Notice:Due to a lapse in appropriations, the majority of USGS websites may not be up to date and may not reflect current conditions. Websites displaying real-time data, such as Earthquake, Volcano, LANDSAT and Water information needed for public health and safety will be updated with limited support. Additionally, USGS will not be able to respond to inquiries until appropriations are enacted. For more information, please see www.doi.gov/shutdown.
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.
