عنوان مقاله [English]
Determining the contribution of each of the effective processes in the formation of river flow plays an important role in the accuracy of the simulation of these processes via hydrological modeling. Although water balance provides an overview of the volumetric changes of its components, the origin of the outflows and their temporal changes require utilization of approaches based on water tracking. In this study, we developed a three-dimensional physical and integrated hydrological model and coupled it to a water tracking model (ParFlow-CLM-EcoSLIM) to determine the contribution of rainfall, snowmelt, and groundwater to the streamflow and evapotranspiration. Also, the travel time distribution of outfluxes has been simulated and studied. To demonstrate the applicability of the developed models, we chose the Godarchay basin, located in the southwest of Lake Urmia, as the study area. The results showed that snowmelt is the main source of river discharge and evapotranspiration in the region, such that the contribution of snowmelt, rainfall and groundwater in the runoff production during a water year, on average, is equal to 56%, 5% and 39%, respectively. Also, about 55% of the incoming snow during the water year is stored in the soil after the process of melting and infiltration, and is then removed from the system in the following years. While only 22% of the new rain is stored in the system, 78% of it leaves the system in the same year.