A hybrid modelling approach was developed to predict daily streamflows by coupling the SWAT model with other SCMs like ANN, RF, and SVR models, resulting in SAWT-ANN, SWAT-RF, and SWAT-SVR models. In this approach, the outcomes of the SWAT model with its default parameter combination (without calibration) were employed as inputs for the soft computing models. During this development, SWAT was considered a comprehensive interface that integrated weather, terrain, LULC, and soil to produce output variables, which serve as input to the SCMs. The summary output files (output.std and output.sed) of the SWAT model contain the required output variables. The output variables are listed in Table 3.
SWAT models output variables (Input variables for SCMs)
| Sr. No. . | Variable Name . | Description . |
|---|---|---|
| 1 | PREC | Daily mean precipitation in the watershed (mm) |
| 2 | SURQ | Surface runoff contribution from streamflow from HRU (mm) |
| 3 | LATQ | Daily lateral flow (mm) |
| 4 | GWQ | Daily groundwater contribution to stream (mm) |
| 5 | PERCOLATE | Daily water percolation (mm) |
| 6 | SW | Daily amount water stored in soil profile (mm) |
| 7 | EVAP | Average daily rate of water loss from reach by evaporation (m3/s) |
| 8 | WATER YIELD | Daily water yield to streamflow from HRUs (mm) |
| 9 | SED_OUT | Daily total sediment transported out of reach (tons) |
| Sr. No. . | Variable Name . | Description . |
|---|---|---|
| 1 | PREC | Daily mean precipitation in the watershed (mm) |
| 2 | SURQ | Surface runoff contribution from streamflow from HRU (mm) |
| 3 | LATQ | Daily lateral flow (mm) |
| 4 | GWQ | Daily groundwater contribution to stream (mm) |
| 5 | PERCOLATE | Daily water percolation (mm) |
| 6 | SW | Daily amount water stored in soil profile (mm) |
| 7 | EVAP | Average daily rate of water loss from reach by evaporation (m3/s) |
| 8 | WATER YIELD | Daily water yield to streamflow from HRUs (mm) |
| 9 | SED_OUT | Daily total sediment transported out of reach (tons) |