The Experimental Research On Law Of Reducing Leakage And Influential Factors Of Multi-way Infiltration Of Muddy Water Film Hole Irrigation

Multi-way infiltration is a common infiltration form in muddy water film hole irrigation.In this paper,multi-way infiltration of muddy water film hole irrigation experiment was made in laboratory and filed respectively to analyze the influence of different factors on muddy water film hole irrigation.The conclusions were as follows:(1)By laboratory experiment,the influence of muddy water sand content,film hole diameter,pitch of film holes and initial soil water content to multi-way infiltration of muddy water film hole irrigation was simulated and analyzed.With the changing of infiltration way,the difference of soil water content will become obvious,which will lead to the changing of water gradient,and then have an influence on water infiltration rate.With the increase of muddy water sand content,the accumulated infiltration capacity in unit area of film hole is decreasing gradually.And the function model of infiltration capacity,accumulated infiltration time and muddy water sand content is established.With the increase of sand content,the migration speed of wetting front is decreasing.And the mathematic model of intersection and muddy water sand content is established.With the increase of film hole diameter,the accumulated infiltration capacity is also increasing,while the accumulated infiltration capacity of unit film hole is decreasing.And the muddy water infiltration model and intersection timing model is established in different film hole diameters.The smaller of pitch of film hole,the shorter of intersection time,and the smaller of accumulated infiltrated capacity.While the migration speed of wetting front in vertical direction will increase with the decrease of pitch of film hole.The smaller pitch of film hole and the bigger diameter of film hole are good for increasing irrigation uniformity.With the increase of initial soil water content,the accumulated infiltration capacity is decreasing gradually.The mathematic model of accumulated infiltration capacity in unit film hole area in freedom infiltration,water content and infiltration time is established.And the mathematic model of accumulated infiltration capacity,initial soil water content and infiltration time is also established.Compared with freedom infiltration,the accumulated infiltration capacity in the condition of bilateral interference decreased,while the migration rate of wetting front increased.(2)By field experiment,the influence of muddy water sand content,film hole diameter and pitch of film holes on infiltration of muddy water is analyzed,and the infiltration rule is similar with laboratory experiment.But the infiltration index difference is little obvious because of the difference of experiment soil.On the same condition,with the increase of muddy water sand content,film hole diameter will decrease,while the pitch of film hole and the sediment retention rate on film surface will increase.The sediment retention rate measured in experiment is larger than actual value.The higher of muddy water sand content,the bigger of film hole diameter and the smaller of pitch of film hole is good for the distribution of soil water in wetting body,and is also good for the increasing irrigation uniformity.(3)Based on 3D Green-Ampt infiltration model,The average suction at the wetted front for different sediment content generalized model,infiltration reduction force for different muddy water sand contains generalized model and Infiltration reduction force for different film hole diameter generalized model are established.