Continuous monitoring of sediment and nutrients in the Illinois River at Florence, Illinois, 2012-13

Scientific Investigations Report 2015-5040
Prepared in cooperation with the Illinois Environmental Protection Agency
By: , and 

Links

Abstract

The Illinois River is the largest river in Illinois and is the primary contributing watershed for nitrogen, phosphorus, and suspended-sediment loading to the upper Mississippi River from Illinois. In addition to streamflow, the following water-quality constituents were monitored at the Illinois River at Florence, Illinois (U.S. Geological Survey station number 05586300), during May 2012–October 2013: phosphate, nitrate, turbidity, temperature, specific conductance, pH, and dissolved oxygen. The objectives of this monitoring were to (1) determine performance capabilities of the in-situ instruments; (2) collect continuous data that would provide an improved understanding of constituent characteristics during normal, low-, and high-flow periods and during different climatic and land-use seasons; (3) evaluate the ability to use continuous turbidity as a surrogate constituent to determine suspended-sediment concentrations; and (4) evaluate the ability to develop a regression model for total phosphorus using phosphate, turbidity, and other measured parameters. Reliable data collection was achieved, following some initial periods of instrument and data-communication difficulties. The resulting regression models for suspended sediment had coefficient of determination (R2) values of about 0.9. Nitrate plus nitrite loads computed using continuous data were found to be approximately 8 percent larger than loads computed using traditional discrete-sampling based models. A regression model for total phosphorus was developed by using historic orthophosphate data (important during periods of low flow and low concentrations) and historic suspended-sediment data (important during periods of high flow and higher concentrations). The R2of the total phosphorus regression model using orthophosphorus and suspended sediment was 0.8. Data collection and refinement of the regression models is ongoing.

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Continuous monitoring of sediment and nutrients in the Illinois River at Florence, Illinois, 2012-13
Series title Scientific Investigations Report
Series number 2015-5040
DOI 10.3133/sir20155040
Year Published 2015
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Illinois Water Science Center
Description vii, 61 p.
Time Range Start 2012-05-01
Time Range End 2013-10-31
Country United States
State Illinois
City Florence
Other Geospatial Illinois River
Projection Albers Equal-Area Conic projection
Online Only (Y/N) Y
Additional Online Files (Y/N) N