The Soil and Water Assessment Tool (SWAT) is a public domain model jointly developed by USDA Agricultural Research Service (USDA-ARS) and Texas Agricultural Experiment Station at the Temple, Texas, USA. SWAT is a river basin scale model to simulate the quality and quantity of surface and ground water and predict the environmental impact of land management practices on different soil patterns and land use patterns. It is developed for assessing the impact of management and climate on water supplies, sediment, and agricultural chemical yields in watersheds and larger ricer basins.

　　SWAT is widely used in soil erosion prevention and control, non point pollution control and regional environmental management in watersheds. The major components of SWAT include hydrology, weather, erosion, plant growth, nutrients, pesticides, land management, and stream routing. 　　

　　SWAT is applied in various fields worldwide. In order to promote the development and application of SWAT in China and international communications, Beijing Normal University (BNU) successfully held the First International SWAT Workshop in China on November 5-7, 2006. Authorized by USDA-ARS, the 5th SWAT International Conference will be organized by School of Environment, BeijingNormalUniversity on October 15-19, 2008.