Model:TUGS

TUGS

Model:	The Unified Gravel-Sand (TUGS) Model
Contact person:	Yantao Cui
Institute:	Stillwater Sciences
City:	Berkeley
Country:	USA
Email:	yantao@stillwatersci.com
2nd person involved:	--
3rd person involved:	--

Model type:	Single model for the terrestrial domain.
Description:	TUGS is a 1D model that simulates the transport of gravel and sand in rivers. The model predicts the responses of a channel to changes made to the environment (e.g., sediment supply, hydrology, and certain artifical changes made to the river). Output of the model include longitudinal profile, sediment flux, and grain size distributions in bedload, channel surface and subsurface.

Supported platforms:	Windows, Can be compiled to other systems
Programming language:	Fortran77, Fortran90, in Excel for input/output manipulation
Model was developed started from:	2006. Currently there is no further development
To what degree will the model become available:	The model may potentially be available as a teaching tool
Current license type:	Propritary software
Memory requirements:	Depending on node,number of sizes and number of layers information has to be stored
Typical run time:	Hours to hundredes of years, but typically annual output

Input parameters:	describe input parameters: Initial longitudinal profile and estimated surface/subsurface grain size; sediment input, including both rate and grain size distribution, and typically at a long-term-avearged basis; and water discharge, typically daily average discharge.
Input format:	ASCII, Other: A Excel-VBA workbook is available for input data processing and simple error checking
Output parameters:	Time variation of longitudinal profile, sediment flux and grain size distributions of bedload, surface and subsurface sediment.
Output format:	ASCII, Other: Output results must be processed with a Excel-VBA workbook
Post-processing software (if needed):	yes: A Excel-VBA workbook is available to extract the output files into various Excel worksheets.
Visualization software (if needed):	no

Processes represented by model:	The two key elements of TUGS model are a surface-based bedload transport equation that allows for calculation of transport rate and grain size distribution of both gravel and sand (Wilcoco and Crowe 2003), and functions that link bedload grain size distributions with surface and subsurface grain size distributions (Hoey and Ferguson 1994; Toro-Escobar et al. 1996; Cui 2007a).
Key physical parameters & equations:	See Cui (2007a) for detail: http://dx.doi.org/10.1029/2006WR005330
Length scale & resolution constraints:	Length varies, resolution is on the order of several channel width (i.e., 1D model produces only reach-averaged results).
Time scale & resolution constraints:	For typical application in a natural river as a prediction tool, the recommended resolution is annual, although it can be as high as hours for simulation of a specific known event.
Numerical limitations and issues :	TUGS was developed with a fairly low budget, and thus, bugs may still exist. There are, however, no known numerical limitations at this point.

Available calibration data sets:	See two papers: Cui (2007a) http://dx.doi.org/10.1029/2006WR005330 Cui (2007b) http://dx.doi.org/10.1002/rra.1012 A manuscript with regard to its application to the Waipaoa River, NZ is currently underway by Basil Gomez and others.
Available test data sets:	St. Anthony Falls Laboratory downstream fining experiments (Rebecca Soileau, Chris Paola and Gary Parker)
Ideal data for testing:	--

Currently or plans for collaborating with:	Collaboration is always welcomed. The developer, however, does not have any funding to cover such activities. So it may take a fairly long time to finish a modeling exercise if it is done in his spare time.

Key papers of the model:	Cui (2007a) http://dx.doi.org/10.1029/2006WR005330 Cui (2007b) http://dx.doi.org/10.1002/rra.1012
Is there a manual available:	No
Model website if any:	--

Comments:	--