The inefficient evaporation of surface soil exacerbates the shortage of agricultural water in arid and semi-arid areas． In order to reveal the effect of surface sand covering on soil evaporation during the seasonal freeze-thaw period，the soil evaporation，soil temperature and soil moisture content were monitored under 3 kinds of surface treatment conditions，including bare plot ( LD) ，surface sand mulching with thickness of 1 cm and particle size of 0．5 ～ 1．5 mm ( XS) and 1．5 ～ 2 mm ( CS) ． The results show that the change range of daily soil evaporation can be effectively changed by surface sand mulching during the freeze-thaw period; in the unstable freezing stage，the effect of sand mulching on the inhibition of evaporation is not obvious; during the stable freezing stage，sand mulching can effectively inhibit soil evaporation and aggravates the evaporation in the melting stage; the cumulative soil evaporation of LD，XS and CS during the freeze-thaw period is 29．87，34．32 and 33．43 mm，respectively，and the accumulated soil evaporation is well fitting with the power function relationship with time． The results provide scientific and reasonable measures of maintaining soil moisture and a basis for effective inhibition of soil evaporation during the freeze-thaw period．

In order to study the effect of water and fertilizer coupling on the nitrogen distribution and utilization efficiency of jujube trees，the jujube of 13 a age was used as test material，the 15 N tracer method was used for the field experiment，three irrigation levels，including normal water ( 70% ～ 80%FC) ，mild water deficit ( 60% ～ 70%FC) and moderate water deficit ( 50% ～ 60%FC) ，and three fertilization levels， including high nitrogen ( 420 kg /hm2 ) ，medium nitrogen ( 330 kg /hm2 ) and low nitrogen ( 240 kg /hm2 ) ，totaling 9 treatments were set． The results showed that: under the same fertilizer ratio，light and moderate water stress could enhance the uptake of nitrogen fertilizer in jujube plants; under the same water condition，the ratio of different fertilizers had a certain effect on the 15 N abundance，and the difference did not reach the significant level; under the same fertilizer ratio，light and moderate water stress could increase the fertility rate of the organ; at the same time，the nitrogen use efficiency of the plant was the highest． According to the results，it is suggested that the irrigation water quantity of 900 mm with the nitrogen fertilizer of 420 kg /hm2 is the best fertilizer and water ratio; the fertilizer and water management should be carried out in the management of jujube to improve the utilization of nitrogen fertilizer rate，increase nitrogen accumulation，and protect the tree vegetative growth． The study can provide theoretical basis for effective drip irrigation and fertilization management of dwarf close planting jujube．

For the purpose of researching the morpholog and physiolog response under drought stress of Marsellan grape in different root stock grafted mode，the Marsellan was grafted onto three root stock，including 5BB，3309A and 1103P，with the own-rooted grafted as control． The experiment used pot experiment to study the drought resistance and physiological mechanisms of Marsellan grape under natural drought stress． The results show that the net photosynthetic rate ( Pn) ，stomatal conductance ( Gs) ，transpiration rate ( Tr) and the content of chlorophyll reduce，but cell membrane permeability increases when increasing drought stress level． Drought damage indexes of different rootstock-scion combination are different，the treatment of M/1103P is the lowest and the plant growth is the largest，while the rootstock diameter of M/5BB is the largest． The drought resistance of different grafted combinations is M/1103P，M/3309A，M/5BB and M/M．

In order to study the water transport law under different straw returning amount and irrigation amount，a study on the soil water migration and distribution characteristics under different straw return amount and irrigation amount is conducted through soil column test in laboratory． The results show that: the accumulation infiltration amount of the treatments with returning amount of 0．5%，1%，1．5%，2% is 0．96%，4．3%，7．31% and 11．98%，respectively，more than that in the no returning field at the boundary between the straw returning layer and the no returning soil layer，which indicates that the increase of the straw returning amount to the soil increased the water retention capacity of the soil． Under the same irrigation amount，the water content of the same soil layer mainly shows that: the higher the content of straw，the higher the soil water content，and when the irrigation water amount is increased from 1．0 V to 1．5 V，the soil moisture content is increased by 2．53% and 11．52% in the straw returning layer and under the straw returning layer，respectively． This maybe because that with the increase of irrigation amount，the pores in the soil of the straw returning layer are gradually filled with water and the water conductivity of the soil is increased，which promotes the downward movement of the water，thus improving the infiltration capacity of the soil．

Suitable irrigation schedule can save water, increase yield and improve field salinity. In this study, we investigated the influence of different irrigation schedule on soil water and salt distribution of maize field and growth and yield of maize under mulched drip irrigation in the arid and cold region of Shanxi. Four treatments were designed including control without irrigation (CK), irrigation amount of 675, 900 and 1125 m3/hm2. The measurements included soil water content, soil EC, plant height, leaf area, aboveground biomass and yield of maize. The influence of different treatments on soil properties and maize growth was analyzed. The results showed that:1) soil water content at 40-cm depth was greatly affected by irrigation amount. During the period that maize required large quantity of water, soil water content was not different greatly. 2) After maize harvest, soil surface EC was lowered. The EC value for the treatments of the irrigation amount of 900 and 1125 m3/hm2was lowered by 14% and 28% (P<0.05) respectively than the initial soil EC value. It indicates the growth condition is improved at soil surface. 3) The growth index of maize increased with the irrigation amount, but they were not significantly different between the treatments of the irrigation amount of 900 and 1125m3/hm2（P>0.05）. Different from the yield change, the IWUE decreased with increasing irrigation amount. Considering the yield and water-saving together, we suggested that the irrigation amount of 900m3/hm2 is suitable for maize cultivation in the study area. The study can provide valuable information for the promotion and application of mulched drip irrigation technology in the arid area of Shanxi.

In this paper，a microporous ceramic emitter was used as the research object to carry out in-situ soil tank infiltration simulation test to study the influence of initial moisture content of soil on infiltration characteristics of porous ceramics，which provided reference for determining the field application parameters of porous ceramic infiltration irrigation． An empirical model was established to simulate the relationship between the cumulative infiltration volume and the wet front migration distance and the initial moisture content and infiltration time． The results showed that the initial moisture content of the soil under the no-pressure condition had a great influence on the cumulative infiltration，and as the infiltration time increased，the rate of change of the cumulative infiltration decreased gradually． At the same infiltration time，the greater the initial soil moisture content，the smaller the cumulative infiltration，and this phenomenon is more and more obvious with the increase of infiltration time． Under different initial moisture content conditions，the migration distance of the wet peak in each direction is a power function of time．

The experiment was conducted from 2012 to 2014 in Turpan，by monitoring the change of some indexes，including temperature， humidity and fruit volume index，under the micro spray mist control treatment，to analyze the effect of micro spray mist control on the micro climate，fruit size and yield． The results show that: the average annual temperature and humidity increment is － 2． 01 ℃ and 9． 62%， respectively; the average fruit volume of micro spray treatment is higher than that of CK in 2012 to 2014 by 3． 5，4． 4 and 2． 9 cm3 ， respectively，and the average growth rate is higher than that of CK by 0．12 cm3 /d; the average yield of micro jet processing is higher than that of CK in 2012－2014 by 2 627．22，1 295．46 and 3 733．31 kg /hm2 ，respectively．This indicates that the treatment of drip irrigation with 1h mist spray irrigation every day，which controls the average temperature at 26 to 29 ℃ and the humidity in 57% ～ 59%，can significantly increase the fruit volume，improve fruit growth rate and yield of grape．This study provides supporting data for the rational regulation of the microclimate environment of grape vines，and has important practical significance for improving the quality and yield of grape and ensuring the sustainable development of the important grape base production in China．

Through the experiment on the infiltration of muddy water under combinations of two sediment concentrations and four different sediment gradations under the irrigation condition, it has been found that sediment particle sizes affect the infiltration law of muddy water significantly: the smaller the sizes of sediment particles in muddy water are, the smaller their accumulative infiltration capacity and infiltration rates are and the longer their infiltration durations are for the same accumulative infiltration capacity. The kostiakov equation and the universal equation are used to fit the relationship of accumulative infiltration capacity, infiltration rates and infiltration durations of muddy water with different sediment gradations. The correlation is strong and the coefficients of determination are greater than 0.90. The results indicate that the sediment impact value with particle sizes smaller than 0.01 mm is the main factor that affects the infiltration of muddy water. The study has found that the accumulative infiltration capacity and the sediment impact values of muddy water with different sediment gradations have an exponential function relationship for the same infiltration duration and that the infiltration rates and the sediment impact values of muddy water with different sediment gradations have a linear relationship for the same infiltration duration. The relationship of parameters in the infiltration equations with the sediment impact value is built and the sediment impact value with particle sizes smaller than 0.01mm is used to characterize the closely correlated parameters.

In this study，the seasonal frozen ground area in Northeast China is used as a reference area to explore the effect of unsaturated frozen soil on the porosity under different conditions． At first，at the temperature of －5，－10，－15，and －20 ℃，the porosity of unsaturated frozen soils is measured at 10% moisture content，and the effects of different temperatures on porosity are explored． Then the porosity of unsaturated frozen soils at 5%，10%，15%，and 20% moisture content is measured at －10 ℃，and the effect of different water content on porosity is explored． It is concluded that the porosity of frozen soils does not change at different temperatures，but the porosity of frozen soils gradually decreases with the increase of water content． 

Aiming at the problems of insufficient water resources and unreasonable management of water fertilizer in arid area of central Ningxia, this paper carried out a study on the soil water transport law under different nitrogen fertilizer concentration with the same dripper flow rate.【Method】Using point source infiltration, two factors were set up: droplet flow(0.3, 0.5, 0.7, 0.9 L/h) and nitrogen fertilizer concentration(200, 300, 400, 500 mg/L).【Result】① In the 0 ~ 20 cm soil layer, the average water content of the soil was not affected by the nitrogen fertilization concentration. and the average water content of the soil was negatively related to the nitrogen fertilization concentration in the 20 ~ 40 cm soil layer.② The concentration of nitrogen fertilizer had no significant effect on the change of water content in the radial soil.③ The change of longitudinal soil water content is affected by the dripper flow and nitrogen fertilizer concentration, and the order of the influence of them on soil moisture content is:dripper flow>nitrogen fertilizer concentration.【Conclusion】To sum up, the size of nitrogen fertilization concentration has a great effect on the longitudinal and deeper soil water transport, but has no significant effect on the radial soil water transport.

In order to apply drip irrigation in Aeolian sandy soil more reasonably，soil water movement under drip irrigation of single-point and double-point sources was simulated by an indoor physical experiment． The spatial-temporal dynamic distribution of soil wetting front was mainly studied under different dripper discharge rates． The results show that under same irrigating time，soil wetting front moves longer with larger discharge rate; as for the same irrigation amount，the effects of dripper discharge on soil wetting front in horizontal direction are not obvious，while in vertical direction，soil wetting front moves deeper with larger discharge rate． The soil wetting front moves fast at the beginning of irrigation and its velocity increases with dripper discharge，then the movement quickly slows down and tends to stable，besides that，the effects of dripper discharge on the transport velocity of soil wetting front are relatively low． Under the double-point drip irrigation， before the intersection of each soil wetting front，the movement of soil wetting front is as the same as that under single-point drip irrigation; as the irrigation proceeds，soil wetting front meets earlier with higher discharge rate and the soil wetting front of intersection interface infiltrates faster; however，in the treatment of higher discharge rate，soil water content right under the dripper is larger than other treatments， which results in larger difference of soil water content in radial direction and increases its spatial variability in the soil profile．

The Hanyan-canal?irrigated district has a long-term history in its irrigation agriculture. In recent years, its total water usage for local irrigation has been witnessed a continuous decreasing trend. Realizing the fact that, the keys to improve the local water resource management and to advance a water-saving irrigation program lie to a good knowledge of the local water consumption pattern as well as the controlling factors behind its variation. Motivated by this, the study takes the Hanyan-canal irrigation district in Ningxia Autonomous Region as the target to explore the potential impacts factors related to the irrigation schedule, effective irrigated area and plantation structure. Based on the explored relationships of three factors with total saved water quantity, three models are built up to quantify the contribution associated with individual impact factor. Via attribution analysis, it turns out that a shrinkage of local irrigated areas and the adjustment of growing patterns were identified as primary reasons in reducing the local total irrigated water consumption, then followed by the improved canal effectiveness index. The conclusions drawn by this study provide insights on how to allocate limited water resource and design a more sustainable water-saving program for irrigated areas like Hanyan district.

Remote sensing technology has developed rapidly over the last 30 years. On the basis of this, a variety of algorithms have been proposed and applied to estimate land surface ET on field, regional and large scales, based mainly on energy balance theory which is well-defined. The main object of this paper reviewed and compared the advantages, disadvantages and application conditions of several typical single and dual-source model from basic principles and assumptions to indicate the problems and sources of errors, such as spatial and temporal scaling effects, selection of cold and hot anchor pixels, surface temperature, etc. And the paper also explained the difficulties of model accuracy verification. Newly-developed and selected models with dialectical thought between results and processes should be the future trends and prospects. Using high resolution and great expertise remote sensing data, selecting efficient pixel extraction methods, developing physically statistic or dynamic-feedback interpolation methods based on remote sensing data or making use of atmospheric reanalysis data at high spatial-resolution may be the promising subjects in the future for regional ET estimates.

At present，the Huai Ｒiver Basin of China is facing serious water resources problems． In order to solve the water crisis，it is necessary to improve water use efficiency． In this paper，the CＲITIC-TOPSIS-Gray relation degree evaluation model is used to evaluate water use efficiency of the Huai Ｒiver Basin． The CＲITIC method is used to determine the weight of each index in the evaluation index system， while the TOPSIS method and the gray relation degree analysis method are combined to calculate the relative closeness of the Huai Ｒiver Basin and its four areas． The analysis results show that: the Huai Ｒiver Basin has an upward trend on the whole，which indicates that our country is paying more and more attention to the problem of water resources． Among them，Jiangsu area has the lowest water use efficiency． The analysis of its reason can reveal the existing problems of water use in the Huai Ｒiver Basin． The evaluation method is scientific and reasonable，and the research results can provide some references for the decision-making of water resources management departments． At the same time，the evaluation method can be extended to other areas.

By introducing the basic principles of single factor index method，F value method，fuzzy comprehensive evaluation method and grey clustering method，and taking groundwater quality measurement data of 13 sampling sites in Yanshi City in 2013 as an example，the four water quality evaluation methods are compared． The results show that single factor method is more one-sided，but identifies major pollutants; the disadvantage of F value method is treating all evaluation factors equally and ignoring the ambiguity of water quality environment; fuzzy comprehensive evaluation method and grey clustering method are fuzzy in reflecting the water quality boundary through the method of establishing the function，but fuzzy comprehensive evaluation method ignores that the weight of different water quality categories in the same evaluation factor is different． So grey clustering method has relatively accurate results． The comparative analysis of the four methods can more accurately reflect the groundwater quality and provide some theoretical support for improving groundwater quality．

In order to clarify the effect of salt reduction under the shaft salt drainage measures and the salt migration rules of salinization jujube soil，so as to improve the theoretical research on the well drainage measures for treating salinized soil． In this study，the Jujube farmland of the 3rd battalion of the 224th regiment of the 14th division of Xinjiang Construction Corps was selected as research area，the diagonal sampling method was used to take the soil samples of 0～ 20，20～ 40，40～ 60，60～ 80 and 80～ 100 cm，respectively，at the position 0，10，30，60，100 and 150 m away from the shaft． By measuring the soil conductivity，pH and the content of K+ ，Na + ，Ca2+ ，Mg2+ ，SO2－ 4 ， CO2－ 3 ，HCO－ 3 and Cl － ，and further calculating the soil sodium adsorption ratio ( SAＲ) and the salt-based ions equivalent ratio，the effects of well drainage on soil salinity in jujube field were analyzed． It was found that: the minimum salt content was at the position 60 m away from the shaft; in addition，the adsorption ratio of soil sodium at the position 60 m away from the shaft decreased significantly，the soil salt damage remarkably decreased，and the salt-based ions changed from the Na + ，Cl － into Ca2+ ，Mg2+ and SO2－ 4 ． The results showed that the optimum range of salt water drainage was about 60 m away from the shaft

In order to explore the rule of soil salinity transport under mulching and different irrigation schedules，a field experiment was conducted in Hetao Irrigation District of Inner Mongolia，and irrigation was controlled by the tensiometer． A total of three irrigation treatments，in which the matrix potential was controlled as three lower irrigation limits of －20，－30，－40 kPa，were set and each treatment was repeated 3 times with random layout． The results showed that the salinity of all the treatments shifted from the membrane to the outside of the membrane and accumulated in the surface soil; the treatment of controlling matrix potential as lower irrigation limit of －20 kPa effectively eroded the salt content of 0～ 100 cm soil layer，but salt still appeared in 0～ 40 cm soil layer; the treatment of controlling matrix potential as lower irrigation limit of －30 kPa has the highest water use efficiency; during the whole growth period of sunflower，the changes of total salt content in soil and membrane were the same，and the content of total salt in topsoil varied greatly; with the depth of soil increased，the variation of salt content was less; the effects of salt stress in 40 ～ 80 cm soil layer were better than those in 0 ～ 40 cm soil layer; with the increase of irrigation frequency，the pressure salt effect was more obvious; after the crop growth period，the 0 ～ 40 cm soil layer showed different degrees of salt accumulation． It is recommended to adopt flood irrigation to clean the soil salt during the non-growth period．

In order to solve the problem of the high sensitivity of the flux to the pressure change and the unsatisfactory working performance under the low pressure condition, the paper presents a kind of variable curvature flow channel emitter. The emitter is combined with the principle of circumferential flow and circulation, with reference to the main channel design concept, the design of the curved wall is adopted. CFD software is applied to carry on the simulation about the internal flow state of the emitter, the pressure-flow curve, the water flow chart and the particle trajectory chart under certain inlet pressure are obtained, and designs the hydraulic performance test and anti-blocking performance test to verify it. The internal flow characteristics and dissipation mechanism of the emitter are revealed, which provides a theoretical basis for the development of new emitter.

According to the irrigation requirements of modern agricultural water -saving and fertilizer production increase，this article introduces a three-channel by-pass fertilizer-type water and fertilizer integrated automatic fertilizer spreader． The mixed fertilizer system is based on the parallel connection of the jets to realize the independent suction of various single element liquid fertilizers; the pressure difference generated by the inlet and the suction pump is used to realize the inhalation of the liquid fertilizer and the output of the water and fertilizer mixture; the control system uses the Siemens PLC as the control element． With the Siemens EM231 analog input module and electric proportional control valve as the executing parts，each actuator is controlled by logic program to realize the quantitative absorption of single element liquid fertilizer． Using SolidWorks to complete the structural design of the whole machine，the FLoEFD software is used to simulate the water and fertilizer application of the fertilizer applicator，and it is verified that the fertilizer applicator can perform stable，uniform and continuous water and fertilizer inhalation and output． Through the equipment selection and construction test，the maximum error of the maximum absorption amount and simulation analysis value of the three channels is 2% and less than 3%，indicating that the design of the three-channel fertilizer applicator has higher suction accuracy for each channel．

In view of the lack of storage capacity curve at the level of dead water of Zhaopingtai Reservoir, the curve fitting method was used to estimate the water level storage capacity relationship below the dead water level. the reservoir capacity changes under different scenarios were calculated and adjusted in the dry year according to the actual water supply conditions of Zhaopingtai reservoir, The results show that the actual available storage capacity is small that is from 159.6m to the dead water level and below the dead water level. Considering the extreme conditions of continuous drought, the water supply plan should be dynamically and timely adjusted. The proposed reservoir emergency countermeasures can provide reference for the management of Zhaopingtai Reservoir.

Taking the eggplant under the conditions of greenhouse cultivation as the research object，an irrigation experiment was conducted and the contents of meteorological factors，soil moisture content，leaf transpiration rate and eggplant growth traits were measured． The transpiration rate of eggplant leaves was measured with a CI－340 portable photosynthesis analyzer． The water demand changes of eggplant along with time were fitted using the water balance theory，the groundwater flux model and the transpiration rate of eggplant leaves． The results show that the transpiration rate of the leaf increases with the growth of the plant，the transpiration rate at the seedling stage is relatively small，and the minimum value is 1． 2 mm/d; the transpiration rate during flowering and fruit setting stage is relatively large，and the maximum transpiration rate reaches the peak of the fruiting period; at the rate of 6．78 mm/d，the transpiration rate in the later period begins to decrease again; the peak water demand of eggplant appears in the fruiting period，reaches 6． 444 mm/d，and the minimum water requirement appears in the seedling stage，which is 0．7 mm/d． In the whole growth stage，the seedling stage is smaller，the flowering and fruit setting period is gradually increased，and the result reaches the maximum at the end of the fruiting period，and gradually decreases at the later stage．

To obtain a high accuracy of precipitation prediction in semi-arid area, the paper proposes a new hybrid model support vector machine considering co-integration theory. Based on the monthly rainfall date of Haidong and Guoluo, Qinghai Province, compared with the traditional approaches, the proposed model can get outstanding predictive performance according to the three indicators MAE, NMSE and NS.

In order to enable the effective irrigation area of ulan buh develop healthily and understand the development trend of effective irrigation area of ulan buh and irrigation area, this study introduces the regression sliding prediction model of support vector machine,the effective irrigation area data of 2007-2016 was used as a training sample, and the effective irrigation area data for 2017 was used as a test sample,combined with metabolic method, the effective irrigation area of ulan buh irrigation field is predicted. In order to verify the effectiveness and superiority of the model, the Logistic grey prediction model is introduced and compared with support vector machine regression sliding prediction model,the results show that the prediction accuracy of the support vector machine regression sliding model is significantly higher than that of the Logistic grey prediction model. On this basis,the regression model of support vector regression was used to predict the effective irrigated area in each year of Ulanbu and Irrigation from 2018 to 2025 , the effective irrigation area of ulan buh irrigation field in 2022 reached its limit, limit is 53,600 hectares, The effective irrigation area of ulan buh irrigation field in 2017 is 52,440 hectares,is close to its limit, therefore, It can be seen from the predicted results that the growth rate of effective irrigation area in ulan buh irrigation field will start to slow in 2018, and the effective irrigation area will even have negative growth in some years,therefore,it is necessary to analyze the factors affecting the development of effective irrigation area and lay the foundation for healthy development of ulan buh irrigation field.