Ridge-furrow tillage is one of the main measures to increase rainfall use efficiency in the rain-fed cropland， which has been widely applied all over the world. Currently， the effects of ridge-furrow tillage on water cycle over the rain-fed cropland has been carried out by many scholars both at home and abroad， mainly focused on four aspects， i.e.， the atmospheric process， land surface processes， soil process and ground water process， and have achieved some results showed that the ridge-furrow tillage could enhance the functions of rainwater harvesting and preservation soil moisture. In addition， the analytical methods of the effects of ridge-furrow tillage on water cycle has been concluded to three kinds： the laboratory simulation tests， the field experiments， and the numerical simulation method. Furthermore， the optimized ridge and furrow pattern to realize the highly efficient use of rainfall has been studied by the optimization analysis method or the mathematical modelling.

The main physical properties， water capacity and infiltration characteristics of forest soil in Shangbao terrace is analyzed by field sampling and laboratory experiments. The results show that the soil bulk density of the study area increases with the depth， the soil porosity and aeration porosity decreases with depth， and the water capacity of surface soil is higher than deep soil. The maximum water capacity and effective water capacity of bamboo stands are the highest in the experimental samples. It indicates that bamboo plays an important role in forest eco-hydrology process. The initial infiltration rate and steady infiltration rate of forest soil in the experimental samples both exhibits the development rule of decreasing with depth. Moreover，there is a great difference between the surface soil’s initial infiltration rate and steady infiltration rate， the difference of deep soil is insignificant. Water conservation function of soil is enhanced by forest vegetation， which plays an important role in soil conservation. And we can properly increase the bamboo implantation rate to reinforce the ecological function of regional forest system.

To investigate the effect of irrigation quota on the ion in the maize in Tianjin coastal saline alkali land， maize is used for the comparison of changes in Na⁺， K⁺， Ca²⁺ and Mg²⁺ contents. The drip irrigation under the mulch technique and two kinds of irrigation quotas treatments of 10 mm（FI₁₀） are used in the experiment and 20 mm（FI₂₀） are set. The results show that the content of Na⁺ in root， stem and leaf of FI₁₀ treatment is higher than that of FI₂₀ treatment during the whole growth period， and the content of K⁺ in root， stem and leaf of maize treated by FI₂₀ is higher than that of FI₁₀ treatment. Under two kinds of irrigation treatments， the Ca²⁺ and Mg²⁺ contents in maize change similarly；

the quality of Na⁺， K⁺， Ca²⁺ and Mg²⁺ in leaf of FI₂₀ treatment from seedling stage to heading stage is higher than that of FI₁₀ treatment； in the process of ion selection of soil-to-root， the absorption and selection ability of K⁺ and Mg²⁺ of maize is higher than that of Ca²⁺； in the process of root-to-stem transport of ions， the maize is mainly transported by K⁺ to inhibit Na⁺ upward； in the process of stem-to-leaf transport of ions， the maize mainly inhibits Na⁺ through Ca²⁺. Based on the comprehensive analysis of the test results， it can be concluded that under higher irrigation quota with the lower contents of Na⁺ and higher contents of K⁺ of maize， which provides a theoretical basis for rationally determining the irrigation system of maize growing in the coastal saline soil land in Tianjin.

In order to reveal the transpiration water consumption law of Spring Maize in arid areas of Northwest China and provide theoretical basis for water-saving irrigation management， “Woyu No.3” spring maize was used as test material and field planting mode was adopted. The in-situ experiment was conducted in Yuyang District， Yulin City， Shaanxi Province in 2018， and the drip irrigation amount was set at 1.2 ET ₀， the stem flow rate of spring maize and the surrounding environmental factors were observed by using wrapped stem flow meter and small weather station， and the relationship between stem flow rate and environmental factors under different weather conditions was analyzed. The results showed that the diurnal variation curve of stem flow rate of spring maize was similar to “several” shape， but it showed different characteristics under different weather conditions. The correlation coefficient of Pearson was 0.828，0.728，0.693 and 0.367，respectively. The correlation between solar radiation and stem flow rate was the strongest， while VPD showed a certain lag. The multiple regression equation between solar radiation and VPD could predict the stem flow rate better.

An experiment about the change of soil organic carbon and its active components of paddy field during the whole growth stage was conducted to determine the effect of joint regulation of organic fertilizer and water-saving irrigation on soil organic carbon of paddy field. The results showed that water-saving irrigation accelerated the decomposition of soil organic carbon. And the combination of water-saving irrigation and organic fertilizer application increased the accumulation of soil organic carbon in paddy field. Compared with the conventional irrigation and fertilizer management， the content of soil organic carbon and soil microbial carbon was promoted by 11.2% and 9.5% under the combination of water-saving irrigation and the organic fertilizer application. By contrast， the average value of dissolved organic carbon was reduced by 16.9% in paddy field with combination of water-saving irrigation and the organic fertilizer application compared to conventional irrigation and fertilizer management. Meanwhile， the combination of water-saving irrigation and the organic fertilizer application were propitious to enhance the stability and quality of soil organic carbon in paddy field.

Based on MODIS Vegetation Index （NDVI） and Land Surface Temperature （LST） data， using ENVI software and ArcGIS technology， the agricultural drought evaluation index was constructed， and the spatial and temporal variation characteristics of agricultural drought in Guizhou Province during 2006-2015 were analyzed. Combined with the agricultural product harvest statistical data， the impact of agricultural drought distribution on Grain output was studied by correlation analysis. The results showed that： ① in the past ten years， the agricultural drought in the first half of the year mainly occurred in the west of Guizhou Province， while the agricultural drought in the second half of the year mainly occurred in the East， and the drought intensity and area showed a trend of gradual increase. ② In the study period， the intensity of agricultural drought is as follows： July > September > March > May； ③ In the early stage of crop growth， the occurrence of agricultural drought will inhibit grain growth and reduce grain yield， while in the middle and late stage of crop growth， agricultural drought will promote crop maturity and increase grain yield.

In order to study the effect of the collaborative design of the number of blades and the thickness of the blades on the performance of the centrifugal pump impeller， the k-Epsilon turbulence model is used in the ANSYS CFX commercial software， the steady-state and unsteady numerical simulations of the nine models with three kinds of blade numbers and three kinds of blade thickness co-designed at 0.8Q_d， 1.0Q_d and 1.2Q_d flow rates respectively. The external characteristic curve， internal flow field and pressure pulsation characteristics of the impeller flow path of each group scheme are analyzed. Research indicates that properly increasing the number of blades and reducing the thickness of the blades in the synergistic scheme can increase the efficiency of the centrifugal pump， improve the uniformity of the liquid velocity distribution of the impeller cross section， and reduce the pressure pulsation at the impeller flow path. In each collaborative scheme， the number of blades plays a leading role in the static pressure of the impeller cross section at each flow rate and the area of the turbulent kinetic energy area at small flow rates. The maximum static pressure value and the uniformity of static pressure distribution increase with the number of blades.

In order to investigate the effects of rotor with leading-edge tubercles on the hydraulic characteristics of the axial flow hydraulic machinery， combined with bionic airfoil. Structured mesh and the shear-stress-transport scale-adaptive-simulation turbulence model was used to simulation for the flow characteristics of an axial flow waterjet selected. Five rotor， each with different leading-edge tubercles designed were configured to analysis effects on the hydraulic pump performance， and the reason of effects under large flow rate are mainly studied. The results obtained show that tubercles reduce the hydraulic performance of the axial flow hydraulic machinery at low flow rate and improve the hydraulic performance at high flow rate. The main reason is that the tubercles provides passive flow control， which suppresses the unsteady flow in the rotor at high flow rate， reduces the energy loss caused by it， and improves the hydraulic performance of the axial flow hydraulic machinery. It is also found that the tubercles with different wavenumber and amplitude configuration provides different effect. In the present study， the tubercles configuration is optimal for 4/s and 0.12C.

On the basis of summarizing the working combination of the multi-stage pumping station system， the calculation methods of the inherent energy consumption parameters and the actual energy consumption parameters of the multi-stage pumping station system are derived， the inherent energy consumption parameters refer to the energy consumption parameters in the case of no diversion in the multi-stage pumping station system. Taking the measured data of the Xinmin system for 2019 winter irrigation in Donglei Yellow River pumping system as an example， the relationship between the inherent energy consumption parameter and the actual energy consumption parameter is discussed， and the operation of the pump unit and pumping station system is analyzed. For a fixed multi-stage pumping station system， the inherent energy consumption parameter is a certain value when the performance of each pump unit is stable， and its actual working efficiency varies with operating conditions. The inherent device efficiency is usually less than the actual device efficiency. The energy consumption parameters of the pump unit and the pumping station system can be used as standards for operating status monitoring， optimal operation scheduling and energy-saving transformation， and can also provide a basis for the formulation of irrigation district water prices and financial subsidies for irrigation districts.

In view of the arid environment in Northern Xinjiang， the suitable irrigation methods under water stress caused by water shortage and reduced irrigation frequency were explored. In this experiment， different irrigation frequency was set up to observe the effects of water stress and rewatering on cotton growth indexes in different growth stages， and the water use efficiency was analyzed through the final yield to determine the key period of rewatering control. The results showed that reasonable irrigation could slow down the inhibition of water stress on cotton physiological growth， and plant type and root / shoot ratio were more suitable for water stress. The results showed that water stress at seedling stage was beneficial to root deep rooting at bud stage （compared with CK treatment， root shoot ratio increased by 25.3%， 96.7%， 34.3% and -13.1% respectively） compared with CK treatment in the later stage of bud stage， which increased root absorption and synthesis ability， and was conducive to improving water use efficiency； plant height with higher compensation effect and early development of branches and leaves， compact plant type and good ventilation and light transmission conditions were obtained after rewatering in bud stage， It was beneficial to the accumulation of nutrients and dry matter under water stress （the accumulation of dry matter in flowering and boll stage of each treatment was 79.7%， 60.5%， 74.4% and 46.1% of CK）， which provided conditions for the development of cotton boll at flowering and boll stage， and alleviated the effect of water stress on cotton yield. Under the condition of this experiment， irrigation frequency of 25 days can exercise the drought tolerance of cotton plant at seedling and bud stage， increase root water absorption capacity and improve water use efficiency； on this basis， increasing irrigation frequency （25~10 days） at flowering and boll stage can ensure cotton yield to the greatest extent.

Improved PML-V2 remote sensing GPP-ET coupling model by introducing soil water stress factors， based on the improved model， the gross primary productivity （GPP） and evapotranspiration （ET） of the grassland ecosystem in China are estimated by using the remotely sensed data from 2000 to 2015， and the water use efficiency （WUE） is further calculated. The temporal and spatial variation of WUE and its correlation with climate factors are then analyzed via trend analysis and partial correlation analysis methods. Results show that the GPP estimates from the PML-V2 model and its observations from the flux station have a linear coefficient （R² ） and root mean squared error （RMSE） values of 0.65 and 1.046 gC/（m²?d）， respectively； while the corresponding results for the ET are 0.72 and 0.590 mm/d. The mean annual WUE of the grassland ecosystem shows an increasing trend from the northwestern to southeastern China. The change trend of the WUE has significant difference spatially， and it is mainly dominated by the GPP. Specifically， the WUE increases generally over the Inner Mongolia， while it decreases in the central part； in the Qinghai-Tibet Plateau， the WUE increases in the west and decreases in the east； in the Loess Plateau， it generally shows a decreasing trend with its degree increasing from the northwest to southeast. The correlation between the precipitation and WUE is negative， while the temperature and the WUE is positively correlated in most areas. And the spatial distribution of the correlation between WUE and solar radiation is complex. Temperature and solar radiation affect the main climatic factors of WUE changes.

It is of great significance to study the practical application of the reef on the inland river bank for the restoration of fish habitat. Based on the marine reef engineering， the reef block is applied to the mountain channel as a new ecological revetment structure， the structure size of the reef revetment block is designed， the flow field around the reef and reef field is simulated by using the finite element method， and the reef flow field effect under different arrangement modes is studied. The results show that the swimming speed of target fish is the upper limit and the spacing of 5 m is reasonable. In inland revetment engineering， it is appropriate to adopt the linear arrangement mode， for larger volume of upwelling flow and back eddy flow， more energy loss and better water resistance effect. The research results aim to enrich the inland river revetment form and provide theoretical basis for the application of fish reef in revetment engineering.

To ensure the safety of the embankment， the bank foot protection must be fixed first. The near-shore water flow is more turbulent， especially in the wandering river. Many existing bank foot protection structures are easy to break， making the embankment foot easy to scour and damage， which causes the embankment safety problem. This research selects the widely used stone cage net structure as a basis for carrying out the model test of river engineering， and designing test groups with different water flow， flow rates and flow directions. According to the experimental results， a horizontal flexible cushion structure for embankment foot is proposed. The width can be 1.5 to 2 times of the scouring depth and increase the appropriate safety margin. The volume of the gabion unit is based on the setting of no less than 3 to 4 gabions within the protection width. The structure has strong anti- rush performance and water permeability， and has integrity and strong terrain adaptability. When the external river bed at the embankment foot is preliminarily scoured， it can protect the river bed at the embankment foot the slope， to prevent the river bed from being further washed away， so as to improve the protection effect of the embankment foot.

The slope protection using soilbags is a new environment-friendly technology to reinforce the sand slope. To investigate the anti-erosion performance of the slope protection using soilbags， large-scale rainfall and erosion experimental tests are carried out on the soilbag-protected sand slope， the gabion-protected sand slope as well as the non-protected sand slope. The amount of rainwater infiltration and soil erosion of three slopes is measured. The test results show that the slope protection using soilbags can effectively intercept the infiltration of rainwater into the sand and greatly reduce the loss of soils. There is no obvious runoff channel at the contact area between the soilbags and the slope， while the non-protected slope forms lots of deep crisscrossed runoff channels. The erosion of soilbag-protected slope occurs mainly in the gaps between two rows of soilbags. The mechanism of anti-erosion performance in the slope protection by soilbags is summarized as four aspects： ① pressuring the slope； ② dissipating the energy of raindrops； ③ preventing the rainwater infiltrating into the soils of the slope； ④ filtering the ready-to-run-off soils.

Land subsidence caused by over-exploitation of groundwater is a relatively common geological disaster， which has the characteristics of long duration and wide range of influence. When constructing linear projects such as high-speed railways and underground oil pipelines in such areas， project safety is bound to be affected by ground subsidence， especially uneven settlement. The quantitative analysis of the uneven ground settlement and its evolution characteristics along the linear project is of great significance to ensure the long-term safety and stability of the project. In this paper， taking the Heze-Qufu section of the Lunan high-speed railway as an example， the three-dimensional fluid-solid coupling numerical model of the study area is established by cross-fusion of groundwater seepage theory and soil Biot's consolidation theory. The study uses the established three-dimensional fluid-solid coupling model of ground subsidence to analyze and calculate the uneven ground subsidence along the high-speed railway under different scenarios of groundwater mining schemes， the evaluation determines the relatively serious area of ground subsidence within the line interval. At the same time， from the perspective of subsidence control， the ground subsidence analysis and prediction under the conditions of reduced groundwater extraction are carried out. The results show that reducing groundwater extraction can effectively reduce the amount of ground subsidence and the maximum settlement curvature， alleviate the harm caused by uneven settlement， and ensure the safety of high-speed rail operation. The results of this paper functions as a reference for the engineering safety assessment of ground subsidence induced by groundwater mining in similar areas， and it has certain academic and engineering application reference value.

Sediment pollution is a worldwide problem， and sediment remediation is a key link to protect the water ecological environment in the future. However， the research on sediment remediation technology in China is immature at present， and it needs development and experience accumulation to shift from technology research to engineering. Based on the review of sediment in-situ remediation technologies that have been focused on at home and abroad in recent years， the research status and future development of these technologies are summarized from the perspectives of physics， chemistry and biology respectively， and then the technical route of sediment remediation is proposed. This paper emphasizes building remediation systems combining multi-technology with in-situ and ex-situ technologies. It points out that bio-remediation is the foundation and attention should be paid to the research and development direction of emerging remediation technologies.

The general laws and differential characteristics of the land use/cover temporal and spatial structure changes in the ecological function areas of glaciers and water conservation can reflect the use process of land resources and the change process of the ecological environment， thereby reducing the response time and delay mechanism of ecological environmental protection. Using Landsat TM satellite images in 1985， 1995， 2005， 2015， and slope data and watershed information extracted based on DEM and SWAT models as data sources， combined with in-situ investigations， the characteristics of land use/cover temporal and spatial structure as well as transfer were been analyzed， and studied on the response process of land use/cover structure changes to slope and watershed distribution. ① In the past three decades， the land use/cover structure dominated by forest and grass cover in Sunan Yugu Autonomous County of Gansu Province was relatively stable. The average proportion of forest land was 14.56%， and the average proportion of grassland was 56.77%， the area of woodland remained basically unchanged， grassland decreased by 35.28 km²， and arable land increased from 87.29 km² in 1985 to 194.8 km² in 2015， mainly due to the conversion of grassland and other types of land. ② Forest land is mainly located on slopes of 15°~25° in the central and southern part in the County. Grassland covers most parts areas in Heihe， Liyuan River， Beida River， Hongshui River， and below Grade VI in the river slopes of 15°~25°， the grassland area decreased mainly on the 15° slopes of rivers below grade 6 during 1995-2005， on the slopes of Beida River >25° and <15° as well as on slopes of Liyuan River 15°~25° and <15°. Cultivated land is mainly distributed in the Hongshui River， Liyuan River， Beida River， and rivers below grade 6. The newly added cultivated land area is mainly located on the > 25°slopes land in the Beida River of Minghua Township， and the <15°slopes of the rivers below the sixth level. The process of land use/cover change in Sunan County was relatively stable， but existing a trend of grassland decreasing and arable land increasing. The forest and grass coverage could be increased and local ecological protection would be better promoted by making full use of slope dominant position and watershed waters.

The public policy of water resources governance is the main way to remove the water shortage and flood disasters. The public policy effect of water resources governance is an issue valued by both academia and government. How to evaluate the public policy effect of water resources is the key to achieve the policy goal. This paper makes a comprehensive evaluation and analysis of the policy effect before and after the implementation of “A Total of Five Water Treatment” based on the current situation of water resources and water environment in Qiantang River Basin and the principal component analysis. The results show that the effect of public policy is positive， and the water quality and overall water environment have been significantly improved.The characteristics of policy instruments are obvious.The economic effect of market regulations is not obvious.The latter stage effect of public policy is declining smoothly and the combined effect and sustained effect of public policy need to be further improved.

The management of sand mining in rivers is very difficult due to lack of technical means and supervision manpower， which makes illegal sand mining uncontrollable. Against mobility， concealment and difficulty in obtaining evidence of illegal sand mining， image recognition technology based on deep learning is researched to improve the identification and supervision ability of sand dredges and break through the key points and difficulties in supervision. In combination with intelligent tracking technology， timely detection and early warning of illegal action is realized， and enough evidence chain is formed to confirm the fact. Therefore， the application of these technology has great significance for improving the efficiency of sand mining supervision.

In order to study the impact of coal mining on groundwater level， the groundwater flow in the study area is simulated and predicted by establishing the 3D geological model， groundwater flow numerical model and climate change scenarios in the future based on the analysis of hydrogeological characteristics and groundwater level monitoring data in the study area， which paves the way to delve into the change of groundwater level during the process of coal mining situation. The results show that： ①Under the current conditions of coal mining， the total amount of groundwater recharge in the research area is 573.22×10⁴ m³ the total amount of discharge is 1 038.5×10⁴ m³， and the balance difference is 465.28×10⁴ m³. The groundwater system in the research area is in a negative balance state. ②It is predicted that the amount of groundwater resources in the research area will decrease gradually from 2020 to 2035， and the phreatic water level will generally decrease. With the decrease in groundwater exploitation， the water level will rise in some areas， and the scope of groundwater depression funnel will decrease.

This research takes the Chengbi River Basin in Southwest China as an example to study the impact of climate change on the frequency analysis of extreme runoff in karst basins. Four indices including annual maximum 1-day runoff， 3-day， 5-day runoff and annual maximum peak discharge are selected. First， the trend and mutation analysis of extreme runoff indices in the basin are carried out by using linear trend and Mann-Kendall test method. Then the Annual-Maximum （AM） and Peak-over-Threshold （POT） are used for sampling， and the generalized extreme value distribution （GEV） and generalized Pareto distribution （GPD） are applied to data fitting. PP figure， QQ figure and Kolmogorov-Smirnov test are employed to determine the best-fitting model. Finally， the best distribution model is used to calculate and compare the extreme runoff under the different return periods in the basin. The result shows that climate change has affected the distribution parameters of extreme runoff sequences in the Chengbi River Basin， and the GPD distribution outperforms GEV distribution. In addition， the four extreme runoff factors in the Chengbi River Basin has decreased at different level induced by climate change.

Numerous reservoirs and hydropower stations have been built in the middle and lower reaches of the Yalong River. Choosing proper precipitation products to build hydrological models for runoff simulations in the upstream of the Yalong River shows significant importance for the downstream water resources development and reservoir dispatching. The study area of this study is the Xinlong Catchment， located on the upper reach of Yalong River. This study evaluates model performance for different data inputs and model structures. The precipitation data in China Meteorological Forcing Dataset （CMFD-P） is first evaluated in the study area against the gauged precipitation in daily data set of China's surface climate data （V3.0）. Then， CMFD-P and gauged precipitation are used as input to run the lumped three-source Xin'anjiang model and the lumped Xin'anjiang model with snow-melting module， respectively. The results show that： CMFD-P has a high consistency with surface precipitation data in the study area. The three-water source Xin'anjiang model with snowmelt module greatly improves the simulation ability of the three-water source Xin'anjiang model. Using CMFD-P to run three-water source Xin'anjiang model with snowmelt module can better simulate spring runoff， compared with using gauged precipitation. The results of this study serve as a practical reference for data selection and model optimization in the study area.

Based on the official statistics of flash flood related data， this paper first summarizes the current status of China's flash flood prevention construction from three aspects： construction content， achievements， and effectiveness， and initially builds a flash flood prevention system covering 2 058 counties in China with an area of 4.63 million km². The typical cases and governance models in flash flood prevention are extracted. The characteristics of flash flood disasters induced by heavy rainfall in China's new defense situation are explored as follows： ①strong suddenness and great harm， flash floods usually occur in tens of minutes to several hours； ②Floods in streams and rivers occur frequently， accounting for 54.3% of the total number of flash floods； extra-large flash floods caused serious disasters， including 2 extra-large flash floods， which result in the death of 316 people； ③the time span of flash floods is prolonged， and both the initial occurrence time and ending time are extended in one year； ④the same area experienced multiple flash flood， and the same county experienced up to 5 times repeatedly， with a minimum interval of 10 days before and after； ⑤ the proportion of elderly people， children and foreigners who died in flash flood has increased. Among them， elderly people， children， and foreigners （e.g. migrant workers and tourist workers） accounted for 50.2% and 25.6% of the corresponding proportions respectively. It also discusses the specific and practical countermeasures of flash flood prevention.

Large-scale water transfer projects usually use deep-water open channels for transportation. Due to the limitation of the water supply guarantee rate， the repair of the slope lining board can usually only be carried out under the condition of continuous water supply. The current internal static and external dynamic steel cofferdam is a new underwater construction technology for deep-water channels. In order to evaluate the impact of construction on the channel water delivery， it is necessary to carry out research on the hydraulic characteristics of the steel cofferdam. By using the method of combining three-dimensional hydrodynamic numerical simulation and generalized physical model verification， the spatial variation of the water depth field and velocity distribution of the steel cofferdam canal section is compared and analyzed. Studies show that the flow around the steel cofferdam affects the flow patterns of the upstream and downstream channels， resulting in a local head loss of about 0.11 m； the upstream backwater length is about 40 m， and the average backwater height is about 0.15 m； the local water surface of the narrowing section drops， and the flow velocity increases to the upstream flow is 1.58 times.The downstream diffusion section has a back flow zone， which causes the turbulent kinetic energy to be dissipated centrally. At the same time， the entrainment effect is beneficial to intercepting construction floating debris. Although the water flow structure of the steel cofferdam canal section has undergone adjustments of contraction and diffusion， the overall flow is relatively smooth and has little effect on the flow capacity of the channel. The research results can provide technical support for the continuous water maintenance of the deep-water open channel slope protection.

For large pipeline projects involving multiple seismic zones， it is very important to accurately assess the pipeline safety of typical sites. For example， buried water pipelines crossing faults are inevitably adversely affected by fault displacement. This paper takes the fifth section of the Ahong main canal pipeline in Yuxi area of the second stage diversion project in central Yunnan as an example to study the failure risk of pipeline under the action of active faults. The built-in pipe-soil interaction （PSI） element of ABAQUS software is used to establish a finite element model controlled by seismic displacement， taking into account the uncertainty of seismic displacement load， pipe strength and undrained shear strength of soil， and the maximum axial tensile strain and compressive strain are used as the response values to obtain the distribution of pipeline response. Based on the Monte Carlo simulation method， the failure probability of the pipeline under a given working condition is calculated. Then， this paper studies the influence of earthquake magnitude， pipe wall thickness and filling depth on the failure probability of the selected pipeline. Results show that the safety of buried pipelines across faults is very sensitive to the magnitude of an earthquake. Increasing the thickness of the pipe wall can reduce the probability of failure of the pipe while the depth of the buried pipe has little effect on the safety of the pipeline.

Jiangxi is rich in water resources， but the spatial and temporal distribution of precipitation is uneven， and floods and droughts are frequent. Affected by the uneven spatial and temporal distribution of water resources， the insufficient allocation of river water and the low and dry water level of Poyang Lake， the engineering water shortage problem in Jiangxi Province is becoming increasingly prominent. Through time and space distribution of water resources， water resources development and utilization in Jiangxi Province， the water resources allocation system， urban and rural water supply security ability， change of hydrology， protection and restoration of the ecological analysis of the provincial physical cause outstanding short board， water shortage problem oriented， this paper studies the construction of resolving water shortage problems physical project， promotes the global water ecological environment quality， project construction， promotes the economical and intensive utilization of water resources development countermeasures， and enhances the level of water use efficiency. Solving the engineering water shortage in Jiangxi Province provides certain guiding significance.

In order to reveal the quality of drinking water cellar in karst mountainous areas and ensure the safety of drinking water in karst mountainous areas. Based on the physical， chemical and microbial indexes of drinking water cellars and public catchment pools monitored in typical karst mountainous areas in southeast Yunnan， the single index method and comprehensive index method are used to evaluate the water cellars. The results show that： ①the chemical index （Si， Mn） and microbial index of the water tank exceeds the standard seriously， the single index exceeds the standard degree： CF>SL>Si>Mn>TC=EC₁>residual chlorine=total chlorine； The total chlorine and residual chlorine exceed the standard in the transitional period， and the pH， chroma and turbidity of a few water pits exceed the standard. ②The water quality in the cellar is 66.07% of grade II and 33.93% of grade III， All the treated water is drinkable. ③The quality of water cellar is space-time characteristics， which is influenced by rainwater runoff， regional geological background and human activities.

Based on 964 valid questionnaires of household water consumption survey in Beijing， the current situation of household water consumption in Beijing is analyzed. According to the model algorithm of probability statistics and the basic principles of economics， combined with the survey data analyzed by SPSS software， the overall influencing factor model of per capita daily household water consumption is constructed， and the functional relationship between per capita daily domestic water consumption and its influencing factors is obtained. The results show that the per capita daily water consumption of families in Beijing is 107.01 L/（person·d）. The factors that have obvious influence on domestic water consumption are household per capita annual income， bath frequency， washing water saving degree and cooking frequency. Among them， the annual per capita income is significantly correlated with the degree of water saving in laundry and the frequency of bathing， the annual per capita income is negatively correlated with the frequency of cooking， and the per capita daily water consumption is significantly correlated with the annual per capita income and bathing frequency. It provides the focus and direction for Beijing household water saving.

On the basis of the Taihu Basin model algorithm and various data resources， an event-driven Taihu Basin consultation and decision-making system is built. The system judges different events such as optimal allocation and scheduling of basin water resources， flood scheduling， water pollution emergency scheduling and triggers corresponding event-driven mechanisms according to the real-time updated comprehensive early warning and forecasting information of the basin. Under the scheduling topic of corresponding events， historical similarity analysis and model calculation are carried out according to the current overall situation of the basin， the situation in a period of time in the future is predicted， and the recommended scheduling scheme is proposed through simulation scheduling comparison function. With the continuous accumulation of scheduling cases， the event-driven scheduling consultation and decision-making system will be more scientific， timely and efficient.

Water conservancy project governance involves many stakeholders，and it is difficult to coordinate. In order to systematically analyze the relationship between the influencing factors of water conservancy project governance， 17 main factors are selected based on the systematic analysis of the influencing factors of water conservancy project governance. Then， the Adversarial Interpretive Structure Modeling Method （AISM）， based on the extended algorithm， is used for modelling. And a set of directed topological hierarchy diagrams with game relations are used to analyze the relevant factors affecting the governance of water conservancy projects， and the factor hierarchy and correlation are obtained.In view of the level of factors and the relationship between levels， this paper puts forward suggestions on governance optimization and improvement， providing reference for the practice of project governance.

Unit state evaluation and fault diagnosis are based on feature extraction. Feature extraction of nonlinear and non-stationary vibration signal of hydropower units is a hot research topic in the field of hydropower. A feature extraction method for vibration signal of hydropower units based on ensemble empirical mode decomposition （EEMD） and multi-scale entropy （MSE） is proposed. Extreme learning machine（ELM） is used for pattern recognition. The denoised signal is decomposed by EEMD， and screen effective intrinsic mode function （IMF） is based on kurtosis - standard correlation coefficient index. MSE of the effective IMF is calculated and characteristic vector set is built. The fault feature set is put into ELM to evaluate the unit operation state and realize the unit fault early warning. The feasibility and superiority of the method for vibration signal feature extraction of hydropower units are verified by field test data.

The permeability of fractured rocks is an important hydraulic property for seepage analysis and design of seepage control system in the surrounding rocks. The water pressure test in borehole is an effective technique for characterizing the permeability in the fractured rocks. With the mirror-image method， a Darcy’s law-based analytical model is established and numerically verified to estimate the hydraulic conductivity of the tested rocks. Given that the expression of hydraulic conductivity k is consistent with the Hvorslev equation recommended in the currently-applied codes of borehole water pressure test under certain conditions， the proposed model is hence an extension of the recommended formula. With its simple form and clear physical meaning， the proposed model can be treated as an important basis for revision of the codes of water pressure test in borehole.

Water conservancy and hydropower projects have a long construction period and a large amount of wastewater discharge. If it is directly discharged without treatment， it will have adverse effects on the water environment. Taking Xulong hydropower station of Jinshajiang River as an example， this paper studies the impact of sand and gravel processing system and domestic sewage accident discharge on the water environment of Jinsha River. The results show that： in the case of accident discharge， the horizontal impact of domestic sewage is concentrated in the range of 4m away from the bank， and the longitudinal impact is concentrated in the range of 200 m downstream of the sewage outlet. The maximum increment of COD concentration at the outlet is 0.5 mg/L compared with the background concentration； the length of SS pollution zone can reach 16.5 km in the case of accident discharge of waste water from sand and gravel processing system S concentration is about 13.4 times of river background value. The results can provide a scientific reference for the study of water environmental impact during the construction period of hydropower projects， and provide support for the selection of risk prevention measures of waste water accident discharge during the construction period of Xulong hydropower station.

In water conservancy and hydropower engineering， the hydraulic conductivity of the fracture rocks is a necessary parameter for the simulation of seepage flow， and the accuracy of its value will directly affect the simulation process. This research selects the adaptive penalty Heaviside function and Signorini’ type variational inequality formulation finite element method combined with PEST， an automatic optimization algorithm widely applied in groundwater models， to perform inverse analysis on hydraulic conductivity of the fractured rocks with an objective function based on the time series data of flow rates and hydraulic head. The calculation results of a simple 2D case conducted by PEST shows that the method is reliable and accurate in the inverse analysis， which is applied successfully to determining seepage parameters and evaluating the characteristics of seepage field on a hydropower project in southwest China. Several commonly used time series analysis indicators are selected to evaluate the specific errors between the calculated value and monitored values of flow rates and hydraulic head. The results show that the average absolute error， root mean square error and average absolute percentage error of flow rates and hydraulic head are basically not more than 2.5 L/s， 2.5 L/s， 30% and 10 m， 10 m， further indicating that the inversion results have a certain accuracy and reliability.

Slab deformation monitoring of high-face rockfill dams has always been a technical problem in the dam industry， and it is difficult for conventional instruments to deal with this problem. In this regard， a micro-inertial monitoring system based on MEMS three-axis gyroscope and three-axis accelerometer is proposed to monitor the deflection and deformation of dam panels. Compared with the old monitoring system， the new monitoring system is cheaper and more accurate. The specific composition and monitoring principles of the new monitoring system are explained. At the same time， in order to improve the measurement accuracy， a lossless Kalman filter is used to process the monitoring signal. Experiments show that the lossless Kalman filter algorithm effectively improves the accuracy of attitude calculation. The new monitoring system was used to measure the deflection of the slab of the Monkey Rock Dam and compared with the FOG monitoring system. The results show that the measurement data of the new monitoring system can truly reflect the deformation of the slab with high accuracy.

Crack resistance of concrete face slab is very important for the service life of concrete faced rockfill dam （CFRD）. The effects of fly ash， MgO expansive agent and shrinkage-reducing admixture （SRA） on the mechanical properties， drying shrinkage and crack resistance of face slab concrete are studied and compared with the reference concrete. The results show that the addition of 20% fly ash （by weight of binder） enhances the strength of concrete at the late age. In contrast， the addition of 6% MgO expansive agent or 1% SRA reduces the compressive strength， splitting tensile strength and ultimate tensile to some degrees at various ages. The incorporation of 20% fly ash， 6% MgO expansive agent and 1% SRA can reduce the dry shrinkage at various ages and improve the early crack resistance of concrete， while the incorporation of 6% MgO expansive agent is more conducive to inhibiting the shrinkage development and improving the crack resistance of concrete than the addition of 20% fly ash or 1% SRA.

A hydropower station adopts the form of two units sharing a tailwater open channel，and power oscillations occur among the units during operation. Tests and historical data analysis show that this phenomenon is related to the hydraulic design of the tailrace system open channel. In order to effectively solve the problem of active power fluctuation， it is necessary to increase the damping of the tailwater open channel runner， and it is planned to set up energy elimination sill. CFD technology is used for hydraulic design of the energy dissipation sill， and the form and size of the energy dissipation sill are determined based on the numerical simulation calculation of FLUENT. The design results are applied to engineering practice， and it successfully solves the power oscillation problem caused by the tailwater system of a certain hydropower station， and provides new ideas and methods for solving such problems.

For hydropower stations that use “valves replacing wells”， the dynamic characteristics of the small fluctuations transition process are one of the key issues affecting the safe and stable operation of hydropower units. According to the actual situation of a foreign project， the author uses matlab/simulink to establish a mathematical model of the hydraulic turbine regulating system. For some typical working conditions， the acceleration time constant Tn， the buffer time constant Td and the transient slip coefficient bt are respectively used as parameter variables， and the root locus analysis method is used to study its dynamic characteristics， the optimal parameter setting values of the speed control system are obtained. The dynamic quality of small fluctuations has been improved.