Study On The Characteristics And Simulation Of Wetting Body In Rainfall Infiltration Irrigation

In order to solve the economic hong-mei Lin ning nanshan district apricot drought and little rain(5?16 mm)deep root the problem of economic forest is hard to use,with powder clay(ningxia evalution,the former fort obviously by peng town ShenZhuang village)(poa pratensis)as the research object,the indoor rainfall collecting(poa pratensis)experiments and HYDRUS-2 d software simulation of the research method of combining the related research on irrigator collecting rainfall characteristics and a simulation was carried out,mainly studied different(poa pratensis)precipitation over time and the change rule of the soil water movement,the influence of wetting body features and the influence of wetting body effectively.The results of this study provide theoretical support for the application of rainfall concentration and infiltration irrigation system in the economic forest of red plum apricot in the southern mountain area of ningning.The main research results are as follows:(1)In the process of infiltration irrigation,soil moisture first goes through a rapid rise and then a slow decline,and finally becomes stable.About 3 days after the end of infiltration irrigation,soil moisture basically reaches a relatively stable state.At the same depth,the water content decreases with the increase of the horizontal distance from the permeator.There was little difference in water content at different depths on the same vertical plane from the horizontal distance L15cm to the permeator.The water content at different depths on the same vertical plane at a horizontal distance of L25cm from the infiltration irrigator was only smaller at a distance of 10cm from the ground,while the water content at other depths was closer.The water content D40cm depth of>D30cm depth of>D20cm depth of>D10 depth from the horizontal distance of the infiltration irrigator to L35cm.The depth of water content D20 and D10 at the horizontal distance of L45cm from the infiltration irrigator basically did not change.D40 depth and D30 depth have a slight increasing trend and the difference between them is not much.(2)The area with the highest water content distribution after irrigation is 10?40cm from the ground.The wetting body is like a "jar" and the water content distribution decreases with the increase of distance from the edge of the permeator.At the end of 1 day after irrigation,the area with the highest water content was 10?60cm away from the ground,and the high-water content area could move down about 20cm compared with the area at the end of irrigation.The change of the wet body was still like a"jar",and the waist of the jar increased.End of the irrigation water again after three days the moisture content distribution area of the highest in 10?70 cm off the ground,high moisture content area down significantly,compared with those of water at the end of the high moisture content area down 30 cm,and the end of the water was compared with its high moisture content area down 10 cm,and the moisture content distribution decreases with the increase of distance from the edge of the irrigator.(3)In the study of effective wetting body with different infiltration rainfall,the effective wetting body was determined with 60%field water holding capacity as the boundary of effective wetting body.The effective wetting body boundary at the end of infiltration irrigation,one day after the end of infiltration irrigation,and three days after the end of infiltration irrigation was determined by using Surfer software,and then the effective wetting body volume was determined by using auto-cad software.This method can reduce the computational work of effective wetting body and has higher computational accuracy.There was a logarithmic relationship between the effective wetting body and the different infiltration rainfall,and the correlation coefficient R2 was above 0.96.(4)The soil moisture simulated by HYDRUS is in good agreement with the soil moisture at the actual observation points,with the NSE between 0.6259 and 0.7659,and the root mean square error between 0.0089 and 0.0145.(5)After the installation of rainfall concentration and infiltration irrigation system,the soil moisture content of the installation of rainfall concentration and infiltration irrigation device was higher than that of the natural growth condition after the same natural small rainfall after the installation of the red plum apricot economic forest.After one year,the land diameter of the installation of rainfall concentration and infiltration irrigation system was 1.2 times of the natural growth condition;The leaf area index was 56.8%higher than the natural condition,and the ground diameter and leaf area index were significantly better than the natural growth condition after the installation of the device.