2.6
River Erosion [fig 2.6(a)]
fig
2.6(a)
2.6.1
Corrasion
Otherwise
known as abrasion, is the
grinding of rock fragments
carried by the river against
the bed and banks of the
river. This action both
widens and deepens the
channel. The power of the
grinding is especially
powerful in floods when
large fragments of rock are
carried along the river bed
eroding the bed and the
banks.
2.6.2
Attrition
Attrition is
the knocking of rock
fragments in the water
against one another. The
fragments are broken into
smaller pieces and become
smoother along the process.
2.6.3
Solution
Solution,
also known as corrosion, is
the process by which river
water reacts chemically with
soluble minerals in the
rocks and dissolves them.
For
example, when a river stream
flows over an area of
limestone (calcium
carbonate), it erodes the
limestone by reacting
chemically with it and
dissolves it.
