The document discusses features formed by rivers in different parts of their courses. It describes how waterfalls are formed in the upper course when a harder rock overlays a softer rock, causing the softer rock to erode away and form a ledge and plunge pool. In the middle course, features like meanders and slip-off slopes can form as the river energy decreases and causes deposition along banks into bends.
4. WATERFALL FORMATION
In this world waterfalls are found
anywhere.
Rivers or streams run through
rocky landscapes.
Waterfalls are also human
attractions but some times they
are dangerous.
5. WATERFALL FORMATION
Where are waterfalls common found?
Waterfalls are often found on rivers or streams that
run through rocky landscapes.
But not just on every landscape the land it should
have a harder rock overlays a layer of softer rock.
Harder rock
Softer rock
6. Waterfall formation
As the river continues to passes over the
sorter rock, it is able to erode the soft rock at a
faster rate because it is not strong enough to
hold the volume of the water
Because of that the soft rock is slowly eaten
away or eroded forming a curved ledge
underneath the hard rock.
Collapsed rocks
7. When this happens a plunge pool can
be formed at the bottom once the
water had started tumbling down.
when the water starts tumbling down
some of the water goes under the
waterfall and under cuts the soft rock.
when more of the soft rock is eroded
there isn’t enough support under the
harder rock and it collapses into the
plunger pool.
8. WATERFALL FORMATION
• The processes of erosion continues further eroding
the notch and plunge pool.
• The harder rock above will collapse again meaning
the waterfall will retreat upstream over time and it
looks like this.
9. What is a gorge?
A canyon or gorge is a deep
ravine between cliffs often
carved from the landscape by a
river. Rivers have a natural
tendency to reach a baseline
elevation, which is the same
elevation as the body of water
it will eventually drain into.
10. How is a gorge formed?
Most gorges are formed through
water erosion. For
example, waterfalls erode the rocks
they fall over and the falls move
gradually back - leaving a gorge
behind them. Some gorges are formed
as rift valleys; land stretches and a
central area drops down - this has
formed the Great Rift Valley in Africa
and the Great Glen in Scotland.
13. Slip off slope
A slip off slope is formed when the rivers’
energy is too low. The current is too slow
when the river energy is low so the river
cannot carry any load.
The slip off slope is formed as a result of
deposition along the river bank. Material
that was being transported is deposited
because friction between the water and
the bank is greater on the inner bank.
16. Meanders
A meander is a bend in the river, it is
usually in the lower and middle course of
the river where the water slides from one
side of the river to the next, this erodes
one side of the river bed and deposits
sediment on the other to make a bend.
17. How it is formed.
As water in the
river flows in the
middle course of
the river the
gradient of the
river is less steep
so the river begins
to meander.
18. This is
because the
fast flowing
water on the
outside of the
bend erodes
the side the
side of the
river.