Revising River Landforms
You need to know about these river landforms;
Erosion Landforms
1. Waterfalls and gorges
2. V shaped valleys (to show you understand vertical
erosion)
Erosional and Depositional Landforms
1. Meanders and Ox Bow Lakes
Depositional Landforms
1. Levees
2. floodplains
Most commonly in the exam you will get a 4 mark question on how
one of these features is formed such as “explain the formation of an
oxbow lake.” (2011)
The mark scheme for this question was:
Level 1 Basic (1-2 marks)
Simple points.
Order not correct – jumps about. Sequence may be
incomplete.
CMI annotation
• L1 Simple points, incomplete sequence
Level 2 Clear (3-4 marks)
Complete, clear, statements.
Statements are developed and
linked.
Sequence and formation of ox bow lakes is complete and clear.
So the way to get better and full marks is to:
1.
2.
3.
4.
Have the sequence (order) correct
Explain as well as describe the way the landform is made
Use key words
Try to give an example (even if you aren’t asked for one)
To help you gain top marks in such questions we have designed
these revision aids for each of the landforms you need to know
about. Simply arrange these statements into the correct order.
When you go in to the exam you should be confident that you
know how to explain how any of these has been formed.
Waterfalls and Gorges
1/ As the step gets more and
more eroded it becomes a
waterfall
3/ As the waterfall retreats
further upstream this creates a
gorge
5/ The softer rock erodes more
quickly than the harder rock
causing a ‘step’. These can turn
into rapids.
7/ Apart from the abrasion what
other erosion is happening?
2/ Water flows over hard rock
and then soft rock
4/ The collapsed material causes
abrasion of the soft rock which
creates a plunge pool
6/ The hard rock is undercut by
erosion. It collapses and the
waterfall retreats up stream
Example: High force on the River Tees on NE England
V shaped Valleys
1/ Steeper land means more
vertical erosion than lateral
erosion
3/ In the upper course of the
river basin land is steeper
2/ This creates V- shaped valleys
4/
Example: High force on the River Tees on NE England
Meanders
1/ So more deposition happens
2/ As it is shallower there, water
here and slip off slopes are
goes slower on the inside bend
created
3/ As it is deeper there, water
4/ So more erosion happens on
goes faster on the outside of a
the outside bend and river cliffs
bend
are formed
5/ Always remember its both
erosion and deposition that forms
a meander. Which happens
where? And what types?
(on the River Amazon)
Ox Bow Lakes
(as meanders grow they can turn into oxbow lakes)
1/ After the flood deposition will
cut off the old meander creating
an ox bow lake
3/ As a river erodes the outside
of the bends more these can get
closer together
5/ Link erosion and deposition to
the energy of the river. What type
of each happens when in this
process?
2/ As meanders get close
together they leave only a small
piece of land called a neck.
4/ When water levels are high in
a flood the river can break
through the neck.
(on the River Amazon)
Flood Plains
(the flat area of land either side of the river in its lower course)
1/ By spreading out the water
slows right down as the land is
flatter and there is more friction
to slow it down
3/ The deposition on the inside of
meanders also helps add to a
floodplain
5/ Meanders migrate across the
flood plain and so can make it
wider
2/ When it slows down on the
land it will therefore deposit
material creating a flood plain
4/ When the river overflows its
banks the water spreads out
quickly over the land
6/ this is all about deposition.
Make sure you know why it
happens. The bit about meanders
is a real A/A* part to an answer
An example is the land in Laverstock the other side of the road from
school. The river is called the River Bourne
Levees
1/ Over many floods this process
is repeated and the mini wall
becomes a levee
3/ This heavy material forms a
mini wall by the edge of the river
2/ By spreading out the water
slows right down as the land is
flatter and there is more friction
to slow it down
4/ When the river overflows its
banks the water spreads out
quickly over the land
6/ By slowing down it will lose
energy and so deposit material
5/ The heaviest and biggest
material will be deposited first
right on the river banks
7/ When the river is high it has
8/ The key to all this is knowing
lots of energy so it is transporting when a river deposits and when it
lots of material
transports or erodes material
You know from your Bangladesh flooding video that there are natural
levees there (which people have built up as a defence)