BioNet Documentation
FHI Suboptimal Parameters
During the development of the Fish Habitat Index (FHI), a new composite metric, Percentage of Suboptimal Habitat Metrics (PctSubOpt), was among the metrics that most strongly correlated to the FIBI. To calculate PctSubOpt, data for twenty-five individual habitat metrics are compared against suboptimal thresholds that were identified through graphical and quantitative analysis.
These habitat metrics, along with their thresholds, are as follows:
| Category | Description | Abbrv. | 2016 Adjusted Suboptimum Ranges (used in calculator) |
| Bank | % Horizontal (0-15 degrees) | bnkahz% | <2.5 or >67.5 |
| Bank | % Moderate (20-50 degrees) | bnkamd% | <17.5 |
| Bank | % Vertical (55-110 degrees) | bnkavr% | >42.5 |
| Bank | Streambank - Average Percent Bare | bnkbare% | <17 or >93.75 |
| Canopy/Shade | Average Percent of Channel Shaded | chshdav% | <8.2 or >89.5 |
| Canopy/Shade | Standard Deviation - Percent of Channel Shaded | chshdsd% | <10.2 |
| Dimension | Transect Depth - Average | dpthav | >1.41 |
| Dimension | Transect Depth - Coefficient of Variation | dpthcv | <0.46 |
| Dimension | Maximum Depth | maxdep | <1.62 |
| Dimension | Stream Width - Average | strwdtav | <13.6 |
| Dimension | Stream Width - Standard Deviation | strwdtsd | <3.41 |
| Dimension | Thalweg Depth - Average | thwgdpav | <0.55 |
| Dimension | Thalweg Depth : Stream Width Ratio | thwgwdr | <10.3 or >54.7 |
| Instream Cover | Depth/Pool - Average Percent - DNR Method | cvrdpl% | >20.6 |
| Instream Cover | Total Proportional Areal Cover - EPA Method | cvrepa% | <13.25 |
| Instream Cover | Overhanging Vegetation - Average Percent | cvrovhg% | >10.4 |
| Instream Cover | Woody Debris - Average Percent | cvrwdbrs% | <0.25 or >14 |
| Macrohabitat | Maximum macrohabitat type proportion | rchmxhb% | >90.3 |
| Macrohabitat | Pool | rchpool% | <5.4 or >84.8 |
| Substrate | Coarse Rock Embededness - Average | embdrtg | >3.4 |
| Substrate | Clay | subclay% | >17 |
| Substrate | Clay+Silt+Sand | subfines% | >84.5 |
| Substrate | Grvl+Cbbl+Bldr | subrock% | <11.5 |
| Substrate | Silt | subsilt% | >38.5 |
| Substrate | Maximum substrate type proportion | substrmx% | >82.5 |
This page was created 5/30/2018 8:06:49 AM