Effect of infiltration water head on soil water transport and distribution characteristics under injection irrigation

In order to analyze the effect of infiltration water head on the characteristics of soil water transport and distribution,the cumulative infiltration,the transport distance of wetting front and soil profile water content of the injection irrigation under various infiltration conditions are measured through the relevant indoor simulating experiment. The study shows that a power function relationship is there between the cumulative infiltration and time,i. e. the larger the infiltration water head is,the higher the cumulative infiltration is to be in the same time. The wetting front is approximately to be the center of a semicircle a little bit lower under the water outlet and the transport speed of the wetting front slows down gradually along with time passing. The soil wetted area is larger below the water outlet than that above the water outlet with larger soil water content. Meanwhile,the larger the infiltration water head is,the greater the soil wetted area is to be at the same location. This study result enriches the theory of injection irrigation,and then can provide some references for the selection of infiltration head.