7762 - Laserfiche WebLink

Home Browse Search

12 I I I I I I I I I I I I I I I I I I I Table 6. Summary of average surface ice thickness, tree water depth, temperature and dissolved oxygen for 14 backwaters sampled during Ice Measurement Trip I (January 31 - February 4, 1994 and Trip II (February 21 . 24, 1994) of the Wmter Ice Study, 1993-94. Average Surfacel Average Free Average Average D.O. Ice Thickness (ft) Water Depth (ft) Temperature ("C) (mg/I) Site Trip I Trip n Trip I Trip IT Trip I Trip Trip I Trip IT IT 1 2 0.5 1.0 0.09 11.7 3 0.6 1.0 0.06 11.7 4 5 <0.1 1.9 0.92 12.2 6 0.1 0 0.9 12 2.03 0.88 13.6 12.2 7 02 0.3 1.3 0.8 0.84 0.91 12.4 12.2 8 1.0 0.7 1.3 1.6 0.18 0.45 11.8 10.9 9 0.9 1.4 1.9 1.1 0.10 0.46 10.5 6.0 10 11 0.3 0.7 0.29 12.5 12 0.6 0.3 1.7 1.8 1.09 2.91 11.1 9.6 13 0 2.9 3.66 10.8 14 0.5 0 1.5 1.0 3.22 11.0 lIncludes both solid surface ice and frazjJ ice. 6.2.1 Reach 1 Reach 1 extended from Island Park (RM 333) to Split Mountain Canyon (RM 327). Four backwaters were sampled in this Reach. River ice conditions in included minima) shoreline ice formed the last week of January with surface ice rarely extending more than a meter from shore. Small amounts of frazi1 ice were observed the first week of February. No ice jams were observed in this section. Ice accumulations slowly decreased after peak formation the first week of February. Most ice was absent by the last week of February. Site 1: Site 1 was a downstream oriented chute channel located in Island Park (RM 332.0). This backwater had an area of 130 m2 and a maximum depth of 2.0 ft. By February 3, changes in channel morphology had eroded most of the habitat leaving only 20 m2 of the original backwater. This reduction in size exceeded the minimum habitat requirements. None of the original backwater remained by the second site visit