LANDFORMS AND THEIR
EVOLUTION
C H A P T E R
A fter weathering processes have had
their actions on the earth materials
making up the surface of the earth, the
geomorphic agents like running water, ground
water, wind, glaciers, waves perform erosion.
It is already known to you that erosion causes
changes on the surface of the earth. Deposition
follows erosion and because of deposition too,
changes occur on the surface of the earth.
As this chapter deals with landforms and
their evolution first start with the question,
what is a landform? In simple words, small to
medium tracts or parcels of the earth’s surface
are called landforms.
If landform is a small to medium sized part
of the surface of the earth, what is a landscape?
Several related landforms together make
up landscapes, (large tracts of earth’s surface).
Each landform has its own physical shape, size,
materials and is a result of the action of certain
geomorphic processes and agent(s). Actions
of most of the geomorphic processes and
agents are slow, and hence the results take a
long time to take shape. Every landform has a
beginning. Landforms once formed may
change in their shape, size and nature slowly
or fast due to continued action of geomorphic
processes and agents.
Due to changes in climatic conditions and
vertical or horizontal movements of land-
masses, either the intensity of processes or the
processes themselves might change leading to
new modifications in the landforms. Evolution
here implies stages of transformation of either
a part of the earth’s surface from one landform
into another or transformation of individual
landforms after they are once formed. That
means, each and every landform has a history
of development and changes through time. A
landmass passes through stages of
development somewhat comparable to the
stages of life — youth, mature and old age.
What are the two important aspects of
the evolution of landforms?
The evolutionary history of the continually
changing surface of the earth is essential to be
understood in order to use