The Soil and Water Assessment Tool (SWAT+) is a hydrologic and water quality modeling system that is used to predict the impacts of land use, land management practices, and climate change on water, sediment, and agricultural chemical yields in large, complex watersheds. It was developed by the Agricultural Research Service (ARS) of the United States Department of Agriculture (USDA). The SWAT+ model is a comprehensive, integrated model that combines various sub-models to simulate various hydrologic and water quality processes. It includes a soil erosion model, a surface water routing model, a groundwater model, and a water quality model. It can be used to simulate a wide range of processes, including erosion, sediment transport, nutrient cycling, water balance, crop growth, and water quality.