Comparing the performance of semi-distributed SWAT and lumped HEC-HMS hydrological models in simulating river discharge (Case study: Ab-Bakhsha Watershed)

In many flood control projects, watershed management and water resources development, calculation of the river flow discharge is of the paramount importance which requires a comprehensive hydrological modeling of the region of interest. In this respect, lack of the existence of hydrometric and meteorology measuring stations in most of watersheds, has caused numerous problems in development and management of water resources planning. The hydrological models which are used to simulate watersheds are generally categorized into two groups of lumped anddistributed models. In this study SWAT and HEC-HMS models were used to compare the capability of semi-distributed and lumped models in watershed simulation. For this, 31-year data of Abakhsha Watershed - including the whole information of hydrometer and meteorology stations in the region which are located in Bardsir County in Kerman province - have been used. The obtained results indicate that both models have acceptable accuracy; however, semi-distributed SWAT model is superior to HEC-HMS model. Being semi-distributed is one of the most important reasons for SWAT’s superiority which gets the advantage of considering climate components and using hydrological response units.