The phytoplankton community structure is an important parameter for water eutrophication evaluation，and its density and species composition can be used to evaluate the water eutrophication． However，there is less eutrophication evaluation，and less study on the river eutrophication by phytoplankton in the Huaihe River． December 2012，July 2013，December 2013，and July and December 2014． 5 field experiments are carried out on 10 ecological monitoring sections in the upper and middle reaches of Huaihe River，and phytoplankton species，density and water physicochemical indexes have been got． Eutrophication status are evaluated by phytoplankton indicator biological method，abundance assessment method and comprehensive nutrition state index method． The results show that during the study period，Bacillariophyta and Chlorophyta occupy the dominant position，and the dominant species are different in the different monitoring sections，and Bacillariophyta and Chlorophyta are the dominant species． On the whole，water body eutrophication is greater in the middle and downstream of Shaying River than the monitoring sections of Shaying River upstream and Huai River．

This paper Bases on the theory of institutional change, and analyzes the evolution process, the motives of changing, and the path choices of the River Chief system from the aspects of the causes of institutional change, the way of institutional change, and the subjects of institutional change. The River Chief system stems from the crisis of water resources and the water management system crisis. The original system could not better solve externality and transaction costs. it eventually formed the River Chief system under the influence of induced institutional change and mandatory institutional change.

Complete outdoor randomized trials are used to study how green Myriophyllum Verticillatum＇s water purification effect respond to the concentration of ammonia nitrogen，nitrate nitrogen and total phosphorus in water． We find that: Green Myriophyllum Verticillatum can purify water best in a stationary environment when ammonia nitrogen and nitrate nitrogen are 25，15 mg /L respectively． The concentration threshold of ammonia nitrogen and nitrous nitrogen exists in water purification effect，and the purification effect is positively correlated with concentration under the threshold． In the environment of high ammonia nitrogen concentration between 15 ～ 25 mg /L，green Myriophyllum Verticillatum is more affinity for ammonia nitrogen and can inhibit the absorption of nitrous nitrogen，and then makes nitrous nitrogen purification worse． Purification is also positively correlated with concentration when total phosphorus is under 35 mg /L． Besides，high total phosphorus can promote the absorption of ammonia nitrogen，nitrous nitrogen and total phosphorus，and improve the removal rate． Green Myriophyllum Verticillatum is more suitable for purifying high phosphorus water． The removal rate of ammonia nitrogen，nitrous nitrogen and total phosphorus can arrive at 78． 1% ～ 81． 1%，59． 1% ～ 63． 9%，85． 7% ～ 91． 9% after 30 d under the summer environment，and is more significant for total phosphorus and ammonia nitrogen．

The potential ability of rainfall lead to soil erosion that is called rainfall erosivity，research its changes is significant for forecast soil erosion． Around the Songtao Reservoir has become a more serious and concentrate area of erosion in Hainan Province． The method of Empirical Orthogonal Function and Mann －Kendall was used to analyze the changes of spatial and temporal pattern for 25 meteorological stations from 1975－2015 annual and seasonal rainfall erosivity in Songtao Reservoir Basin． This paper concludes that: ① Rainfall erosivity of the basin shows a spatial pattern is larger in east and smaller in south． ② Due to dry and wet rains and typhoons，annual and seasonal rainfall erosivity shows inconsistent trends，summer，fall and winter after 1993＇s age of rainfall erosivity increased was raised． ③ The spatial structure of annual and seasonal rainfall erosivity has difference，the area where rainfall erosivity increased are mainly concentrated in annual south，spring＇s central and west，summer＇s north，autumn＇s east and north，winter＇s southeast． ④ There is an anti－phase change pattern of rainfall erosivity in year and season within basin，it is maybe about the difference of uneven rainfall during the year． Due to heavy rain and number of rainstorms in Hainan is increasing，since the 1990s the trend of rainfall erosivity is on raise． At present，there have been reports of rainfall and soil erosion in the Songtao Reservoir Basin． However，it is rare to research the rainfall erosivity in this basin，hope this study can provide a theoretical basis and formulate related to policies for protecting the ecological environment of the basin．

A two－dimensional mathematical model for suspended sediment transport is established under combined waves and currents． On the basis of full verification of the model，the tidal current and sediment in the sea area of Yangxi Power Station in Guangdong Province are numerically simulated，the characteristics of tidal current field and sediment field are analyzed，and the change of erosion and deposition in the vicinity of the sea engineering area as well as sudden siltation after storm are calculated． The results show that after the implementation of the engineering project，there is a relatively large flow pattern change around the intake and drainage outlet，both sides of the breakwater as well as the east side of the breakwater． The velocity in the area around the drainage outlet increases evidently，increasing by 167%． The east side and the south side of the intake are siltation area and the annual thickness of the siltation is 0．1m/a to 0．2 m/a． After the breakwater is lengthened，the area on the east side of the dike will erode，the maximum thickness of the erosion is around 0．2 m/a． Under the effect of the typhoon，the sediment concentration in the sea area increases obviously，resulting in a strong siltation in the harbor basin and around the water intake，especially the southeastern side of the intake，and thickness of the siltation is 0．20 to 0．25 m around the water intake． The area on the east side of the breakwater head will erode after the breakwater is lengthened，and the maximum thickness of the erosion can reach 0．5 m．

In the process of beautiful countryside construction in Jiangxi Province, combining with the management of water ecological environment, integrating ecological civilization construction and rural revitalization, different types of water ecological civilized village construction model under actual conditions are initially formed, such as the natural and ecological type (ecological protection - pastoral planting - leisure sightseeing), industry development type (land circulation - uniform planning - green development) and safety-guaranteed type (river protection - soil and water conservation - ecological use). The construction of water ecological civilized villages requires the promotion of governments’ support and peasants’ participation. The government tries to create the necessary basic conditions for rural development. At the same time, it needs to mobilize and encourage farmers to actively participate the constructions and support the development of peasant organizations.

Considering the characteristics and requirements of flood prevention in Shijiazhuang City，based on the internal hydrodynamic model of city． the risk monitoring and warning system for urban waterlogging in Shijiazhuang City is established in this paper and the functional structure，system framework and model construction principle of the system are introduced in detail． A typical product waterlogging caused by heavy rain process in 2017，for example，is used to verify this system comparison． Results show that the system realize the function，the simulation precision and stability can reach the expected design goal，to meet the demand of business use．

In order to study the differences of water supply sources for different river reaches in various periods，then provide data support for the hydrological cycle research of Lancang River，large variation ranges were observed for δD ( －16．90% ～ －12．50%) and δ18O ( －2．012% ～ －1．694%) in the dry season，δD ( －10．55% ～ －7．65%) and δ18O ( －1．438% ～ －1．102%) in the wet season by measuring δD and δ18O values of the surface water of Lancang River in Yunnan Province during the dry season ( February 2017) and the wet season ( June 2017) ．The spatial distribution characteristics of hydrogen and oxygen isotopes in the watershed were preliminarily revealed． The results showed that:The variation trends of δD and δ18O values of the surface water of Lancang River in Yunnan Province during the dry season were similar to those during the wet season and that Moreover，δD and δ18O values in the dry season were much lower than those in the wet season． During the dry season，the surface water in the upstream natural reach of the study area was mainly influenced by glacier snowmelt and the strong evaporation，in the middle reach by the evaporation and the tributary inflow，and in the downstream natural reach by the precipitation． During the wet season，the surface water of the whole Lancang River in Yunnan Province was mainly affected by the precipitation． Meanwhile，the surface water in the middle reach was somewhat affected by the tributary inflow，and in the downstream natural reach by human activities．

Setting the Yellow River source area as the research area，a macro－scale land surface hydrological model is established． The model is then applied to carry out numerical simulations of hydrological cycle in the basin between 1971 and 2014． Simulation accuracy is calibrated and validated by using discharge data from main gauging stations located at main streams． The results of simulations indicate that，water balance coefficient is close to 1，and correlation coefficient is higher than 0．85，with Nash efficiency factor higher than 0．72． Therefore，the capacity of the model to simulate peak flows is yet to be improved． While the spatial and temporal distribution of the main elements of hydrological cycle simulated has a relatively high precision and accuracy，this model can be applied to simulate hydrological cycle in the Yellow River source area．

An indicator frame system of water vulnerability is established by water resources pressure－development pressure－ecosystem health－management capacity by using the fuzzy mathematics and entropy weight method of comprehensive evaluation to assess the water resources vulnerability of Shanxi Province from 2010 to 2016． The result indicates that water resources vulnerability inter － annual variation is not obvious of Taiyuan City，belongs to the medium fragile． The water resources vulnerability of the rest city is basically decreasing in the remaining seven years，and the middle vulnerability gradually improved to mild vulnerability in Datong，Yangquan，Linfen，Jincheng， Jinzhong City．

Takes the artificial excavation of the river channel as the research object in the coastal watershed，and uses the hydrological analysis software MIKE BASIN as the simulation platform． Under the condition of lack of data resources，the application of the schematic catchment area and the application of the NAM rainfall runoff model are applied． The preliminary model of the river flow hydrological simulation model was constructed，and the model was verified by two methods: sample segmentation method and similar watershed evaluation method． The results show that the calibration and verification process of the model is successful，and the hydrological change process under the special terrain condition and data loss conditions can be simulated． It shows that the MIKE BASIN/NAM model is used for artificial excavation in plain areas． The river section has strong applicability．

The variable-parameter probabilistic distribution model is one of the important methods to describe the probabilistic distribution characteristics of the nonstationary hydrological extreme series. The best model is determined by analyzing the fitting effects of different variable parameter probability distribution models. However, because the change rule of the variable-parameter probabilistic distribution model is unknown, the best-fitting model may not accurately represent the probability distribution characteristics of the non-stationary series, resulting in a certain uncertainty. Therefore, this study proposes the synthesis of multi-model calculations. Constructing several variable-parameter probabilistic distribution models, and some suitable models were selected based on the Akaike information criterion. Hydrological design values of selected models were deduced using equivalent reliability methods. The estimation results of different models were weighted and synthesized to obtain comprehensive design values to reduce the influence of model selection on the uncertainty of hydrological design values and improve the reliability of hydrological frequency analysis results.

The characteristics of the pipe drainage project are analyzed and the typical pipe drainage area is selected for periodic monitoring in this paper based on the field investigation of the underground pipe drainage engineering in Yinbei irrigation area of Ningxia. On the one hand, it affirms their enormous function in treating the saline disaster and ameliorating the mid-and-low-yield farmlands. On the other hand, in order to provide reference for the planning and design, construction and operation management of these projects in Northern Yinchuan or other similar irrigation areas, it sorts out all technical problems and existing disadvantages after investigating the present situation of drainage projects in the irrigation area and puts forward constructive suggestions.

In order to find out the regularity of rill morphological changes under unsteady flow, this research investigated the geometry of the transverse section of the rill and the influence of various factors on it under four types of flow combinations (increased, uniform, concave and peak) and five slopes (4°, 6°, 8°, 10° and 12°) in the loess area based on the indoor artificial simulation water discharge scouring experiment. The results showed that: (1) Cross-sectional width-depth ratio of the rill was between 1.97 and 5.32, and both of them decreased with the increase of slope; The influence of flow change had no obvious effect under the same slope. The cross-sectional morphology co-efficient was between 0.29 and 0.54. (2) The cross-sectional shape of the increased and peak type rills was mainly "inverted trapezoid"; the uniform cross-section of the rill was mainly "V-shaped" inner wall convex; the concave type cross-section of the rill was mainly "deep V-shaped". (3) The pit development co-efficient SP of the longitudinal section morphological characteristics was between 1.014 and 1.100, and the pit development co-efficient increased with the increase of the slope, and the SP of the peak type was the largest under each slope.

In order to study the change rule of annual average groundwater salinity in the Yichang Irrigation District of Hetao Region, this paper selects annual evaporation, water diversion and annual groundwater depth as the influencing factors, and establishes the annual average groundwater salinity based on the Support Vector Machine method（SVM）. The prediction model was compared with multiple regression prediction model and Back-Propagation Artificial Neural Network（BPANN)）prediction model. The results show that the multiple regression prediction model has poor prediction accuracy, and the BP neural network prediction model has greater accuracy than the multivariate regression model, and has certain prediction accuracy. But the prediction effect of the SVM prediction model is the best, and the determination coefficient reaches 0.81. Basically consistent with the actual situation in the area. From this, it can be seen that the SVM method is practical and feasible in the prediction of annual average salinity in the irrigation area, providing new ideas for groundwater research and ecological environment improvement in the irrigation area.

In order to reveal the situation of soil pollution caused by livestock and poultry breeding in the plain area of Haihe River Basin，eighty－eight soil samples including eight sampling sites inside and outside of four typical pig，cow，sheep and chicken farms are collected in Guantao county，Hebei Province． The heavy metals ( Pb，Cd，As，Hg，Cr) and nutrients( TN，TP，NO－3，NH+4 ) concentrations are analyzed．The vertical distribution of the heavy metals shows that livestock and poultry breeding have little impact on heavy metals in the soil environment． Heavy metal concentrations are within the secondary standard of the soil environmental quality standard both inside and outside of the farms，and heavy metal concentrations in most of the points are within the first standard of the soil environmental quality standard．Livestock and poultry breeding have a great influence on the content of soil nutrients，and nutrients are enriched in the surface soil． The concentrations of nutrients on the surface soil of each farm are extremely high，while the nutrients concentrations decrease rapidly with the depth of the soil profile． As a result，the concentrations of pollutants reach the natural background value at the depth around 60 cm ( the deepest up to 100 cm) ．

In order to find out the effect of contaminated soil containing residual film on wetting body characteristics of point source infiltration, the experiment was carried out with three factors, namely different initial soil moisture, soil bulk destiny and emitter flow rate, using the method of indoor soil box simulation and using 360 kg·hm-2 residual film quantity. The process of soil wetting front and the characteristics of aspect ratio under different drip discharge were studied. The results showed that the wetting front migration distance increased with the increase of initial soil moisture and emitter flow rate at the same infiltration time. The horizontal migration distance increased with the increase of soil bulk density under different soil bulk density, while the vertical migration distance decreased with the increase of soil bulk density. The relationship between the characteristic value of soil wetting body and time was power function, and based on this, the prediction model of horizontal and vertical migration distance of wetting front was established respectively. With the increase of irrigation duration, the aspect ratio gradually decreased and it negatively correlated with flow. Under different drip discharge, aspect ratio and infiltration time was also power function, the determining coefficient R2 was more than 0.98.

To study alfalfa buried under the condition of drip irrigation fertilization, fertilization rate, drop head design flow, drip irrigation belt buried depth on the influence of the drip irrigation belt drop head congestion, preliminary to the following conclusion: use 2 years later, the clogging of the drop head accounted for 3.6%, 1.9% completely blocked. So the drip irrigation belt that use 2 years blockage to a lesser degree. Trials found that drip with buried depth of drip irrigation belt head drops flow effect is not obvious in fertilizing times, fertilizer rate is not obvious effects on drip irrigation belt congestion; With the increase of drip irrigation belt design head flow, drip drop head with actual flow lower percentage is increasing. Design flow of 3.0 L/h drops head flow lower percentage is 10.33%, is a design flow of 1.38 L/h drop head flow 3 times lower percentage.

This study was conducted to investigate the effects of soil salinity on growth and physiology of processing tomato． The experiment is in barrel form，different salt content soil were prepared． It was studied the changes of physiological growth indices，chlorophyll parameters of processing tomato under soil salinity under drip irrigation conditions． The results show that，the effects of S1 on the growth indexes of processed tomatoes，net photosynthetic rate Pn，transpiration rate Tr，stomatal conductance Gs，leaf water use efficiency WUE and chlorophyll content were promoted to a certain extent，but there was no significant ( P＞ 0．05) ． S2 and S3 showed inhibition on the above indexes． Compared with CK，S1 treatment increased yield by 2．1%，S2 and S3 treatment decreased yield by 18．7% and 65．4%． Generally speaking，S3 treatment inhibited the growth and development of processing tomato most significantly． In the late growth stage，the decrease of photosynthetic capacity of processed tomato was mainly caused by non－stomatal limiting factors of stomatal closure caused by high salinity stress

In order to solve the problems of poor information sharing ability and low intelligence level of water use decision－making in large－scale irrigation districts，a universal smart irrigation system for large－scale irrigation district is developed based on B/ S architecture and some technologies including real－time information collection and distribution optimization，real－time information monitoring，real－time irrigation forecasting model，canal dynamic water distribution model，internet technology，and gate monitoring and control technology． The system consists of 6 modules: information monitoring subsystem，information communication subsystem，historical and real－time data management subsystem，real－time irrigation forecasting and canal dynamic water distribution subsystem，gate monitoring and control subsystem，and file management subsystem． The system is applied to the Ganfu Plains Irrigation District，realizing comprehensive real－time monitoring of water use information，optimization management of water distribution，and monitoring and control of gate． Compared with traditional management model，it saves 15% of water use and improved water use management level in large－scale irrigation districts．

The distributed hydrological model effectively combines the topography of the basin, including the characteristics of the geographic information such as basin boundary, slope, flow direction, river network, etc. It takes into account the uneven spatial and temporal distribution of rainfall, underlying surface conditions, etc., and is the hotspot of hydrological model research at this stage. one. In this paper, a grid-based distributed Xin'anjiang model is constructed based on the storage regulation of reservoirs, and it is used in the flood forecasting of Puding reservoir and Gaoche hydrology stations in the Sancha river basin in the upper reaches of Wujiang River. The results show that the flood simulation Nash efficiency coefficients of Puding Reservoir and Gaoche hydrology stations reached 0.85 and 0.95, which can provide support for flood forecasting in this area and precipitation warning at any point in the basin.

Considering the dynamic change characteristics of the construction flood season，the scheduling process of the limited emergency resources is analyzed，and the logical relation of solving the emergency resource adjustment problem in the construction flood season is clarified，and the factors that the resource scheduling needs to be considered are clarified． Based on the basic equations of Markov theory，the basic equations for emergency resource scheduling in flood season construction are transformed，and an emergency resource scheduling model is established． For the emergency resource scheduling alternatives for the critical state of the construction flood season，the initial solution of the contingency resource scheduling is drawn up，the emergency resource scheduling model is replaced，the expected cost under each scheduling strategy is calculated，the scheduling scheme selection is iteratively optimized，and the optimal scheduling scheme for the emergency resources of the construction flood season is sought． The results show that the emergency resource scheduling of construction flood season based on Markov chain theory can balance the emergency cost and emergency time at the same time to ensure the safety of the flood season，and the emergency resource scheduling solution for the construction of the flood season is in line with the engineering practice，and the calculation method is simple，which can provide a scientific basis for the engineering practice．

The Hangjiahu area is located in the Yangtze River Delta plain river network area． With the rapid development of urbanization in recent years，the underlying surface and condition of hydraulic projects have changed greatly compared to the project condition when flood control planning in Taihu Basin． Especially for the urban expansion and reduction of water body outside the polder，the flood control ituation has become more severe． A hydrology and hydrodynamics model for Hangjiahu area was proposed in this paper． The negative influence of change of land use pattern on flood control was simulated． The flood control situation of Hangjiahu area was analyzed and the governance measures were proposed． The effect of plan for flood control projects in near feature was simulated． The results showed that the capacity of regional flood discharge after the implementation of the scheme is enhanced，and the maximum flood levels would drop significantly． The flood control requirement of Hangjiahu area would be satisfied，the sustainable development of economy and society in the region is ensured．

According to the meteorological drought in Zigong area，the daily average temperature，precipitation and soil humidity of meteorological data are chosen to get the precipitation anomaly percentage，wetness index，soil moisture content and SPI index． The weight of the indicator is determined by the method of weighted in order to avoid casualness of subjective weight． The comprehensive evaluation model of regional historical drought is established based on improved TOPSIS，it can reasonably determine the classification of drought by Evaluation Index． The results indicate that Improved TOPSIS model of evaluation is the same as the actual condition． Due to the evaluation and monitoring the space－time distribution of the precipitation and different time scale，there are some differences of drought evaluation between evaluate and monitoring results in April and May． Through an analysis of the distribution of precipitation and soil moisture analysis，the evaluation results of the improved TOPSIS method is objective and exactly the same as the actual condition． So this valuation methodology is suitable for classification of drought comprehensive assessment of Zigong．

For gravity dams with weak foundation, the creep behavior of the bedrock causes the stress of the foundation to adjust with time. The present elastic-plastic calculation can not obtain the long-term deep sliding stability of the dam. In this paper, the creep-considered strength reduction method based on Cvisc model and the conventional elastic-plastic strength reduction method were used to calculate the deep anti-sliding stability through typical examples, and the results were compared. The results show that the safety factor of deep anti-sliding stability of gravity dam is smaller and the displacement of characteristic points is larger when the creep characteristics of bedrock are considered. When the foundation rock of gravity dam is weak and the creep characteristics are obvious, the influence of the creep characteristics of the foundation rock on the deep sliding stability of the dam must be fully considered.

The design of foundation pit is the process of ensuring the safety and reliability of the supporting structure and then searching for more economic and reasonable combination of design parameters by multiple trial calculations． It is highly professional and high dependence on the designer＇s practice experience． We treat each calculation as test and use the principle of uniform design to reasonably arrange the trial calculation scheme，which can effectively reduce the experience dependence of the designers，reduce the number of trial calculations，improve the efficiency of the foundation pit design，and ensure the safety and economy of foundation pit support structure． This research takes the foundation pit support of gravity retaining wall of cement soil mixing pile in deep soft soil area as an example． We choose the width of retaining wall，the embedded depth，the depth and width of soil reinforcement in the passive zone as parameters of the uniform design test．And based on the regression analysis of test results，we establish the approximate function relationship between the safety indexes and the design parameters． Aiming at the minimum volume of cement soil mixing gravity retaining wall，we combine the requirements of standard as the constraint conditions，establish the programming solution，and complete quickly the optimization of design parameters of the supporting structure of foundation pit． Finally，based on the principle of uniform design，we obtain the design flow chart of the foundation pit．

In order to study the scouring effect of water flow on the weak interlayer with continuous cracks，an infinitely extended runoff－seepage coupled hydraulic scouring model is established． The model uses the Navier－Stokes equation to describe the fracture flow in the fracture channel，and uses the Brinkman－extended Darcy equation to describe the seepage of the rock and soil in the weak interlayer． Then，based on the boundary conditions of equal flow velocity and continuous shear stress at the interface of different media，the velocity distribution in each medium is derived． According to the mathematical relationship between the incipient flow velocity and the force，the critical incipient velocity of the soil particles at the bottom of the crack is derived． Considering the friction effect of the bottom soil particles washed by the water flow and combined runoff－seepage coupled hydraulic erosion model，solving the critical depth of the soil particles at the bottom of the crack channel when washed by water flow． The analysis shows that the critical water depth increases with the weight of the particles and the cohesive force between the particles，and decreases with the slope of the crack channel，the porosity and permeability of the rock mass．

Aiming at the problem of optimal control of differential settlement of rigid and flexible structures in deep silt foundations，the differential settlement transition between rigid piled seawalls and flexible earth－rock seawalls foundation treatment is analyzed． And the large finite element calculation software is used to adopt three different foundation treatment schemes for the transition section of the rigid－flexible structure． The results of settlement and differential displacement under the three different foundation treatment schemes of the joint section are presented． Calculation results show that the maximum post－construction settlement of the seawall near the earth－rock embankment at the bottom of the pile foundation frame is 16．02 cm，which is 3．88 cm less than that of scheme 2，and 4．02 cm less than scheme 1，and scheme 3． When the overall integrity of the frame embankment is good． Finally，through actual project monitoring data，it is shown that the design of scheme 3 achieves the expected differential settlement control effect．

To consider the effect of partial aeration in discharge flow out of diversion outlet structure, three-dimensional numerical simulation including turbulence model, air entrainment model and drift-flux model was utilized to simulate a practical diversion project. Firstly, the CATIA software was used to build the geometric model with complex terrain that matched the real project. Then, based on RNG turbulence model, the air entrainment module and TruVOF method tracing free surface in Flow-3D software, the whole flow field of the diversion project considering partial aeration of the spillway flow was calculated, the distribution rule of water flow regime, water level, flow velocity and bottom pressure in the spillway was obtained. Compare the computing results with the results of model test, the results show that the numerical simulation had better results, and reasonability of the upstream cofferdam design elevation is verified. The numerical simulation with air entrainment module of three-dimensional flow field obtained better velocity distribution, pressure distribution, the aeration concentration, aeration range of the flow, which provides one theory and method for flow field calculation of similar river diversion project.

The rational use of water resources in irrigation districts has always been the key to the development of water－saving agriculture in China． According to the actual demand of Shule River Irrigation Area，this paper develops an automatic gate system based on the original channel gate． The system consists of an automatic metering gate installed on the channel and a monitoring system running at the remote central station． It can realize closed－loop control according to the target flow or the total amount of water flowing through the gate，so as to supply water on demand． The test shows that the system realizes the intelligent control of the canal gate and the reasonable distribution of field water，with complete functions，high reliability，and convenient operation and maintenance． It can effectively improve the utilization rate of water resources in irrigation districts．

In order to study the effects of final-stage Seal Clearance on pressure pulsation distribution characteristics in chambers of multistage centrifugal pump,the steady and unsteady flow field numerical simulation of the two stage centrifugal pump was carried out on the basis of the three combination models of final-stage seal clearance, the RNG k-ε turbulence model are used,based on the ANSYS-CFX software.The numerical results was compared with the experimental data, verifying the reliability of the numerical calculation model and method.The steady pressure distribution trend and unsteady time domain and frequency domain distribution characteristics of multistage centrifugal pump was obtained under the working condition.The results showed that the constant pressure coefficient of the first stage pump chamber increases and the constant pressure coefficient of the final stage pump chamber gradually decreases with the increase of the final-stage seal clearance under the working condition,the wider final seal clearance facilitates rapid pressure decay inside the pump chamber with high pressure and the attenuation is maximized,the pulse frequency of the pressure pulsation in the first and last stage pump chambers are the blade passing frequency under different final seal clearances.

Taking a centrifugal pump rotor as a research object, the stiffness and damping of the centrifugal pump seal is done and used in “wet” critical speed analysis. 3D finite element model was done by ANSYS software to analyze the critical speed. Compared to dry condition, the critical speed of wet condition increased. The first order “wet” critical speed is 4738r/min, which is much larger than the actual speed 2980r/min. Meanwhile, using APDL program to reduce the 3D centrifugal modal under wet condition due to many degrees of freedom, stress stiffening and Coriolis effect are considered. 68% degrees of freedom of pump rotor model was reduced. The maximum critical speed error is 0.17%. Unbalance response calculated by the reduced modal is just the same as the non-reduced modal.

In order to ensure the safety，reliability and efficiency of operation for Dayuanzi Pumping Station，a method of three－dimensional turbulent flow numerical simulation is used as the optimum hydraulic design of the inlet and outlet conduits． Uniformity of axial velocity distribution，water flow weighted mean angle and drag coefficient，which are based on the result of numerical calculation of three－dimensional flow field，are used as integrated evaluation indicators of inlet flow． Average velocity distribution of outflow and hydraulic loss are used as integrated evaluation indicators of outlet flow． The results indicate the regularity of hydraulic performance，which is influenced by the internal curvature radius of elbow－shaped inlet conduit and the external curvature radius of bow－shaped outlet conduit，curvature radius which is too sharp or too small turns out to be no good to an excellent hydraulic performance． Appearance of separation vortex form transition of the bow－shaped outlet conduit is inevitable，the more continuity of change of curvature radius of bow－shaped outlet conduit and the more smooth of the line type，the better hydraulic performance; the consideration of linear optimization contains the result of theoretical flow numerical simulation and the actual works of conduit．

The inlet sumps are shared by many units in large pump stations. The flow pattern in the inlet sump varies with the operation of different units, and the flow conditions at the inlet of the flow passage are also different. Combined with a pump station project, a three-dimensional mathematical model is used to simulate the inlet flow pattern of the pumping station. The uniformity of flow velocity and the weighted average deviation angle of flow velocity at the inlet of the passageways are taken as the judging indexes of the flow regime. The results show that the inlet conditions of pump station are different with different power-on combinations，and mainly reflected in the weighted average drift angle of velocity. The inlet conditions of adjacent units of pumping stations are better than those of interval operation，also intermediate units are better than that of two side units. According to the full combination test research, the better combination scheme for different units starting is put forward. The research results can be used as reference for similar projects.

Based on the cavitation model，the Mixture multiphase flow model and model of SST k－ε，at the angle of attack of the committee of 8 ° in NACA－ 0016 type on the three－dimensional airfoil increasing airfoil surface roughness and micro holes are simulated on the basis of the analysis． The influence of the surface roughness of micropore and airfoil on the cavitation performance and hydraulic performance of airfoil are determined according to the variation factors of air bubble share distribution，lift coefficient，drag coefficient and lift － drag ratio coefficient． The research results show that the multiphase flow and the cavitation model can well simulate the three dimensional airfoil cavitation conditions，and the simulation results increasing airfoil surface roughness and micro hole of the airfoil cavitation has certain effect，but that will increase the airfoil surface roughness of the airfoil hydraulic characteristics have a certain impact． This paper only studies the airfoil profile，and it can be used to further study the cavitation simulation of turbine blade in practical engineering．

Lazhai Hydropower Station is characterized by high water head，high sediment concentration in the reservoir，a long distance from the intake of the power station and small discharge of the bottom outlet． It is not feasible to adopt the conventional sand－washing bottom outlet to discharge sediment． By using the natural topographic conditions at the entrance of diversion tunnel，a spur dike is added to the upstream of the dam，and the diversion tunnel is rebuilt into a flood－discharge and sediment－scouring tunnel． A complete sediment－discharge funnel is formed． Through theoretical calculation and model experiment of the funnel，the results show that the theoretical calculation value of the longitudinal and transverse slope of the funnel is basically close to the experiment value of the model，and the transverse slope of the fun．The gradient of the funnel is steeper than that of the longitudinal funnel． The height of the top of the spur dike is higher than that of the top of the sand funnel，and the spur dike effectively cuts off the upstream sediment． A funnel with a diameter of about 92 m is formed on the riverbed and runs through the banks of the reservoir． The sediment passage is cut off on the left and right banks． The sediment is directly led into the funnel and discharged into the lower reaches of the dam through the flood－discharge and sand－washing tunnel． The effective storage capacity is maintained to ensure that the intake reaches the“gate clearance”and the normal power generation of the power station． The discharge velocity，siltation thickness in front of the hole，the longitudinal and transverse slope of the scouring funnel are basically within the range of 11 scouring funnels．