Study And Numerical Simulation Of Soil Water Migration Under The Wide Ridge Furrow Irrigation

Furrow irrigation technology is mainly divided into two kinds of irrigation technologies that conventional furrow irrigation and wide-ridge furrow irrigation.Because of the shortage of water resources and low water use efficiency,the furrow irrgation is a kind of efficient water-saving irrigation method proposed,and it is widely used in different furrow irrigation methods in agricultural production.This paper in the relevant literature at home and abroad based on the theory and technology of furrow irrigation,studied different specification parameters of wide-ridge furrow irrigation to select the optimum parameters specifications combination in the wide-ridge furrow irrigation.In order to take enhances the quality for the purpose of wide-ridge furrow irrigation,the combination of field experiment and HYDRUS-2D software simulation is adopted to carry on the analysis of the condition of soil moisture migration process in the different wide furrow ditch specifications of furrow irrigation.The main research results are as follows:(1)Performance of bare soil furrow irrigation in field soil water migration test: Different specification parameters of wide-ridge furrow irrigation have different effects of soil water infiltration and flow characteristics in wide-ridge furrow irrigation,as well as the effects that post-irrigation on soil moisture distribution varied with different degrees.The influence of ridge width,groove width and groove depth on the cumulative infiltration is more significant,while the gradient of the groove bottom has little effect on the cumulative infiltration.The water flow is mainly influenced by the ridge width,groove width and the gradient of the groove bottom.The ridge width,groove width and groove depth on soil moisture distribution is relatively more significant impact,while the gradient of the groove bottom on soil moisture distribution is relatively less affected;The influence of ditch head and ditch center on soil water content distribution is relatively small before and after irrigation.However,the tail of ditch on soil moisture distribution is relatively large impact before and after irrigation.Through the analysis of soil water movement in the wide-ridge furrow irrigation,the results showed that the combination of the groove width is 40 cm,the groove depth is 20 cm and the gradient of the groove bottom is 2‰ is optimum in the ridge width treatment which is 70 cm.(2)Select of the optimal specification parameters combination of wide-ridge furrow irrigation and judge by HYDRUS-2D software model of wide-ridge furrow irrigation to simulate two-dimensional infiltration law of soil water at different time periods.The simulation values of soil moisture infiltration line and soil water content were compared with those measured in field experiments.And the result displays that the simulated values are in good agreement with the measured values,particularly the simulation results were good when it is 24 hours after the end of the irrigation.