Table 3 Initial values, ranges, and calibrated values of the selected parameters for SWAT–MODFLOW calibration using PEST

v__SFTMP.bsn

–

0.175

− 0.946 to 0.351

0.351

v__SMFMN.bsn

–

1.287

1.117–1.424

1.424

v__SMFMX.bsn

–

2.467

2.387–3.129

2.387

v__SMTMP.bsn

–

−1.342

− 1.687 to − 0.46

− 0.46

v__SURLAG.bsn

–

6.379

4.452–8.151

4.964

v__ALPHA_BNK.rte^a

–

0.912

0.7–1

0.7

v__ALPHA_BNK.rte^b

–

0.533

0.206–0.617

0.231

v__CH_K2.rte^a

–

57.068

29.322–59.779

59.779

v__CH_K2.rte^b

–

45.018

30.246–60.088

41.182

r__CN2.mgt^a

–

− 0.279

− 0.3 to  0.106

− 0.3

r__CN2.mgt^b

–

0.137

− 0.019 to 0.175

0.0004

v__EPCO.hru^a

–

0.163

0.077–0.436

0.436

v__EPCO.hru^b

–

0.255

0.01–0.334

0.304

v__ESCO.hru^a

–

0.466

0.227–0.681

0.227

v__ESCO.hru^b

–

0.931

0.684–1

0.943

r__OV_N.hru^a

–

− 0.037

− 0.2 to  0.02

− 0.02

r__OV_N.hru^b

–

− 0.025

− 0.155 to  0.005

− 0.023

r__SOL_AWC().sol^a

–

− 0.675

− 0.8 to  0.316

-0.508

r__SOL_AWC().sol^b

–

0.786

0.344–0.8

0.8

r__SOL_BD().sol^a

–

− 0.067

− 0.187 to  0.05

− 0.185

r__SOL_BD().sol^b

–

0.156

0.077–0.2

0.172

r__SOL_K().sol^a

–

1.29

0.902–2

0.902

r__SOL_K().sol^b

–

1.831

1.012–2

1.012

COND_1

Drain conductance (m² s⁻¹)

0.00467

0.00311–0.00622

0.00543

COND_2

Drain conductance (m² s⁻¹)

0.02487

0.01658–0.03316

0.03316

HK_CLAY

Hydraulic conductivity of clay (m s⁻¹)

3.84E-08

1E-09–4.4E-08

2.2E-08

HK_SILT

Hydraulic conductivity of silt (m s⁻¹)

5.00E-07

1E-07–9E-07

1E-07

HK_SS

Hydraulic conductivity of silty sand (m s⁻¹)

6.70E-06

1.51E-06–7.50E-06

7.5E-06

HK_SSCS

Hydraulic conductivity of silty sand and clean sand (m s⁻¹)

1.79E-05

1E-05–8E-05

1.79E-05

HK_CS

Hydraulic conductivity of clean sand (m s⁻¹)

0.000327

1E-04–5E-04

3.15E-04

SS_CLAY

Specific storage of clay (m⁻¹)

0.001099

9.19E-04–1.28E-03

1.28E-03

SS_SILT

Specific storage of silt (m⁻¹)

0.000755

4.92E-04–1.02E-03

1.02E-03

SS_SAND

Specific storage of sand (m⁻¹)

0.000166

1.28E-04–2.03E-04

2.03E-04

SY_CLAY

Specific yield of clay (%)

0.06

0.04–0.08

0.04

SY_SILT

Specific yield of silt (%)

0.2

0.15–0.25

0.22

SY_SAND

Specific yield of sand (%)

0.32

0.25–0.35

0.35

AUTO_WSTRS

–

30, 40, 60

30, 40, 60, 80