Abstract
In this paper, a long-term runoff model including infiltration equation was developed to discuss the application of the model. By consideration of water budget among rainfall and evapotranspiration and infiltraion into the soil, increasing or decreasing process of infiltration by them was able to be described. Using the runoff model, daily discharge was simulated for experimental forest catchment. The results showed acceptable agreement between the observed and calculated discharge. By reference to the identified parameters of infiltration, the depth of soil which controls the subsurface runoff and evapotranspiration was discussed and the change in soil moisture of surface soil was calculated. As the result, it was shown that this runoff model was able to provide available information about some physical properties. Therefore, It was expected that it will be possible to evolute the effects of change in land use on the hydrologic cycle in catchments.
