Kansas Real-Time Water Quality

Kansas Real-Time Water Quality

NRTWQ Home >> Kansas >> View Data >> 07144100

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

Model Form #1

log₁₀(ATR) = 0.237 - 0.7452 cos(2π D / 365) + 0.5043 sin(2π D / 365) - 0.000647 SC

where:

ATR is computed atrazine, in micrograms per liter
D is day of year, in the range of integers 1 through 365
SC is specific conductance at 25 degrees Celsius, in microsiemens per centimeter

Model Archive Summary

The model archive summary for computed atrazine can be viewed in pdf form here.

Model Calibration

Basic Data

Number of measurements:	205
Mean squared error:	0.18395521
Multiple R²:	0.6038
Bias correction (smearing) factor:	1.44198

Explanatory Variables

Variable	Value	Standard error
Intercept	0.237	0.0868
cos(2π D / 365)	-0.7452	0.0681
sin(2π D / 365)	0.5043	0.0462
SC	-0.000647	0.0001

Correlation Matrix

	Intercept	cos(2π D / 365)	sin(2π D / 365)	SC
Intercept	1	0.6239	0.0963	-0.8259
cos(2π D / 365)	0.6239	1	0.072	-0.2386
sin(2π D / 365)	0.0963	0.072	1	-0.1922
SC	-0.8259	-0.2386	-0.1922	1

Reference

Christensen, V.G., Ziegler, A.C., Rasmussen, P.P., and Jian, Xiaodong, 2003, Continuous Real-Time Water-Quality Monitoring of Kansas Streams, in Proceedings of 2003 Spring Specialty Conference on Agricultural Hydrology and Water Quality, May 12-14, 2003, Kansas City, Missouri: Middleburg, Virginia, American Water Resources Association, AWRA Technical Publication Series No. TPS-03-1, compact disc.

Notes

Old model used through 2006.