TABLE 5.
SWAT Parameter definition for the most sensitive (p ≤ 0.05) parameters and their “best” values after first calibration iteration of SWAT models with different precipitation sources.
| Parameter | Description | Parameter range | Default value | GHCN-D | DAYMET | NLDAS | GLDAS | PRISM |
|---|---|---|---|---|---|---|---|---|
| Alpha_BNK | Bank flow recession constant | 0 to 1 | 0 | 0.76 | 0.76 | 0.83 | 0.36 | 0.47 |
| CH_K2 | Main channel saturated hydraulic conductivity (mm/h) | 0 to 150 | 0 | 50.25 | 50.25 | 17.85 | ns | 47.25 |
| CN2 | Moisture condition II curve number | −0.21 to 0.21 | Varies from 38 to 98 | −0.08 | −0.08 | −0.01 | −0.04 | −0.06 |
| NDTARGR | Number of days to reach target storage from current reservoir storage | 0 to 200 | 1 | 40.60 | 40.60 | ns | ns | 39.4 |
| SURLAG | Surface runoff lag time (days) | 0.05 to 10 | 4 | 3.14 | 3.14 | 1.71 | 7.18 | 7.2 |
| ESCO | Soil evaporation compensation factor | 0 to 1 | 1.0 | ns | ns | 0.21 | ns | ns |
Note: ns is “not sensitive” at p ≤ 0.05.
Relative change to parameter values.