In order to study the effect of irrigation in alleviating heat stress in rice, rice variety(Oryza sativa L.), Liangyou Peijiu as the study objects was adopted at Nanjing, field trials were carried out using two irrigation treatments during heat stress at heading stage (T1, Field waterless coverage; T2, Maintain 10cm water layer in the field), the canopy temperature and the soil temperature were measured, the diurnal variation of each energy balance component in the rice field was calculated. The results showed: During the day, T2 treatment can reduce the daily maximum temperature and average temperature of rice canopy, paddy soil temperature, and the time of maximum soil temperature were delayed 1h. Irrigation mainly affects the exchange of sensible heat flux (H) and latent heat flux (LE) in rice fields, resulting in differences in canopy temperature. Under the T2 treatments, the LE/Rn ratios were increased by 9.71%, and the H/Rn ratios were decreased by 31.87% compared to those ratios under the T1 treatment, it indicates that the latent heat exchange in rice fields is increased and the sensible heat exchange is reduced under water cover, which is conducive to evapotranspiration in the field, making the canopy temperature and soil temperature rise slower than T1. Water cover in the field can alleviate the hazard of heat stress in rice at heading stage.

In view of the energy consumption caused by the medium－high pressure and large－flow sprinkler gun of the Hose reel irrigator， this paper combines the water distribution curves of two HY50 guns with a 12 m gun spaces based on the moving water distribution characteristics of the HY50 gun under low pressure conditions． The combination enables double travelling rain guns to be sprayed at low working pressure without reducing the spray width，so as to reduce energy consumption and improve production efficiency． It was found that the spray width and sprinkler depth of the double travelling rain guns increased with the increase of working pressure． At the same time，the distribution pattern of the moving water distribution of the double travelling rain guns gradually changed to“triangle”，which was beneficial to the combined spray of multiple rain guns; The hydraulic performance of the double travelling rain guns under the working pressure of 0．15 and 0．25 MPa was tested in the field． The maximum deviation between the field test result and the calculated value of the 12 m double travelling rain guns was less than 11．62%．To a certain extent，the double travelling rain guns could achieve the purpose of reducing pressure and not reducing the spray area，and it also had certain reference significance for the research of sprinkler irrigation equipment under low pressure．

Hydrogen and oxygen stable isotope technology was used to find the water absorption depth of dwarf anvil apple trees’ root system. In this study, during the germination stage, new shoot growing stage and fruit expansion stage of the 7 years old dwarf anvil apple trees, the stable isotopic values of soil water in different depths of soil were measured and analyzed by multivariate linear model named IsoSource to find out the water contribution rate. The results show that for dwarf anvil apple trees, the main water absorption depth of root system was 0-20cm（59.5%）in germination stage;0-20cm（42.9%）and 20-40cm（11.1%）in new shoot growing stage in June; 0-20cm（24.3%）and 20-40cm（29.1%）in new shoot growing stage in July; 0-20cm（23.6%）、20-40cm（37.1%）and 40-60cm（11.6%）in fruit expansion stage In August; 0-20cm（26.3%）、20-40cm（27.3%）and 40-60cm（13.8%）in fruit expansion stage in September.

In order to explore the feasible discharge under border irrigation of wheat in Northwest China，the field experiment was carried out． After comparing the characteristics of water consumption，plant height，dry matter，yield and water use efficiency of 3 levels of discharge，it is found that the average daily water consumption showed a tendency of increase first and then decrease． The distribution uniformity and fertilization evenness treated by Q2［3．0 L/( m·s) ］were higher than that of Q1［4．0 L/( m·s) ］and Q3［2．0 L/( m·s) ］． There was no significant difference in yield components between the 3 treatments． The yield and water use efficiency of Q2 were all higher than those of Q1 and Q3，and the difference between the latter 2 treatments was not obvious． The yield of Q2 reached 10180．1 kg / hm2，which was 15% higher than that of Q3．Comprehensively comparing of Q1，Q2 and Q3，Q2 is the best choice to increase production． The results could provide a reference to the local farmers in border irrigation of spring wheat in Northwest China and similar environmental conditions． 

The“dual mulching”technology composed of mulch and straw has the characteristics of increasing temperature，preserving moisture，improving fertility and improving soil quality． The effects of different mulching methods on maize seedling emergence rate，plant height，leaf area，dry matter accumulation and distribution were analyzed． The results showed that mulching with film or composite mulching could increase the emergence rate of maize，increase the ground temperature and keep water better after sowing． The growth and development of maize was faster in early stage，and the plant height，leaf area and dry matter growth rate of maize were all higher than those of wheat straw mulching and non－mulching treatment． The proportion of dry matter in maize ear area was higher than that in wheat straw mulching and no mulching treatment． Under suitable composite mulching treatment ( SFH4) ，the proportion of dry matter in ears of maize could be increased， and photosynthetic products could be fully transferred to grains，so as to achieve the purpose of regulating the formation of dry matter in maize and increasing yield．

In order to explore the effects of different alternating cycles on the growth and development of greenhouse pepper under the premise of alternate moistube irrigation，the experiment set three treatments，including 4 d alternating cycle ( A treatment) ，8 d alternating cycle ( B treatment) ，continuous uninterrupted irrigation ( C treatment) under the premise of 1m pressure head，and ordinary irrigation ( D treatment) was set as control． By analyzing the soil moisture content，stem diameter，plant height and other indicators during the growth of pepper，it was expected to obtain the effects of different micro－irrigation cycles on crop growth． The results showed that the plant growth index and production of every moistube irrigation treatment group were higher than those of the ordinary irrigation group，and the irrigation water productivity was 2．13，2．09 and 1．35 times of that of the ordinary irrigation group，respectively; the 4d alternating cycle treatment had the highest irrigation water productivity．

In order to study the effect of “Gengnong Drought-Resistant Bao”on potato growth in Chaidamu area, and the optimum application rate was selected. This experiment was using “Qingshu 6” as the test material, using “Gengnong Drought-Resistant Bao” with different amounts (22.5, 27, 31.5 kg/hm2) as the test group，and using free of “Gengnong Drought-Resistant Bao” as the control group, field experiments were conducted in Xiangride Test Station in Qinghai Province. The effects of it on soil moisture content, morphological characteristics of different growth stages, chlorophyll, proline, yield and quality of potato were contrasted and studied. Studies have shown that with the increase of soil depth, soil water content increased. In the application layer of “Gengnong Drought-Resistant Bao”, the decrease of soil water content in the same layer was as follows: control group > experimental group; the application of “Gengnong Drought-Resistant Bao” could effectively reduce soil bulk density and improve soil pore structure; when the application rate was 31.5kg/hm2, it was beneficial to the accumulation of potato aboveground parts; when the application rate was 22.5kg/hm2, The photosynthetic efficiency of plants was the highest; the Leaf Proline content was the lowest when the application rate was 27kg/hm2; the yield and quality of potato increased first and then decreased with the increase of the application rate of "Gengnong Drought-Resistant Bao". When the application rate was 27 kg/hm2, the yield and starch content were the highest, 13.2% and 52.26% higher than those of the control group, respectively. Considering comprehensively, 27 kg/hm2 of"Gengnong Drought-Resistant Bao" is the most beneficial to the accumulation of Potato Yield and the development of water-saving benefits.

In order to explore the effect of full mulching and double ridge－furrow planting technology and supplemental irrigating on the growth and yield of maize，using a completely randomized block design，the dry matter accumulation，leaf area index，leaf SPAD value and soil moisture of 0 ～ 200 cm in maize were compared and analyzed． The results showed that FMＲF70 treatment could not only significantly promote the growth and development of maize，but also contribute to the performance of maize grain traits under the condition of irrigation in water－ deficient years; dry matter accumulation was increased by 2．51% to 26．88%，leaf area index was increased by 5．06% to 14．37%，SPAD value of leaves was increased by 1．56% to 8．75%，spike length was increased by 0．3% to 13．3%，and 100－grain weight was increased by 3．3% to 4．7%． FMＲF70 planting pattern could make full use of limited water resources，and increased the average water storage of 0 ～ 200 cm soil by 8．0 mm to 23．54 mm． The economic yield and water use efficiency were both shown as FMＲF70 ＞FP ＞FMＲF60 ＞FMＲF50，yield was increased by 19．20% to 8．96%，and WUE was increased by 15．97% to 70．00%，with significant difference ( P＜0．05) ． It can be found that FMＲF70 planting pattern combined with appropriate supplemental irrigation in the grouting stage is an appropriate planting pattern in semi－ arid areas．

Soil moisture content in the field is an important index to measure the degree of soil moisture and drought． Due to the different measuring environment of field moisture content，such as season，environment and other factors，the results of soil moisture content measurement in the same area may be different． In this paper，the soil types of 122 artificial moisture stations in Henan province were determined through particle analysis experiments，and three sites with different soil types were selected to carry out field moisture content experiments in different seasons and environments． The results show that: ① from the perspective of the whole province，the soil in Henan province is mainly loam soil type，and the water storage characteristics of this soil type should be fully considered during flood control and drought resistance; ② according to the analysis of experimental data，the relationship between the field water holding capacity and dry bulk density is inversely linear; ③ in different seasons and laboratory temperature environments，the results of field water holdup measurement of the three soils have little difference，so it can be concluded that field water capacity is basically not affected by temperature seasons．

micro－irrigation; corn; irrigation volume; yield; water use efficiency

Aiming at the limitations of traditional subjective and objective weighting methods, a combination weighting idea is proposed. The G2 weighting method is used to determine the subjective weight, the CRITIC weighting method determines the objective weight, and the weighting information is fully exploited through the combined weighting idea of game theory. Considering the credibility of combination weighting, Kullback's relative entropy theory is introduced to verify the consistency between the three. At the same time, the normal cloud model is used to identify and compare the water quality, which fully reflects the change trend of water quality. The model was applied to the water quality evaluation of 8 groups of water samples in Dushanzi District, Xinjiang, and compared with the results of fuzzy comprehensive evaluation method. The research shows that the method is accurate and relatively simple, and it is a scientific and practical evaluation method.

In order to study the water quality of Tangcun reservoir during flood season and non－flood season，according to the characteristics of the Tangcun reservoir，the EFDC two－dimensional water quality model was established． The concentration of COD and NH3－N in the water exchange period and static period were simulated and analyzed． The results showed that: ①The water environment capacity of reservoir area increased with the increase of storage capacity，contaminant concentration decreased with the increase of storage capacity; ② During the water static period，with the growth of water body time，the increase of NH3－N concentration in the reservoir was much higher than the increase of COD concentration; ③ The water body residence time in Tangcun reservoir should be controlled at 26 ～ 30 d，The water quality of the reservoir could be effectively guaranteed by the reasonable operation of the reservoir． The research results can provide scientific basis for the dispatching operation and management of Tangcun Ｒeservoir．

The basis of groundwater resource evaluation mainly includes two aspects: data processing and spatial regionalization． The regionalization analysis of Songnen plain mainly studies the basis of groundwater resource evaluation from spatial aspect，which is of great significance． It is pointed out that: ① based on the principle of leading factors，comprehensiveness and proper consideration of administrative division，the groundwater is divided into 5 subregions，the surface water is divided into 10 watershed regions，and the administrative division is divided into 13 secondary administrative regions． ② the groundwater regionalization of Songnen plain after superimposed surface water factors，a total of 20 zones were obtained，which facilitates the study of groundwater recharge mechanism and calculation of groundwater recharge，so as to predict the allowable exploitation amount of groundwater and then carry out groundwater resource evaluation． ③ the groundwater division of Songnen plain with the superposition of the administrative and surface water factors is divided into 43 zones． The addition of administrative factors can provide technical support and data support for the evaluation of groundwater resources，facilitate the comprehensive management of groundwater resources in the basin，and effectively develop the evaluation and management system．

Based on the monitoring data of soil salinity and groundwater characteristics of typical high－water saline－alkali land in Yinbei irrigation area，the relationship between soil salinity and groundwater depth and groundwater hydrochemical characteristics was analyzed by using correlation analysis method and principal component analysis method． The results showed that: ① the vertical distribution of soil salt in the study area showed obvious surface accumulation，the mean value of total salt content in the 0 ～ 20 cm soil layer was 3．34 g / kg，and the mean pH value was 8．81． 71% of the underground water samples in the study area are brackish water with an average salinity of 2．69 g /L． The total salt and salinity composition of soil showed moderate variation，and the pH value of soil showed weak variation． ② the total salt content in the surface layer was significantly positively correlated with other ions in the soil except CO2－ 3 and HCO－ 3，among which the correlation coefficient with Na+ ，Cl－ ，and SO2－ 4 plasma was greater than 0． 9，and the degree of correlation with various indexes in the groundwater was ranked as SO2－ 4 ＞ salinity ＞ Cl－ ＞ Na+ ＞ groundwater depth; the mineralization of groundwater was positively correlated with other ions in groundwater except CO2－ 3 and HCO－ 3，and the correlation coefficient with Na+ and Cl－ was greater than 0．9． Na+ and Cl－ in soil are negatively correlated with groundwater depth，and positively correlated with groundwater salinity and SO2－ 4 in groundwater． SO2－ 4 in soil is negatively correlated with groundwater depth，and positively correlated with groundwater salinity and S SO2－ 4 in groundwater． ③ the results of principal component analysis showed that the main factors affecting the degree of soil salinization in the study area were，in turn，the groundwater salinity and main salt ions，the main salt ions in the soil，and the groundwater depth．

Guiyang is a typical karst basin landform，the groundwater system is very complex and has unique hydrogeological and geochemical characteristics． In order to ascertain the groundwater chemical characteristics and water quality of the main urban area and surrounding areas of Guiyang City，the monitoring data of 60 groundwater samples in the area were analyzed，the hydrochemicl characteristics of the area were analyzed by mathematical statistics，piper three － line diagram and Schoeller diagram，and the GＲA － AHP based groundwater quality assessment model was used for water quality evaluation． The results show that: the hydrochemical indicators in the groundwater of the study area meet the drinking water standards; except the strong variability of K+ and Fe3+ ，the groundwater chemical parameters are relatively stable，the dominant cations in hydrochemical composition are Ca2+ and Mg2+ ，and the dominant anions are HCO－ 3，SO2－ 4 ，the groundwater chemical type is mainly HCO－ 3 ．SO2－ 4 －Ca type，、HCO－ 3 －Ca．Mg type and HCO－ 3 －Ca type． Correlation analysis shows that the groundwater shows high Ca2+ ，Mg2+ ，SO2－ 4 characteristics from the dissolution of different rock－forming minerals in limestone，dolomite and gypsum in the study area． The results of water quality evaluation by using GＲA－AHP model based on index scale in study area show that the quality of karst groundwater in rainy season in this study area is better than that in dry season． In flood season，type Ⅱ water accounts for 33%，type Ⅲ water accounts for 63%，while in dry season，type Ⅱ water accounts for 16%，and type Ⅲ water accounts for 75%．The results of this study provide a basis for the protection of water－rock－ecological－environment in Guiyang City.

Accurate prediction of soil moisture dynamics is crucial for crop growth and water－saving irrigation． In order to reflect the daily dynamic changes of soil moisture，the calculation models of soil moisture in 10，30 and 50 cm soil layers during the whole growth period of winter wheat were established by using time series analysis method and the actual measured data of soil water from 2017 to 2018 in Wudaogou hydrological experimental station． The results showed that the variation coefficient of soil moisture content at 10，30 and 50 cm was significantly different and gradually decreased with the increase of soil depth，which was 0． 190，0． 103 and 0． 040，respectively． AＲIMA model was used to fit soil moisture． Calculation models of soil moisture in 10，30 and 50 cm soil layers were AＲIMA( 4，1，7) ，AＲIMA( 1， 1，2) and AＲIMA( 2，1，3) ，respectively． Ｒ2 of goodness of fit was greater than 0．95．The calculation models of soil moisture in different soil layers had good prediction ability，and the prediction accuracy increased with the increase of depth，and the maximum relative error increased from 10 cm to 50 cm，and decreased from 15．6% to 5．1%． The research results are.

Water efficiency of canal system is an important index to measure water conveyance efficiency of irrigation district canal system, and its accurate calculation is of a positive significance for evaluating canal system condition and management level of irrigation district. The control range of Renmin branch canal in Hetao irrigation district of Inner Mongolia was taken as the research area, and water efficiency of canal system in the research area was calculated through surveying the distribution of canal system using the calculation software of water efficiency of canal system based on the canal seepage empirical formula in this paper. According to possible lining condition, canal flow and groundwater depth, different scenarios were set up to calculate water efficiency of canal system. The results show that, (1) water efficiency of canal system in this area is 0.728 in present situation; (2) if all canals do not take seepage control with cement concrete lining, water efficiency of canal system is only 0.567; (3) if all canals take seepage control with cement concrete lining, water efficiency of canal system can be as high as 0.934. The analysis shows that, (1) if canals take partially seepage control with cement concrete lining, the upstream position is preferred and water efficiency of canal system can be improved; (2) if lining conditions are the same, water efficiency of canal system is higher when canal flow is larger or groundwater level is higher. Above results are of practical significance for selecting the lining scheme and for operation management of canals.

Abstract: This paper studied on data mining of sugarcane field environmental data, so to provide scientific guidance for sugarcane growth as well as technical support for the prediction of sugarcane yield and quality in the later period.In this study, JN5168 wireless module from NXP Corporate was used to design a field IoT system to collect environmental data such as air temperature and humidity, illumination, soil moisture and soil temperature. The environmental data collected in a sugarcane experimental field were then analyzed and evaluated. Difference method was first used to preprocess the environmental data to remove abnormal data, then the hierarchical clustering method was used to cluster the environmental data of different growth stages, meanwhile the clustering results were evaluated into three categories in accordance with the suitable growth environment of sugarcane. The cophenetic correlation coefficient of the hierarchical clustering results in germination stage, seedling stage, tillering stage and elongation stage were 0.8491, 0.8355, 0.8239 and 0.8175, respectively, indicating that hierarchical clustering worked well in data classification.

In order to improve the dry shrinkage deformation performance of concrete in a large number of canal lining works in Hetao irrigation area，two types of nano－particles，including nano－silica ( NS) and nano－silicon carbide ( NC) ，were used to prepare concrete specimens． On the basis of strength tests，the effect of nano－particle content on the drying shrinkage performance of different specimens was studied，and the mechanism was analyzed theoretically． The results show that nano－particles can improve both the compressive and bending strength of fly ash concrete，so as the drying shrinkage performance． The optimum adding quantity of NS and NC is 2% and 2% with the drying shrinkage rate of drying enhanced by 90% and 120% respectively． The dry shrinkage rate is significantly increased in the early stages， and the effect of single and double mixing on the dry shrinkage of concrete are not very different． The surface energy of aggregate is increased and the micro－structure pore is filled，so the drying shrinkage performance of fly ash concrete is improved based on the surface effect of nano －particles and micro－aggregate filling effect． The research results have certain guiding significance for designing high strength and drying shrinkage performance of concrete in Hetao irrigation area．

In order to deeply study the soil permeability characteristics of the canal slope of the middle route of the south－to－north water transfer project from the perspective of microstructure，the micro CT scanning test of expansive soil was carried out to obtain the two － dimensional image and three－dimensional fracture network model of the soil sample crack，and the fractal characteristics of the crack were systematically analyzed． The results show that the internal fracture network of expansive soil is very complex，and the fracture size distribution range is wide，which can be divided into three categories: large，medium and small． It can be seen from the number distribution characteristics of fractures that the number of large fractures in expansive soil is small，but the area is relatively large． According to the shape，large fractures can be stratified into 4 categories，including flat，elliptic polygon，long strip and dendritic． Dendritic fractures are mostly connected fractures，and connected fractures are the prerequisite for expansive soil to absorb water，expand and dehydrate． From the fractal geometry point of view，it is found that the internal crack of expansive soil has obvious non－uniformity，which can be used as a potential factor to affect the stability of channel slope．

Accurate water quantity in irrigation area is the key to achieve sustainable development of water resources. In this paper, an open channel flow measuring method based on the relationship between the swinging angle of the pendulum and the instantaneous flow of the channel cross section is proposed for the open channel flow measurement technology. In order to study the characteristics of flow measurement in open channel with different slope lever, the current measurement test is carried out on the D50 U-shape-channel by using the pendulum bar flowmeter. The test results were treated with dimensional analysis. Research shows: the relationship between the angle of the pendulum pole of open-channel flowmeter and the instantaneous flow Q of the water cross section of the channel is Q= K(sinθ)^(2.5). In the D50 U-shape-channel with slope of 1/500, 1/1000, 1/2000, 1/5000 and 1/10000, the correlation is good, and the coefficient K decreases as the gradient increases. The measurement accuracy can meet the requirements of open channel flow measurement.