YELLOWSTONE LAKESHORE MONITORING: AN UPDATE

In 2005, cross-shore profiles, nearshore bathymetric mapping, survey photography, and sediment samples were acquired along both armored and adjacent un-armored sections of the Yellowstone Lake shore. Analyses of these data indicated significant geomorphic differences in shore profiles, dry beach width, and sediment grain size. During 2006 and 2007, all shore sites were resurveyed in an effort to 1) document short-term changes in armored and un-armored shore profiles, 2) document potential differential changes in armored and un-armored shore profiles, and 3) establish a foundation of shore profiles for long-term monitoring of shore zone changes. Shore profiles acquired during 2006 and 2007 were compared to baseline profiles acquired in 2005. The significance of observed changes in these profiles was assessed using Student's T-test and McNemar's Test of Change. Results indicate that the morphology of armored shore profiles are consistently and significantly different from adjacent un-armored shore profiles. However, some armored and un-armored shore profiles exhibit significant annual change whereas others do not. Processes driving significant versus insignificant annual changes in shore profiles are not well-understood at present. Ongoing investigations are attempting to identify potential drivers of shore zone variation along Yellowstone Lake. Insights gained from this study improve understanding of shore zone processes at Yellowstone Lake and provide a baseline for long-term documentation of shore zone change responding to natural and anthropogenic processes.