Scientific Investigations Report 2007-5152
Abstract
This report was prepared to help address concerns raised by local residents, State, and Federal agencies about the current geomorphic conditions of the Middle Fork Saline River. Over the past 30 years the Middle Fork Saline River Basin has experienced a marked increase in urbanization. The report summarizes the Middle Fork’s current (2003) channel characteristics at nine stream reaches in the upper 91 square miles of the basin. Assessments at each study reach included comparing measured stream geometry dimensions (cross-sectional area, top width, and mean depth) at bankfull stage to regional hydraulic geometry curves for the Ouachita Mountains Physiographic Province of Arkansas and Oklahoma, evaluations of streambed materials and sinuosity, and classification of individual stream reach types. When compared to the Ouachita Mountains’ regional hydraulic geometry curves for natural, stable, stream reaches, five of the nine study reaches had slightly smaller crosssectional areas, longer top widths, and shallower depths. Streambed material analysis indicates that the Middle Fork is a bedrock influenced, gravel dominated stream with lesser amounts of sand and cobbles. Slight increases in sinuosity from 1992 to 2002 at seven of the nine study reaches indicate a slight decrease in stream channel slope. Analyses of the Middle Fork’s hydraulic geometry and sinuosity indicate that the Middle Fork is currently overly wide and shallow, but is slowly adjusting towards a deeper, narrower hydraulic geometry. Using the Rosgen system of channel classification, the two upstream study reaches classified as B4c/1 stream types; which were moderately entrenched, riffle dominated channels, with infrequently spaced pools. The downstream seven study reaches classified as C4/1 stream types; which were slightly entrenched, meandering, gravel-dominated, riffle/ pool channels with well developed flood plains. Analyses of stream reach types suggest that the downstream reaches of the Middle Fork are more vulnerable to streambank failure than the upstream reaches of the stream. |
Version 1.0 Posted March 2008 |
Pugh, A.L., Garday, T.J., and Redman, Ronald., 2008, Geomorphic characterization of the Middle Fork Saline River: Garland, Perry, and Saline Counties, Arkansas: U.S. Geological Survey Scientific Investigations Report 2007–5152, 65 p.
Abstract
Introduction
Purpose and Scope
Description of the Middle Fork Basin
Location
Land Use
Drainage Areas
Topography
Geology
Basin Disturbances
Methods
Study Reach Locations
Hydraulic Geometry
Streambed Sediment
Sinuosity
Stream Reach Classification
Photographs
Geomorphic Characterization
Hydraulic Geometry
Streambed Sediment
Sinuosity
Stream Reach Classification
Implications
Summary
Selected References
Appendix 1. Highway 7
Appendix 2. Baily Road
Appendix 3. Above Coleman Creek
Appendix 4. Coleman Creek
Appendix 5. Talley Cemetery Road
Appendix 6. Above Mill Creek
Appendix 7. Mill Creek
Appendix 8. Below Danville Road
Appendix 9. Vance Road
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