Abstract
Abstract. Permanent gullies grow through head cut propagation in response to overland
flow coupled with incision and widening in the channel bottom leading to
hillslope failures. Altered hydrology can impact the rate at which permanent
gullies grow by changing head cut propagation, channel incision, and channel
widening rates. Using a set of small physical experiments, we tested how
changing overland flow rates and flow volumes alter the total volume of
erosion and resulting gully morphology. Permanent gullies were modeled as
both detachment-limited and transport-limited systems, using two different
substrates with varying cohesion. In both cases, the erosion rate varied
linearly with water discharge, such that the volume of sediment eroded was a
function not of flow rate, but of total water volume. This implies that
efforts to reduce peak flow rates alone without addressing flow volumes
entering gully systems may not reduce erosion. The documented response in
these experiments is not typical when compared to larger preexisting
channels where higher flow rates result in greater erosion through nonlinear
relationships between water discharge and sediment discharge. Permanent
gullies do not respond like preexisting channels because channel slope
remains a free parameter and can adjust relatively quickly in response to changing flows.
Subject
General Earth and Planetary Sciences,General Engineering,General Environmental Science
Reference85 articles.
1. Abrahams, A. D. and Parsons, A. J.: Resistance to overland flow on desert
pavement and its implications for sediment transport modeling, Water Resour.
Res., 27, 1827–1836, 1991.
2. Adediji, A., Jeje, L. K., and Ibitoye, M. O.: Urban development and informal
drainage patterns: Gully dynamics in Southwestern Nigeria, Appl. Geogr., 40, 90–102, 2013.
3. Agsco technical Data: http://www.agsco.com/assets/pdfs/Silica-Sands-Flours-Tech-Data-Sheet-06-04-2014.pdf,
last access: 7 February 2018.
4. Alonso, C. V., Bennett, S. J., and Stein, O. R.: Predicting head cut erosion
and migration in concentrated flows typical of upland areas, Water Resour. Res.,
38, 39-1–39-15, 2002.
5. Ambers, R. K., Druckenbrod, D. L., and Ambers, C. P.: Geomorphic response to
historical agriculture at Monument Hill in the Blue Ridge foothills of central
Virginia, Catena, 65, 49–60, 2006.
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献