Neotectonic effects on sinuosity and channel migration, Belle Fourche River, Western South Dakota

Earth Surface Processes and Landforms
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Abstract

Short-term instability in the behaviour of a small, meandering alluvial channel is identified from the relation between sinuosity and either floodplain slope or channel slope within 17 reaches along an 81-kilometre section of the Belle Fourche River in western South Dakota. In reaches 1 to 4 and 11 to 17 the channel is relatively stable and sinuosity varies inversely with channel slope. In reaches 5 to 10, sinuosity is positively related to floodplain slope. Sinuosity increases markedly in reaches 5, 6, and 7 (which are immediately downstream from a discontinuity in the long profile of the floodplain) in association with an increase in floodplain slope. Immediately upstream from the discontinuity, bankfull channel depth and sinuosity decrease and the area of the floodplain reworked by meander migration between 1939 and 1981 increases, in association with a decrease in floodplain slope. Channel behaviour in reaches 5 to 10 is best explained as a consequence of neotectonic activity, as indicated by changes in elevation recorded along geodetic survey lines that cross lineaments that may delimit the eastern boundary of the Black Hills uplift. Sinuosity acts as a barometer of the effects of neotectonic activity on alluvial channels. Initial indications of channel and floodplain instability due to neotectonic activity may be derived from evidence of anomalously active channel migration, as documented from photographic or topographic sources.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Neotectonic effects on sinuosity and channel migration, Belle Fourche River, Western South Dakota
Series title Earth Surface Processes and Landforms
DOI 10.1002/esp.3290160304
Volume 16
Issue 3
Year Published 1991
Language English
Publisher Wiley
Contributing office(s) Toxic Substances Hydrology Program
Description 8 p.
First page 227
Last page 235
Country United States
State South Dakota
Other Geospatial Belle Fourche River