Kansas Real-Time Water Quality

Kansas Real-Time Water Quality

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USGS station:	Go to NWISWeb
Constituent:
Time period:
Model Form:

Model Form #3

log₁₀(TNR) = - 0.154 + 0.281 log₁₀(TURB) - 0.184 log₁₀(Chls) + 0.0716 sin(2π D / 365) + 0.00669 cos(2π D / 365)

where:

TNR is computed total nitrogen, in milligrams per liter as nitrogen
TURB is turbidity, YSI EXO, in formazin nephelometric units
Chls is chlorophylls, in relative fluorescence units
D is day of year, in the range of integers 1 through 365

Model Calibration

Basic Data

Number of measurements:	74
Mean squared error:	0.00703921
Multiple R²:	0.814
Bias correction (smearing) factor:	1.02

Explanatory Variables

Variable	Value	Standard error
Intercept	-0.154	0.0472
log₁₀(TURB)	0.281	0.0238
log₁₀(Chls)	-0.184	0.0301
sin(2π D / 365)	0.0716	0.0141
cos(2π D / 365)	0.00669	0.0162

Correlation Matrix

	Intercept	log₁₀(TURB)	log₁₀(Chls)	sin(2π D / 365)	cos(2π D / 365)
Intercept	1	-0.956	-0.522	-0.0834	-0.402
log₁₀(TURB)	-0.956	1	0.352	0.0858	0.463
log₁₀(Chls)	-0.522	0.352	1	0.173	0.211
sin(2π D / 365)	-0.0834	0.0858	0.173	1	0.0822
cos(2π D / 365)	-0.402	0.463	0.211	0.0822	1

Reference

Williams, T.J., 2021, Linear Regression Model Documentation and Updates for Computing Water-Quality Constituent Concentrations or Densities using Continuous Real-Time Water-Quality Data for the Kansas River, Kansas, July 2012 through September 2019: U.S. Geological Survey Open-File Report 2021-1018, 18 p.