At this site, real-time estimates of water quality depend on the availability of instantaneous discharge and specific conductivity measurements. During winter months, real-time water quality estimates may not be available for this site due to effects of ice.
Model Form #1
ln(Se) =
- 7.868 + 1.4053 ln(SC)
+ 0.0418 sin(2π D / 365)
+ 0.1408 cos(2π D / 365)
where:
- Se is computed selenium, in micrograms per liter
- SC is specific conductance at 25 degrees Celsius, in microsiemens per centimeter
- D is day of year, in the range of integers 1 through 365
Model Calibration
Basic Data
| Number of measurements: | 16 |
|---|---|
| Mean squared error: | 0.01734489 |
| Multiple R2: | 0.909488 |
| Bias correction (smearing) factor: | 1.006 |
Explanatory Variables
| Variable | Value | Standard error |
|---|---|---|
| Intercept | -7.868 | 1.2724 | ln(SC) | 1.4053 | 0.192 | sin(2π D / 365) | 0.0418 | 0.066 | cos(2π D / 365) | 0.1408 | 0.0619 |
Correlation Matrix
| Intercept | ln(SC) | sin(2π D / 365) | cos(2π D / 365) | |
|---|---|---|---|---|
| Intercept | 1 | -0.9996 | -0.7375 | 0.5787 |
| ln(SC) | -0.9996 | 1 | 0.7351 | -0.575 |
| sin(2π D / 365) | -0.7375 | 0.7351 | 1 | -0.4884 |
| cos(2π D / 365) | 0.5787 | -0.575 | -0.4884 | 1 |
Reference
- Linard, J.I., Schaffrath, K.R., 2014, Regression models for estimating salinity and selenium concentrations at selected sites in the upper Colorado River Basin, Colorado: 2009 - 2012 (in publication process): U.S. Geological Survey Open File Report 2014-1015, 28 p.