Evaluation of Modified Van Genuchten Model in the Pattern of Soil Water Movement Under Drip Irrigation System

To assess the ability of modified van genuchten models to simulate soil moisture distribution and front under Drip Irrigation Systems Research was conducted on research farm of Bu-Ali Sina University in hamedan. Implementation of drip irrigation system in a land with dimensions of 10 m was used. Due to limited irrigation for 5 hours was considered. After time and complete distribution of irrigation water from the dropper bulbs, profiles of soil were dug in the middle of wetting the soil moisture content by weight in the time period immediately consecutively in different parts Progressive Front, 1/5, 3, 6, 24, 48 and 72 hours after irrigation, were measured. To simulate the water distribution hydraulic properties model using inverse method of Van genuchten modified software was used hydrus-2d. The results showed that the modified van genuchten model could be estimate cross sections of soil moisture at all times after irrigation with accuracy. But was not successful in estimating soil moisture depth. Also in estimating the Width and depth profiles showed underestimate.

Keywords:

modified Van genuchten , drip irrigation , hydrus-2d , soil moisture