Results of accelerated erosion on certain constructed surfaces in southeastern Arizona appear similar to those described by Bryan as gully gravure. Twenty cross-section excavations in eight rills inclised into silt-rich lacustrine and fluvial deposits reveal partial filling of the rills by debris derived from overyling fluvial sand, gravel, and cobbles. Interstices of the coarse material gradually fill with fine-grained erosion products, decreasing permeability of the fill and deflecting subsequent runoff to the margins of the fill. Rills and rill fillings thus increase in width with time, and complete veneering of the surface by coarse debris ultimately may occur. Through incision, filling, lateral planation, and armoring, channels of the dissected surface heal and the new hillslope approaches an equilibrium condition. Natural hillslopes in the area with similar geologic conditions have inclinations of 16??-22??, have generally unbroken veneers of coarse debris, and appear subject to the same erosional processes identified at constructed hillslopes. -from Authors
Additional publication details
Publication type:
Article
Publication Subtype:
Journal Article
Title:
The healing of disturbed hillslopes by gully gravure