Date of Graduation

Spring 2003

Degree

Master of Science in Geospatial Sciences

Department

Geography, Geology and Planning

Committee Chair

Robert Pavlowsky

Subject Categories

Geomorphology | Sedimentology | Water Resource Management

Abstract

Land-use change, both historical and present, has been a source of channel degradation within Ozark streams. This study examines the influence of land use on channel morphology within the South Dry Sac Watershed which drains 78.5 km2. The main objectives of this study are to: (1) perform a geomorphic assessment of stream channel and sediment characteristics; (2) evaluate the effects of watershed factors on channel morphology and dynamics; (3) quantify the geomorphic relationships for use in stream restoration projects in the Springfield Plateau area. Thirty-six reaches were surveyed and evaluated in the field for channel cross-sectional geometry, longitudinal profile, and planform in both urban and rural areas of the South Dry Sac Watershed. Geospatial technologies were used to assess watershed land-use, channel planform and riparian buffers. Urban channels were found to have approximately 10% greater bankfull widths, 5-9% greater mean depths and 15-20% greater cross-sectional areas than rural channels. Additionally, urban channels were found to have about 32-47% lower maximum residual pool depths and about 40% lower meander amplitudes. While overall trends are in agreement, differences between urban and rural channel size are not as obvious in the Ozark streams studied when compared to similar studies in Pennsylvania and North Carolina. This result may be due to low channel migration rates and presence of cohesive banks that limit geomorphic response. In addition, rural channel form in the South Dry Sac Watershed may still reflect disturbance by historical land clearing and row crop agriculture. Regression equations that predict channel morphology based on drainage area and land use are developed for use in channel restoration projects.

Copyright

© John M. Horton

Open Access

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