Multivariate Models of Watershed Suspended Sediment Loads for the Eastern United States

Аннотация

Estimates of mean annual watershed sediment load, derived from measurements of suspended sediment concentration and streamflow, are often not available at locations of interest. The goal of this study was to develop multivariate regression models of mean annual suspended sediment loads useful for most ungaged locations in the Eastern United States to enable prediction of sediment loads from basin characteristics. The analysis is based on long-term mean sediment load estimates and explanatory variables obtained from a combined dataset of 1,201 USGS stations obtained from a SPARROW study and the GAGES database. The resulting regional regression models, summarized for major U.S. water resources regions 1 through 8, and estimated in logarithmic space, exhibited prediction R2 values ranging from 76.9% to 92.7%. Results from cross-validation experiments suggest that a majority of the models will perform well in practice. The regional models outperformed a national SPARROW model of suspended sediment load based on larger regional Nash Sutcliffe Efficiency values. The results indicate that mean annual sediment loads in the Eastern United States are generally influenced by a combination of basin area, land use patterns, seasonal precipitation, soil composition, hydrologic modification, and to a lesser extent, topography.