TREX: Two-Dimensional Runoff Erosion and Export

Spatially Distributed Model To Assess Watershed Hydrology, Sediment Transport, and Contaminant Transport and Fate




   Extreme Storms (pdf)

   Metals Transport (pdf)

User Manual (pdf)

Source Code


   Hydrology (zip)

   Sediment Transport (zip)

   Chemical Transport (zip)

   Rainfall Options (zip)

TREX Tools






To illustrate TREX set-up and operation, a series of example files are available. Hydrology and sediment transport examples are available for the 17 October 1981 storm event on the Goodwin Creek, Mississippi watershed.  A chemical transport example is also available for a hypothetical case.  These example files are meant to be illustrative but are not intended to document every possible model feature or combinations of inputs and options. Examples are available for:

  1. Hydrology:  TREX-Hydrology-Example (zip)
  2. Sediment Transport:  TREX-Sediment-Example (zip)
  3. Chemical Transport:  TREX-Chemical-Example (zip)
  4. Rainfall Options:  TREX-Pueblo-Examples (zip) [13 MB]

Samples of selected output for these example simulations is also included.

TREX is operated from a command line interface (the command prompt under the Windows operating system or a teminal window under unix/linux) and requires that the user specify one argument. This argument is the path and file name of the main input file. For example:

C:\> trex.exe inputfile.inp


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Department of Civil and Environmental Engineering - Colorado State University
Fort Collins, Colorado 80523-2028  USA   (970) 491-5048

Last update: 07 August 2018