Date of Award
Master of Science
Gregory Nathaniel Taff
Landscape and geomorphic characteristics within watersheds in the North and South Umpqua Basins in Southwestern Oregon were summarized at five spatial scales (basin, sub-basin, network, sub-network, and segment) and incorporated into multiple regression models to determine the relative effects of each on stream morphology and provide a potential predictive model of stream habitat characteristics using GIS-managed landscape variables. Measures of stream morphology included mean stream depth, mean corrected width, width-to-depth ratio, percent shade provided to habitat units, and substrate composition, summarized for 200 stream segments. While certain variables were demonstrated to have a consistent influence across more than one scale, the scale-dependency of other relationships between landscape and stream characteristics was revealed between the vegetation, lithology, and geomorphology and measures of stream morphology. Stream dimensions were most sensitive to variability in the size of analytical unit (drainage basin/sub-basin or riparian buffer) and the relative presence or absence of vegetation as represented by the percentage area of each analysis unit encompassed by open and semi-closed canopy cover. Stream substrate material composition was related most strongly to drainage density, topographic complexity, and steepness of land within each analysis unit. Such methods proved helpful in determining to what degree and at which scale the included landscape variables operated.
Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Sanderson, Andrew M., "Multi-Scale Analysis of Landscape and Geomorphic Controls on Stream Habitat Structure" (2010). Electronic Theses and Dissertations. 32.