National and regional comparisons between Strahler order and stream size

Abstract

AbstractWater-body size is one of the most important factors affecting the structure and function of aquatic ecosystems. The categorical variable, Strahler stream order, is commonly used as a surrogate for stream size, perhaps because stream size is a multidimensional attribute that defies simple definition. Some stream-size attributes, including continuous variables, such as catchment area, distance to source, and model estimates of discharge also are available as geographic information system (GIS)-derived or modeled variables. These GIS measures are commonly used by stream ecologists along with field-derived attributes, such as discharge, stream cross-sectional area, width, and depth, which are more direct measures of stream size as experienced by aquatic organisms. Our objective was to quantify how well some commonly used stream-size attributes are predicted from Strahler order in the US as a whole and within major ecoregions and hydrologic landscape regions. We based our analysis on field-channel-sur...