News

CFSR Weather Data

14 September 2015

Worldwide CFSR daily climate data since 1979 have been available in SWAT input format on the SWAT website since November 2014 and have already provided almost 30,000 downloads. A similar interpolated version of the CFSR data base is available from Zach Easton and Daniel Fuka at Virginia Tech, from which data have already been downloaded more than 40,000 times. A number of studies have demonstrated the utility of this global daily data base for SWAT applications; however, biases in rainfall estimates have been discovered for several regions. Recent experience shows that the utility of these databases can be increased by application of a bias correction tools that are available on the SWAT and Virginia Tech websites. Contact Dr. Srinivasan (r-srinivasan@tamu.edu), Dr. Easton (zeaston@vt.edu), or Daniel Fuka (drfuka@vt.edu) for more information.

SWAT+ Theoretical and User Manual

7 September 2015

A new SWAT manual is under development to support the roll-out of SWAT+. It will contain chapters on all the major component processes simulated by SWAT+ written by expert SWAT users from around the world. In addition, it will include chapters on model sensitivity analysis, calibration, and evaluation. Selected datasets and exercises will also be provided to be used in academic and professional courses. The theoretical and sensitivity/calibration/evaluation components will be provided in both hard-copy and electronic formats, and example datasets and exercises will be available on line to facilitate updates. For more information contact Drs. R. Srinivasan (r-srinivasan@tamu.edu) or Jeff Arnold (Jeff.Arnold@ars.usda.gov).

SWAT+

31 August 2015

A new modular version of SWAT, SWAT+, is under development! The new version will have a much-improved modular design and input file structure to facilitate addition of new and improved algorithms and subroutines. The simplified structure will be easier for users and developers to understand, and it should stimulate exchange of algorithms with other models. The new SWAT code and associated software should be available on the SWAT website before the 2016 International SWAT Conference in Beijing.

There will be a special session at the upcoming Purdue Conference, Oct. 14-16, covering the new SWAT code, input/output file structure, test datasets and a developers’ interface.

For more information contact Dr. Jeff Arnold (Jeff.Arnold@ars.usda.gov).

SWAT Version Control

24 August 2015

JAVA Forge has been selected for SWAT version control. The site will include all SWAT revisions, notes, and the code for each model version. It can be obtained at: javaforge.com/svn/swatmodel. Any SWAT user can become a Java Forge member, create a login, and contact Nancy Sammons (nancy.sammons@ars.usda.gov) for access to the SWAT site

SWATlite for the World

17 August 2015

Because of SWATlite’s simplified input requirements and speed of execution, it is being used to simulate subbasin hydrology and soil erosion for the entire world. Preliminary runs for the major continents have already been executed, and the project can serve as a foundation for more complex analyses using the complete full SWAT model. Contact Dr. Srinivasan (r-srinivasan@tamu.edu) for more information.

• Land use: available at 30 m and larger grids.
• Digital elevation: USGS, 1 km resolution.
• Daily weather: generated from CFSR.
• Soils: FAO, 1:1 million.

SWAT-DEG to SWATlite

10 August 2015

SWAT-DEG is a simplified version of SWAT2012. Originally developed by Peter Allen (Peter_Allen@baylor.edu) and Jeff Arnold (Jeff.Arnold@ars.usda.gov), it  greatly simplifies hydrology and plant growth and does not simulate nutrients, concentrating on gulley formation and stream degradation (deepening and widening). Because of its rapid execution time and simplified input requirements, it is finding a number of previously unanticipated applications. As a result, SWAT-DEG has been renamed SWATlite and will soon be available on the SWAT web site. Contact Drs. Allen or Arnold for more information.

SWAT-MODFLOW

3 August 2015

Ryan Bailey (rtbailey@engr.colostate.edu) has incorporated MODFLOW into SWAT to facilitate integrated surface water – ground water assessments. The model has been applied to watershed-aquifer systems in Colorado USA, and in several Pacific islands. Anyone interested in obtaining this software should contact Dr. Bailey.

A one-day SWAT-MODFLOW workshop will be offered at Purdue University, October 13. A three-day international SWAT conference will follow. Register and learn more!

Representative Watersheds of the World

28 July 2015

A continuous, long-term effort has begun to document and make available example SWAT projects for representative watersheds around the world. These SWAT projects are being contributed by their developers to assist other users by making available input and output data for representative large and small watersheds in every corner of the world. The work was begun by Hendrik Rathjens (hrathjen@purdue.edu) and Katrin Bieger (kbieger@brc.tamus.edu). Scientists contributing their SWAT projects will benefit from the large number of citations expected to be generated by use of the models in peer-reviewed papers. Representative watersheds that will soon be available on the SWAT website include: Little River in Tifton, Georgia; Middle Bosque River in Central Texas; and Wildcat Creek in Indiana. Other watersheds with good measured data for model validation will be added in the near future. If you would like to contribute a SWAT project to this data base, contact Dr. Jeff Arnold (Jeff.Arnold@ars.usda.gov).