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Erosional and depositional changes wrought by the flood of May 1978 in the channels of Powder River, southeastern Montana

Scientific Investigations Report 2013-5035

By:
and
DOI: 10.3133/sir20135035

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Abstract

Powder River’s second largest flood of record (1919–2012) moved through northeastern Wyoming and southeastern Montana during May 1978. Within a ninety-kilometer reach of the channel in southeastern Montana, the most prominent planform effects of the flood were the growth of meander bends by bank erosion (this was most intense just downriver of bend apexes, causing 1–2 channel widths of lateral displacement) and the erosion of new cutoff channels through the necks of two large and two small meanders. Surveys of cross sections, made before and after the flood, show the responses of the channel to the flood waters, which ranged from minimal (bedrock control) to large (maximum channel curvature in unconsolidated bank and terrace deposits). Geomorphic work done during two weeks of extreme flooding in May 1978, as measured by cross-channel erosion and new sediment deposition, was approximately equal in magnitude to the work done during the two decades (1978–1998) that followed the flood.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Erosional and depositional changes wrought by the flood of May 1978 in the channels of Powder River, southeastern Montana
Series title:
Scientific Investigations Report
Series number:
2013-5035
DOI:
10.3133/sir20135035
Year Published:
2013
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
National Research Program - Central Region
Description:
Report: iv, 29 p.; Map: 46.0 x 42.0 inches
Number of Pages:
36
Country:
United States
State:
Montana
County:
Powder River County
Other Geospatial:
Powder River
Datum:
North American Datum of 1927
Projection:
Universal Transverse Mercator projection
Scale:
20570
Online Only (Y/N):
Y
Additional Online Files(Y/N):
Y