Random forest models to estimate bankfull and low flow channel widths and depths across the conterminous United States

Abstract

Channel dimensions (width and depth) at varying flows influence a host of instream ecological processes, as well as habitat and biotic features; they are a major consideration in stream habitat restoration and instream flow assessments. Models of widths and depths are often used to assess climate change vulnerability, develop endangered species recovery plans, and model water quality. However, development and application of such models require specific skillsets and resources. To facilitate acquisition of such estimates, we created a dataset of modeled channel dimensions for perennial stream segments across the conterminous United States. We used random forest models to predict wetted width, thalweg depth, bankfull width, and bankfull depth from several thousand field measurements of the National Rivers and Streams Assessment. Observed channel widths varied from <5 to >2000 m and depths varied from <2 to >125 m. Metrics of watershed area, runoff, slope, land use, and more were used as model predictors. The models had high pseudo R2 values (0.70–0.91) and median absolute errors within ±6% to ±21% of the interquartile range of measured values across 10 stream orders. Predicted channel dimensions can be joined to 1.1 million stream segments of the 1:100 K resolution National Hydrography Dataset Plus (version 2.1). These predictions, combined with a rapidly growing body of nationally available data, will further enhance our ability to study and protect aquatic resources.

finsyncR, an R package to synchronize 27 years of fish and invertebrate data across the United States

“…In addition, the package provides Strahler stream order 18 and wetted width as measures of stream size. Measured wetted width is only available for EPA data, so the package also provides predicted wetted width data gathered from StreamCat 19 originally from Doyle et al ( 2023) 20 . Finally, because of known ecoregional differences in species pools and sampling designs, the package provides NARS aggregated Omernick level III ecoregions for each site 21 .…”