Bank-collapse processes in a valley-bottom gully, western Iowa

Auteur(s) et Affiliation(s)



Description :
Widening and bank-slope reduction of a valley-bottom gully in western Iowa was correlated to increasing subsurface flow over a 36-year period. To study bank collapse at this gully, the AA. measured rainfall, air temperature, hydraulic head near the banks and bank movement nearly continuously over a 2-year period. Bank movement was commonly correlated to rainfall or snowmelt and associated head increases in the banks. If the banks are modelled as a two-dimensional slab with an adjacent tension crack partly filled with water, measured heads were sufficient to cause bank failures through reduction of frictional support at the base of the slab. Deformation of the banks by heaving and thawing during winter may weaken them and prime them for failure during spring rains and snowmelt, when the frequency of mass-wasting events is highest.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2009, vol. 34, n°. 1, p. 109-122, nombre de pages : 14, Références bibliographiques : 1 p.

Date :
2009

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley