Study On Border Irrigation Water Current Movement Mathmatical Simulation And Irrigation Technique Index In The West Of Guanzhong

In this paper, the study on water current movement mathematical simulation and reasonable irrigation technique element of border irrigation is carried out in Yangling, Shaanxi Province. Field experiment of border irrigation was selected in local peasant farmland. In the spring of 2004, winter and spring of 2005, the experiment is processed in floodplain and terrace of north side of Weihe River. The surface soil types of experimental field are sandy loam and medium loam respectively. The main crops are winter wheat and fruiter;the main irrigation kind is ground border irrigation, and the irrigation water requirement is according to the local irrigation ration. On the basis of plentiful experiments and analysis, this paper is about the primary research on the space distribution of infiltration moisture parameters in unsaturated soil, and key research on water current movement mathematical simulation and reasonable irrigation technique element of border irrigation. The results are as follows:(1) Built mono-parameter model of water moisture infiltration parameters based on the experiment. The model has higher simulation accuracy;the mono-parameter is changed with the soil character, can be used as the variation coefficient to describe the space variation of infiltration moisture parameters. The variation coefficient is fit to research on the space variation of infiltration moisture parameters in wide scale. This mono-parameter model is modified the Philip Infiltration Model. Through measuring one point in the curve, the infiltration-processing curve can be acquired with this modelaccurately.(2) Built up a mathematical model of water current movement and infiltration of border irrigation. According to some boundary condition and field experiment data, two methods are worked out. One is using the water depth to evaluate the roughness;the other is in virtue of mathematical model of water current movement of border irrigation. The two methods are all feasible. The better result can be got if the average roughness is calculated by the above two methods simultaneously. It can reflect the surface roughness of field surface soil more precisely and veritably. Comparing the experimental data with the simulation data, this model and its result are validated. It is reasonable and feasible.(3) Applied the mathematical model. Through simulating the ground irrigation applied the mathematical model of water current movement;the result is the optimized correlation of the border length and the water discharge of per second multiplied by per meter in different gradient.(4) Acquired the optimized correlation of reasonable irrigation technique element with high irrigation quality index. It can be used to guide the farmers' irrigation, reduce the waste of water resources, enhance the irrigation application efficiency and distribution efficiency, and attain the aim of saving water.