ABSTRACT
The Soil and Water Assessment (SWAT) model is a follow-up of almost 30 years of the USDA Agricultural Research Service’s modeling efforts. The SWAT is one of the most widely used eco-hydrological models globally, with over 4,000 publications. The SWAT is a comparatively tiny watershed to river watershed model that predicts the environmental impacts resulting from land use, land management practices, and climate change by simulating the ground and surface water both qualitatively as well as quantitively. SWAT is widely used in watersheds worldwide to assess soil erosion control and prevention, sediment production, nonpoint source pollution control, and regional management. The SWAT application categories include river discharge calibration and related hydrologic evaluations, comparisons with other models, sensitivity analyses, and calibration techniques. However, application for extreme river discharge conditions is still rare. SWAT study compilations for specific or relatively new applications, such as eco-hydrological simulation, ecosystem services, sub-daily algorithms, and insecticide fate and transport simulations, have focused on SWAT application reviews. The United States and China have done the majority of studies reporting SWAT since 1999. However, there is still room for more SWAT research, such as bias correction of GCMs and regional climate estimations, SWAT+ and SWAT advancement for exceptional flow simulations in various types of arid/nonarid basins integration of machine learning in the SWAT model. In this chapter, a detailed review of multiple applications of SWAT has been presented to provide a holistic understanding of the use and scope of the SWAT model in hydrologic applications.
