Table 1 Sensitive parameters and optimized values of SWAT using SUFI-2

CN2

SCS runoff curve number

− 10–10%

3.8%*

ALPHA_BF

Base flow alpha factor (day)

0–0.5

0.37

SOL_K

Saturated hydraulic conductivity (mm/h)

0–5

3.76

SOL_AWC

Available water capacity of the soil layer (mm)

− 30–30%

25%*

SLSUBBSN

Average slope length (m)

0–55

51.28

ESCO

Soil evaporation compensation factor

0–1

0.82

CH_K2

Effective hydraulic conductivity in the main channel (mm/h)

0–50

43

GWQMN

Threshold depth of water in the shallow aquifer required for return flow to occur (mm)

100–1000

567.7