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ARS Home » Plains Area » El Reno, Oklahoma » Grazinglands Research Laboratory » Agroclimate and Natural Resources Research » Research » Publications at this Location » Publication #171638


item Garbrecht, Jurgen
item Campbell, James
item Martz, Lawrence

Submitted to: Grazinglands Research Laboratory Miscellaneous Publication
Publication Type: Government Publication
Publication Acceptance Date: 11/2/2004
Publication Date: 12/1/2004
Citation: Garbrecht, J.D., Campbell, J., Martz, L.W., 2004. TOPAZ Installation Manual-Updated Manual. Grazinglands Research Laboratory Miscellaneous Publication. Available:

Interpretive Summary: The layout of the land surface is often needed for water resources, runoff, erosion, water quality, and soil and water conservation investigations. Traditionally the layout was determined by time consuming and resource intensive surveys. A software tool was developed by the USDA, Agricultural Research Service, Grazinglands Research Laboratory, El Reno, Oklahoma, to automate the process of identifying the location of streams, drainage boundaries, land-surface slope, etc. with the help of a computer and digital maps of the land surface. The name of the software tool that performs the land surface analysis is TOPAZ (TOpographic PArameteriZation). This User Manual provides a detailed description of the input and output files for each TOPAZ sub-program, and guides the user in a step-by-step procedure through the operation of the software. Example input and output files are provided to help users set up their own application.

Technical Abstract: TOPAZ (TOpographic PArameteriZation) is a software package for automated analysis of digital landscape topography. TOPAZ processes a raster digital elevation model (DEM) to identify and measure topographic features; define surface drainage, flow direction and flow paths; subdivide watersheds along drainage divides into subcatchments; quantify the drainage network and calculate channel parameters; and, estimate representative subcatchment parameters. TOPAZ is designed primarily to assist with topographic evaluation and watershed parameterization in support of hydrologic modeling and analysis. The overall objective of TOPAZ is to provide a comprehensive evaluation of the digital landscape topography with particular emphasis on maintaining consistency between all derived data, the initial input topography, and the physics underlying energy and water flux processes at the landscape surface. The purpose of this report is to provide detailed guidelines for the operation of software TOPAZ. The input and output file specifications are provided for each TOPAZ sub-program, and a step-by-step procedure guides the user through the operation of each sub-program. Listings of example input and output files are provided to help the user setup their own applications. This TOPAZ Version 3.2 is an upgrade of TOPAZ Version 3.12, which was released in April 1999. Upgrades are primarily the addition of spatially distributed characterization of the channel network parameters and expanded output and interface capabilities that were requested by users.