2. Waterfalls
• Waterfalls are usually
formed when a river moves
over resistant bedrock and
erodes it slowly while
downstream it happens
faster.
• As this happens material is
plucked from a river bed
which causes the waterfall to
carve deeper into the
riverbed and recede
upstream
• part of the bedrock (hard
rock) will later break off,
exposing the soft rock, and
form a waterfall.
• The rest is in the diagram on
your right
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3. OX BOW LAKES
• An ox bow lake is a U - shaped water body or
meander that is cut of by erosion to form a lake.
• They are formed when a river has a very curve
us meander, which is nearly meeting the other
side of the river.
• Due to erosion and deposition the neck of the
meander becomes very narrow which allows
water to pass straight, flowing past the old
meander.
• Deposition then occurs, sealing of the meander.
• The deposition then totally covers up the
meander so no more water can pass.
• Over time the closed meander completely cuts of
from the rest of the river.
• The end result is a straight river separated from
a curved C-shaped lake.
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5. V-shaped valleys.
• In the upper course of a river,
water flows at a high speed
through a narrow channel with a
steep gradient.
• As it does, so it cuts downwards.
• This vertical erosion results in a
number of distinctive landforms
including, the steep sloped v-
shaped-valleys
• Through this the river flows in it's
upper course.
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6. Formation of v-shaped-valleys.
• Vertical erosion leads to the
development of steep sided,
narrow valleys shaped like the
letter V.
• The valley sides are steep due to
the soil and loose rock being
washed downhill following periods
of heavy rainfall.
• The material is then added to the
load of the river.
• The river itself forced to wind its
way through protruding hillsides.
• These hillsides known as
interlocking spurs restrict the view
up or down the valley.
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7. RAPIDS
• A river rapid is a section of a river
with a steep gradient, which cases
an increase in the water velocity
and the turbulence.
• A rapid is caused by the river
becoming shallower and having
some materials, like rocks, to be
exposed above the flow surface.
• In rapids, water turns white
because flowing water splashes
over and around the rocks, and air
bubbles mix with them.
• This colour is normally called
“White water”.
• Rapids normally occur when the
river bed is highly resistant to
erosion.
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8. Rapids
• Rapids are categorized into several
classes:
• Class 1- This is when the river has small
waves in fast flowing water and has very
few obstacles, e.g. rocks.
• Class 2- When the river has wide
channels and rapids , without many
turns and obstacles.
• Class 3- This class has strong currents
with many obstacles in the river.
• Class 4- Powerful rapids with big waves
• Class 5-Very violent and dangerous
rapids with tight turns
• Class 6- This last stage is the most
violent and strong. This rapid can cause
death easily.
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9. Rapids
• Many people use these river
rapids to have fun.
• Rafting, is a sport which requires
rapids.
• Rafting courses are also
classified using these rapid
classes.
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