Two-Dimensional Modeling of Salts Leaching, in the Soil Profile between Two Drains

Leaching modeling in the conditions of non-uniformity leaching in soil profile is desalination challenges. The final salinity in the soil profile has different values in two dimensions of soil depth and distance from the drainage pipe. Therefore, estimation the salinity values in the soil profile requires two-dimensional modeling of leaching. In this research, the data required for modeling were prepared by soil profile leaching in a physical model with dimensions (height × width × length) of 1×0.5×2 m. In this model, soil drainage conditions were created for half the distance between the two drains. The target of this study was to compare the relationships of one-dimensional (in soil depth) and two-dimensional (in soil depth and distance from drain) in leaching modeling. Regression models included linear, exponential, logarithmic, polynomial and power functions. The results showed that in one-dimensional modeling, the coefficientR^2 for linear, exponential, logarithmic, polynomial and power functions were equal to 0.392, 0.557, 0.404, 0.406 and 0.562, respectively. But in two-dimensional modeling, it was equal to 0.796, 0.94, 0.55, 0.614 and 0.587, respectively. Therefore, increasing the coefficient R^2 in two-dimensional modeling, showed an increase in validity in leaching modeling. In evaluating two-dimensional models by terms of ME, RMSE,R^2,R_adj^2and EF, were selected exponential and linear models as the optimal model, respectively. For leaching modeling in the soil profile between two drains, using the two-dimensional model had better performance than the one-dimensional model.