Erosion
For morphological image processing operations, see Erosion
(morphology)
For
use
of
in
dermatopathology,
see
Erosion
(dermatopathology)
Severe soil erosion in a wheat field near Washington State
University, USA.
Erosion is the removal of solids (sediment, soil, rock
and other particles) in the natural environment. It usu-
ally occurs due to transport by wind, water, or ice; by
down-slope creep of soil and other material under the
force of gravity; or by living organisms, such as burrow-
ing animals, in the case of bioerosion.
Erosion is distinguished from weathering, which is
the process of chemical or physical breakdown of the
minerals in the rocks, although the two processes may
occur concurrently.
Erosion is a noticeable intrinsic natural process but
in many places it is increased by human land use. Poor
land use practices include deforestation, overgrazing,
unmanaged construction activity and road-building.
Land that is used for the production of agricultural crops
generally experiences a significant greater rate of
erosion than that of land under natural vegetation. This
is particularly true if tillage is used, which reduces ve-
getation cover on the surface of the soil and disturbs
both soil structure and plant roots that would otherwise
hold the soil in place. However, improved land use prac-
tices can limit erosion, using techniques such as terrace-
building,
conservation tillage practices,
and tree
planting.
A certain amount of erosion is natural and, in fact,
healthy for the ecosystem. For example, gravels continu-
ously move downstream in watercourses. Excessive
erosion, however, does cause problems, such as receiv-
ing water sedimentation, ecosystem damage and out-
right loss of soil.
Causes
Soil erosion exposing roots
The rate of erosion depends on many factors. Climatic
factors include the amount and intensity of precipita-
tion, the average temperature, as well as the typical
temperature range, and seasonality, the wind speed,
storm frequency. The geologic factors include the sedi-
ment or r