Precipitation is the most direct source of water resources in the basin with affecting runoff process as well as the generation and convergence of water resources. In this paper, the thiessen polygon method and inverse distance weight method are used to calculate the surface rainfall. The XAJ model is used to simulate the daily runoff series from 2008 to 2012 in Fujiang River basin. On this basis, the influence of rain-gauge network intensity and interpolation methods on results of area rainfall and runoff simulation accuracy is studied, and the relationship between relative deviation of area rainfall calculation and runoff simulation relative deviation is further discussed. The results show that the more rainfall stations, the less the uncertainty of area rainfall calculation, the higher the accuracy of runoff simulation. When there are few rainfall stations for interpolation in Fujiang Basin, the accuracy of runoff simulation results by inverse distance weight method is better. When there are more rainfall stations for interpolation, the accuracy of runoff simulation results by thiessen polygon method is slightly better than that by inverse distance weight method. There is no obvious correlation between the runoff simulation relative deviation and the area rainfall calculation relative deviation. With the increase in the regional rainfall calculation relative deviation, the runoff simulation relative deviation shows a oscillating change.

Aiming at the shortage of water resources in Ganzhou District of Heihe River Basin, based on the total available water resources in Ganzhou District, this study takes into account the water demand of economic development and water environmental protection, and by taking the maximum economic benefits of domestic, livestock, industry, agriculture and ecological water use and the minimum consumption of water resources as optimization objectives, this paper advocates sustainable development. The linear programming model of multi-objective rational allocation of water resources puts forward a rational allocation scheme for the allocation of water resources in Ganzhou District.

Based on the precipitation, runoff and sediment data from 1956 to 2011, the variation trend of the runoff and sediment by using the Mann-Kendall method and sliding t-test is analyzed to look for the abrupt change points. The double mass curve is also used to calculate the influence of rainfall and human activities on the runoff and sediment decline. The abrupt variations results show that the annual runoffs and annual sediments at Gaojiachuan Station show a trend of decline. The runoff series changed abruptly in 1976, and the sediments series changed abruptly in 1996. The runoff and sediment decline was mainly affected by human activities. The contribution rates of human activities to the runoff and sediment were 35.94% and 86.42% respectively.

In order to predict and control the quantity and quality factors of regional water resources carrying capacity quantitatively, the prediction and quantitative control method of water resources carrying county- level capacity based on system dynamics is proposed. Taking Lujiang County in Chaohu Basin as an example, firstly, on the basis of diagnostic indexes of regional water resources carrying capacity quantitative and qualitative elements, a simulation and prediction model of water resources carrying capacity based on system dynamics is constructed. Secondly, the indicators of water resources carrying capacity are inferred from diagnostic indexes, and the dynamic predictive values of water resources carrying capacity qualitative elements are obtained. Secondly, according to the operability and sensitivity of variables, some variables are screened from diagnostic indexes. Finally, based on the forecasting model, the orthogonal experimental method is used to optimize the control index to achieve the purpose of quantitative regulation of the quality factors of regional water resources carrying capacity. The results show that the relative errors of the four factors are less than 20% when selecting the representative total population, total water consumption, COD emissions and ammonia nitrogen emissions. In 2035 and 2050, the quantity and quality factors of water resources carrying capacity in Lujiang County are in overload state. The water quantity and water quality factors selected from the diagnostic indexes are controlled in stages according to orthogonal experiments. The results show that the quantity and quality factors of water resources carrying capacity in Lujiang County reached critical condition in 2035 and 2050, which indicates that WCCPDR-SD model has a good application value in the prediction and quantitative regulation of regional water resources carrying capacity.

In order to make a more reasonable use of groundwater resources in the Cherchen River Basin in the southern part of the Tarim Basin, this paper uses the multi-year atmospheric precipitation isotope data from two monitoring stations in Hetian and Urumqi to fit the local atmospheric precipitation line LMW: δD=7.5 δ18O+5.9(n=178,R2=0.9526). Combined with the local hydro-geological conditions, this paper explores the groundwater supply source of Cherchen River Basin in Tianma County by using the variation characteristics of surface water and groundwater isotopes (δD, δ18O, T) of different geomorphic units and the relative change rule of Cl- δ18O. The results show that the groundwater of different geomorphic units in the study area is mainly supplied by glacial snowmelt water and alpine rainfall, and the source area is the southern high mountain area. In addition, in recent years, water-saving facilities such as canals and civil wells are built to divert water for irrigation, so that the groundwater in the irrigation area is also supplied by a large number of canal system diversion water and seepage of backwater from farmland irrigation. In the desert area, the T isotopes of groundwater are low, and the δD and δ18O values are close to the local atmospheric precipitation line, so it is speculated that the groundwater in this section is also recharged by local atmospheric precipitation.

Taking a road in Pingxiang City, Jiangxi Province as the research object, after generalizing, calibrating and validating the research area, the SWMM model is used to simulate the runoff process of road exit under designed rainfall conditions from 2 to 100 years, and the control effect of three typical sponge measures combination schemes, sunken lawn, permeable brick and permeable pavement are analyzed. The results show that under the rainfall conditions of 2 to 100 years, the peak flow reduction rate is 0.20%~59.69%, the total runoff reduction rate is 12.69%~63.99%, and the peak lag time is 2~5 min. The combination schemes of sponge measures can reduce and delay the rainfall runoff, and the rainwater control effect of scheme 3 is better than other schemes.

Aiming at a series of problems existing in the water system in the process of urbanization in low hilly areas, this paper takes Wangcheng New District of Nanchang as an example, nine evaluation indexes are selected from three aspects of structural connectivity, hydraulic connectivity and geo-morphological characteristics, fully considering the influence of water flow capacity and water conveyance efficiency, the formula of water flow potential is improved, and a comprehensive water system connectivity evaluation system is constructed. The pattern and connectivity of water network before and after the planning are compared and analyzed. The result shows that after the planning, the indexes of the water system increase in different ranges, and the connectivity of the water system is enhanced. The application example of Wangcheng New District shows that the evaluation index system constructed can reflect the connection status of water system in low hilly areas.

Taking a road in Pingxiang City, Jiangxi Province as the research object, after generalizing, calibrating and validating the research area, the SWMM model was used to simulate the runoff process of road exit under designed rainfall conditions from 2 to 100 years, and the control effect of three typical sponge measures combination schemes, sunken lawn, permeable brick and permeable pavement were analyzed. The results show that under the rainfall conditions of 2 to 100 years, the peak flow reduction rate is 0.20%~59.69%, the total runoff reduction rate is 12.69%~63.99%, and the peak lag time is 2~5min. The combination schemes of sponge measures can reduce and delay the rainfall runoff, and the rainwater control effect of scheme 3 is better than other schemes.

Rivers in urban polder areas generally have poor natural fluidity and low self-purification capacity, so the water environment deterioration is a common problem in these areas. Dongting Street, belonging to Wuxi, is a diked area in the Yundong Polder. It has the general characteristics of the urban polder areas. Dongting Street has a large amount of domestic sewage discharge, suggesting the main pollution factor is ammonia nitrogen. This research uses the MIKE 11 model intended to control the concentration of ammonia nitrogen. By using the MIKE 11 model, this research analyzes the reduction rate of the concentration of ammonia nitrogen under the condition that one or more of the three factors improved. Results suggest that the peripheral water quality has the greatest impact on the water environment at the studied area. When the peripheral water quality was improved to class Ⅳ surface water standard of China (GB3838-2002), the reduction rate of ammonia nitrogen was 67.3%. The reduction rate was 53.6% when the pollution level increased to 98%. At last, when the Ⅳ water source (6 m3/s) was input through gate and pump station, the reduction rate was 50.3%. When two or more factors were simultaneously improved, there was a superposition effect on the improvement of water environment, and the ammonia nitrogen concentration reduced by about 85.5% at most.

In order to study the effect of nitrogen and phosphorus removal by dominant species in typical lakes of Jiangsu Province, six typical lakes in Jiangsu Province, Baima Lake, Baoying Lake, Gaoyou Lake, Changdang Lake, Gehu Lake and Shaobo Lake, are selected as the research objects. Six dominant species are selected according to the distribution of aquatic plants in this area, explores the experiments on the absorption of nitrogen and phosphorus in surface waters of class V standard waters (TN: 2 mg/L; TP: 0.2 mg/L) by dominant aquatic plants in Jiangsu Province. The results show that the six dominant species are Phragmites australis, Zizania latifolia, Myriophyllum spicatum, Hydrilla verticillata, Trapa natans, Nymphoides peltata. Purification experiments show that the removal rate of TP and TN by Phragmites australis and Zizania latifolia is higher than that of other aquatic plants, and the removal rate of ammonia nitrogen by Myriophyllum spicatum spicata is the best.

Water pollution accidents occur frequently, and timely acquisition of relevant parameters of pollution source is needed to carry out emergency treatment. This paper presents a new method of two-dimensional instantaneous point source parameters inversion based on least square method. Firstly, the analytical solution of two-dimensional instantaneous point source is used to generate the observed data of hypothetical examples. Then the proposed method is used to process the observed data, and the parameters such as pollutant emission position and time, emission intensity and longitudinal dispersion coefficient are obtained. This paper explores the influence of observation data errors on the inversion results, as well as the influence of the number of monitoring points. The results show that the method can get the source parameters and key hydrodynamic parameters of two-dimensional instantaneous point source simultaneously. The inversion results are less affected by the errors of the observed data; the number of observation data also has an effect on the inversion results, but the effect is not significant; this method can be used in practice.

The efficient utilization of agricultural water resources is an important part of water conservation, and water conservation in irrigated areas is the key field of agricultural water conservation. Taking the second main canal of the Zhanghe Irrigation District as the research object, this paper conducts a comparative study of the “merge after calculation” and “merge and then calculate” approaches to channel flow evolution based on Maskinghen method, focusing on the flow change characteristics with multi-division. The results show that the average discharge of the canal head calculated by the two methods is more accurate, but the flow process simulated by the method of “merge and then calculate” is closer to the measured process. This study can not only be used to deduce the water distribution process of canal head and simulate the water level process of each section, but also provide a decision-making basis for the scientific and accurate scheduling of water amount in irrigation areas.

In the process of pouring water tower in the cold area, concrete often produces cracks due to the complex and changeable environmental climate in the area. Therefore, according to the special climate in the area, adopting appropriate temperature control measures is crucial to preventing the cracking of concrete in the water tower. Taking a water tower in a cold area as an engineering example, this paper analyzes the sensitivity of cooling water pipe spacing, water temperature, water length and insulation layer thickness by using three-dimensional finite element simulation software. The maximum temperature in the center of each sensitive factor is analyzed, and the temperature field of the typical elevation of the water intake tower during the entire pouring process is compared, so that the most favorable temperature control measures are optimized. The results of calculating the characteristic points of different parts of concrete under the recommended measures are obtained, and the temperature and temperature stress of different parts of the water tower are obtained when pouring to a typical elevation and long intermittently pouring block. The results meet the needs of the project. The research results serve as a reference for the optimization of similar engineering temperature control measures.

Artificial turf and triangular prism brick are adopted to imitate ecological revetment, and the roughness coefficient of trapezoidal open channel flow with revetment is investigated based on the experiments conducted in an asymmetric trapezoidal flume with different flow rates and bed slopes, the influence of revetment roughness on flood carrying capacity in trapezoidal open channel under non-uniform flow and different wide-depth ratios is analyzed based on numerical simulation. The results show that，the composite roughness increases with an increase in flow depth, and conforms to the logarithmic profile, while the variation of flow rate or bed slope has no obvious effect on roughness coefficient. Under both the uniform flow and non-uniform flow, the flow depth increases with an increase in composite roughness; in the non-uniform flow, the stream-wise variation of composite roughness has the positive correlation with the stream-wise variation of water depth. The impact of revetment roughness on flood carrying capacity is obvious in the narrow and deep river while it is not significant in the wide-shallow river.

Although ultra-large diameter PCCP pipeline has been widely used in large-scale water diversion projects in China, its wire breakage repair technology is still immature, and there is little analysis on the effect of wire breakage repair, and there are few related literatures based on engineering practice. Fracture of prestressed steel wire has been already appeared in a ultra-large diameter PCCP Water Conveyance Project in China, In order to avoid interruption of water supply, in addition to the reinforcement measures of pasting carbon fiber cloth and coating epoxy coating on the broken area of PCCP pipe, measures such as soil settlement monitoring, groundwater level monitoring and real-time wire breakage monitoring are added to monitor and protect the ultra-large diameter PCCP water conveyance project. The protection method after wire breakage repair is introduced in detail, and the repair effect is analyzed by monitoring data, in order to apply this technology to engineering practice more.

Taking a multi-sluice overflow dam of a reservoir as an example, the flow model is established by Flow-3d software to study the optimal operation of gates under small flow. By analyzing the different combinations of the multi-sluice gates under normal operation water level (Q=300 m3/s), the flow characteristics of the rake surface, the characteristics of the pick-up flow, the flow velocity of the river under the dam, the pressure at the bottom of the river, and the hydraulic factors of the energy dissipation rate are summarized. The hydraulic law of the multi-sluice overflow dam dispatching operation is given, and the optimal scheduling mode of the project under small flow is given. The results show that under the six opening modes, the continuous opening of the 2-3 gate holes is better than the other opening modes, and the hydraulic conditions are relatively stable.

In order to study the effect of micropores on the cavitation performance of NACA5412 airfoil, the Euler multiphase flow model and the turbulence model are used to calculate the flow field around 13 different NACA5412 airfoil structures, and analyze the pressure distribution around different airfoil structures. The results show that range of the lower pressure zone above the non-porous airfoil is larger than that of the below. Moreover, both of upwards and downwards pressures of different airfoil structures-firstly decreases and then increases. The micropores change the flow field of the non-porous airfoil around the flow, pull down The range of the low pressure zone, and suppress the initial cavitation occurs. The area ratio studied in this paper ranges from 0.001 7% to 0.162 9%, The 1.5mm quincunx hole (0.091 7%) has a minimum range of low pressure regions around the airfoil. The research results can provide some basic theoretical basis for further research to solve the cavitation problem of hydraulic machinery.

In order to analyze the effect of divisionpier on the discharge capacity of WES weir quantitatively, the discharge coefficient of a semicircular divisionpier under different water heads are studied by means of an experimental method in this paper, and the results are compared with those without divisionpier, the reasons for the decrease in discharge coefficient after setting up the divisionpier are analyzed by numerical simulation method. The results show that: the effect of divisionpier on discharge capacity can be reflected by the lateral contraction coefficient, there is little effect on the lateral contraction coefficient of the divisionpier with or without draining open channel in front of weir. The same is true of abutment pier. What's more, the lateral contraction coefficient is 0.969~0.978 under the experimental shape of this paper. Finally, the numerical simulation shows that the energy loss mainly occurs at the tail of the divisionpier.

Crop evapotranspiration (ET) is a key parameter of agricultural water management, the accurate estimation of ET is of great significance to the realization of precise irrigation management and the allocation of regional water resources. In order to effectively improve the prediction accuracy of summer maize ET in Northwest China, a model for estimating summer maize evapotranspiration in Northwest China is established based on generalized regression neural network (GRNN) by using summer maize crop index and meteorological factors from 2011 to 2013, and the results are compared with those of Shuttleworth-Wallace (S-W) physical model. The results show that, compared with the ET measured by large-scale transpirator in different periods of summer maize, the simulation effect of GRNN on ET in different growth stages and whole growth stages of summer maize is better. In the whole growth stages, the optimum simulation model of ET for summer maize is M12 (input T, n, LAI), MAE, NSE,R2,MRE, RRMSE and GPI ranking were 0.925 2 mm/d, 0.550 0, 0.553 6, 0.836 8, 0.430 7 and 4, respectively. The optimum simulation model of ET for summer maize from seedling to tasseling stage is MⅠ-14 (input fc, H), MAE、NSE、R2、MRE、RRMSE and GPI were 0.866 0 mm/d, 0.391 7, 0.425 2, 0.360 6, 0.399 0 and 2, respectively. The MAE、NSE、R2、MRE、RRMSE and GPI ranked were 0.5 933 mm/d, 0.753 7, 0.760 1, 0.229 9, 0.284 0 and 1 respectively for the optimal model MⅡ-9 (input n, T, RH, LAI) in tasseling to grouting stage, and the related parameters were 0.325 8 mm/d, 0.857 0, 0.885 2, 0.211 2, 0.215 5 and 2 for the optimal model MⅢ-11 (input RH, n, T) for the filling-harvesting period. At the same time, the simulation value of GRNN model is much more accurate than that of S-W model. Therefore, the evapotranspiration estimation model based on generalized regression neural network can be used to accurately simulate the evapotranspiration of Summer Maize in different growth stages in Northwest China with fewer input parameters.

Soil infiltration is a complicated process, and the rock fragment cover will affect soil infiltration properties. In this paper, the related parameters of soil infiltration properties are analyzed through gravel covering experiment and soil-gravel mixing experiment. The results show that the stable infiltration rate, sorptivety, hydraulic conductivity and soil effective porosity decrease with the increase in gravel coverage soil-gravel mixing degree. In the infiltration of different gravel coverage soil-gravel mixing degree, the variation of relative parameters is significant (P< 0.05). This shows that the effective porosity of the soil decreases with the increase in the gravels, and the water movement channel is so complicated as to limit the infiltration of water. In the soil-gravel mixing experiment, sorptivety, hydraulic conductivity and soil effective porosity decreases sharply with the increase in gravel coverage soil-gravel mixing degree, which is higher than those in the gravel covering experiment. The gravels in the soil can change the soil infiltration properties. Studying the effect of gravel on soil infiltration characteristics further is of practical significance. It is significant to study the possibility of using the rock fragment cover to maintain soil and water for engineering slopes.

Double-ring method is adopted to measure the soil infiltration process of 36 test points, and infiltration parameters are developed with Kostiakov, Horton and Philip model in order to investigate infiltration law and its influencing factors of Daxing District, Beijing. At the same time, regression coefficient of infiltration model, statistical values of the characteristic parameters, and spatial variability of the characteristic parameters are calculated or analyzed by using classical statistical and geo-statistics methods. Results indicate that the Philip model can be used as the optimal infiltration model in the study area, its mean value of the correlation coefficient reaches 0.934, and probability distribution of each infiltration parameter obeys the normal distribution or the lognormal distribution. Characteristic parameters have moderate or strong spatial correlation, indicating that random factors have less influence on soil spatial variability. Based on Kriging interpolation method, spatial distribution pattern of characteristic parameters is obtained, and characteristic parameters shows a certain increasing trend from west to east.

In order to determine the suitable maize planting density and irrigation mode in the north region of Shanxi Province, the experiment of mulched drip irrigation is carried out in the maize field in Yanggao County, Shanxi Province in 2015. The effects of various combinations of planting density and irrigation times on water content, water consumption, the growth and development of plant, and water use efficiency in maize fields are studied. The results show that the planting density and irrigation times have a significant effect on maize growth, which affects maize yield. Under the combination of the planting density of 82 500 plants/hm2 and the irrigation times of 3 during the growing period, the growth, water use efficiency and yield of maize are the best. It is the optimum combination with a yield of 8 418 kg/hm2, a water consumption of 4 057.03 m3/hm2, and a water use efficiency of 2.08 kg/m3.

Most of the water needed for the growth and development of Pleurotus ostreatus comes from the culture materials, and the lack of water in the culture materials can easily lead to the reduction of Pleurotus ostreatus. In this experiment, different proportions (0.1%, 0.2%, 0.3%, 0.5%) of SAP are added to the culture materials to study and analyze the effect of adding SAP on the growth of Pleurotus ostreatus. The results show that the application of SAP promotes the increase in the number of picking times, total yield and water use efficiency of Pleurotus ostreatus. The total yield increases by 8.73%, 17.68%, 50.94% and 45.32%, respectively. The water use efficiency increases by 0.74%, 1.70%, 22.07%, and 4.27%, respectively. Through comprehensive analysis of total yield and water use efficiency, when the proportion of SAP is 0.3%, the total yield and water use efficiency are better. According to the correlation analysis between water retention capacity and total yield of water retention agent, it can be seen that when the SAP addition ratio is 0.455%, the total yield reaches the maximum. Therefore, it is recommended that the proportion of SAP added in the production of Pleurotus ostreatus is 0.3%~0.455%.

Ammoniation straw returned to find out the different amount of Shanxi medium saline-alkali soil water and salt factor, the influence of the growth characters and yield of corn, knick-knacks in 2018 in Shanxi Province has carried on the field experiment, the design of the four different ammoniated straw counters-field amount (1.2, 0.9, 0.6, 0.3 kg/m2), and there is no straw for field as the control group (CK), in the maize growth period on soil salinity, soil moisture content, maize growth properties index and yield are determined. The results show that the accumulation of soil salinity surface strongly presents the “plant” type, and the leaching effect of salinity in different treatment groups is significantly different from that of CK (P<0.05), which can create an environment with less salt for agricultural growth. Water retention effect becomes more and more obvious with the growth of crops, and the difference between treatment group and CK is significant (P<0.05). All the growth indicators show rapid growth in the early growth stage, gradually slow down and stabilized in the later growth stage, and the area index in the middle period show a trend of decline in the later growth stage. F1.2 and F0.9 in the treatment group has little difference in the impact on each index. Considering the benefits of water-saving and water conservation and yield, it is advisable to return 0.9 kg/m2 of ammoniated straw to fields in moderately saline and alkaline lands.

In order to analyze the effect and uniformity of herbicide application during the integrated irrigation of micro-spray water and herbicide, the experiment of applying herbicide with water in the field micro-spray belt is carried out in Wuwei. The commonly used 32 oblique 5-hole micro-spraying belt is used as irrigation equipment, with a length of 40 m. Under the normal working pressure of 55 kPa and the total dose of 1.522 5 kg/hm2, the concentration of the liquid in the applicator is adjusted (test area A: 1.5 g/ L, area B: 2.0 g / L, area C: 3.0 g / L) The herbicidal effect and uniformity of application of the micro-spray zone with herbicide application with water are analyzed. The results show that the test A, B and C areas are in the direction of vertical micro-spraying zone, and the control effect of weed plants increases first and then decreases, which is consistent with the water distribution of micro-spray zone. In the case of the same total herbicide volume, at the 3 m position of the micro-spray zone, A1 and B1 and C1 are significantly different (P<0.05), and the difference between the two concentrations at 20 m is not significant. There is a significant difference between A1, B1 and C1 at 37 m (P<0.05). The uniformity of the weeds in the direction of the micro-spray belt gradually decreases, and the uniformity of the vertical micro-spray belt becomes larger and then smaller. The uniformity of weed control in test area C is significantly lower than that in areas A and B. The uniformity Cu of A and B areas was around 0.98, and the maximum value of Cu in area C was 0.98, and the minimum value is only 0.78. The difference is significant. Based on the improvement of the uniformity of the micro-spraying application and the weed control effect, the concentration of 2.0 g/L is better when the herbicide is applied by the micro-spraying water.

Based on the channel water infiltration theory and the experimental data of channel flow and loss, this paper studies the process of channel water infiltration, analyzes the influencing factors of infiltration, and establishes channel water loss and canal characteristics (canal distribution, channel section, design flow). The relationship between the characteristics of the canal bed (type of lining, soil texture, depth of groundwater, etc.), the empirical formula of the original water loss coefficient is improved, and it is concluded that both the Kostiakov empirical formula calculation and the integral improvement formula calculation, the channel flow rate and the length are It has a positive correlation with the channel loss flow, but with the increase of the channel length, the Kostiakov empirical formula shows a deficiency, and the relative error between the calculation result and the calculation result of the integral improvement formula is gradually increased. At the same time, the improved empirical formula was verified by using the measured data by using the dynamic water measurement method in the irrigation area of the Jiangxio Plain of Jiangxi Province. The verification results show that the irrigation water utilization coefficient of a certain channel is used as an expansion index in the calculation process of the improved empirical formula method. The flow of other channels can not truly reflect the whole channel system, which is different from the actual situation. However, the results obtained by the improved empirical formula represent the existing lining conditions of the channel, which is more reasonable and reliable.

It is important to study the change of agricultural production conditions and its countermeasures in the background of climate change, which is the current international research focus. The change of suitable planting area for main crops is a significant aspect. In order to study the effect of climate warming on the rice production in the cold area of Heilongjiang Province, and develop the regionalization and rational allocation of agricultural planting in the rice planting area of Heilongjiang region in China, exploring spatiotemporal variation of suitable planting area for rice is necessary. In this paper, the meteorological data of 15 stations in rice planting area of Heilongjiang Province from 1956 to 2015 are collected, and the change trend of temperature and its cumulative process are analyzed. Based on the requirements of rice light and temperature, the characteristics of accumulated temperature zone and time window suitable for rice planting are analyzed. The results show that: in the past 60 years, the suitable planting range of Heilongjiang rice has been expanding northward; The 2 300 ℃ and 2 400 ℃ accumulated temperature line extends from 48.86 °N and 48.39 °N to 50.12 °N and 49.49 °N. The suitable planting time window of rice in Heilongjiang Province has increased significantly, which meets the planting conditions of rice in different growing seasons.

Considering the problem that the offset and jitter of the displacement sensor for the main distribution valve of governor in Xiangjiaba Hydropower Plant caused the governor's adjustment quality to drop, the reasons of the inaccurate measurement are analyzed, and the corresponding technical modifications are put forward. After the modification, the measured value of the sensor is stable and accurate, and there is no offset and jitter, which greatly improves the stability of the governor.

This paper is based on the basic working principle of the turbine governor hydraulic servo system, the corresponding relationship between the variables of the hydraulic servo system under equilibrium is discussed, the causes of frequent pumping of the main control valve in the water turbine governing system are analyzed in detail. Technical measures to solve the frequent adjustment of the main control valve are proposed. The analysis results of this paper are verified and satisfactory engineering results are obtained.

At present, the calculation of one-dimensional transient process of pumped storage power station is approximate, which ignores the pulsating pressure of the unit during the transition process. This paper decomposes the pulsating term in the signal extracted from the field load rejection test data based on VMD algorithm, and predicts total inlet pressure of the draft tube combined with one-dimensional computation. The results show that the trend term of inlet pressure of draft tube decomposed by VMD algorithm is water hammer fluctuation with zero frequency. The pulsation term is concentrated in the low frequency band, and the pulsation amplitude shows a trend of increase and decrease close to the change curve of speed. The prediction of the total pressure of the inlet of the draft tube combined with the pulsation term is closer to the measured result than the one-dimensional simulation, which provides a reference for the analysis and prediction of the field load rejection test.

Low resistance backflow preventer is widely concerned and praised by the industry, because it can effectively solve the problem of backflow pollution of water supply system, and has the advantages of good sealing performance and small pressure loss. The structure characteristic and working principle of low resistance backflow preventer are introduced in this paper. The pressure loss test of LHS743X-16Q DN100 backflow preventer is carried out by using valve flow resistance device. The test result is qualified and its low resistance characteristic is verified. The flow field distribution is numerically simulated under the condition of fully open backflow preventer and different flow velocity. From the velocity distribution cloud diagram, it is observed that the main medium in the middle chamber presented S-type flow, and from the pressure distribution cloud diagram, it is observed that the pressure is mainly divided into two check discs and presented a three-section distribution. By comparing and analyzing the test results and simulation results, it is concluded that the working process of the backflow preventer is basically open, and the feasibility of the numerical simulation method is verified, which provides an effective reference for the structural design and optimization of the backflow preventer.

In order to explore the influencing factors of urban residents' water consumption in Ningxia, eight influencing factors are selected, and the model of 2009-2016 data is used to establish the model. The principal component analysis method is used to analyze the factors affecting the domestic water demand of urban residents in Ningxia and Ningxia. Specifically, the following conclusions are drawn: From the perspective of Ningxia, shower water heaters, population, and per capita disposable income have a significant impact on the domestic water consumption of urban residents in Ningxia. That is, household indicators> urbanization level> economic indicators. The main influencing factors of urban residents' water consumption demand in Wuzhong City are: water price, per capita disposable income and per capita housing area.The influencing factors in Guyuan City are: per capita disposable income, domestic water withdrawal, and water price. The influencing factors of Shizuishan City are: per capita disposable income, domestic water withdrawal, and shower water heaters. The influencing factors of Zhongwei City are: per capita disposable income, per capita housing area, and washing machine. The main influencing factors of domestic water consumption demand of residents in Yinchuan City are per capita disposable income, population, washing machine and shower.

In order to study the effect of rotational speed on the pressure fluctuation characteristics and flow-induced noise in an axial flow pump, the pressure fluctuation characteristics at different monitoring points in an axial flow pump under three sets of rotational speeds are obtained by calculating the unsteady values of the axial flow pump. The noise field caused by rotating dipole source of blade is further simulated, and the effect of rotating speed on flow induced noise of axial flow pump is analyzed. The results show that the main and secondary frequencies of pressure fluctuation monitoring points are basically the same at three groups of rotating speeds. With the decrease in rotating speed, the amplitude of pressure fluctuation decreases gradually, and the sound pressure level of radiated sound field decreases gradually. The study of pressure fluctuation characteristics inside the axial flow pump has a guiding role in the control of flow-induced noise.

The ecological security of water for Xiongan New Area is provided by Dashuliu Pumping Station Project, which solved the problem that the water diverted from the Yellow River can't flow by gravity into Baiyangdian. In this paper, the pump type, the number of pump-units, the inlet and outlet conduit, the device efficiency, the noise control and other aspects of the pumping station are all studied. Based on the model test results of the same testing, the South-to-North Water Transfer Project in Tianjin City, this paper selects the suitable pump type for the hydraulic conditions of the project, and decreases the operation cost through improving the hydraulic performance and device efficiency. High reliability of water supply provides theoretical basis for safe, efficient, stable and environmentally friendly operation of the project. After the testing running of the pumping station, the pump unit runs steadily, and all the indexes are normal, and the noise during the operation is below 75 dB (A), which further proves the rationality of the unit selection design.

To solve the serious problem of oil mist from guide bearing in Huizhou Pumped Storage Power Station, an analysis is carried out on the formation mechanism and oil mist leakage path.Through reforming the oil mist pumping device of the upper and lower guide bearings, and installing the anti-oil mist device of the water guide bearings. The problem of oil mist in guide bearing has been solved thoroughly, and the ideal effect has been achieved finally. The results show that the modification of the oil mist prevention device of guide bearing is effective, which serves as a reference for the oil mist control of guide bearing in other power stations.