Table 2.
Variables used to predict MMI scores and their code. Variables are ordered by class used for data interpretation.
| Variable (units) | Code | Variable (units) | Code |
|---|---|---|---|
| Water Quality | Watershed Land Use | ||
| Total Nitrogen (ug/L) | TN* | Agriculture (%) | AGR_WS |
| Total Phosphorus (ug/L) | TP* | Developed Land (%) | DEVL_WS |
| Conductivity (μS) | COND* | Wetlands (%) | WETL_WS |
| Dissolved Organic Carbon (mg/L) | DOC* | Population Density (#/km2) | POPDEN* |
| Chloride (μeq/L) | CL* | Road Density | ROADDEN* |
| Sulfate (μeq/L) | SO4* | Dam Disturbance Index | DAM* |
| Turbidity (NTU) | TURB* | ||
| pH | PH | Climate | |
| Mean Precipitation (cm/yr) | PRECIP* | ||
| Physical Habitat Condition | Mean Runoff (cm/yr) | RUNOFF* | |
| Riparian Cover Index | RIPCOV* | Maximum Temperature (°C) | TEMPMAX |
| Natural Fish Cover (% area) | FISHCOV* | Minimum Temperature (°C) | TEMPMIN |
| Fast Water Habitat (% length) | FASTPCT | ||
| Pool Habitat (% length) | POOLPCT | Geophysical | |
| Riparian Disturbance Index | RIP_DIST | Latitude (degrees) | LAT |
| Agricultural Riparian Disturb. | RIP_AGR | Longitude (degrees) | LON |
| Non-Agricultural Riparian Disturb. | RIP_NOAG | Site Elevation (m) | ELEV* |
| Watershed Area (km2) | WSAREA* | ||
| Substrate | Mean Thalweg Depth (cm) | DEPTH* | |
| Fine Substrate (% area) | FINES | Mean Wetted Width (m) | WIDTH* |
| Sand+Fine Substrate (% area) | SANDFINE | Channel Slope (%) | SLOPE* |
| Geometric Mean Diameter (mm) | SUBSIZE | Soil Erodibility Factor | ERODE |
| Relative Bed Stability Index | RBS | Boatable or Wadeable | LOTIC |
*
Log10(x+1) transformed for data analysis, except for SLOPE (Log10(x+0.001), and DAM, RIPCOV, and FISHCOV (Log10(x+0.1).