Regression Models for Estimating Sediment and Nutrient Concentrations and Loads at the Iroquois River near Foresman, Indiana, March 2015 through July 2018

Scientific Investigations Report 2019-5087
Prepared in cooperation with the Iroquois River Conservancy District
By: , and 

Links

  • Document: Report (855 kB pdf)
  • Data Releases:
    • USGS data release – Suspended sediment, total nitrogen, and total phosphorus loads for Iroquois River near Foresman, Indiana, April 2015 to July 2018
    • USGS data release – Data and regression model for suspended sediment for Iroquois River near Foresman, Indiana, March 20, 2015, to July 19, 2018
    • USGS data release – Data and regression models for total nitrogen and total phosphorus for the Iroquois River near Foresman, Indiana, March 20, 2015, to July 19, 2018
  • Download citation as: RIS | Dublin Core

Abstract

In 2015, the U.S. Geological Survey, in cooperation with the Iroquois River Conservancy District, deployed continuous water-quality monitors and began collecting representative discrete water-quality samples at the Iroquois River near Foresman, Indiana, streamflow-gaging station (U.S. Geological Survey station 05524500). By relating continuously monitored water-quality data and discrete water-quality samples collected from April 2015 through July 2018, regression models that estimate concentrations of suspended sediment, total nitrogen, and total phosphorus were developed. Developed regression models indicated a strong correlation between turbidity and streamflow with suspended-sediment concentration (adjusted coefficient of determination equals 0.84, predicted residual error sum of squares equals 0.493), nitrate plus nitrite and streamflow with total nitrogen (adjusted coefficient of determination equals 0.99, predicted residual error sum of squares equals 0.0202), and specific conductance and turbidity with total phosphorus (adjusted coefficient of determination equals 0.84, predicted residual error sum of squares equals 0.0935).

Daily loads of suspended sediment, total nitrogen, and total phosphorus were computed as the product of daily mean regression model concentrations and daily mean streamflow. During periods when regression model concentrations could not be computed, rloadest models, the R programming language version of the LOADEST FORTRAN program, were used to compute daily loads of each constituent. For 2016 and 2017, the estimated annual suspended-sediment loads were 25,000 and 32,100 tons; estimated total nitrogen loads were 4,260 and 5,780 tons; and estimated total phosphorus loads were 104 and 128 tons, respectively.

Suggested Citation

Lathrop, T.R., Bunch, A.R., Downhour, M.S., and Perkins, D.M., 2019, Regression models for estimating sediment and nutrient concentrations and loads at the Iroquois River near Foresman, Indiana, March 2015 through July 2018: U.S. Geological Survey Scientific Investigation Report 2019–5087, 14 p., https://doi.org/10.3133/sir20195087.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Purpose and Scope
  • Study Area
  • Approach and Methods
  • Results of Data Collection—Discrete and Continuous Water-Quality Data
  • Regression Models
  • Constituent Load Models
  • Limitations
  • Summary
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Regression models for estimating sediment and nutrient concentrations and loads at the Iroquois River near Foresman, Indiana, March 2015 through July 2018
Series title Scientific Investigations Report
Series number 2019-5087
DOI 10.3133/sir20195087
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Indiana Water Science Center, Ohio-Kentucky-Indiana Water Science Center
Description Report: vi, 14 p.; Data Releases
Country United States
State Indiana
County Newton County
City Foresman