Geology Reference
In-Depth Information
through hillslopes include leaching, rainflow, through-
wash (suffossion), creep, dry ravel, mass wasting, and
mixing by organisms (bioturbation). Transport-limited
processes, such as creep and rainsplash, are distinct from
supply-limited processes, such as solute leaching and
debris avalanching. Hillslopes with transport limitations
tend to carry a thick soil mantle, and their slopes tend
to decline with time. Hillslopes limited by the supply of
material through weathering tend to be bare or have thin
soils, and their slopes tend to retreat at a constant angle.
Mathematical models based on the continuity equation
for mass conservation and geomorphic transport laws
provide a means of probing long-term hillslope develop-
ment. Human activities alter hillslope processes. This is
evident in the erosion of soil-mantled hillslopes caused
by agricultural practices, logging, road building, and so
forth. The movement of people, animals, and vehicles
along trails may also cause soil to erode.
FURTHER READING
Anderson, M. G. and Brooks, S. M. (eds) (1996)
Advances in Hillslope Processes
, 2 vols. Chichester: John
Wiley & Sons.
A very good state-of-the-art (in the mid-1990s) and
advanced text.
Morgan, R. P. C. (2005)
Soil Erosion and Conservation
,
3rd edn. Oxford: Blackwell.
Probably the best introductory text on the topic.
Selby, M. J. (1993)
Hillslope Materials and Processes
, 2nd
edn. With a contribution by A. P. W. Hodder. Oxford:
Oxford University Press.
An excellent account of the geomorphology of hillslopes.
Thornes, J. B. (ed.) (1990)
Vegetation and Erosion:
Processes and Environments
. Chichester: John Wiley &
Sons.
A collection of essays that, as the title suggests, consid-
ers the effects of vegetation on soil erosion in different
environments.
ESSAY QUESTIONS
1 Compare and contrast the role of
surface and subsurface process in
hillslope development.
2 How useful are mathematical models
in understanding long-term evolution
of hillslopes?
3 How important is slope gradient in
predicting soil erosion on hillslopes?
