Date of Graduation

Spring 2017

Degree

Master of Science in Geospatial Sciences

Department

Geography, Geology, and Planning

Committee Chair

Robert Pavlowsky

Abstract

Channelization, levee construction, and gravel mining are land management practices that are used for flood control. However, they often alter the balance between sediment supply and available sediment transporting power in streams, causing channel instability. Streams can respond to instability through channel incision and sediment aggradation which can degrade riparian habitat, increase flood risks, and cause property damage. These problems have been observed along segments of Big Barren Creek, which drains 190 km² of the Missouri Ozarks in Mark Twain National Forest. Field assessment and modeling methods were used to evaluate the spatial distribution of channel instability along the upper 20 kilometers of Big Barren Creek and quantify the changes in channel morphology, hydrology, and sediment transport capacity related to channel modifications. Results show that channelized reaches of Big Barren Creek are generally steeper, up to two times deeper, and can transport up to four times more sediment than nearby natural reaches. High sediment transport capacity given unchanged sediment supply can account for headcuts, bed coarsening, and downstream sediment aggradation that are associated with channelized reaches of Big Barren Creek. These findings identify channelization as the primary contributor to channel instability within Big Barren Creek. Restoration efforts should focus on development plans to mitigate channelization and enhance channel recovery.

Keywords

geomorphology, instability, channelization, sediment transport, Ozarks

Subject Categories

Environmental Indicators and Impact Assessment | Geomorphology

Copyright

© Matthew S. Thies

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