Abstract
Using inverse modeling to determine soil hydraulic properties has become increasingly popular in the last few decades, enabling investigators to obtain more accurate estimates of soil hydraulic parameters compared to laboratory methods. A field experiment study was conducted to estimate the soil hydraulic parameters and investigate some scenarios during the optimization process using an inverse solution in HYDRUS-1D software to simulate the water flow in bare soil. Twelve scenarios were studied at four depths of the simulation domain and three simulation periods. Statistical indices were used to judge the optimization process accuracy for all scenarios. The results showed that the use of field experiments (internal drainage method) to determine soil hydraulic parameters via an inverse solution in HYDRUS software is rather easy, low-cost, and accurate enough for non-academic pumoses, such as irrigation water management that does not require a high accuracy. However, the inverse solution method had a better performance than the ROSETTA method in terms of the soil hydraulic parameter estimation. The optimization period of 25 days at a soil depth of 1 m or so is appropriate to obtain a better accuracy of the estimated soil hydraulic parameters.