HR: 17:15h
AN: H44B-06    [Abstracts]
TI: Regional Variation in Landscape Controls on the Width of Wadeable Streams Across the Conterminous United States
AU: * Faustini, J M
EM: john.faustini@oregonstate.edu
AF: Dept. of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331, United States
AU: Herlihy, A T
EM: alan.herlihy@oregonstate.edu
AF: Dept. of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331, United States
AU: Kaufmann, P R
EM: kaufmann.phil@epa.gov
AF: U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, United States
AB: We examine regional variations in landscape controls on the width of wadeable streams across the conterminous United States using a unique dataset from the U.S. Environmental Protection Agency's (USEPA) Wadeable Streams Assessment (WSA). The WSA dataset includes a probability sample of over 1,300 randomly selected stream reaches (drawn from the 1:100,000 scale USGS digitized stream network) and over 500 hand- picked reference sites covering 48 states sampled between 2000 and 2004. The scaling of bankfull stream width with drainage area varies significantly among the nine ecological regions (ecoregions) defined for the WSA: width increases more rapidly with basin area in the humid Eastern Highlands (encompassing the Northern and Southern Appalachians and the Ozark Mountains) and the Upper Midwest (Great Lakes region) than for the West (both mountainous and xeric areas), the southeastern Coastal Plain, and the Northern Plains (the Dakotas and Montana). Stream width increases least rapidly with basin area in the Temperate Plains (cornbelt) and Southern Plains (Great Prairies) in the heartland. Besides basin area, key predictors of channel width included particle size and precipitation, although the relative importance of these factors varies among ecoregions. Precipitation was only significant (p < 0.01) as a predictor of bankfull width in the Western Mountains, the cornbelt, and to a lesser degree the Great Prairies. Width was significantly positively related to bed material size (p < 0.01) in the mountainous and xeric West, the cornbelt, and the Southern Appalachians, but was only weakly related or unrelated elsewhere. Preliminary analysis suggests that riparian vegetation cover is an important predictor of channel width only in the Northern Plains and Great Lakes regions, and that width does not seem to be related to measures of woody debris abundance in any region.
DE: 1804 Catchment
DE: 1825 Geomorphology: fluvial (1625)
DE: 1839 Hydrologic scaling
DE: 1856 River channels (0483, 0744)
SC: Hydrology [H]
MN: 2007 Fall Meeting