Statistical criterion

Value

Classification of performance

Reference

Nash-Sutcliffe coefficient

0.75 < NSE ≤ 1.00

0.65 < NSE ≤ 0.75

0.50 < NSE ≤ 0.65

0.4 < NSE ≤ 0.50

NSE ≤ 0.4

0.4 ≤ NSE ≤ 0.70

Very good

Good

Satisfactory

Acceptable

Unsatisfactory

Acceptable

[34] [41]

Percent bias

PBIAS < ±10

±10 ≤ PBIAS < ±15

±15 ≤ PBIAS < ±25

PBIAS ≥ ±25

Very good

Good

Satisfactory

Unsatisfactory

[41]

Root mean square error

Value below half the standard deviation

Satisfactory

[45]

Ratio of the RMSE to the standard deviation of the observations

0.00 ≤ RSR ≤ 0.50

0.50 < RSR ≤ 0.60

0.60 < RSR ≤ 0.70

RSR > 0.70

Very good

Good

Satisfactory

Unsatisfactory

[41]