Table 2
Mathematical formulations of the objective functions and evaluation index
| Objective function | Mathematical formulation | Range of values | Reference |
|---|---|---|---|
| NSE |  |  | Nash & Sutcliffe (1970) |
| lnNSE |  |  | Kim & Lee (2014) |
| Objective function | Mathematical formulation | Range of values | Reference |
|---|---|---|---|
| NSE | | | Nash & Sutcliffe (1970) |
| lnNSE | | | Kim & Lee (2014) |
Note: Oi is the observed discharge at time step i; Si is the simulated discharge; Ō is the mean observed discharge over the entire simulation period of length N; 
is the mean simulated discharge over the entire simulation period of length N.