Data Sources and Measurements
| Variable | Measurement | Source and Tools | Range | Mean | S.D. | |
|---|---|---|---|---|---|---|
| 1 | Mean annual peak unit discharge | Average maximum daily runoff (units in mm) at each USGS gauge station (2014–2016) by water year (natural log‐transformed) | USGS gauge stations, SWAT modeling, ArcGIS | 6.86–8.22 | 7.34 | 0.20 |
| Average maximum daily runoff (units in mm) at each USGS gauge station (2014–2016), by water year (log‐transformed) | USGS gauge stations, SWAT modeling, ArcGIS | 2.98–3.57 | 3.20 | 0.08 | ||
| 2 | Precipitation | Mean annual precipitation (units in cm) | PRISM data; SWAT modeling, based on climatologically aided interpolation (CAI) | 125.92–171.19 | 147.17 | 10.10 |
| 3 | Slope | Average watershed slope (units in percentages) | NHDPlus V2; NED; ArcGIS | 0.09–7.35 | 3.41 | 1.10 |
| 4 | Soil Permeability | Average watershed soil permeability (units in inches per hour) | NRCS; ArcGIS | 0.76–12.48 | 2.59 | 1.07 |
| 5 | Floodplain Area | Area within the FEMA‐defined 100‐year floodplain (units in percentages) | FEMA Flood Map Service Center; ArcGIS | 0–100 | 25.90 | 28.70 |
| 6 | Natural Drainage Density | Ratio of total stream length to basin area | NHD Flowline | 0–5.17 | 1.36 | 1.34 |
| 7 | Wetland | Proportion of wetland (units in percentages) | NLDC 2016 codes 90 & 95; ArcGIS | 0.61–100 | 32.50 | 22.10 |
| 8 | Impervious Rate | Proportion of developed surfaces (units in percentages) | NLCD 2016 codes 21, 22, 23,24; ArcGIS | 0.00–95.90 | 4.81 | 9.35 |