| Variables | Description | Variable type | Unit |
| EC | Electric conductivity of survey site | Continuous | μS |
| Dep | Water depth of survey site | Continuous | m |
| Do | Dissolved oxygen of survey site | Continuous | mg∙L−1 |
| Turb | Turbidity of survey site | Continuous | NTU |
| Vel | Current velocity of survey site | Continuous | m∙s−1 |
| Con | Connected by an annual flood or not | Dummy | 0, 1 |
| Dist | Route distance from the nearest river | Continuous | km |
| FA | Floodplain area around each survey site | Continuous | km2 |