A cross-scale comparison of drainage basin characteristics derived from digital elevation models

The feasibility of using small-scale digital elevation models (DEMs) to ext ract various drainage basin characteristics was evaluated by comparing basi n parameters derived from the 1:250 000 DEMs with those from the 1:24 000 D EMs. Twenty basins ranging approximately from 150 km(2) to 1000 km(2) in We st Virginia, a geologically complex region, were examined in this study. Th e basin parameters examined included those commonly used in hydrology and g eomorphology such as elevation, slope, stream length, drainage density, rel ief ratio and ruggedness number. Our results suggested that the 1:250 000 D EMs can provide accurate estimates for elevation-based and stream-length-ba sed basin parameters, but not for slope-based parameters. After examining t he differences between the DEM-derived basin parameters from the two differ ent scales, we found that the performance of the 1:250 000 DEMs was not sig nificantly influenced by basin size, while terrain complexity seems to be a n important factor of accuracy of the estimated basin parameters. Copyright (C) 1999 John Wiley & Sons, Ltd.