Tackling big problems with
Erosion processes in each part of the landscape are
described below. Numbers refer to annotations in
figure above.
collapse. May be initiated
Undercutting: Free water
sodic soil at the bottom o
leading to undercutting a
Headwall and sidewall ero
Overland flow into the gu
erodes dispersive spoil th
profile.
Headwall and sidewall ero
catchment): Rainfall on th
dispersive spoil throughou
Stream gradient: As gully
steam bed is lowered, incr
drainage line and velocity
erosion. Will propagate e
erosion and contributing runoff: Physical
1 Surface
transport of sediment in overland flow due to 3
4
2 5
6
volume and depth of flow. Will be amplified where
soil permeability and vegetation cover are low. May
also include dispersion of colloidal soil particles
into the overland flow stream. Will contribute to
downstream erosion.
Tunnelling: Tunnels commence above the gully head
and discharge into the gully, resulting in erosion
of dispersive soil at the gully wall and gully extension
above the pre-existing gully head by episodic tunnel
P40 | ISSUE 1, April, 2018