Effect of Land Use on the Performance of selected soil water Infiltration Models

Soil water infiltration is one of the key properties for designing irrigation systems, hydrological studies, water resources management, drainage projects and soil conservation practices in watershed scale. Also, an accuracy assessment amount of infiltration considering the time for estimation of stored water in the root zone plant is great important in the design and planning irrigation. For this purpose, researchers always drift suitable model for quantity expression of infiltration water to soil. The importance of infiltration has caused to develop different physical and empirical models to estimate the process. In this study, the performance of Green and Ampt, Philip, Horton, Soil Conservation Service (SCS), Kostiakov and Kostiakov-Lewis infiltration models under different land uses were evaluated
Studied soils were in the order of Aridisol, Inseptisol, Entisol and Mollisol and were in the land use of including agronomy, gardens and grassland. The number of measured infiltration in land use of agronomy, garden and grassland were 37, 25 and 20 types of soil, respectively. For this purpose, the infiltration data were obtained by double rings method from 82 point of in different region of Meshkin, Ardabil province. The parameters of these models were then obtained, using least square optimization method. In order to evaluate the accuracy of the models, the root mean square error (RMSE), standard deviation of RMSEs (SDRMSED) and R2 statistics were calculated.
The results showed that compared with other models, estimation of the cumulative infiltration Kostiakov-Lewis model has been consistent trend in all three land use ranked first (R2=0.997, RMSE=0.206 and SDRMSED=0.201). Considering obtained from total evaluation, estimation of cumulative infiltration by infiltration models in this study were as Kostiakov-Lewis and Horton models in first and second rank, Green-Ampt and SCS model in third rank and Kostiakov and Philip in fourth and fifth rank, respectively. So, we can say that the infiltration models examined, Model Kostiakov-Lewis is the best model for quantifying the process of infiltration. One reason for the excellence of Kostiakov-Louis model was great number of parameters than SCS, Kostiakov, Green-Ampt and Philip models and the fitting method is to determine the parameters mentioned models. This feature makes more flexible of this model than other model.