| Abstract: In order to reveal free infiltration law of muddy water film hole irrigation, on the basis of related literature at home and abroad, In this paper, combined with the production practice of muddy water irrigation in the Yellow River Irrigation District, the method of combining indoor test with theoretical analysis and model simulation, the experimental study on the free infiltration characteristics of indoor muddy water irrigation was carried out. This paper analyzes the influence of different factors on the free infiltration characteristics of muddy water film hole irrigation, and establishes the free infiltration model of muddy water film hole irrigation. The following mainly results are obtained:(1) The characteristic between single point source free infiltration and vertical one-dimensional infiltration of muddy water film hole infiltration and clean water is analyzed.In this paper, the cumulative infiltration, infiltration rate, wetting front and the distribution of water content and time in the wetted surface of the single point source infiltration of muddy water film are studied. Results show: The cumulative infiltration, infiltration rate, infiltration rate of infiltration unit with single point source infiltration, and wetting front migration distance of muddy water film are in accordance with power function model. After the irrigation, at the same distance from the center of the membrane hole, the moisture content of the muddy water film is lower than that of the clean water infiltration.(2) The cumulative infiltration and infiltration time of the free infiltration unit membrane area with different sediment gradation, viscosity index and soil bulk density were all in accordance vwith the Kostiakov power function model. However, the parameters of the model are mainly affected by the sediment gradation, the viscosity index and the soil bulk density, and the relationship between the cumulative infiltration model parameters and the sediment gradation, the viscosity index and the soil bulk density is established. The cumulative infiltration model of the unit membrane pore area with different sediment gradation, viscosity index and soil bulk density is proposed.(3) Freedom of muddy water film hole irrigation infiltration and wetting front transport distance are in power function relationship between the infiltration time, but the model parameters by the sediment gradation, the effect of viscosity index and soil bulk density is larger, established the wetting front migration model parameters and the corresponding influencing factors, the relationship between puts forward the influencing factors of wetting front transport models.(4) After irrigation, different sediment gradation, viscosity index and soil bulk density of muddy water freedom of film hole irrigation infiltration moist soil moisture content in the body are increased with the increase of distance from the center of film hole decreases, and the sediment gradation, the effect of viscosity index and soil bulk density is larger, established muddy water wet body moisture distribution freedom of film hole irrigation infiltration model parameters and the corresponding influencing factors, the relationship between puts forward the influencing factors of muddy water wet body moisture distribution freedom of film hole irrigation infiltration model.(5) Muddy water relative to the freedom of film hole irrigation infiltration has reduced infiltration function under the condition of water infiltration, the reduced infiltration amount as physical clay content in the sediment increases, infiltration late accumulation reduced infiltration volume increased linearly, basically reduced infiltration rate after the first rapid increase slowly decreasing along with the change of time;Muddy waters of free infiltration of film hole irrigation reduced infiltration rate decreased with the increase of muddy water viscosity index, and the reduced infiltration rate and negative correlation between viscosity index accords with power function relationship.(6) Freedom of muddy water film hole irrigation infiltration model is established and the muddy waters of different viscosity index of freedom of single point source infiltration of film hole irrigation unit of film hole area of cumulative infiltration amount, horizontal wetting front and vertical wetting front and soil moisture distribution along with the change of time is simulated, the consistency of the simulated values and the measured values is better.Used Hydrus model on the muddy waters of different soil bulk density of freedom of single point source infiltration of film hole irrigation unit of film hole area of cumulative infiltration amount,the wetting front and soil water redistribution are simulated, the simulation values and experimental values alignment is higher, the relative error is within 5%. |
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