TABLE 5.
Principal Component Analysis Loadings (PC 1 through 4) of the Eight Hydrologic Metrics That Were Significantly Correlated With Benthic Index of Biological Integrity Scores in 16 Study Basins.
| Variable | PC 1 | PC 2 | PC 3 | PC 4 |
|---|---|---|---|---|
| log (Low Pulse Count) | 0.883 | −0.341 | 0.070 | 0.005 |
| log (Low Pulse Duration) | −0.930 | −0.172 | −0.066 | −0.121 |
| log (High Pulse Count) | 0.866 | 0.423 | −0.196 | −0.115 |
| log (High Pulse Duration) | −0.836 | −0.010 | −0.397 | 0.359 |
| High Pulse Range | 0.874 | 0.418 | −0.139 | 0.030 |
| Flow Reversals | 0.860 | −0.032 | 0.234 | 0.389 |
| TQmean | −0.827 | 0.393 | 0.328 | 0.067 |
| R-B Index | 0.915 | −0.269 | −0.103 | −0.025 |
| Eigenvalue | 6.116 | 0.728 | 0.398 | 0.314 |
| Explained variance (%) | 76.4 | 9.1 | 5.0 | 3.9 |
| Cumulative explained variance (%) | 76.5 | 85.5 | 90.5 | 94.4 |