Simulation of Soil Moisture under a Line Ssource in a Heavy Soil Texture with HYDRUS-2D

As irrigation system installation is expensive and time consuming، it would be better to have an estimate of the water content provided by the system in the active root zone before designing an irrigation system. In this study، HYDRUS-2D performance was assessed under a tape irrigating in-situ with a heavy textured and relatively heterogeneous soil in Rasht region. Three different flows i. e. 2. 5، 5، and 6 L/h/m and four irrigation times i. e. 1، 2، 3، and 4 hours were considered as the main treatments with three replications. Measured data were compared with the simulated results for both the whole soil profile and the part under the tape using two statistical indices، i. e. RMSE and efficiency factor (EF). The model performance was evaluated as good، with a low average RMSE of 0. 0123 and 0. 0236 cm3/cm3 for the whole soil profile and under the tape، respectively، with the corresponding average EF values of 77% and 76%، for this soil texture. Overall، the model could satisfactorily simulate soil moisture in a heavy textured and heterogeneous soil.