SWAT+

Introducing SWAT+, a completely revised version of the SWAT model. SWAT+ provides a more flexible spatial representation of interactions and processes within a watershed.

Download the SWAT+ installer 2.3.4 released 30 August 2023. Now available for Windows, Linux, and MacOS.

Over the past 20 years, the Soil and Water Assessment Tool (SWAT) has become widely used across the globe. The large numbers of applications across the globe have also revealed limitations and identified model development needs. Numerous additions and modifications of the model and its individual components have made the code increasingly difficult to manage and maintain. In order to face present and future challenges in water resources modeling SWAT code has undergone major modifications over the past few years, resulting in SWAT+, a completely revised version of the model.

Even though the basic algorithms used to calculate the processes in the model have not changed, the structure and organization of both the code (object based) and the input files (relational based) have undergone considerable modification. This is expected to facilitate model maintenance, future code modifications, and foster collaboration with other researchers to integrate new science into SWAT modules. SWAT+ provides a more flexible spatial representation of interactions and processes within a watershed.

Getting Started

The SWAT+ model is a command-line executable file that runs text file inputs. While you can set up these inputs yourself, we provide interfaces to make it easier. There are two pieces to the interface:

  1. QSWAT+, a QGIS interface for setting up your watershed
  2. SWAT+ Editor, a user interface for modifying SWAT+ inputs and running the model

Please refer to the following guides to start using SWAT+:

Need Help?

Please identify which area of SWAT+ you are having difficulty with and choose the appropriate group:

Additional Tools

  • gwflow module for SWAT+
    The gwflow module for SWAT+ is a physically based spatially distributed method for simulating groundwater storage, groundwater head, groundwater flow, and groundwater inflows/outflows (groundwater-stream exchange, groundwater-tile exchange, groundwater-lake exchange, groundwater-soil exchange, groundwater pumping). When in use, this module replaces the original groundwater module of SWAT+.
  • SWAT+ Toolbox v1.0.5
    SWAT+ Toolbox is designed to work with the SWAT+ model. You can use it for sensitivity analysis, model calibration, evaluation, and validation. The software is currently only available on Windows. There are built-in updates through which more features, functionalities and bug fixes will be delivered. Check for updates as soon as you install. Check the user documentation here.
  • SWATrunR
    The SWATrunR package integrates SWAT+ and SWAT2012 models in modeling workflows in R. Taking advantage of the powerful R environment SWATrunR provides a large toolset for parameter sensitivity analysis, model calibration and the analysis of SWAT model results.
  • SWATplus-CUP
    Calibration Uncertainty Program for SWAT+. License purchase required.
  • R-SWAT
    Free, open source, graphical user interface for SWAT/SWAT+ calibration, parameter sensitivity/uncertainty analysis. For help see the user group and tutorial videos.
  • IPEAT+ Source Code & Example
    IPEAT+ is a FORTRAN-based, built-in, and open source optimization and automatic calibration tool of SWAT+ rev. 59.2.

Publications

2023
Field scale SWAT+ modeling of corn and soybean yields for the contiguous United States: National Agroecosystem Model Development

Natalja Čerkasova, Michael White, Jeffrey Arnold, Katrin Bieger, Peter Allen, Jungang Gao, Marilyn Gambone, Manyowa Meki, James Kiniry, Philip W. Gassman. "Field scale SWAT+ modeling of corn and soybean yields for the contiguous United States: National Agroecosystem Model Development". Agricultural Systems, 2023, 103695, doi.org/10.1016/j.agsy.2023.103695.
2020
Development of Reservoir Operation Functions in SWAT+ for National Environmental Assessment

Wu, J., H. Yen (corresponding author), J. G. Arnold, Y. E. Yang, X. Cai, M. J. White, S. Chinnasamy, C. Miao, R. Srinivasan (2020) “Development of Reservoir Operation Functions in SWAT+ for National Environmental Assessment.” Journal of Hydrology, 583, 124556. doi.org/10.1016/j.jhydrol.2020.124556
2019
Representing the Connectivity of Upland Areas to Floodplains and Streams in SWAT+

Bieger, K., Arnold, J.G., Rathjens, H., White, M.J., Bosch, D.D., and Allen, P.M.. 2019. “ Representing the Connectivity of Upland Areas to Floodplains and Streams in SWAT+.” Journal of the American Water Resources Association 55 ( 3): 578– 590. doi.org/10.1111/1752-1688.12728.
IPEAT+: A Built-in Optimization and Automatic Calibration Tool of SWAT+.

Yen, H., S. Park, J. G. Arnold, R. Srinivasan, C. J. Chawanda, R. Wang, Q. Feng, J. Wu, C. Miao, K. Bieger, P. Daggupati, A. Griensven, L. Kalin, S. Lee, A. Y. Sheshukov, M. J. White, Y. Yuan, I. Yeo, M. Zhang, X. Zhang (2019) “IPEAT+: A Built-in Optimization and Automatic Calibration Tool of SWAT+.” Water, 11(8), 1681, pp. 1-17. doi.org/10.3390/w11081681
2018
Use of decision tables to simluate management in SWAT+

Arnold, J.G.; Bieger, K.; White, M.J.; Srinivasan, R.; Dunbar, J.A.; Allen, P.M. Use of Decision Tables to Simulate Management in SWAT+. Water 2018, 10, 713. doi.org/10.3390/w10060713
2017
Introduction to SWAT+, a completely restructured version of the Soil and Water Assessment Tool

Bieger, Katrin, Arnold, Jeffrey G., Rathjens, Hendrik, White, Michael J., Bosch, David D., Allen, Peter M., Volk, Martin, and Srinivasan, Raghavan, 2017. Introduction to SWAT+, a Completely Restructured Version of the Soil and Water Assessment Tool. Journal of the American Water Resources Association (JAWRA) 53( 1): 115– 130. doi.org/10.1111/1752-1688.12482
Enhancing the SWAT Model for Simulating Denitrification in Riparian Zones at the River Basin Scale

Hoang, L., A. van Griensven, and A. Mynett. 2017. “Enhancing the SWAT Model for Simulating Denitrification in Riparian Zones at the River Basin Scale.” Environmental Modelling & Software 93: 163–79. doi.org/10.1016/j.envsoft.2017.03.017.
Featured Series Conclusion: SWAT Applications for Emerging Hydrologic and Water Quality Challenges

Merwade, Venkatesh, Baffaut, Claire, Bieger, Katrin, Boithias, Laurie, and Rathjens, Hendrik, 2017. Featured Series Conclusion: SWAT Applications for Emerging Hydrologic and Water Quality Challenges. Journal of the American Water Resources Association (JAWRA) 53( 6): 1390‐ 1392. doi.org/10.1111/1752-1688.12601
Development of a Hydrologic Connectivity Dataset for SWAT Assessments in the US

White, M.J.; Beiger, K.; Gambone, M.; Haney, E.; Arnold, J.; Gao, J. Development of a Hydrologic Connectivity Dataset for SWAT Assessments in the US. Water 2017, 9, 892. doi.org/10.3390/w9110892