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Failure Sequence of Gully Headwalls in Western Iowa
Author(s) -
Bradford J. M.,
Piest R. F.,
Spomer R. G.
Publication year - 1978
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1978.03615995004200020025x
Subject(s) - loess , geology , sequence (biology) , gully erosion , erosion , slope failure , hydrology (agriculture) , geomorphology , glacial period , geotechnical engineering , landslide , genetics , biology
Abstract A characterization of the failure sequence of gully headwalls and banks is necessary to predict gully erosion rates and to develop controls. A model is given for the sequential nature of gully growth in the thick loessial area of western Iowa. The failure sequence includes a popout or alcove failure near the toe of a near‐vertical wall, columnar sloughing of the overhanging material, and finally the transport of the eroded material downstream. The initiating failure at the base of the wall is a result of weakening of the soil material by wetting. The gully bank failure sequence and geometry in the western Iowa loess region is compared to gully erosion studies in the glacial drift region of northwestern Missouri and in the Piedmont of South Carolina.