Numerical Simulation and Verification of Soil Water Movement under Horizontal Moistube-irrigation

ZHAO Tong; FAN Yanwei; ZHAO Tinghong

doi:10.13522/j.cnki.ggps.2017.0219

Abstract：[Objective]The objective is to understand the soil water movement under moistube-irrigation.[Meth-ods]Based on the theory of unsaturation soil water dynamics, a mathematical mode was established with the soil water movement under the way of moistube standard of laying and the SWMS-2 D software was applied to solve the model numerically. Based on the laboratory tests and the existing literature, the infiltration amount of a unit length micro tube, the transport value of soil wetting front, soil wetting volume and soil profile moisture content were analyzed and verified.[Results]There was a difference between the simulation results and measured values of moistube infiltration in per unit length, and the relative error average was 11.7％at the beginning of infiltra-tion. In the later period of infiltration, the simulation result agreed well with measured values and the relative er-ror average was 4.7％. When the moistube was buried horizontally, the soil wetting front is a cylindrical distribu-tion along the microtube. The simulated values of each time period were basically consistent with the measured values, and the mean relative error of the absolute value was 7.38％. The relationship between the simulated value of the volume of soil wetting body and the measured value became better as the time increasing. The contour of soil moisture content was the concentric circle around the moistube. With the increase of the radius of the wetted soil, the soil moisture content of the soil was the largest at the pipe wall of moistube.[Conclusion]The model can truly reflect soil water movement under the way of moistube standard of laying. The model and the SWMS-2D software can be used to simulate the soil water movement of the level moistube-irrigation.