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) =
- 10.985 + 1.8861 ln(SC)
+ 0.2214 sin(2π D / 365)
- 0.0909 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: | 10 |
|---|---|
| Mean squared error: | 0.01435204 |
| Multiple R2: | 0.930232 |
| Bias correction (smearing) factor: | 1.004 |
Explanatory Variables
| Variable | Value | Standard error |
|---|---|---|
| Intercept | -10.985 | 1.4854 | ln(SC) | 1.8861 | 0.2098 | sin(2π D / 365) | 0.2214 | 0.0804 | cos(2π D / 365) | -0.0909 | 0.0612 |
Correlation Matrix
| Intercept | ln(SC) | sin(2π D / 365) | cos(2π D / 365) | |
|---|---|---|---|---|
| Intercept | 1 | -0.9997 | -0.7385 | 0.4494 |
| ln(SC) | -0.9997 | 1 | 0.7397 | -0.4438 |
| sin(2π D / 365) | -0.7385 | 0.7397 | 1 | -0.3114 |
| cos(2π D / 365) | 0.4494 | -0.4438 | -0.3114 | 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.