This model archive summary documents the sediment acoustic index model for suspended-sediment concentration developed to compute 15-minute suspended sediment concentration for the U.S. Geological Survey (USGS) station, San Juan River near Bluff, UT (USGS ID: 09379500) from May 2, 2018, onward. This is the first model developed for the site to compute continuous suspended sediment concentration. The methods used follow USGS guidance as referenced in relevant Technical Memoranda and USGS Techniques and Methods, book 3, chap. C5 (TM3-C5, Landers and others, 2016).

Model archive summary describing the development of an acoustic derived suspended sediment time series computation model. The model archive summary describes the methods and techniques used to develop the model for the Willamette River at Portland site – USGS site ID# 14211720. The time series suspended sediment data will help determine the suspended sediment concentration at the site in real-time enabling science entities, managers, and others, track the movement of sediment in the Lower Columbia River System.

Model archive summary (MAS), "381410121395801_MIR_ExpandedMAS.docx", describing the development of a continuous 15-minute suspended-sediment concentration (SSC) time series regression model for the site: Miner Slough near Rio Vista (U.S. Geological Survey (USGS) site # 381410121395801). The SSC time series is computed from instream turbidity data that is managed by the California Department of Water Resources (CDWR) using a YSI 6-series multi-parameter water quality sonde. Complete methods for turbidity data collection are described in the attached methods document.

Model archive summary (MAS) describing the development of a continuous 15-minute suspended-sediment concentration (SSC) time series regression model for the Mokulemne River at Andrus Island near Terminous, CA (USGS site # 11336930). The SSC time series is computed from instream turbidity data that is managed by the California Department of Water Resources (CDWR) using a YSI 6-series multi-parameter water quality sonde.

This model archive summary (MAS), "11455420_RVB_ExpandedMAS.docx", describes the development of a continuous 15-minute suspended-sediment concentration (SSC) time series regression model for the site: Sacramento River at Rio Vista, California (U.S. Geological Survey (USGS) site # 11455420). The SSC time series is computed from instream turbidity data that is managed by the California Department of Water Resources (CDWR) using a YSI EXO multi-parameter water quality sonde. Complete methods for turbidity data collection are described in the MAS.

Model archive summary (MAS) describing the development of a continuous 15-minute suspended-sediment concentration (SSC) time series regression model for the site: Grant Line Canal near Tracy, California (USGS site # 11313240). The SSC time series is computed from instream turbidity data that is managed by the California Department of Water Resources (CDWR) using a YSI 6-series multi-parameter water quality sonde.

This Model Archive Summary (MAS) describes the development of a turbidity derived suspended-sediment concentration (SSC) time-series computation model. The MAS includes all the methods and techniques used to develop the model for USGS station 11455420 Sacramento River at Rio Vista, Ca. The time-series suspended-sediment concentration data are representative of the cross section and are adequate to compute suspended-sediment flux, to help managers and others to track the movement of sediment in the Sacramento-San-Joaquin Delta and to better understand habitat dynamics.

A series of linear regression models were developed and calibrated for the Minnesota and Mississippi Rivers. The linear regression models were calibrated using acoustic and suspended-sediment concentration data collected from March through November 2016 and 2017. The estimates of suspended-sediment concentrations from the simple linear regression were used to calculate loads. The calibrated models were used to improve understanding of sediment transport processes and increase accuracy of estimating sediment concentrations and loads for the Lower Minnesota River, the Mississippi River, and Lake Pepin.

These model archive summaries document surrogate regression models developed to estimate suspended-sediment concentration (SSC) at three USGS streamgages in New York: Mohawk River above State Highway 30A at Fonda, USGS site number 01349527; Schoharie Creek at Burtonsville, USGS site number 01351500; and Mohawk River at Cohoes, USGS site number 01357500. Ordinary least squares regression equations were developed between suspended-sediment concentration and turbidity using the U.S. Geological Survey Surrogate Analysis and Index Developer (SAID) Tool (Domanski and others, 2015) and methods described in Rasmussen and others (2009). Model summaries were developed following guidance in USGS Office of Surface Water Technical Memorandum (TM) 2016.07, Office of Water Quality TM 2016.10.

Datasets of suspended sediment concentration and percent fines, sampling information, and daily streamflow data were compiled and harmonized for 16 sites to better understand sediment transport and delivery in the Lower Mississippi and Atchafalaya Rivers. The compiled data were harmonized by removing unnecessary columns, screening data for laboratory or sampling issues, creating consistent entries for character columns, and dropping irrelevant data, among other steps. Fourteen of the sites are in the Lower Mississippi-Atchafalaya River Basin with two additional sites on the Middle Mississippi and Ohio Rivers. Suspended sediment concentration (total, all size fractions) and percent fines for multiple size fractions were retrieved from the U.S. Geological Survey (USGS) National Water Information System (NWIS) database. These data were matched to related sampling information, such as sampler type and sampling method, also retrieved from NWIS. Continuous daily streamflow was compiled (or estimated where missing) for all sites and these data were from NWIS and the U.S. Army Corps of Engineers (USACE). Daily streamflow records extend as far back as possible and contain no gaps, whereas suspended sediment data and sampling information were measured and reported periodically and may contain multiyear gaps depending on the site. Note, siteIndex is used as the main sediment site identifier since sediment records from more than one USGS site are combined for at least one siteIndex. Additionally, gageIndex is used as the main streamgage identifier since streamflow records from multiple streamgages are sometimes combined for a single gageIndex and a single gageIndex may be used for more than one siteIndex. See the siteTable.csv for linkages between siteIndex, gageIndex, and USGS and USACE site/streamgage numbers.