Influences of High-flow Events on a Stream Channel Altered by Construction of a Highway Bridge: A Case Study

摘要

Impacts of highway construction on streams in the central Appalachians are a growing concern as new roads are created to promote tourism and economic development in the area. Alterations to the streambed of a first-order stream, Sauerkraut Run, Hardy County, WV, during construction of a highway overpass included placement and removal of a temporary culvert, straightening and regrading of a section of stream channel, and armourment of a bank with a reinforced gravel berm. We surveyed longitudinal profiles and cross sections in a reference reach and the altered reach of Sauerkraut Run from 2003 through 2007 to measure physical changes in the streambed. During the four-year period, three high-flow events changed the streambed downstream of construction including channel widening and aggradation and then degradation of the streambed. Upstream of construction, at a reinforced gravel berm, bank erosion was documented. The reference section remained relatively unchanged. Knowledge gained by documenting channel changes in response to natural and anthropogenic variables can be useful for managers and engineers involved in highway construction projects.