratio is 0.25， C-S-H is layered and stacked layer by layer. When the water-binder ratio is 0.3， C-S-H shows mesh fiber.

A three-dimensional finite element model based on an actual project is established to study anti-vibration performances of the plate-beam-column system in a pumped storage power plant. This paper studies the natural vibration characteristics of plate beams， thick plates， thick plates， side beams and the dynamic response under the pulsating pressure in the flow passage. It is found that when the boundary conditions around the plant are the same， three floor structure types， floor thickness and the small adjustment of the column section size have limited influence on their natural vibration characteristics. However， from the perspective of reducing the peak value of floor forced vibration response， when the excitation frequency in the spiral case channel is 35~45 Hz， the relatively preferred structural type is thick plate and side beam. When it is 50~60 Hz， the slab beam is better. When it is 65~75 Hz， the pure thick plate performs better， and increasing the plate thickness can reduce the vibration response. In addition， when the excitation frequency in the plant is close to the natural vibration frequency of the column， increasing the section size of the column has an obvious effect on reducing the vibration response of the column. Considering the complex vibration sources in the powerhouse of pumped storage power station， it is suggested that the anti-vibration optimization design of the powerhouse structure of pumped storage power station should be carried out by dynamic finite element method with the main objective of the number frequency of runner blades and its double frequency.

Based on the review of previous studies， a hydropower development benefit sharing model is constructed to quantify benefit sharing amount scientifically and rationally， and a case study is conducted. The results show that based on the stakeholder theory， the benefit sharing model can be established by net present value method. In this model main stakeholders such as immigrants taking the product of cumulative discount value of hydropower projects and its investment proportion as benefit sharing amount， which is affected by deterministic and uncertain factors. The latter can be predicted by Monte Carlo simulation method， and then the amount of benefit sharing is calculated. The case of Xiluodu Hydropower Station proves the feasibility and rationality of the model. Based on the results of the model， through the establishment of immigrants shared development fund and taking into account the interests of other interested parties， we can achieve a new mutually beneficial and win-win pattern of stable income of power stations， prosperity and stability of reservoir area， and wealthy of immigrants.

In order to explore the influence of different throat height on the hydraulic performance of winnowing inlet channel， establish inlet pools， inlet chamber and winnowing inlet channel inlet structure physical model and turbulence mathematical model， based on the Reynolds average N-S equation， the standard k-ε model is selected， SIMPLE algorithm is adopted， numerical simulation is carried out for the hydraulic performance of the dustpan inlet passage with the throat height of 0.7~0.9 times the impeller diameter， and the velocity distribution， hydraulic loss of the inlet passage， velocity distribution uniformity and velocity weighted average angle of the inlet passage with different throat height are analyzed. The results show that the flow velocity in the channel with high throat height is low and uneven after entering the winnowing chamber， the uniformity of flow velocity distribution at the outlet of the channel changes greatly with the flow， and the hydraulic loss of the channel is large. When the throat height is too low， the flow velocity is higher and the distribution is more uniform. The uniformity of flow velocity distribution has nothing to do with the flow size and the hydraulic loss of the flow passage is large. According to the analysis of the hydraulic performance of the channel at different throat heights， the optimal scheme is 0.8 times the impeller diameter. The hydraulic loss of the channel， the distribution uniformity of outlet velocity and the weighted average angle of velocity are 96.2% and 88° respectively， which are close to the ideal value of the objective function.

In view of the rough selection of hysteresis time in the existing statistical model of piezometric level in the earth-rock dam，it cannot reasonably reflect the cumulative hysteresis effect of reservoir water level and rainfall. This paper firstly introduces the hysteresis effect function to reflect the influence of continuous change of reservoir water level and rainfall on seepage. Then particle swarm optimization is used to identify the hysteresis days and influence days of reservoir water level and rainfall. Finally，a statistical model for piezometric level of the earth-rock dam considering hysteresis effect is established，and the effectiveness of the new model is demonstrated by combining nearly 20 years seepage monitoring data from the composite geomembrage embankment earth-rock dam of Wangfuzhou Hydraulic Project. The results show that compared with the traditional model， when the water level of piezometric fluctuates greatly， the statistical model with hysteresis function has a better fitting effect. The lag days influenced by the water level of GY5 section reservoir increase with the increase in the distance between the piezometric and the water surface. The monitoring data of GY5-2 are divided into 6 time periods and calculated. It is found that the lag days affected by reservoir water level basically remained stable at 16d， indicating that the working behavior of composite geomembrane in GY5 section maintained well.

Due to the characteristics of the rural water supply network， such as long data networking distance， a large number of monitoring points， and poor operating conditions of field equipment， it is difficult for the traditional networking methods to comprehensively take into account various requirements （i.e.， economics， reliability， and implementation difficulties） and problems （i.e. peripheral power supply support and coordination of the installation position）. A self-organizing wireless network-Ad Hoc， on the other hand， is an economical and efficient choice， especially in mountainous rural areas， pasture areas， and alpine regions. However， there are many limitations to the existing universal self-organizing network and supporting equipment， which makes it difficult to support the combined power supply of solar energy and battery, facilitate on-site installation and support low-end chips. In particular， long-distance communication through pipe networks is faced with practical problems， including the need to purchase base station relay equipment. Based on the central link planning method， this paper proposed a proprietary ad hoc wireless communication protocol for rural water supply networks， analyzed from the aspects of data packet definition， message forwarding mechanism， node relationship acquisition method， and central unified routing management strategy. Compared with the traditional methods， the hardware equipment based on this protocol reduce power consumption and allow the power supply of low-end chips and small solar panels， thereby enabling quick on-site installation without relying on peripheral power supplies. At the same time， this protocol can realize stable and efficient data networking and transmission without intermediate base stations.

In order to better fit the cavitation test data of the centrifugal pump， this paper sets up a closed horizontal centrifugal pump cavitation test rig and collects the cavitation test data. Firstly， three， four， five and six times of normal polynomial fitting are performed on the cavitation test data. The fitting effect of the five-order polynomial fitting method on the cavitation test data is better， but with the increase in fitting times， the oscillation of the cavitation curve becomes more serious. Secondly， PSO and WVPSO algorithms are used to perform piecewise polynomial fitting of the cavitation test data respectively. By comparing the fitting results of the two algorithms， it is found that WVPSO algorithm has a better fitting effect on the data， and it can eliminate the oscillation phenomenon of the cavitation curve after polynomial fitting， making the cavitation curve smoother.

The Phase-II Project of the Central Yunnan Water Diversion Project is a typical and rare complex pipe-canal combination system， in which the length of the pressure section accounts for about 69.7%. Automatic regulation is the key to ensuring the smooth deliveries of the whole diversion project. Taking the connecting section of Wuzhuang-village turnout as the study object， the one-dimensional unsteady flow numerical simulation platform of the pipe-canal combined system was developed based on the Preissmann Slot Method and Finite Difference Method. On the platform， the hydraulic response process of the study object under adverse scenarios was analyzed， and then the local flow controller`s parameters were optimized. The simulation results show that the control schemes of the pipeline pressure valve play a role of great significance and there is a high degree of nonlinearity and coupling. The shorter the valve control interval and the faster the valve speed， the more timely the system responds to the disturbance， and the better the comprehensive control performance， but the influence of the valve dead zone on the control effect is limited. After schemes comparison， it is recommended to adopt a pressure valve with a dead zone of 5 cm and a maximum opening and closing speed of 0.5 m/min. Moreover， the corresponding valve control frequency is set to 10 min/time. The research results and methods can provide references for the hydraulic automatic control of other connecting sections along the Phase-II Project of the Central Yunnan Water Diversion Project or other similar pipe-canal combined systems.

Aiming at exploring the effect of rotating stall on unsteady flow of solid-liquid two-phase centrifugal pump， this paper uses three-dimensional numerical simulation by Mixture multiphase flow model under four flow conditions of 0.25 Q_d~0.4 Q_d， and analyzes head-efficiency curve， internal liquid velocity distribution， solid volume fraction distribution and pressure pulsation characteristics are analyzed and calculated. The results show that under the condition of C_V = \mathrm{1} \%， the centrifugal pump head increases slightly and the efficiency decreases obviously as the flow rate decreases and enters the rotating stall condition. The rotating stall has a great influence on the flow field inside the centrifugal pump. The liquid flow rate in each passage of the centrifugal pump decreases， and the solid particles are concentrated on the back of the blade. When the flow rate decreases to 0.25 Q_d， the fluctuation of pressure pulsation is significantly more than that of other flow conditions. The stall vortex caused by rotating stall has a great influence on the pressure pulsation of the centrifugal pump. Due to the influence of stall vortex， the pressure pulsation waveform at the impeller outlet is chaotic， and the amplitude of pressure pulsation increases with the decrease in the flow rate.

The plastic tee pipe set at the bottom of the excavated canal section of the South-to-North Water Diversion Project is the key component of the connection between the check valve and the permeable concealed pipe at the canal foundation. In the restoration project of South-to-North Water Diversion Project’s canal， in order to form dry land restoration conditions， this paper proposes implementing gasbag plugging at this position to effectively block the connection of concealed pipes in the canal to form a relatively closed area so as to facilitate the maintenance of channel lining boards. The tee pipe of the main canal in the middle route of South-to-North Water Diversion Project is used as the prototype to carry out the equal scale indoor plugging test. Combined with the finite element software ABAQUS for numerical simulation， the stress distribution and evolution law of the plastic of plastic tee pipe under the local internal pressure formed by plugging gasbag are studied， and the strength evaluation is carried out. According to the analysis， the stress concentration of the tee pipe under the internal pressure of gasbag mainly appears on the shoulder and abdomen of the inner of the tee pipe.When the water level in the canal is 6m， that is， the upper limit of the pressure generated by the gasbag is 0.06 MPa， the tee pipe will not yield and produce local failure. So， it is considered that the tee pipe is safe and stable. The research results can provide a basis for the safety evaluation of tee pipe when gasbag is used for plugging in the channel repair project of South-to-North Water Transfer Project.