Regional channel geometry equations: a statistical comparison for physiographic provinces in the eastern US

Abstract

AbstractRegional stream channel equations are created to solve for a specified discharge or channel dimensions as a function of drainage area. In recent years, regional equations have been developed by the US Geological Survey (USGS) and US Fish and Wildlife Service (USFW), as well as various state agencies for use in the preliminary design of stable channels. The regional equations are created using measured stable channel dimensions. Physiographic provinces have been used as boundaries for the development of these equations due to the perceived roles of climate, geology and physiography in shaping channels. Data collection within each physiographic province has typically been confined to a study area which encompasses parts of one or more states, but not the whole physiographic province. Thus, the use of the equations is restricted to the physiographic province(s) and the state(s) for which they have been developed. The purpose of this study was to determine whether the regional equations are statistically different within a single physiographic province and different between physiographic provinces. The results of the statistical analyses of the regional equations and their associated data showed that the majority of the equations are similar within their respective physiographic provinces. Testing between provinces showed that the Appalachian Plateau, New England and Valley and Ridge provinces have statistically similar equations. Based on the evidence presented in this study, separating regional equations by physiographic regional boundaries is valid. New equations for those data that showed statistical similarity were developed. Copyright © 2008 John Wiley & Sons, Ltd.