SWAT model
{{Use dmy dates|date=July 2023}}
SWAT (soil and water assessment tool) is a river basin scale model developed to quantify the impact of land management practices in large, complex watersheds. SWAT is a public domain software enabled model actively supported by the USDA Agricultural Research Service at the [http://blackland.tamu.edu/ Blackland Research & Extension Center] in Temple, Texas, USA.{{cite web|title=SWAT: Soil & Water Assessment Tool|url=http://swatmodel.tamu.edu/|publisher=Texas A&M University|access-date=1 March 2012}} It is a hydrology model with the following components: weather, surface runoff, return flow, percolation, evapotranspiration, transmission losses, pond and reservoir storage, crop growth and irrigation, groundwater flow, reach routing, nutrient and pesticide loading, and water transfer. SWAT can be considered a watershed hydrological transport model. This model is used worldwide{{cite journal|last=Gassman|first=P. W.|author2=M. R. Reyes |author3=C. H. Green |author4=J. G. Arnold |journal=Transactions of the ASABE|date=May 2007|volume=50|issue=4|pages=1211–1250|url=http://www.card.iastate.edu/environment/items/asabe_swat.pdf|access-date=19 July 2012|doi=10.13031/2013.23637|title=The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions}} and is continuously under development. As of July 2012, more than 1000 peer-reviewed articles have been published{{cite web|title=SWAT Literature Database|url=https://www.card.iastate.edu/swat_articles/|access-date=19 July 2012}} that document its various applications.
Model operation
SWAT is a continuous time model that operates on a daily time step at basin scale. The objective of such a model is to predict the long-term impacts in large basins of management and also timing of agricultural practices within a year (i.e., crop rotations, planting and harvest dates, irrigation, fertilizer, and pesticide application rates and timing).
It can be used to simulate at the basin scale water and nutrients cycle in landscapes whose dominant land use is agriculture. It can also help in assessing the environmental efficiency of best management practices and alternative management policies. SWAT uses a two-level dissagregation scheme; a preliminary subbasin identification is carried out based on topographic criteria, followed by further discretization using land use and soil type considerations. Areas with the same soil type and land use form a Hydrologic Response Unit (HRU), a basic computational unit assumed to be homogeneous in hydrologic response to land cover change.
Interfaces
See also
- Storm Water Management Model
- Stochastic Empirical Loading and Dilution Model
- Swat-CUP
- IPEAT - Integrated Parameter Estimation and Uncertainty Analysis Tool{{cite journal|title=IPEAT |journal=Environmental Modelling & Software |date=April 2014 |volume=54 |pages=211–221 |doi=10.1016/j.envsoft.2014.01.004 |url=https://www.sciencedirect.com/science/article/abs/pii/S1364815214000139 |access-date=20 June 2022|last1=Yen |first1=Haw |last2=Wang |first2=Xiuying |last3=Fontane |first3=Darrell G. |last4=Harmel |first4=R. Daren |last5=Arabi |first5=Mazdak |url-access=subscription }}
- [https://www.ars.usda.gov/plains-area/temple-tx/grassland-soil-and-water-research-laboratory/docs/193226/ ALMANAC (software model)]
References
- {{cite web |author1=S.L. Neitsch |author2=J.G. Arnold |author3=J.R. Kiniry |author4=J.R. Williams |author5=K.W. King | title=Soil Water Assessment Tool Theoretical Documentation |url=https://swat.tamu.edu/media/1290/swat2000theory.pdf |year=2002 |url-status=live |archive-date=Jul 2, 2022 |archive-url=https://web.archive.org/web/20220702134930/https://swat.tamu.edu/media/1290/swat2000theory.pdf |language=en |access-date=28 July 2023}}