Watershed Modeling Using Swat for Hydrology and Water Quality : A Review

Abstract

According to World health Organization Global health Observatory, 600 million Indians are facing extreme water stress and about two lakh people die every year due to inadequate access to safe water. This scenario indicate that many parts of the country will soon face a crisis in both water quantity and water quality unless management of water resources planned in a sustainable way. Many major rivers are polluted as a result of urbanization and industrialization, thereby quality parameters also violating the standards. In India, more than 50% of population depends on agriculture and many farmers use fertilizers, consists of harmful chemicals. The Nitrogen and phosphorous are the two nutrients originating from inorganic and organic fertilizers, that affect the water quality due to intensive agricultural farming and livestock grazing. Water availability in a catchment is necessary to plan/allocate the water resources in an equity manner. This can be estimated using a hydrologic model, which is designed to simulate the rainfall-runoff processes of watershed systems. An ArcGIS-based user interface could be used to model hydrologic and water quality parameters. SWAT is a continuous simulation-based model and is developed through a distributed hydrological modeling approach, which is one of the few hydrologic models with water quality coupling capability. This review mainly focuses on the broad aspects related to the execution and applicability of SWAT for various catchments to simulate the runoff and other quality parameters with various calibration techniques, thereby to make policies for best management practices and to promote sustainable development.