Evaluating and Sensitivity analysis of a macro scale hydrological model (VIC-3L) for simulation of stream flow at different time scales

Macro scale hydrological models, due to their physically based structure and consideration of most important process in energy and water balances, have high potential for illustrating the spatial distribution of soil moisture, soil temperature, evapotranspiration and stream flow. One of the most popular models that have been considered in recent decades is VIC-3L (Variable Infiltration Capacity) which is a semi distributed and macro scale model. This paper addresses the VIC-3L model in the Callous river basin which is located in the north of Iran. As a semi-distributed macroscale hydrological model, VIC-3L calculates the water and surface energy balances within each grid cell while captures the sub-grid variations statistically. Distinguished characteristics of this model include: subgrid variability in land surface vegetation classes; subgrid variability in soil moisture storage capacity; drainage from the lower soil moisture zone (base flow) as a nonlinear recession [1]. VIC uses a separate routing model based on a linear transfer function to simulate the streamflow [2, 3]. Since its existence, VIC has been well calibrated and validated in a number of large river basins over the continental US and other parts of the world. Applications using the VIC model cover a variety of research areas. The VIC-3L model, with a variety of updates, has been widely used in studies which ranging from water resources management to land-atmosphere interactions and climate change [4].