Master of Science (MS), Ohio University, 2015, Geography (Arts and Sciences)

Channel planform change of the Hocking River was documented over 75 years between Sugar Grove and Athens, Ohio, to determine whether any significant changes were associated with major human activities or selected physiographic variables in the watershed. Channel planform change was mapped by acquiring and analyzing aerial photographs and digitizing the channel in GIS. Planform variables of sinuosity, width, asymmetry, and channel migration were calculated. Of the studied human and environmental variables, human-induced changes through the advent of transportation infrastructure, specifically US Route 33, and channelization to mitigate property damage within the floodplain were the leading causes of significant planimetric change of the upper Hocking River over the 75-year span. Significant changes in sinuosity, width, and channel migration occurred directly in the modified reaches as well as the reach immediately downstream from a modification. Historic floods triggering meander cut-offs was the second most important variable affecting planimetric change. Finally, the percent change in riparian vegetation was shown to have a moderately negative correlation with percent change in channel width, while a correlation between percent change in riparian vegetation and rate of change in channel position was not found. Overall, while the upper Hocking River displayed natural planimetric variability over the study interval, the greatest impacts, both directly and indirectly, upon channel planform were associated with human modifications.

Committee: Dorothy Sack (Advisor); James Dyer (Committee Member); Timothy Anderson (Committee Member) Subjects: Earth; Geography; Geomorphology; Physical Geography; Water Resource Management