(Goodness of fit)
5 statistical measures listed below are adopted to determine the calibration results.
| Residual Bias | Mean Absolute Error (MAE) | Relative Root Mean Square Error (RRMSE) | Coefficient of Efficiency (EF) | Coefficient of Determination (CD) | |
| Equation |
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| Unit | Same as O & P | Same as O & P | Dimensionless | Dimensionless | Dimensionless |
| Optimal Value | 0 | 0 | 0 | 1 | 1 |
| Range | Any | > 0 | > 0 | -infinity < EF < 1 | 0 < CD < infinity |
| Remarks | Measures the bias of prediction (P). | Not relative measure, only suitable for one calibration objective. | A measure of the overall spread with respect to the mean value. | Nash & Stucliffe (1970), measure the
spread difference between the observation and prediction and the variance
of observation. (Goodness of fit) |
Measure the scatter of the predicted and observed values around the mean of observation. (Peak) |