Freshwater Creek, California...Annual and Storm Analysis, Turbidity Threshold Sampling (TTS) | ![]() Oncorhynchus Kisutch |
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Data analysis began by appending each data dump taken over the course of the 2000 hydrologic year. Appending was completed using a processing program called TTS_MAIN_PRO written by R. Field and J. Fisher, employees at Redwood Sciences Laboratory (RSL). TTS_MAIN_PRO allows the user to plot the raw stage data and allows the user to adjust the stage data based on observations recorded by personnel in the field. |
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DIS DATA
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The plot shown here is the linear regression fit to the 2000 DIS data set using EXCEL. From the slope of this regression (1.01) one can infer nice agreement with point samples taken by the ISCO and depth integrated samples taken by field personnel. The variance from this linear regression model is likely attributed to the level of precision in the laboratory work. ![]() DIS Linear Regression |
A paired f-test was used to test whether we could reject the model DI = PS; a linear model with slope of one and intercept of zero (Note: DI - Depth Integrated and PS - Point Sample). The outcome of the test was that we could not reject the DI = PS model. What this boils down to is that the annual load predicted from point samples were not adjusted for the entire cross section. More DIS data will narrow the range in confidence of both the slope and the intercept. Perhaps next year ISCO concentrations may heve to be adjusted to account for a greater sediment concentration across the whole cross section due to more confidence in the intercept of the linear regression model.
![]() Annual Load Without Bottle Numbers |
![]() Annual Load With Bottle Numbers |
This first plot shows the complete data set for hydrologic year 2000. Sample bottles show up as solid dots on the sedigraph. On the sedigraph the left scale is suspended sediment concentration (mg/L) and the right scale is turbidity (NTU). The bottom section of the plot is the hydrograph where the left scale is discharge (m3/s) and the right scale is stage (ft). The load presented on this graph is based on the linear regression model shown below. |
Here we have the same plot as that on the left, only the sample bottles are actual sample bottle numbers within a given dump (refer to codes page). |
![]() Linear, Polynomial, and Cubic Fits to Data Set | ![]() Linear, Polynomial, and Cubic Fits to Data Set |
![]() Linear and LOESS Fits to Data Set |
![]() Linear and LOESS Fits to Data Set |
The plot above shows the linear regression model along with the quadratic and cubic polynomial fits to the 2000 data set. You'll note that the cubic and quadratic fits plot virtually on top of each other. Though they fit slightly better on the lower end, they tend to overestimate the peak concentrations, and thusly are less desirable as compared with the linear model. | Here we show the linear, quadratic, and
cubic fits on a finer scale (Turbidity Range:0-150 NTU, Suspended Sediment Range:0-250 mg/L). |
This plot shows both the linear and LOESS smooth models. Just as we found last year, the LOESS smooth model is superior at fitting the high end of the turbidity-suspended sediment relationship. The linear model slightly under predicts the peak samples. | Above we show the linear
model against the LOESS smooth model on a finer scale. Again the LOESS
model tends to follow the general trend of the data more closely than the
linear model at this range. Though there is a lot of scatter in the data
at this scale, one can make out a definite curve-like trend in the data
set. (Turbidity Range:0-150, Suspended Sediment Range:0-250) |
Linear Regression Stats
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Quadratic Regression
Stats
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Cubic Regression Stats
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LOESS Regression Stats
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DESCRIPTOR | LINEAR | LOESS |
---|---|---|
NUMBER OF OBSERVATIONS | 213 | 213 |
R-SQUARED | 0.96 | 0.97 |
RESIDUAL STANDARD ERROR | 89.4 | 82.6 |
PREDICTED LOAD (kg) | 4554629 | 4479326 |
PREDICTED LOAD (kg/ha) | 1322 | 1300 |
PREDICTED LOAD (ton/mi2) | 378 | 372 |
STORM | START DATE |
END DATE |
LOAD ESTIMATE (kg) |
NUMBER OF SAMPLES |
PEAK STAGE (ft)* |
PEAK TURBIDITY (NTU)* |
---|---|---|---|---|---|---|
1 | 11/29/99 1630 | 12/01/99 0800 | 101274 | 6 | 2.152 | 500 |
2 | 01/10/00 1200 | 01/12/00 2300 | 1311497 | 25 | 4.693 | 696 |
3 | 01/13/00 1000 | 01/15/00 1800 | 1061939 | 14 | 4.622 | 583 |
4 | 01/15/00 2130 | 01/17/00 0000 | 182757 | 8 | 2.872 | 331 |
5 | 02/14/00 0000 | 02/15/00 1330 | 1020729 | 40 | 4.404 | 628 |
6 | 02/26/00 1700 | 03/02/00 0000 | 323404 | 16 | 2.783 | 263 |
![]() Suspended Sediment Scale: 0-2500mg/L | ![]() Suspended Sediment Scale: 0-650mg/L |
![]() Suspended Sediment Scale: 0-250mg/L |
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