Estimating Channel Morphologic Properties from a High Resolution DEM

Channel morphology plays a critical role in the understanding and interpretation of the hydrologic and geomorphic characteristics of an area. Traditional techniques for determining channel width, depth, and cross-section area are time consuming and may not be truly representative of the spatial variability within a watershed. A method for extracting channel morphologic properties from a high resolution digital elevation model (DEM) is presented. Interferometric synthetic aperture radar data was used to build a high resolution digital elevation model for the USDA-ARS Walnut Gulch Experimental Watershed. While a fully automated technique proved elusive, a quasi-automated system using a geographic information system and expert opinion was successful in estimating channel shape properties. This integrated technique was not as effective in estimating channel depth, but estimated values of channel width were highly correlated with field observations.