Theory 80/Measurement & modelling/Water quality sampling
Sampling Is Grabs Against Variability
The claim
The confidence of a water quality estimate is set by the ratio of grab sample count to concentration variability, so a few samples of a variable analyte say almost nothing.
01Mechanism
Estimation error depends on both; the ratio sets the standard error.
02Prediction
Confidence should track the ratio.
03Refutation
Confidence tracking sample count would remove variability.