Effect of discharge on water pattern distribution in surface drip irrigation and simulation it with HYDRUS-2D model

The aim of this study was to investigate the influence of discharge on wetting pattern and simulation by HYDRUS-2D model. After preparing a physical model made of Plexiglas with specified dimensions, and filled with silty clay loam soils. By manually adjustable emitter, four discharges 2, 4, 6 and 8 liters per hour were tested. Irrigation time for each fixed discharge 2 hours and for moisture reparation distribution, 24hours is validated. Comparison of measured and calculated values with HYDRUS-2D model of the diameter and depth of the wetting front revealed that the correlation coefficient was above 90 percent of all discharges and was very low error rate which shows the ability of the HYDRUS-2D model to simulate the moisture but this ability was higher in the lower discharge. A comparison between the simulation with HYDRUS-2D model using data from various input Rosetta and data observations of wet pattern soil showed the input data of the model Rosetta is more will increase accurate simulation with HYDRUS-2D model. By increasing the discharge, the extent of depth decrease and extent of the surface moisture increases. The performance of HYDRUS-2D model in lower discharge is more. And by increases the amount of data inputs to the model Rosetta, HYDRUS-2D model will be having higher accuracy