Accurate determination of soil moisture that takes into account spatial variability is the basis for timely and proper irrigation of crops The available maximum content of soil is the key parameter． Using the classical statistics and geo－statistics,we proposed a method to determine the sampling number and location of soil moisture monitoring optimization,and overcame the shortcoming of poor universality due to the measured soil water content as a parameter． Based on the 3．645 km2 in Beijing Daxing experimental area,we analyzed the spatial variability of soil available maximum content and proposed the optimal sampling number and location． The results are summarized as follows: ① The available maximum water content of soil was normal distribution at 0～ 40 cm and 0～ 80 cm depth,and their coefficients of variation were 14．96% and 13．56%,respectively which showed a medium scale variation． ② Under the circumstances of 90% confidence interval and Sampling error of 10%． The reasonable sampling number are six at 0 ～ 40 cm depth and five at 0 ～ 80 cm depth in the method of classical statistics and determined the specific layout of the location through the geo－statistical． ③ Compared with the measured soil water content of 129 samples,the error is less than 10%． Therefore,based on the available maximum water content of soil moisture monitoring optimization layout method can dramatically reduce the sampling number in the case of regional measurement accuracy assurance

A study ofTHE effect of different irrigation and nitrogen levels on eggplant canopy growth,fruit yield and quality was conducted． The facility eggplant was selected,and six treatments were set up under drip irrigation with the lower limit irrigation of 80%θFC and 70%θFC, and nitrogen level of 300,200,100 kg /hm2 ,respectively．The results indicated that,the results of plant height,stem diameter and leaf area were more under treatment of irrigation lower limit with 70%θFC and nitrogen level 200 kg /hm2,and were not significantly different between all the treatments(P＞0．05)． The yield of eggplant reached 55 603 kg /hm2 and the WUE reached 17．52 kg /m3 under treatment of irrigation lower limit with 70%θFC and nitrogen level 200 kg /hm2 ,which was significantly higher than the other treatments(P＜0．05)． Moreover,the total soluble sugar,reducibility Vc and fiber content can significantly increase under irrigation lower limit was 70%θFC ． The nitrate nitrogen concentration of eggplant increased with more application of nitrogen and reached the peak under 300 kg /hm2 nitrogen level treatment,the total soluble sugar,reducibility Vc were not significantly different between all the nitrogen treatments．In conclusion,the lower irrigation limit of 70% θFC and nitrogen level of 200 kg /hm2 can be a better combination for eggplant growth in greenhouses,under which treatment the canopy growth,fruit yield and quality were all under higher levels

In order to explore the effect of alternate micro-irrigation and different pressure head on the growth and development of Artemisia selengensis in greenhouses,the experiment was conducted with alternating irrigation of 1m pressure head for 12 days ( A treatment), alternate irrigationof 1．5 m pressure head for 12 days (B treatment) and normal irrigation (C treatment) three different treatments,each treatment repeated three times to analyze the growth of Artemisia selengensis and irrigation water utilization． The results show that Microirrigation irrigation treatment group of irrigation can be significantly reduced,the irrigation water productivity is 3．5 times and 2．4 times than that of ordinary irrigation,and the growth advantage of Artemisia major is obvious; In this experiment,the plant growth and yield of 1m pressure head treatment group were both higher than the pressure head of 1． 5 m,but as a new type of irrigation technology,a lot of experiments need to be done to constantly verify the application and promotion of micro-irrigation in the fields．

In view of the feature of abundant rainfall in the rice growing season in the south of China and the goal of saving water and increasing yield, seven kinds of irrigation and drainage patterns were designed to maximize the drought tolerance and flooding resistance during different growth stages of rice. The main results gained are as follows: 1. The traditional field irrigation and drainage management model showed that the main growth indexes tiller and plant height of rice in each growth period were better , but the irrigation water needed is also the most. 2, Excessive adjustment of deficit or regulation and storage, although water-saving effect is better,it is harmful for the growth and yield of rice. When soil moisture is less than 60% of the field capacity or paddy water depth greater than 350mm (over regulation), rice yield is the lowest. The excessive water deficit during heading stage had the greatest impact on the growth of rice throughout its growth period. 3. Moderate regulating irrigation and drainage management mode is the best irrigation management mode in the rainy area in southern China,in which the growth index and yield in each growth stage are the best. Not only the model takes advantage of the drought tolerance of rice,which can reduces the irrigation frequency and optimizes the environment of soil fertility in the field,but make good use of the flooding resistance, which can maximize the utilization of natural rainfall and realize the goal of water saving and yield increase. 4.The optimal parameters of field irrigation and drainage management in super hybrid rice were as follows: During water deficit time, the field soil moisture content should be 60% to 80% of the field capacity; during the rainfall period, Water depth should be controlled at 250mm to 350mm.

Targeted at the actual problems of the Yellow Ｒiver Pumping Irrigation Area＇s simple pattern of maize and high cost of water-saving irrigation,this paper conducts contrastive experiments of adopting different models (maize growth in film＇s side,under the film and on the field ) and irrigation limit (2 400,3 000,3 600 m3 /hm2 ) for maize growth in double film＇s sides． The results show that maize growth duration,plant height,diameter,leaf number,leaf area index,dry matter accumulation and yield are the best under the film-side drip irrigation planting． By comparing the nine planting patterns,the mulching film-side drip irrigation planting with low-volume irrigation quotas had a best water production efficiency (2．75 t /m3 ),while the yield was10．34 t /hm2． The non-mulched drip irrigation planting with highvolume irrigation treatment had a lowest water production efficiency (1．98 t /m3 ),while the yield was9．91 kg /hm2． The mulching film-side drip irrigation planting with high-volume irrigation treatment had a best yield (11．00 t /hm2) but the water production efficiency was only 2．37kg /m3． It was shown that though the yield is great,the water production efficiency is not the same high． The mulching film-side drip irrigation planting was the best suitable water saving irrigation mode with a higher yield and water production efficiency． In addition,the irrigation quota at 2 400 m3 /hm2 which had a highest water production efficiency,lower water consumption and greater yield could be chose as a more appropriate irrigation regime in central Ningxia irrigable area

To provide reference for water saving irrigation of sunflower in North China Plain Area. Two different varieties of sunflower（Xinkui20 and DW567）were used in pot experiment, the irrigation lower limits were set to 80% (T1), 70% (T2), 60% (T3), 50% (T4) and 40% (T5) of field water holding rate, respectively, the effects of different irrigation lower limits on growth, water consumption and yield of potted sunflower were studied. The results showed that T4 and T5 had serious water stress on the growth of sunflower, which affected the normal growth of plants, T2 or T3 could meet the water requirement of normal growth of sunflower, the high soil moisture of T1 was not conducive to the normal growth of sunflower; The water consumption of the whole growth period of potted sunflower decreased with the decrease of irrigation lower limit. The effects of different irrigation lower limits on the yield of potted sunflower were significant. Compared with other treatments, T2 or T3 was more beneficial to increase the 100 seed weight and single plant yield of sunflower. Xinkui20 had the highest water use efficiency at T2; and DW567 had the highest water use efficiency at T3. In general, the 100 grain weight, single plant yield and water use efficiency of DW567 were higher than that of Xinkui20, and the drought resistance of DW567 was better than that of Xinkui20.

Based on the investigation of Chushuxia Irrigation Area in Wuyishan City,the basic information such as water supply and demand,irrigation facilities,and weather conditions have been gained and according to the first and last measurement the effective utilization coefficient of irrigation water of Chushuxia Irrigation Area is deduced． Calculation and analysis results show that the effective utilization coefficient of irrigation water of Chushuxia Irrigation Area is 0．547． Compared with the effective utilization coefficients of irrigation water in 2008－2017,the coefficients increase year by year and the trend is consistent with the general rules． Compared the effective utilization coefficients of irrigation water with investments in 2008－2017,the growth in the coefficient of engineering investment is between 0．19% ～ 3．64% and the engineering investments are positively related to the effective utilization coefficients of irrigation water． That is,the greaterthe engineering investment,the greater coefficient． Compared with the effective utilization coefficients of irrigation water with rainfalls in 2008－ 2017,the influence of rainfall on the comprehensive irrigation quota is negatively correlated． That is,the larger the rainfall,the smaller the comprehensive irrigation quota．

Based on the experimental data of soil moisture characteristics curves in Loess Plateau Ｒegion,the soil viscosity,soil particle size,dry bulk density,organic matter and salt content are used as input variables． Alpha and n model parameters of Van -Genuchten nonlinear prediction model output variables and grey BP neural network prediction model,respectively on two kinds of model error parameters a and n error are based on an analysis of the prediction results of two models of the overall error analysis． The results show that both the parameter a or parameters of n,the average relative error of the nonlinear model of comprehensive accuracy is lower than 10%,the average relative error is 15．73%; the average relative error of the prediction accuracy of grey BP neural network model of the comprehensive precision of less than 4%,the average relative error is 10．01%,the prediction accuracy of grey BP neural network model are better than the prediction accuracy the nonlinear model is high,but the grey BP neural network model which is prone to overfitting． In summary,the two models can realize the prediction of Van-Genuchten model parameter alpha and N,and can choose one of them according to the specific conditions to achieve better prediction results．

Abstract: In order to study the nitrogen loss of surface runoff in farmland, under the condition of simulated rainfall, the effect of initial soil water content on runoff flow rate and nitrogen concentration of surface runoff in bare farmland with different fertilization methods and different rainfall intensities was analyzed. And two fertilization methods named surface fertilization and ditch fertilization were used. The study results showed that The difference between the flow process and the runoff is mainly the result of the joint effect of the two factors: the initial soil water content and the rain intensity. Under the influences of the initial soil water content and the rain intensity, the ammonia nitrogen(NH4+-N)was more susceptible to the initial soil water content, and the nitric nitrogen(NO3--N)was more susceptible to rain intensity. The cumulative loss of nitrogen in surface runoff has a good positive correlation with the cumulative runoff of the farmland. The curve is fitted with the binary primary equation, and the result is in good relationship. And R2 is above 0.96, which indicates that rainfall runoff is an important factor to affect nitrogen loss in surface runoff. Under the condition of large rainfall intensity, the main form of nitrogen loss from runoff in farmland was particulate nitrogen, while the loss form of water-soluble nitrogen was dominated by NH4+-N.Under the two fertilization methods, the loss of nitrogen in runoff with the surface fertilization was significantly higher than that with the ditch fertilization.

Since 1949,China has made great achievements in water conservancy． In particular,since the 16th congress of the communist party of China,China has continuously increased the investment in water conservancy,which has greatly improved flood control and drought relief capacity．However,the water conservancy construction still lags behind the need of agricultural production and development,and the proportion of effective irrigated area to the cultivated land area is relatively small． Although the government has invested heavily in the backbone of water conservancy projects,but farmers lack the interest in the field supporting projects,the result is that a lot of farmland water conservancy investment cannot form real irrigation capacity．This paper analyzes the reasons why farmers lack the willingness to invest in water conservancy,and then put forward three ways,that is,improve the comparative benefit of agriculture by agricultural supply side reform, encourage farmers＇ professional cooperatives to lead farmers to develop water conservancy,and take the rural revitalization strategy as the opportunity to foster new professional farmers,so as to improve the enthusiasm of farmers to invest in water conservancy,and solve the“last kilometer”problem．

Abstract: Abstract: In order to investigate the temporal and spatial variation of soil temperature in unsaturated soil under different nitrogen and nitrogen combinations, nitrate transfer experiment was conducted in freezing-thawing period under six irrigation-fertilizer treatments of three levels of fertilizer application (100,300,500 kg/hm2), two irrigation levels(375,750 m3/hm2). The results showed that the soil temperature at the soil surface of irrigation and fertilization plots was lower than that of non irrigated plots during freezing and thawing period, soil temperature showed a "high low high" distribution in the soil profile, in the unstable freezing period, the soil temperature of 0-10cm was lower in irrigation and fertilization plots. In the early stage of steady freezing, the temperature of 0-30cm soil rised and falled obviously and varied greatly, 30-150cm soil temperature changed little; Soil specific heat capacity increased at the later stage of steady freezing, soil temperature changed more slowly than in the early freezing stage. The sensitivity of soil temperature to external temperature increased during the ablation period, and the soil temperature variability increased in 0-30cm. In the whole freezing thawing period, 0-20cm soil temperature fluctuation amplitude was larger, 30-90cm soil temperature changed gently; The average soil temperature of 0-30cm in the freezing thawing period was higher than N0W0 under W750, however, W375 had no obvious effect on soil temperature; the soil temperature of 30-150cm did not increase with the increase of irrigation amount and fertilizer amount, N300W375 and N500W750 increase temperature effect on 30-150cm is better, and the amount of irrigation was higher, the warming effect was more obvious. The absolute grey relational degree of soil temperature at 0-20cm between irrigation and fertilization plots and N0W0 was (0.791~0.977) higher than that of 30-90cm (0.960~0.995), the combination of water and nitrogen had a great influence on the temporal dynamics of soil temperature at 0-20cm, a slight effect on soil temperature below 30cm depth.

In the construction of sponge city, it is found that full consideration of the difference of urban functional areas is a difficult point and key issue of construction, so it is very necessary to select suitable LID measures. This paper takes Yangzhou sponge city construction as an example, we selected four different urban functional areas to analyze their internal structural features based on the surface cover conditions; we studied the differences in surface features, and discussed the suitable LID measures and the best combinations. In addition, we analyzed the effect and easement of construction, and maintenance requirements of LID measures in different functional areas. Finally, the advantages, disadvantages, and the urgency of LID measures construction are presented. The results showed that the process of Yangzhou sponge city promotion should be carried out in the order of the following sequence: residential area - education area - commercial district - industrial area. The difficulty of the construction ranges from residential area to commercial area, followed by industrial area and education area; the highest construction efficiency is education area, residential area - industrial area - commercial district followed orderly. the construction efficiency follows the order of the academic area, residential area, industrial area, and commercial district.

Abstract The ecological landscape construction measures were put forward including vegetated filter strips (VFS), ecological ditches (ED), constructed wetlands (CW), and biogas plants (BP) with respect to aspects such as water purification, energy generation, and nutrient reduction and recirculation. Findings indicate that RNPS ecological engineering technologies and BMP are key promising approaches to create a sustainable agricultural system, improve the rural energy consumption structure and living conditions, decrease wastewater discharges, and reduce chemical fertilizer application rate. It is proved that the present findings would play important role for agricultural non-point source pollution control.

In order to solve the problem of river drying and engineering water shortage in the irrigation peak of the Chahanwusu River basin, an optimization water supply and allocation scheme was proposed on the basis of the minimum volume of water shortage model and the analysis of supply and demand balance. The papers give priority to the ecological water demand is 27.431 million m3, the ecological water demand outside the river is 18.596 million m 3. It is very important to find the balance between the economic and social water, promote the coordinated development of the regional economic society and ecology, maintain the ecological security of the river and protect the wetland ecology of the downstream lake.

Tidal current and sediment environment changes of Funing Bay are simulated before and after the project called Xiapu Seawall based on FVCOM. The results show that: the flow direction in the seas nearby the seawall appears counterclockwise deflection after the project and the new direction is generally maintained parallel with the shoreline; The flow velocity is affected in partial seas, the maximum is up to 0.024m/s in the south of the shoreline of where the flow velocity increase obviously during high tide and the maximum is up to 0.025m/s in the southeast during ebb. Some area exists slight scour and slight siltation which is generally less than 0.12m/a. The tidal current and the sediment environment are slightly affected.

Ｒeclaimed water drip irrigation experiments were conducted during the growth of greenhouse vegetables,and underground water irrigation as the control,analysis of reclaimed water drip irrigation soil after 8 days of heavy metals in different depth of Cd accumulation and distribution and migration． The results showed that second days after irrigation,soil Cd concentration,drip irrigation after fourth days at the depth of 100 cm Cd the largest concentration of surface soil Cd concentration was slightly reduced,sixth to eighth days,each layer of soil Cd concentration close to 0～ 40 and 80～ 120 cm,the largest concentration of more than 120 cm Cd concentration increased as depth decreased． The proper concentration of reclaimed water drip irrigation condition,soil deep layer Cd concentration in line with GB15618－1995 standard limits,the proper concentration of reclaimed wastewater irrigation will not cause pollution of Cd．

Jiaxing district belongs to Hangjiahu partition, which is one of the 8 hydraulic partition of Taihu Basin. By the south side of Taipu River, Jiaxing district also suffers from the low-lying terrain, the high water surface ratio and the serious ground subsidence. Considering the unique control method in Jiaxing district: classifying-pump/gate-control method, this paper builds a hydrodynamic model of Taipu River and its lateral area on both side based on MIKE FLOOD, and then simulates the classifying-pump/gate-control condition. At last, by comparing the result, this paper analyses the impact on Taipi River and selected polder drainage condition. Comparing the results with and without the application of classifying-pump/gate-control method, there are 3 conclusion: ①For the water level of the main peripheral river, the peak shows more early and correspondingly stretch the water-break period. ②For the flood condition of selected polder area, drown area over 0.05m shrinks to 26%. ③For the water level of Taipu River(using Taozhuang station as representation), the swelling period is longer than common structure-control method, and the peak shows later correspondingly; In all, the classifying-pump/gate-control method could be used to relax the pressure of flood protection of Jiaxing district.

Water environment comprehensive improvement is an important embodiment of the implementation of“speeding up the reform of the ecological civilization system and building a beautiful China”proposed in the report of the 19th National Congress of the Communist Party of China and is also an important task for the comprehensive implementation of the river chief system． The PPP model is the common model to operate this kind of project,and the government credit risk is one of the main risks for the private sector in this kind of PPP project． Firstly,this paper stands on the perspective of the private sector to construct the risk index systems of government credit risk in water environment comprehensive improvement PPP projects based on WSＲ methodology． Secondly,the intuitionistic fuzzy hierarchical analysis (IFAHP) is used to collect the experts＇ opinions about the comparison of the importance of government credit risk indexes and also intuitionistic fuzzy judgment matrix is established to calculate the weight of each index． At the same time,the interval value hesitant fuzzy sets (IVHFSs) are adopted to obtain the scores of risk indexes and then coupled with the results acquired by IFAHP method to obtain the comprehensive scores of indexes． Finally,the feasibility and practicability of this method are verified by an empirical study． This study provides an effective method for the private sector to evaluate the government credit risk of water environment comprehensive improvement PPP projects and serves as a reference for participating in PPP projects

Abstract: The Storm Water Management Model (SMWM) was applied in Lejiahuayuan catchment of Beijing city. Three storms occurred in 2011 and 2012 including the “7·21” extreme rainfall were selected to calibrate and validate the model. For assessing the influence of model structure on simulation results, four models with different structures were established. The results showed that the deterministic coefficient of proposed models were between 0.81 and 0.91, the peak value and time differences also met the national standard. With the increase of model structure complexity, the precision of model reduced in the validation period, which indicated the overparameterization might exist during the model calibration. Considering the limitation of observed data, the forth model with the simplest structure, was selected in the practical application.

According to the water balance method, we use the terrestrial water storage anomaly data from GRACE in Han river basin from 2005 to 2012 to calculate regional-averaged ETa, and use ETWB as true value to evaluate the ETa products from diagnostic model (ETMOD16、ETZHANG、ETGLEAM)、land surface model(ETGNOAH1、ETGNOAH2) and reanalysis(ETJRA55). To improve the accuracy of ET products at monthly scale, γ bias correction is performed to all the ETa products. Results showed that: diagnostic model products performed better than other types of products, and all products showed similar spatial distribution in Han river basin, the ETa in the middle area was higher. The bias correction can improve the error of ETa products effectively, and correction was more obvious in the month with low ETa values. Both ETZHANG and ETGLEAM were shown to have higher applicability in Han river basin before and after bias correction.

Hydrological simulation in ungauged basins has always received much attention from hydrologists． This paper studies the applicability of the four regionalization methods in the Xiangjiang Basin and provides references for the hydrological simulation in the ungauged areas in China． First,the sensitivity of Xin＇anjiang Model Parameters in each basin is analyzed by Sobol method． Then,each sub-basin is successively assumed to be ungauged basin,and the sensitive parameters of the ungauged basin are estimated by multiple regression method,spatial proximity method,physical characteristics similarity method and global mean method． The results show that the four regionalization methods are feasible in Xiangjiang Basin． The effect of the multiple regression method is generally better． The spatial proximity method and the physical characteristics similarity method take second place,and the global average method is poorer．

Traditional manual parameter debugging is subjective and requires professional experience for the debugger. To make up for the deficiencies, a complex genetic algorithm is constructed to calibrate the parameters of Xinanjiang model by combining the genetic algorithm of global optimization with the complex method of local optimization. A study was conducted to verify the performance of the complex genetic algorithm by using the stratification calibration method in the upper reaches of Zhuxi watershed in Zhejiang Province. The results show that the difference between the multi-year average calculated runoff and simulated runoff was 1% and the annual runoff process simulation accuracy reached grade B standard. It is suggested that the complex genetic algorithm can be applied to the parameter calibration of Xinanjiang model.

Based on the connotation analysis of water resources carrying capacity,considering the per capita water consumption per capita,water consumption per capita grain production and water consumption per capita GDP,a water resources carrying capacity calculation model under the constraint of grain production is constructed． Taking the number of population and the scale of GDP as the representation index,taking the year 2015 as the status ( level) year,and 2020 and 2030 as the planning level year,we use two schemes of different living standard and planning level to calculate the water resources carrying capacity of Heilongjiang province． The calculation results show that at the same level of living conditions,population over time shows an increasing trend in Heilongjiang Province． In the planning level,in 2020, Heilongjiang Province in 2030 carrying index are 1． 12 and 1． 11． The research results provide technical support for improving the water resources carrying capacity of the region,promoting the sustainable utilization of water resources and the sustainable development of economy and society．

Based on the theory of system dynamics,this paper establishes the water resources carrying capacity model of Chongqing with vensim,and designs three kinds of scenarios: continuance type,economic development type and water-saving type,to simulate the water resources carrying capacity of Chongqing from 2016 to 2025． The results show that although the water-saving type does not achieve the balance of water resources,the ratio of supply and demand can be kept above 0．8,and the water-saving effect is remarkable． The domestic water consumption increases year by year with the increase in population． The effect of reducing per capita living water consumption is not significant． Ｒeducing the water consumption of 10,000 yuan of industrial added value,the secondary industry water demand remains at 30 ～40 billion m3． The water-saving effect is very significant．

The Dongting Lake connects four rivers in Hunan Province and the four outlets of Jingjiang Ｒiver． Its huge channel storage capacity and unique channel storage characteristic directly affects the overall layout of flood control of the Dongting Lake and the middle and lower reaches of the Changjiang Ｒiver． By using the elevation-capacity curve of the Dongting Lake,we analyze the channel storage characteristics of the Dongting Lake based on the lake ＇s hydrological data in 1991,1995,1996,1998． It is believed that the increment of channel storage capacity has differences when the water depth increment is the same and the discharge is different． Therefore,the flood control level should be rationally planned to make the flood regulation function of the Dongting Lake most efficiently． This paper also compares the differences of channel storage capacity of the Dongting Lake by using the two different methods: geomorphologic method and water balance method and discusses the factors leading to these differences． The research results have important guidance and reference significance for the overall layout of the flood control and water resources allocation scheme in the middle and lower reaches of the Changjiang Ｒiver and the Dongting Lake．

“One-size-fits-all”operation is employed in the traditional flood control of reservoir,which causes the waste of flood resources during flood season． The dynamic control of reservoir flood limit water level can realize the utilization of flood resources,improve the flood control capacity of reservoir and exert the comprehensive benefit of the reservoir． Based on Fenshuijiang Ｒeservoir in Zhejiang Province as an example,from the actual condition and easy-to-operate perspective,this paper establishes a dynamic control domain constraints index system of cascade reservoir flood limit water level,proposes a dynamic control operation with magnitude rain forecast,uses reservoir flood forecast system for risk control of limited water level dynamic control,and forms a practical dynamic control operation of cascade reservoirs flood limit water level．

The traditional study of dam-failure risk and social influence simply considered measurable impacts of important facilities and cultural relics etc, while its effect on “people” was not involved. The project revolve around the dam engineering community under the condition of dam-failure risk, which consists of dam related government, water administrative department, the reservoir management organization, the public within down-stream effects of dam-failure, media and etc. The social influence formation mechanism of dam-failure risk research is demonstrated clearly, the diffusion hierarchy of dam-failure risk social influence is elaborated. This paper analyzes the nine roles assignment under dam- failure risk, which contains the direct encounter, the responsible person, the handler, the regulator, the related encounter, the propagator, the sympathy, the concern and the circumvention. The evaluating indexes of dam-failure risk social influence is studied, that is, personnel loss, publicity, news and duration. And the grade division standard of the four indexes is given. The social influence evaluation method of dam-failure is adopted based on grade evaluation method. Taking a reservoir as an example, practical application shows, the evaluation results are of high reliability, objective and reasonable, classification accuracy. The social influence assessment of dam-failure risk based on grade evaluation provides a platform for the comparative analysis of the social influence of different dam-failure events

Taking the case of Xiannvshan Reservoir with deep overburden under the reservoir basin, finite element calculation on the stress and deformation of composite geomembrane used as the seepage prevention for the whole reservoir basin was carried out to analyze the safety of composite geomembrane. The result indicated that under the water pressure during operation period, settlements are occurred in overburden under the reservoir basin, meanwhile horizontal deformation from both banks slope towards the center of the reservoir. The deformation are well-distributed. According to influence of the deformation, the composite geomembrane at the both banks slope is in tension, while composite geomembrane at the center of reservoir is in compression. The tensile safety factor and strain safety factor are both larger than 5.0. The composite geomembrane can fit the deformation of overburden and be with a certain safety margin.

As an important joint structure between asphalt concrete core and cutoff wall, foundation gallery has very complex stress conditions. and it is the key to the success of the project.Based on the concrete nonlinear constitutive theory, sub-model method is used to analysis the stress and deformation rules of the foundation gallery. The influence of overburden depth,valley width and bedrock part length to deformation and stress of the foundation gallery separately. The results of contrastive analysis show, with the increase of overburden depth,the global stress and deformation of foundation gallery increase. With the increase of valley width,the global deformation increases, deformation of the middle part tends to be a straight line,transverse normal stress distributes more uniformly in the middle part. With the increase of bedrock part length, bending deformation of bedrock part edge becomes more obvious, and the global stress increases. According to the analysis results and the engineering experience, the corresponding engineering measures put forward are helpful for similar projects.

Semielliptical channels are widely used in the farmland irrigation system． The conjugate depth is the essential hydraulic parameter and it is necessary to find its efficient and fast-speed calculation method． Firstly,the dimensionless hydraulic jump equation for semielliptical channels is derived based on its geometric characteristics of cross-section． Both the range of initial depths and the sequent depths are limited for semielliptical channels,so both the dimensionless discharge and dimensionless initial depths are analyzed． In the end,the relationship map of dimensionless conjugate depths is drawn based on a large number of calculations,and the conjugate depth solution of hydraulic jump equation can be obtained rapidly by the map．The method is simple and efficient,and it can be popularized easily in engineering practice．

Aimed at the attendant adverse swirl in the front of bottom hole and persistent adverse water-wing outside the bottom hole due to large lateral space between adjacent sluice, this paper comparatively studies hydraulic characteristics among oval pier program and wedge pier program through physical model. Results show that wedge pier program could not only adjust flow distribution outside bottom hole to avoid deflected stream in the downstream of open diversion channel, but also meet the requirements of diversion design flood, which would maintain the original cofferdam structure and avoid design alteration to save construction investment.

In order to investigate the influence of water -cement ratio and sand ratio on the compressive strength of recycled aggregate concrete,9 different ratios of water-cement ratio and sand ratio are designed to determine the compressive strength of 3,7 and 28 d at different ages,at the same time grey relational analysis method is used to study the water-cement ratio,sand ratio and content of cement on the influence of the 28 d compressive strength of recycled aggregate concrete． The results show that the appropriate sand ratio,compressive strength of ＲAC increases with the increase in water-cement ratio,after the compress strength reaches the maximum value,when increasing the water-cement ratio,the compressive strength decreases． In the case of high sand ratio,compressive strength with water-cement ratio decreases． Under the condition of water -cement ratio,the 28 d compressive strength of recycled aggregate concrete is lower than that of natural aggregate concrete． When the water-cement is relatively high,the compressive strength of 28 d is a little different between the 28 d and the recycled aggregate concrete． By using grey correlation analysis method,the influence degree of various factors on the 28 d compressive strength of recycled aggregate concrete,sand ratio ＞ cement content ＞ water-cement ratio is analyzed．

There are usually some vortexes in the inlet flow of the mixed flow pump ,and if no anti-vortex measures are set ,the bad flow situation in the pump sump and inlet conduit will lead to the phenomena of dropping flow and swirling inside the pump with the result of uneven pressure distribution in the blades,and the increase of energy loss in the pump ,further more ,it can even trigger the vibration of the unit.Based on the one of the mixed flow pump station in China,this paper used the method of numerical simulation to study the effect of M-type anti-vortex on the flow pattern of the inlet conduit and the static pressure distribution of the pump.The results have showed that ,the M-type anti-vortex can improve the flow pattern of the inlet conduit effectively ,reduce and prevent vortexes ,and increase the efficiency of the mixed flow pump when the inlet flow rate is greater than the optimal inlet flow,the maximum increase amplification reaches 2.18%.

In order to study the influence of the number of guide vanes on the performance of the inverted hydraulic turbine of multistage centrifugal pumps, in this paper, the first stage of multistage centrifugal pump inverted hydraulic turbine is taken as the research object, and 3 kinds of vane guide vanes and annular spiral casing matched with each other are designed. Steady and unsteady numerical calculations using CFX software. The outer characteristic curve and the internal flow field distribution of the model pump and turbine condition were obtained, and the internal pressure pulsation data of the guide vane and volute were analyzed. The results show that: the smaller the number of guide vanes, the more uniform the flow inside the model. The power and efficiency of the 7 vane models were the largest, but the less the number of guide vanes, the greater the pressure fluctuation amplitude at the guide vane and volute. When the blade number is greater than or equal to 9, the amplitude of the pressure fluctuation in the model remains almost unchanged.

In view of the randomness of the moment of inertia selection,this paper analyzes its importance to the pump water hammer by the basic principle of water hammer calculation． In this study,Hanjiayuan Pump Station in Shanxi Province as an example． Based on the simulation software of water hammer calculation,the simulation study of valve failure under pump stops is carried out,and the changes of key hydraulic parameters of pump stopping water hammer under different rotational inertia are analyzed． The simulation results show that the positive pressure of the pipeline decreases with the increase in the moment of inertia,and the negative pressure of the pipeline is opposite,and the sensitivity is more obvious．The maximum reversing speed and the maximum discharge flow decrease with the increase in the moment of inertia,but the amplitude of the change is little．The time of the flow and speed has zero increases with the increase in the moment of inertia．The result is expected to provide theoretical support for water hammer protection in engineering．

This paper establishes the water rights trading mode based on the cooperative game theory l. The bidding strategies and the income functions of the water rights trading parties are analyzed, and the Nash bargaining solution of the model is obtained .Taking the city of Jining as an example, a cooperative game model of water rights trading between agriculture and industry is established, and the Nash bargaining solution and Nash equilibrium point of the model are obtained. The results show that the water rights trading between industry and agriculture can bring about significant economic benefits, and the water rights transaction model has important guiding significance for decision-making.

The third amendment of“Ｒegulations on Land Ｒequisition Compensation and Ｒesettlement for Large and Medium-sized Water Conservancy and Hydropower Projects”established the same compensation principle of “the Same Land,the Same Price”between the reservoir engineering construction and other infrastructure construction such as railways and highways,which will affect and activate the legal cognition of reservoir resettlement support,but will not erase the reservoir resettlement support value in laws．Ｒeservoir resettlement at the late stage is not aimed at reservoir resettlement“grace”or“privilege”,nor can it simply be confused with the preferential support for poverty alleviation and development．It belongs to the right of compensation for reservoir resettlement．Based on the idea of institutional guarantee,we need to adhere to the principle of resource development and sharing under the same compensation principle of“the Same Land,the Same Price”so as to reinvent the rule of law supported by the latter,and we also need to establish and improve a more rigid system structure system,a more complete procedural guarantee mechanism and a more integrated and integrated operation mechanism

According to the actual operation conditions of the Dongshen Water Supply Project, an optimal operation model was established, the optimal operation principle was determined, key impact factors were selected, a special supporting scheme was formulated, and an optimized operation management mechanism was finally established. The optimized operation of the large-scale cascade water transfer project was realized, and the average annual electricity savings was about RMB 30.35 million, which has significant social and economic benefits.