Table 1.
Model variable codes, units, scale, and description. Scale refers to spatial area of analysis (point, at the collection; 1 km, watershed area within 1 km of site; 5 km, watershed area within 5 km of site; WS, upstream watershed area)
| Scale | ||||||
|---|---|---|---|---|---|---|
| Variable code | Unit | Point | 1 km | 5 km | WS | Description |
| Response variables-invertebrate metrics | ||||||
| O/E | Ratio | X | Ratio of number of observed taxa at a site to the expected taxa based on modeled reference sites, all taxa | |||
| O/E50 | Ratio | X | Ratio of number of observed taxa at a site to the expected taxa based on modeled reference sites, common taxa with a probability of capture at 50 % sites | |||
| Explanatory variables | ||||||
| Temp | °C | X | 30-year (1971–2000) average max temperature | |||
| PPT | mm | X | 30-year (1971–2000) average annual precipitation | |||
| Slope | % | X | Gradient at reach level | |||
| Elevation | m | X | Elevation at site | |||
| DamDist | m | Distance to nearest upstream dam in catchment | ||||
| Area | km2 | X | Watershed area | |||
| Ag | % | X | X | X | Percent agricultural lands (row crop, pasture) | |
| AgUrb21 | % | X | X | X | Percent developed land (urban, row crop, pasture, nlcd class 21) | |
| Burns20052009 | # | X | Number of burns between 2005 and 2009 | |||
| CalPipe100kPer | % | X | Percent canals or pipes at the 100-k scale | |||
| CanalPipeDist100k | m | X | Total length of FTYPE equal to Canal Ditch and Pipeline in NHD+ | |||
| CaO | % | X | Percent calcite mineral content | |||
| CODE_21 | % | X | X | X | Percentage of urban/recreational grass (nlcd 21) | |
| CondQrm | μS/cm | X | Predicted electric conductivity (Olson and Hawkins 2012) | |||
| DamCount | # | X | X | X | Number of dams | |
| DamDensArea | dams/km2 | X | X | X | Density of dams, by area | |
| DamStorage | km2 | X | Total dam storage | |||
| GravelMines | # | X | X | X | Count of gravel mines | |
| GravelMinesDens | gravel mines/km2 | X | X | X | Density of gravel mines | |
| Grazing | % | X | X | X | Percent of area allotted to grazing on USFS and BLM lands | |
| IMPERVMEAN | % | X | X | X | Impervious surfaces from NLCD | |
| MAFLOWU | cfs | X | Cumulative annual discharge in NHD+, unit area method | |||
| MgO | % | X | Percent magnesium oxide mineral content | |||
| Mines | # | X | X | X | Count of mines | |
| MinesDens | mines/km2 | X | X | X | Density of mines | |
| Ngeo | % | X | Percent nitrogen geology | |||
| NewAg | % | X | X | Percent new ag (nlcd class 36, 46, or 56) | ||
| NewUrb | % | X | X | Percent new urban (nlcd class 32, 42, 52, or 62) | ||
| PctSed | % | X | Percent sedimentary geology | |||
| Pop | # people/km2 | X | X | X | Population density in 2000 | |
| rDDENSC12 | roads/km2 | X | X | X | Total density of paved roads (nlcd class 1 and 2) | |
| rDDENSC123 | roads/km2 | X | X | X | Total density of paved and unpaved roads (nlcd classes 1, 2, and 3) | |
| STREAMORDER | # | X | Strahler stream order | |||
| URBAN | % | X | X | X | Percentage of polygon designated as urban (nlcd class 22, 23, 24) | |