Climate Change and Its Impacts on Streamflow: WRF and SCE-Optimized SWAT Models - Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications - page 414

Statistical Indices of model calibration and validation: R 2 and NE
Calibration

Table 17.2

Validation

River Daily Monthly Daily Monthly

R 2 R 2 R 2 R 2

Basin NE NE NE NE

Dakbla 0.71 0.68 0.94 0.86 0.47 0.46 0.59 0.58

Poko 0.83 0.82 0.90 0.89 0.56 0.55 0.68 0.67

Fig. 17.6 Calibration of the model: Dakbla ( left )andPoko( right ) river basins on the daily ( top )
and monthly ( bottom ) scales

8
<
:

9
=
;

2

P
i D 1 S i O i

P
i D 1 S i

P
i D 1 O i

N

R 2 D s

2 s

(17.3)

P
i D 1 S i

P
i D 1 O i

2

P
i D 1 S i

P
i D 1 O i

N N

where, O and S are observed and simulated discharge values, respectively.
The statistical indices in Table 17.2 show that the values of validation indices
were, as expected, higher on a monthly scale than a daily scale because daily
variability is higher than monthly variability. For climate change impacts study,
longer temporal information is of the main concern. The monthly statistical indices,
for the validation period, showed a value of about 0.6 for both R 2 and NE; this
suggested that the model was reasonably well calibrated. These results suggest that
the SWAT model showed good performance and hence suitable for climate change