Water resources have the dual attributes of quantity and quality，which requires the study of initial water rights allocation from the two－dimensional perspective of water quantity and water quality． This paper takes Hefei City as an example，establishes an evaluation index system，and builds an urban two－dimensional initial water rights optimal allocation model． The analysis results show that while we consider the influence between water volume and pollutant discharge and optimizing the configuration，the amount of water allocated in the urban area has been reduced by 122．3 million m3 ． After optimizing distribution，the amount of pollutant discharged of Chaohu City has been reduced by about 20% compared with that before optimization． Other districts and counties have slightly different amounts of increase or decrease in the amount of water or discharged sewage． The amount of water and pollutants allocated after optimal allocation can better reflect the economic and water resources development conditions in the study area． Based on water rights and emission rights，it is feasible to optimize the two－dimensional initial water rights of the city and the result can provide a scientific basis for improving the utilization efficiency of water resources and formulating the scientific discharge of sewage．

Because of the large amount of underground brackish water resources in Ningxia, which water chemistry type is complex and range of mineralization is wide, it is difficult to meet the requirements by a single desalination technology. In order to solve the problem, the type of water chemistry corresponding to different degrees of mineralization of underground brackish water in Ningxia was analyzed and the technical and economical of brackish water desalination methods such as common reverse osmosis (RO), nanofiltration (NF) and membrane distillation (MD) was compared. Finally, the corresponding relationship between salinity, water chemistry type and desalination method is discussed, and the desalination method corresponding to different salinity and different water chemistry types is finally determined. The results show that: groundwater less than 1g/L in Ningxia is dominated by Ca2+, Mg2+ and SO42, which can be treated by nanofiltration; 1-3g/L brackish water is mainly Na+ and Cl-, and reverse osmosis technology can be utilized; 3-6g / L of brackish water Ca2+, Mg2+, SO42, Na+ and Cl- content is higher, can adopt nanofiltration + reverse osmosis process; more than 6g / L of brackish water, membrane distillation can be used.

During the flood process of steep slope，strong sediment transportation often leads to the reduction of river flood section and the abnormal increase of the water level． However，after the flood，the sediment is often washed down to the downstream，it is difficult to find traces of sediment in the river． The flood overflow caused by the sediment only plays a role in the flood process，which makes people generally think that the root of flood is heavy rainfall，but neglect the additional disaster－causing action of the sediment． For the purpose of exploring the influence of sediment in the flood disaster，the scouring development and water level variation of silt at the early stage of the bed are studied in the variable slope flume in this paper which explains the phenomenon that under the condition of non－exceeding flood，the flood level of the river is abnormally high while there is no obvious unusual disaster of section shrinkage and emphasize the causal link between sediment and flood disaster． The result shows that the larger the flow volume，the strength of sand and the particle size of sediment，the greater the scour depth． The larger the upstream flow，the intensity of sand and the ratio，the smaller the particle size of the sand，the greater the scour speed．

UV－ Visible spectra and three － dimensional fluorescence spectra are used to analyze structural compositions and sources of dissolved organic matter ( DOM) of rainfall in the Summer of 2018 from Urumqi． Uv－visible spectrum analysis shows that DOM with lower molecular weight in the rainwater of June，while the rainwater of July is of high humification degree in terms of the compositions of DOM，the content of humic acid is higher than fulvic acid in the samples of June and July． The molecular condensation degree of organics in DOM in summer is high． Three－dimensional fluorescence spectra analysis showed that the humic acid fluorescence peak in June and August was the main contributer of rainwater fluorescence，and the tryptophan fluorescence peak was the main contributer of rainwater fluorescence in July．The humus in the uv－light area of rainwater was dominant，and the stable component content in humus component was smaller． The DOM of rainwater was influenced by microbial activity and terrestrial inputs．

In response to the cyanobacteria blooms in the Lake in August 2018, guangdong, Experimental study on the best medicament and optimal dosage was carried out, comparing the removal efficiency and secondary pollution of three chemical algae removers, such as copper sulfate, potassium permanganate and polyaluminium chloride, polyaluminium chloride was selected as algae removal agent, which the optimum dosage of liquid polyaluminium chloride was 20 mg/L. According to the experimental results guides the engineering application, The average dosage of algaecide was 150 g /m2, after the emergency treatment, the density of the algae decreased by 90%, and all the other indicators were up to standard, It provides a reference for emergency disposal of cyanobacteria bloom events in the future

Water diversion in the past often focuses on the evaluation of water quality improvement in the water diversion process，in which a fixed flow rate is used for continuous water diversion． Clear water does not fully exert the function of dilution and displacement，which causes a certain amount of waste． In this study，a MIKE 21 hydrodynamic and water quality coupling model for the Aixi Lake in Nanchang City is built by using the intermittent water diversion method． The model is used to simulate water diversion under different conditions． The results show that the time required for water diversion is affected by the amount of water diversion． With the increase in water diversion，the time difference between the two methods decreases gradually． The total amount of clean water used by the method of intermittent diversion is less than the amount of water required for continuous water diversion，when the simulated water diversion plan reaches the same goal of improving water quality． This study can provide references for water diversion of lakes in other cities．

The groundwater pollution of a renewable copper industry in Luonan County of Shaanxi Province was simulated, which could provide scientific guidance for site selection of renewable copper industry and prevention of groundwater pollution. Based on field experiments，the hydrogeology model was established by using the Visual Modflow software . After model calibration, the groundwater flow and solute transport in this region were simulated. The results showed that the Pollution Plume reached its maximum in 30 days when short time tracer mode was predicted. Furthermore, after cutting off the pollution source, the exceeded pollution range of plumbum would decrease at once until disappeared, while the exceeded pollution range of copper would firstly increase, and then decreased gradually. The contaminants in the channel transported mainly along the flow direction, which distributed in a narrow-pinnate condition, and the pollution degree declined as the distance from the point source pollution in-creased. The results provide scientific guidance for groundwater evaluation.

Nowadays，social and economic development has caused damage to the water environment，and water quality deterioration has occurred in a large number of rivers． The evaluation of the water quality of the Lanzhou section of the Yellow Ｒiver can understand the water quality of the Lanzhou section of the Yellow Ｒiver and is of great significance for controlling urban water security． According to the evaluation results，the effective treatment measures should be done． The monitoring data of PH，water temperature，turbidity，dissolved oxygen，conductivity，ammonia nitrogen and permanganate index of two sections of Xincheng Bridge and Shichuan Bridge in 2017 are selected． The Harmony Theory Quantitative Method Harmonic Degree Equation ( HDE) is used to determine the water quality of Lanzhou Section，and provides a new evaluation model for water quality assessment． Finally，it is concluded that the water quality of Lanzhou Section of the Yellow Ｒiver has the third－class water，which is in line with the actual situation． The evaluation method of the harmony degree equation is simple，flexible and reliable，and can provide reference for practical work application．

With the development of economy，society and science and technology，the development and utilization of surface water resources are getting higher and higher． The development and utilization of surface water in North China，especially the Shiyang Ｒiver Basin and the Heihe Ｒiver Basin in Hexi Inland Area of Gansu Province，has exceeded 100%，which seriously affected the balance of the local ecological environment． the area of overexploitation and utilization of surface water in Gansu Province is determined based on the factors affecting the development and utilization of surface water，and the current situation of the development and utilization of surface water in each basin of Gansu Province． The surface water of each basin is put forward in combination with the social and economic development level，and the demand of the people＇s production and life for the water resources． The measures dealing with the development of the basin surface water are put forward．

In order to prove the heavy metal content of rural underground drinking water in Tongren Mining Area，the heavy metal content of underground drinking water in Tongren Songtao Manganese Mine and Wanshan Mercury Mine Area is analyzed in January 2018 and May，and the USEPA recommended health risk model is used to evaluate the health risk of underground drinking water in the research area． The results show that 9 kinds of heavy metal contents in the other points are in accordance with“Sanitary Standard for Drinking Water”( GB5749－2006) except for the Hg exceeding the standard at W2 number，and the average content of heavy metals in the underground drinking water in Wanshan Mercury mine area is much more than that in Songtao－manganese mine． Pearson correlation analysis shows that Zn is significantly positively correlated with Cr，Cd，Pb，Cu，Ni and Mn，and the correlation coefficients are 0．414，0．614，0．589，0．428，0．714，and 0．445．There is a significant positive correlation between As and Cu，with a correlation coefficient of 0．489． There is a significant positive correlation between As and Cr and Hg，and the correlation coefficients are 0．339 and 0．333 respectively． The USEPA health risk assessment showed that the average value of the risk of health hazard caused by non－chemical carcinogens in adults and children is 10－12 ～ 10－10，which is negligible．The mean risk of health risks caused by chemical carcinogens，Cr and As，to adults and children exceeds the health risk rating ( 1．0×10－6) recommended by the Swedish Environment Protection Agency，the Dutch Ministry of Construction and Environment and the Ｒoyal Society． The total cancer risk in children is 3．08×10－6 ～ 1．48×10－4 /a，which is significantly higher than the adult level ( 2．66×10－6 ～ 1．28×10－4 /a) ．Cr and As are the main pollutants of underground drinking water in Tongren Mining Area．

The hydrological process of urban rivers is seriously disturbed by human activities and the river bank nearby region is seriously explored. Further, the water environment in urban river is fragile, and it makes the water crisis increasingly serious. In order to maintain the health of the urban river systems, a case study is carried out in the Qing River in Beijing city to find out integrated solutions of urban river problems. The systematic analysis of the problems of urban rivers focuses on six major contents such as water resources, waterfront shoreline management, river pollution, river environment, water ecology and law enforcement supervision. The solutions are compiled into a “One River, One Solution” plan which is suitable for local conditions, forming a list of 4 major issues such as objectives, tasks, projects and responsibilities. Further, the common problems are summarized during the compiling process for “One River, One Solution” in urban region and the solutions are proposed for all departments to coordinate and to solve problems. The solutions include establishing practical targets, quantifying task indicators, clarifying the tasks of the river chief, and building support systems for the project. The case study is helpful to provide suggestions to promote the River Governor System and to maintain the sustainable health of rivers systems in urban regions.

Plateau city reservoir appears to be the uppermost and only root of drinking water source, the water quality of joint river resdirect will influence on water resources security and ecological civilization construction.Based on the investigation data of the Muyanghe of jointing river in Kunming songhuaba reservoir from 1996 to 2017, the fractal theory and the R/S model were used to analyze the change trend of the annual mean amount and parameter values in different water periods of total nitrogen,total phosphorus,ammonia nitrogen and permanganate index, the results showed that Hurst phenomenon of total nitrogen,ammonia nitrogen,permanganate index of annual average and its indexes in different water periods were obvious, total phosphorous and ammonia nitrogen continuously decreased,other two indexes continuously increased.Except for total phosphorous ,persistent strength of change trend of three indexes in dry season were more than year-round, wet season and normal water season.

In order to study the degradation process of polycyclic aromatic hydrocarbon naphthalene ( PAH － naphthalene ) in shallow groundwater，a petroleum－contaminated site in Songliao Basin is selected as the study area． The pure quartz sand and typical iron－containing minerals magnetite，siderite and chlorite are used to simulate the minerals in aquifers． The adsorption behavior of naphthalene on different types of iron ore is studied by simulating the low－temperature groundwater environment in contaminated sites through batch experiments． The results show that the adsorption capacity of magnetite，siderite and chlorite to naphthalene is magnetite ＞ siderite ＞ chlorite from large to small，and the equilibrium adsorption capacity is 1． 503，1． 049 and 0． 756 mg /g，respectively． The adsorption isotherm of naphthalene accords with Langmuir equation and belongs to surface molecular adsorption． When the mass fraction of iron－containing minerals is 20%，the concentration of divalent iron ions in the solution changes obviously，indicating that iron ions participate in the mineral adsorption process．Based on the adsorption of iron － containing minerals，this study simulates the adsorption of naphthalene by iron － containing minerals in shallow aquifer at low temperature，and explores the adsorption performance of naphthalene by different iron minerals at low temperature，which serves as a reference for other areas with relatively low temperature in North China．

Ｒiver flow is the most important condition of the benign cycle of the ecological environment． This paper selects three outlets( Hudukou，Ouchikou，Songzikou) as the control sections，the minimal ecological flow by year distribution calculation method，IHA－ＲVA method is used to calculate the river optimal ecological flow，and prove the rationality of using the Tennant Method，according to the three outlets status and history of hydrology analysis of ecological water level of protection． The calculation results show that the hudukou，Ouchikou and Songzikou outlets of the minimal ecological flow is 264．3，241．3，680 m3 /s，respectively，the average natural flow 44．4%，16．4%， 46．9%．Hudukou，Ouchi and Songzi outlet of optimal ecological flow is 409．5，613．2，1 017．2 m3 /s，respectively，the average natural flow68．8%，41．7%，70．1%． The results will provide a scientific basis for the rational management and management of water resources and the protection and restoration of the ecosystem．

Ｒelying on national forest ecosystem research station，Larix principis－rupprechtii in Qinling Mountains is taken as the study area in five years． In order to quantitatively reveal the levels of transpiration and evaporation intensity and their relationship with environmental factors，the Larix principis－rupprechtii plantations water consumption and related environmental factors are monitored in this region． Then the effects of vegetation structure on vegetation characteristics of water consumption are analyzed． The weighing method is used to measure the soil evaporation and thermal dissipation probe ( TDP) is used to measure the sap－flow dynamics． Combing with the investigation of environmental factors，the data are analyzed． The results show that soil evaporation and water consumption of Larix principis － rupprechtii plantations vegetation increase and then decrease，which are the highest in July and August，and then decrease． When the soil water content is above18%，the ground cover plants not inhibit soil moisture evaporation． Soil evaporation model shows that the soil evaporation is positively correlated with soil moisture content and temperature． Correlation analysis shows that Larix principis－rupprechtii plantations are positively related to the soil water content，the solar radiation intensity，soil temperature，namely forest transpiration intensity will be increased with the increase in the environmental factor variable values． However，the forest transpiration intensity and own properties ( crown breadth，diameter at breast height，plant height) shows a negative correlation，which is with the growth，forest transpiration will be suppressed． Overall，the main factor that affects forest water consumption is the soil moisture，if the soil water contents decrease，the forest vegetation will solve their demand for water in the first place．

Available Water Resources is a major index for guiding the scientific developing of rivers. Currently, the calculation methods of available water resources are mainly based on quantity of water resources while research on methods that based on quality of water is rare. In this paper, a calculation method of available water resources is proposed, which can be an useful mean for supplement and recheck. It’s also has reference value for determination of available water resources scientifically. Further more, it can be used in guiding the development of river appropriately.

Under the background with different degrees of urbanization, changes in the mechanism of urban rainfall-runoff processes resulted by the differences in underlying surface of urban areas have further increased the flood risk in urban regions. Considering the rapid development of urbanization in Tongzhou District of Beijing, the Yangwazha drainage area is selected as the case study in this paper. According to Landsat satellite image data, a multi-thematic index combination technique is used to extract the urban landuse data in 2010 and 2015, respectively. Based on two different degrees of urbanization, percentage of the impervious area is identified, and then the Storm Water Management Model (SWMM) is developed. Precipitation with different return periods was taken as model input to analyze the changes in flood characteristics due to urbanization. The study results show that the difference in runoff coefficient between the two urbanization scenarios in the study area is 0.13 in one-year return period. From the 50-year return-period on, the runoff coefficients began to gradually approach each other in 2010 and 2015, indicating that when the return period continues to increase, the impact of changes in percentage of impervious area due to urbanization on the runoff coefficient of the study area gradually weakens. Peak flow and degrees of urbanization always show a strong positive correlation. In one-year return period, the 2015 peak time is 3 hours ahead of that in 2010. The flood peak time is the same in 50-year and 100-year return period. The reason is that under heavy precipitation conditions, the flow velocity in the river basin is faster and hence the influence resulted by the delayed time for overland flow concentration become smaller due to the complicated path for overland flow concentration.

On the basis of the geographical features of the hillslope and depression in the karst peak cluster watershed, we establish a semi-distributed hydrological model which reflects the characteristics of infiltration and storage and discharge and the hydraulic connection between hillslope and depression. The model is applied in Chenqi river basin in Guizhou province, the parametric sensitivity analysis and parameter calibration of model is according to the measured discharge of watershed outlet and the observation data of groundwater depth in depression, and calculating multiple discharge of hillslope and depression. The results show that the model has high accuracy in simulating discharge and groundwater regime process; hillslope discharge is an important supply for basin, it accounts for 76 percent of total flow; the surface and fast and slow flow account for 3.8%, 71.8%, 24.4% percent of total flow, it reflects that the fast flow controls the flow process of steep rise and fall.

Based on the hydrographical characteristics of Dongting Lake, hydrological alterations are analyzed and ecological water-level are calculated by using the monthly water level data extracted from the 3 hydrological stations of Dongting Lake. The results indicate that: (1) The variations of diversion flow of 3 diversion outlets of Jingjiang river and the water level of the main stream of the Yangtze River caused by Jingjiang artificial cut-off project and Three Gorges projects are the main reason for hydrological alterations of eastern, southern and western Dongting Lake. And the variations of the water level for the main stream of the Yangtze River play a leading role in the hydrological alterations of eastern and southern Dongting Lake. The variations of diversion flow of 3 diversion outlets of Jingjiang river play a leading role in the hydrological alterations of western Dongting Lake. (2) The impounding effect of Three Gorges project, which leads to decrease of the diversion flow of 3 diversion outlets of Jingjiang river and the water level of the main stream of the Yangtze River, cause a significant reduction of the frequency for monthly water-levels meeting ecology water-levels in Dongting Lake; Jingjiang artificial cut-off project, which leads to decrease of the diversion flow of 3 diversion outlets of Jingjiang river and uplifting of the water level of the main stream of the Yangtze River, cause varying degrees of improvements for the frequency in eastern and southern Dongting Lake and reductions for the frequency in western Dongting Lake; (3) By analyzing hydrological alterations on monthly scale with t test and Mann-kendal test methods, and finding the probability distribution function for Water level sequence before variation with Kolmogorow-Smirnow method, monthly ecological water levels are calculated for eastern, southern and western Dongting Lake. The results is reasonable and could directly describe the monthly water level variation for three hydrological stations, and could provide some guides to the restoration of the Dongting Lake from time and space dimensions.

Based on precipitation data in the upper and middle Heihe Ｒiver basin during 1990－2012，similar precipitation processes and their geographical distribution are firstly investigated by similarity searching method in this study． And then，synchronous－asynchronous probability of precipitation between different regions are analyzed． There are 12 types of precipitation with similar origin in this study area，and geographic partitioning of them runs roughly northwest－southeast． Frequency of the synchronization precipitation in the Heihe Catchment is between 39．1% ～ 78．3%． The precipitation that is not conducive to completing the planning of water transfer is scheduled to be more frequent． Ｒesults of this study can provide references for the management of water resources in the Heihe Ｒiver Basin．

In this paper，the temperature distribution law of the water source well under two conditions is obtained through measuring the field test of water source wells and carrying out the indoor simulation which the water source well model is made by similar principle，The temperature field of the water source well is in a three－stage distribution of“steep－slow－slow”． Under the field conditions，the steep rise zone of the water source well is located at 0～ 1．3 m from the wellhead． Under extreme conditions，the steep rise zone is located at 0～ 0．8 m．The position of the steep rise zone of the water source well increases by 0．5 m under the extreme conditions，which causes the complete freezing of the water source well through analyzing the temperature of the water source well under two conditions． The analysis shows that increasing the temperature of the steep rise zone of the water source well is of great significance to improving the temperature of the water source well and preventing the freezing of the water source，which lays a foundation for the antifreezing research on shallow water source well in the pastoral area

Water requirement of wetland plants is an important part of wetland ecosystem water balance． In this study，a two － year water requirement experiment is carried out by wetland in the Dianchi Lake Basin containing five kinds of typical plants: Typha angustifolia L，Acorus calamus L，Thalia geniculata Lare，Canna indica L，and Scirpus validus Vahl． The total water requirement during the whole growth period of different wetland plants and the daily average water demand at each growth stage is obtained，the crop coefficient of different wetland plants is calculated． The results show that the water requirement of five kinds of wetland plants increased first and then gradually decreased with the growth process，and the peak appeared mainly between June and August． The average daily water requirement for the five species of plants is 4．50 to 5．49 mm/d during the whole growth period． Among them，Typha angustifolia L and Thalia geniculata Lare are the largest，and Acorus calamus L is the smallest． The total water requirement in the whole growth period ranges from 1 088．6 to 1 638．1 mm，with an average value of 1 260．2 mm． Thalia geniculata Lare is the largest，and Scirpus validus Vahl is the smallest． For the five kinds of wetland plants，the changes of the crop coefficients during the whole growth period show a trend of increasing first and then decreasing，and the peaks of Typha angustifolia L，Acorus calamus L and Thalia geniculata Lare appeared in the fruit period，the peaks of Canna indica L and Scirpus validus Vahl appeared in the anthesis． The mean crop coefficient in the whole growth period of five kinds of wetland plants is 1．21 to 1．66，of which Thalia geniculata Lare is the largest and Scirpus validus Vahl the smallest．

Land use /cover change ( LUCC) is dependent on environmental change and socioeconomic development． In this study，the spatial and temporal variations of LUCC has been analyzed by the transfer matrix and comprehensive land use index，according to the data of LUCC in the Yarlung Tsangpo Ｒiver Basin from 1980 to 2015． The results indicate that the main change in LUCC are forest land，unused land and the build－up，increasing by 0．33%，5．33% and 101．03%，respectively． While the area of permanent glacier－snow，cultivated land and water body are diminished by 23．39%，1．66% and 1．14%，respectively． The changes in the spatial pattern of LUCC for Yarlung Tsangpo Ｒiver Basin accord with the distinct regional characteristics of vertical zonation． The types of LUCC are forest land，cultivated land，built－up，water body，grassland and unused land and permanent glacier－snow with the increase in altitude． It should be noted that the decreased cultivated land at the altitude of 3 500～4 500 m account for 75% of total reduction，while the increased forestland and built－up area are 87．7% and 71．4% of total increased area，respectively． There is no significant change in grassland． At the altitude above 4 500 m，the decrease in permanent glacier－snow accounts for 99．7% of total reduction． In contrast，the increased area of unused land is 99．6% of total increased area．Climate and hydrological elements are the main driving factors for LUCC in the Yarlung Tsangpo Ｒiver Basin． The country ＇s ecological restoration policies，economic development and population growth within the basin are the driving forces for the changes in built－up land and cultivated land

In order to explore the influence of different mulching methods and ＲDI patterns on the yield and quality of Lizao jujube． In the 2017 Lizao jujube experiment，15 treatments were set for different mulching ( no cover，plastic film mulching，straw mulching) and different deficit models ( full irrigation，bud burst to leafing stage stress，flowering to fruit set stage stress，fruit growth stage stress and fruit maturation stage stress) ． The results showed that the film mulching and straw mulching treatment could increase the yield of the Lizao jujube，which increased by 41．5% and 60．6% ( p＜0．05) compared with the uncovered treatment． At the same time，the yield of straw mulching treatment was slightly higher than that of the mulching film． At the same time，the yield of straw mulching treatment was slightly higher than that of mulching，but there was no significant difference． Water stress during flowering to fruit set stage and fruit growth stage resulted in a significant decrease in the yield of Lizao jujube． The water deficit during the bud burst to leafing stage and fruit maturation stage did not significantly affect the yield of potted pears． Water stress at the fruit maturation stage can significantly improve the water use efficiency ( WUE) of Lizao jujube，which is 25．9% higher than that of full irrigation treatment ( p＜0．05) ． Both kinds of mulching methods can effectively improve the fruit quality of Lizao jujube，and the improvement effect of straw mulching is better． The effect level of water stress at different growth stages on the quality of Lizao jujube was fruit maturation stage ＞＞ fruit growth stage ＞ bud burst to leafing stage ＞ flowering to fruit set stage． In summary，straw mulching and fruit maturation stage water stress treatment can effectively improve yield and quality，and it is a better management method for Lizao jujube in this region． In addition，the preference analysis of the effects of different treatments on jujube quality found that water stress treatment during fruit maturation stage has a strong positive effect on the various factors of the taste dimension，greatly improving the fruit quality of Lizao jujube． Therefore，this paper recommends carrying out water stress treatment at fruit maturation stage．

Discharge and water level are the basic characteristic parameters of water flow in irrigation channels, which is the basis of water managers making scheduling decision in irrigation area. The standard section method or uniform flow formula is the most common method in the measurement of discharge, but they are no longer applicable in the case where the upstream and downstream conditions vary greatly or frequently. In this paper, a two-point water level method was proposed. Two sections were selected along the irrigation channel, and the instant water level of each section was measured. The discharge of the channel was obtained by numerical simulation. The results showed that compared with the uniform flow formula, the two-point water method can improve the accuracy of flow monitoring.

In order to simulate crop growth and estimate crop raw weight without destroying the plant, and calculate the crop evapotranspiration based on weighing method and water balance principle in potted experiments, we established the relationship model of silage maize raw weight and main appearance measurable agronomic traits. In the potted experiments and field experiments, we selected three silage maize varieties to plant and measured the main agronomic characters and raw weight on the ground in each growth stage, then established the raw weight estimation model of different varieties and different growth stages with regression analysis method. Analysis results showed that under the normal management conditions, varieties of silage maize, plant height, leaf area, stem diameter, panicle length, panicle diameter, panicle weight had effects on estimating maize plant raw weight. The plant height and total leaf area at seedling stage, stem diameter at jointing stage, total leaf area heading stage, the sixth foliage area and panicle weight at maturing stage had a large effect on the total raw weight of each period, which reached extremely significant or significant level. So we could use piece number of green leaves and the first three foliage areas at seedling stage, stem diameter and the third foliage area at jointing stage, leaf area at heading stage, the forth foliage area, panicle diameter and piece number of green leaves at maturation stage to quickly estimate the potted silage maize plant raw weight of each growth stage. The estimating results were effective which the average estimating relative error is 4.0%.

The overturning failure around the toe of the slope is a frequent failure mode of the rock slope under external loads． Based on the principle of moment balance，the expression of anti － overturning stability coefficient of the rock slope under the earthquake，new water pressure distribution and the load of the top of slope is solved． Firstly，the rationality of different water pressure distribution forms and its influence on stability coefficient are analyzed． Then the effects of seismic load，fissure water depth and load of the top of slope on overturning stability are analyzed． The following conclusions can be drawn: ① The new proposed water pressure distribution form ( the midpoint of the structural plane and the water pressure at the bottom of the crack is fixed) overcomes the original water pressure distribution form ( The hydrostatic pressure at the bottom of vertical tensile crack is maximum) and improved the water pressure distribution form ( the hydrostatic pressure at 1 /2 of the groundwater level is maximum) ，it is more reasonable to use the new water pressure distribution form for rock slope stability analysis． ② The outflow seam blocking，the increase in the depth of the fracture water，and the equivalent seismic loading which horizontally outwards the slope and upward vertically are unfavorable for the stability of the rock slope． ③ The slope anti－overturning stability coefficient decreases as the horizontal seismic coefficient increases，regardless of whether the outflow joint is blocked or not; ④ The overload of the slope＇s top is conducive to the stability of the slope．

This paper proposes a Bayesian bivariate distribution identification method for shear strength parameters of soils and rocks． First，the characterization of bivariate distribution for shear strength parameters using Copulas is presented． Then，Monte Carlo simulations are conducted to validate the Bayesian bivariate distribution identification method． Moreover，the identification accuracy in the four methods is compared，and the main factors affecting the accuracy in the Bayesian bivariate distribution identification are identified． Finally，a total of twenty－nine sets of shear strength data are compiled to demonstrate the application of Bayesian theory bivariate distribution identification． The results indicate that with limited project－specific data and prior information，the Bayesian bivariate distribution identification method can successfully identify the best － fit bivariate distribution from a set of alternative bivariate distributions for shear strength parameters． In comparison with AIC，the Bayesian bivariate distribution identification method produces more accurate results for identifying the best －fit bivariate distribution． The sample size，correlation，the type of the true bivariate distribution and prior information of shear strength parameters has a significant impact on the accuracy of the Bayesian bivariate distribution selection method．

The successful application of canal system control algorithm in water conveyance project has greatly improved canal system operation，but the existing canal system control algorithms still have some drawbacks，such as the coupling between the canal and pool time lag，as well as traditional PID control algorithm dealing with high sensitivity mutation and so on． In order to further improve the response speed of the canal system and reduce the water level fluctuation，the model predictive control is introduced into the channel automation control． The linearized ID model is used as the forecasting model，and the objective function is optimized through on－line scrolling to design a PID Controller that can adjust feedback control parameters in real time． Based on the engineering background of three－trunk canals in Zhanghe Irrigation District of Hubei Province，a single canal control model is established and simulated． The simulation results show that MPC control method has the characteristics of a rolling real－time online optimization，demand for changing channels，and the future state of the system can better predicted and used to select the appropriate controller parameters．

Affected by the factor of the limited lateral width of the downstream outlets，the diffused flip bucket of the flood discharge tunnel has the phenomenon that the water entry area of the water jets is too large and the downstream slope is scoured． In view of this phenomenon，based on the overall hydraulic model test of the Nalenggele hydraulic project，two different flip buckets，namely，equal－width bucket and diffused bucket are put forward to analyze the internal flow pattern，water surface profile，flow velocity，time－average pressure，forms of water tongue and erosion situation of downstream channel of them． The results show that amplitude of the lateral water surface is small，the possibility of becoming cavitation is small，the water jet has a small width，and the energy dissipation effect is full． It plays an important role in improving the flow pattern of the bucket and reducing the scouring of the downstream bank slope，which effectively meets the actual local terrain and the needs of engineering operation．

In this paper,the problem of preventing water jet device of the deep outlet is analysised,and the transformation direction and measures are proposed. Finally,a new preventing water jet device is designed.Some of the tainter gates of the Deep Outlet is reformed by the experiment to provide a reference on the designing of the preventing water jet device.

Song－Li Ｒegion is the confluence area of the Lishui Ｒiver and branch of the Yangtze Ｒiver，the Songzi Ｒiver，and it is among the regions of Dongting Lake which suffers from the flood disaster most seriously in history． Based on an analysis of the flood characteristics of the Lishui Ｒiver and Yangtze Ｒiver，and the flood encounter condition between two rivers，the hydrological basic conditions for peak alternation regulation of Songzi Ｒiver and Lishui Ｒiver flood with Songzi flood－regulating sluice is qualified，the calculation methods and results of safe discharge capacity of river channels influenced by downstream backwater in Song－Li Ｒiver network area，calculating approaches of excess flood volume of Song－Li Ｒegion and principles of flood peak alternation regulation by Songzi flood－regulating sluice are proposed． On this foundation，the reducing effect on the excess flood volume of Song－Li Ｒegion by flood peak alternation regulation with Songzi flood－regulating sluice in typical flood years is analyzed． The results show that the excess flood volume of Song－Li region in large flood years will be drastically reduced by peak alternation regulation of Songzi Ｒiver and Lishui Ｒiver flood with Songzi flood－regulating sluice．

the flood limit water level is the key control point for the reservoir to coordinate the flood control and the profit promotion. The rational setting of the flood limit water level is an important way to realize the flood resource utilization. Under the influence of a variety of risk factors, this paper constructs a comprehensive evaluation index system of risk, establishes a comprehensive evaluation model, and comprehensively evaluate the risk of reservoir flood control. Taking the Luhun reservoir as an example, the feasibility of various flood limit water level schemes is discussed. The results show that the design flood process, flood forecast error, and the error of flood forecast are considered. Under the influence of four risk factors, the stagnation time of reservoir operation and the relationship between water level and reservoir capacity, the limit water level of the flood season of the Lu Hun reservoir can be raised to 318.7m, and the capacity of Xingli reservoir can be increased by 0.64m3, and the limit water level of the flood season can be raised to 319.2m, and the capacity of Xingli reservoir can be increased by 0.66m3. This study provides technical support for risk assessment of reservoir flood control operation, and provides scientific reference for the risk control of flood control in Luhun reservoir.

It is difficult to simulate the design flood accurately by traditional calculation methods ( synthetic unit hydrograph and rational method) as the complex hydrological process of rainstorm caused by the underlying surface hardening in urban areas． Taking the Wangjiangli Ｒiver in Huizhou as an example，this paper calculates the design flood of urban streams based on the SCS hydrological model and compared with the traditional methods． Ｒesults show that the peak discharge of the Wangjiangli Ｒiver has a significant positive correlation with urban land area． The design flood calculated by SCS model is 20% larger than traditional methods because the model has considered the underlying surface change thoroughly and the confluence become faster and the peak discharge was larger． The calculation results of the SCS model is more reasonable due to the consideration of underlying surface change． This study can be used as reference for the design flood calculation of urban river without observed data．

To explore the energy utilization of hydro generator and analyze the causes of energy efficiency changes, an energy efficiency evaluation method for hydro generators is proposed. Based on the analysis of the transformation process of water power utilization of hydro generator, a quantitative calculation model for energy efficiency of generator unit is established. Obtain the running state and operation data of the hydro generator, calculate the transformation energy in real time, and the energy consumption and water utilization rate at different time scales are also counted. According to the calculation results, analyze the energy efficiency level, energy efficiency trend and energy consumption of hydro generator. Example analysis shows the condition assessment model proposed is sound and effective.

Yingxiuwan Hydropower Station is located in the mountainous area of Minjiang River. The river often carries a large amount of sediment into power generation water, which brings a tremendous hidden danger to the safe operation of hydraulic turbines. In this paper, based on the water quality of Yingxiuwan Hydropower Station, we studied the sediment characteristics of power generation water, and a monitoring system for sediment concentration was designed and established according to the principle of turbidity measurement, which realized the on-line monitoring of turbidity and sediment concentration. The application shows that the measured value of sediment concentration is consistent with the result of the laboratory analysis. It can effectively reflect the variation trend of sediment concentration in power generation water, and provide information support for the dispatching decision-making, which has a good prospect of application and extension.