Model archive for suspended sediment regression models in rloadest to estimate suspended sediment concentration and loads for the Snake River at Weiser, Idaho, 1977-2022

Regression models for estimating suspended sediment concentration (SSC) and loads were developed using the R package rloadest for U.S. Geological Survey streamgage Snake River at Weiser, Idaho (13269000). Samples for suspended sediment concentration were collected in two periods: the historical (1977-2003) and modern (2017-22) periods. Data and metadata for all samples collected at this streamgage were obtained. Streamflow data were obtained from the U.S. Geological Survey (USGS) National Water Information System database and data for suspended sediment samples were obtained from the National Water Quality Monitoring Council's Water Quality Portal. Then rloadest was used to develop regression models to estimate SSC for the historical and modern periods, and the entire period of record. Model development considered the influence of Snake River discharge and discharge of six tributaries upstream of the Snake at Weiser streamgage. Streaflow data for tributaries were obtained from the USGS National Water Information System and the Idaho Power WebPortal. Regression models were developed for total SSC and the fine (<0.0625 millimeters) and sand (0.0625-2 millimeters) fractions of suspended sediment. Models were used to estimate daily mean SSC for the historical and modern periods and daily and monthly loads for the modern period. Additionally, estimates of total SSC and load for the modern period were compared to estimates from an acoustic surrogate model for SSC previously developed for the Snake at Weiser site for the modern period.