A new analytical method for estimating the 3D volumetric wetting pattern under drip irrigation system

Abstract

The wetting pattern and its components are important factors in the optimum design and operation of a drip irrigation system. In this investigation, the 3D volumetric wetting pattern which occurred under the surface drip irrigation was described analytically. In the laboratory experiment, the spatio-temporal variation of the wetting pattern was observed during the water application period, and the sizes of its components were measured at five-minute intervals. The components of the pattern were the wetted radius on the soil surface at any time during irrigation and the maximum wetted depth and maximum wetted width in the soil profile. In addition, camera records were taken during the experiment. Some physical and chemical features of the soil sample which were important for irrigation were analyzed. Also, the infiltration test was performed by double-ring infiltrometer in the field where the soil samples were taken. The moisture content of the soil was determined at the beginning of the irrigation application. In the next stage, the wetting pattern was located on the Coordinate System, and the main movement equations describing the spatio-temporal variation of the pattern were obtained. The volumetric wetting pattern was determined by processing these functions in the 3D system. Drip irrigation may be applied on various soil textures, with different emitter discharges and application times. Although wetting patterns in various conditions show different properties of shape from each other, the models devised contain the entire main common components of the wetting pattern. As a result, when the models were run with the data from the experiment, the 3D wetting pattern in the drip irrigation system was determined and analyzed comparatively from the points of view of main movement features of water in the soil profile and on the soil surface.