HR: 1340h
AN: H53C-1260    [Abstracts]
TI: The Development of Gullies on the Landscape: a Model of Headcut Retreat Resulting From Plunge Pool Erosion
AU: * Flores Cervantes, J H
EM: homefc@mit.edu
AF: Department of Civil and Environmental Engineering, MIT, Ralph Parsons Lab 15 Vassar St. MIT Room 48-212, Cambridge, MA 02139 United States
AU: Istanbulluoglu, E
EM: erkan@mit.edu
AF: Department of Civil and Environmental Engineering, MIT, Ralph Parsons Lab 15 Vassar St. MIT Room 48-208, Cambridge, MA 02139 United States
AU: Bras, R
EM: rlbras@mit.edu
AF: Department of Civil and Environmental Engineering, MIT, Ralph Parsons Lab 15 Vassar St. MIT Room 48-211, Cambridge, MA 02139 United States
AB: Head advance due to plunge-pool erosion is a common process in gullies incising resistant soils. A model of headcut retreat resulting from plunge-pool erosion is developed and implemented in CHILD, an existing 3D landscape evolution modeling framework. The model estimates horizontal headcut retreat as a function of discharge, height of the headcut, upstream slope and relevant land surface and soil properties for soil erosion. The physical model results compare well with the published data from flume experiments. We analyzed the sensitivity of headcut retreat to flow discharge, upstream slope and surface roughness, and headcut height. CHILD simulations indicate that headcut retreat is most significant in zones with either gentle slopes or large headcut heights. Model parameters have contrasting effects on the retreat rates depending on the size and depth of the pool beneath the headcut, and upstream flow hydraulics, making the process difficult to predict as a function of topographic thresholds and simple geomorphic transport laws.
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting