299 Geomorphology (Posters)

Wednesday, 8 October 2008
8:00 AM - 6:00 PM

Geomorphic Assessment of Pearce Creek, Camp Shelby Training Site, Perry County, Mississippi

Paper number: 299-9
Program: Technical Sessions
Time: 8:00 AM – 6:00 PM

Authors

Abstract

Encompassing more than 134,820 acres, the Camp Shelby Training Site (CSTS) is located in southeast Mississippi and is the largest state-owned and operated field training facility in the United States. The impact area at CSTS is used for the firing of small and large caliber weapons and it consists of approximately 17 square kilometers of gently rolling uplands that have been converted from forest to grassland. A number of streams drain the area and riparian wetlands are common along these streams. Significantly, these wetlands are home to several protected species. Potential erosion and sedimentation-related issues arise due to the impact area as well as high vehicular traffic, logging and recreational activity. During the past 14 years, a program has been in place that addresses wetland delineation and mitigation, fluvial geomorphology and the reinstatement of stream habitat. Within this program ten streams are being studied.

One of the ten, Pearce Creek is a small tributary that was selected to assess channel stability over a 10-yr period. Geomorphically, the area is characterized by broad valleys with terraces in association with floodplains and alluvial/colluvial soils. Comparative analysis of aerial photography and field observations suggest that the environmental impact of recent military activities have generally been minimal as opposed to the historical impact of logging (conversion of forest to grasslands) and recreational activities (e.g., dirt bikes). In fact, most streams exiting the impact area are now “knicked” due to higher velocity runoffs. Similarly, Pearce Creek is also knicked but is only slightly enriched with meandering channels and riffle pool morphology. The stream also has a low gradient that, in turn, causes the stream to have wider and less rugged valleys and a relatively average sinuosity. Major stream change is restricted to a few areas proximal to human inhabitants.