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ARS Home » Pacific West Area » Tucson, Arizona » SWRC » Research » Publications at this Location » Publication #70478


item Miller, Scott
item Guertin, D.
item Goodrich, David - Dave

Submitted to: Environmental Systems Research Institute Users Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/1/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Geographic information systems (GISs) are computer-based tools that assist in the display and management of spatial information such as can be found on traditional maps. Because of the efficient manner with which they store data, a GIS can help researchers investigate the complex processes that shape the land. Flooding and erosion are significant problems in the southwestern United States, and a great deal of research and effort is directed toward the prediction of floods and their impact on the land and people. This project used both field research and computer programs to estimate characteristics of stream channels important to flood prediction. It was found that a GIS can be effectively used to predict the shape of a channel. This information will benefit other hydrology and flood research projects because it reduces the amount of time spent doing field work.

Technical Abstract: Technical issues and time constraints have historically made it prohibitive to complete geomorphologic analysis on relatively large and complex study areas. This paper will present the results of a study that utilized a GIS to investigate watershed and channel morphologic relationships on the USDA-ARS Walnut Gulch Experimental Watershed near Tombstone, Arizona. The goal of this study was to derive predictive relationships of stream channe characteristics using a high-resolution ARC/INFO GIS (ARC) database (1). Over two hundred channel cross-sections were surveyed within the boundaries of the watershed, and a suite of ARC AMLs were developed to analyze each of the subwatersheds contributing runoff to the sample points. Each of these subwatersheds were characterized based on information extracted from the GIS, including such variables as watershed area, stream order, flow length, and slope. Regression analysis was used to develop relationships between the channel characteristics (average width, depth, and cross-sectional area) and watershed variables, yielding highly significant relationships. These results indicate that the procedures used in this study could greatly improve our understanding of geomorphologic processes, as well as provide tools to assist in the parameterization of hydrologic models.