Regional regression models of watershed suspended-sediment discharge for the eastern United States

0022-1694/$ see front matter 2012 Elsevier B.V. A http://dx.doi.org/10.1016/j.jhydrol.2012.09.011 ⇑ Corresponding author. Tel.: +1 617 627 4260; fax E-mail addresses: [email protected] (D.C. Ro du (R.M. Vogel), [email protected] (G.E. Schwarz). 1 Present address: Geosyntec Consultants, 1330 Beaco MA 02446, United States. Estimates of mean annual watershed sediment discharge, derived from long-term measurements of suspended-sediment concentration and streamflow, often are not available at locations of interest. The goal of this study was to develop multivariate regression models to enable prediction of mean annual suspended-sediment discharge from available basin characteristics useful for most ungaged river locations in the eastern United States. The models are based on long-term mean sediment discharge estimates and explanatory variables obtained from a combined dataset of 1201 US Geological Survey (USGS) stations derived from a SPAtially Referenced Regression on Watershed attributes (SPARROW) study and the Geospatial Attributes of Gages for Evaluating Streamflow (GAGES) database. The resulting regional regression models summarized for major US water resources regions 1–8, exhibited prediction R values ranging from 76.9% to 92.7% and corresponding average model prediction errors ranging from 56.5% to 124.3%. Results from cross-validation experiments suggest that a majority of the models will perform similarly to calibration runs. The 36-parameter regional regression models also outperformed a 16-parameter national SPARROW model of suspended-sediment discharge and indicate that mean annual sediment loads in the eastern United States generally correlates with a combination of basin area, land use patterns, seasonal precipitation, soil composition, hydrologic modification, and to a lesser extent, topography. 2012 Elsevier B.V. All rights reserved.