Table 2 Parameters sensitive to streamflow, their default range, fitted value during calibration and final values used in SWAT model for streamflow simulations
Parameter | Description | SUFI2 fitted value | Default SWAT range | Final value in SWAT model |
|---|---|---|---|---|
v__SURLAG.bsn | Surface runoff lag time (days) | 20.76 | 0.05 to 24 | 20.76 |
v__ESCO.bsn | Soil evaporation compensation factor | 0.83 | 0 to 1 | 0.83 |
a__GWQMN.gw | Threshold depth of water in the shallow aquifer for return flow to occur (mm H2O) | 217.08 | 0 to 5000 | 1217.08 |
a__GW_REVAP.gw | Groundwater “revap” coefficient | 0.03 | 0.02 to 0.2 | 0.05 |
a__REVAPMN.gw | Threshold depth of water in the shallow aquifer for “revap” to occur (mm H2O) | 236.07 | 0 to 1000 | 986.07 |
v__ALPHA_BF.gw | Baseflow alpha factor (days) | 0.83 | 0 to 1 | 0.83 |
v__SHALLST.gw | Initial depth of water in the shallow aquifer | 1263.00 | 0 to 5000 | 1263.00 |
v__RCHRG_DP.gw | Deep aquifer percolation fraction | 0.63 | 0 to 1 | 0.63 |
v__GW_DELAY.gw | Groundwater delay (days) | 18.25 | 0 to 500 | 18.25 |
v__CH_N2.rte | Manning’s “n” value for the main channel | 0.11 | − 0.01 to 0.3 | 0.11 |
v__EPCO.hru | Plant uptake compensation factor | 0.50 | 0 to 1 | 0.50 |
a__OV_N.hru | Manning’s “n” value for overland flow | 28.86 | 0.01 to 30 | 28.86 |
a__CANMX.hru | Maximum canopy storage (mm H2O) | 10.78 | 0 to 100 | 10.78 |
a__SLSUBBSN.hru | Average slope length (m) | 40.45 | 10 to 150 | 131.91 |
a__HRU_SLP.hru | Average slope steepness (m/m) | 0.44 | 0.3 to 0.6 | 0.47 |
a__SOL_AWC().sol | Available water capacity of the soil layer (mm H2O/mm soil) | − 0.06 | 0 to 1 | 0.04 |
a__SOL_K().sol | Saturated soil hydraulic conductivity (mm/h) | 21.37 | 0 to 2000 | 39.02 |
a__CH_K1.sub | Effective hydraulic conductivity in main channel alluvium (mm/h) | 85.56 | 0 to 300 | 85.56 |
a__CN2.mgt | Initial SCS runoff curve number for moisture condition II | − 1.87 | 35 to 98 | 83.13 |