Masters Theses

Date of Award

8-2002

Degree Type

Thesis

Degree Name

Master of Science

Major

Geography

Major Professor

Carol Harden

Abstract

Disturbances on land may create a situation of dynamic change in the stream as the fluvial system responds to changing driving and resisting forces. This study looks at North Potato Creek in southeast Tennessee, which has been extremely disturbed by logging, rural development, a century-length period of land denudation, and reforestation. It was undertaken to describe the present channel morphology and sediment dynamics of this stream, as a basis for understanding how changes on the land have affected it. I sought evidence that the fluvial system is adjusting to a history of extended denudation and subsequent reforestation by looking at channel processes and historical land use change. By analyzing GIS images created from aerial photos of the basin, from 1952, 1964 and 1994, I found that bare land has decreased by 39% while forested land has increased by 33%. As bare land is converted to forested land I expect that the sediment yield from the watershed will decrease, causing changes in the fluvial system dynamics in response to the changing driving forces. By conducting measurements of channel geometry and particle size, I compare the processes occurring in different reaches and classify each study site according to the Rosgen classification technique. Lastly, I address the implications for land use management in extremely disturbed watersheds. North Potato Creek is a bedrock stream and the current fluvial system dynamics are a result of land use disturbance. Observations from the most downstream of the three North Potato Creek sites show that North Potato Creek is not in a steady state, thus, it will continue to adjust until the driving and resisting forces are in equilibrium. It is highly improbable that this stream will recover to pre-impact dynamics, but managers, working with nature and developing a long-term plan can restore this stream to function like other bedrock streams in the Southern Metasedimentary ecoregion. Data collected in this study provide a quantitative baseline for researchers addressing this long-term management plan.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS