Transcript v shaped valleys and waterfalls Niagara

The River Long Profile
The river long profile summarises which river processes take place
at each stage of a river’s journey. The level of erosion,
transportation and deposition varies according to a range of
factors.
Do you know the difference between erosion and transport?
Use P. 9 if you’re unsure
1. How might the following affect the rate of
erosion…
a. Gradient (angle of slope)
b. Rock type
c. Bedload (the amount of material being
carried)
d. Human factors
Landforms in the Upper Course Pt 1
LO: To describe two landforms that form in a river’s upper course.
All will be able to describe,
using a diagram, how v
shaped valleys and
waterfalls form
Most will be able to explain
how the landforms can
develop further
Some will be able to use at
least 3 key terms in their
explanation of formation
V Shaped Valleys
Why do V-shaped valleys occur?
Interlocking spurs
Near their source, rivers tend to follow a fairly straight
path but as they move further from the source they
start to wiggle around obstructions this creates areas
that point into the river called spurs. Where these
points mesh in together they are called interlocking
spurs.
3. How do v
shaped valleys
lead to the
formation of
interlocking
spurs?
http://www.cleo.net.uk/resources/displayframe.p
hp?src=308/consultants_resources%2F_files%2Fin
tespur2.swf
Describe this picture
Landforms in the
Upper Course Pt 2
LO: To describe two
landforms that form in a
river’s upper course.
All will be able to describe, using a diagram, how v shaped
valleys and waterfalls form
Most will be able to explain how the landforms can
develop further
Some will be able to use at least 3 key terms in their
explanation of formation
Every second, more than 2 million litres of water plunges over the
Horseshoe Falls segment of Niagara Falls creating one of the world's
largest waterfalls as well as eating away as much as two meters of rock
per year.
Waterfall formation
Waterfall formation
The waterfall retreats back forming
a gorge (steep sided valley)
Overhang
becomes
unsupported
and falls into
the plunge
pool
Waterfall formation
Where does the water come from?
The Great Lakes. The Niagara River that flows over the falls is 58km
long and links Lakes Erie and Ontario
How is the water used?
The waters of the Niagara River are used by 100,000+ Canadians and
US citizens for a range of purposes such as: drinking, boating, fishing,
swimming, birdwatching, Industrial cooling, and hydroelectricity
What is the future of the falls?
The falls keeps on moving back. The Niagara Gorge extends from the
Falls for 11 kilometres (7 mi.)
Erosion is due to freeze thaw in winter, solution from the spray itself,
and abrasion of the shales by fallen limestone boulders.
50,000 years from now, at the present rate of erosion, the falls will
have moved back as far as Lake Erie so there won’t be a falls
anymore.
True or False
1. The plunge pool is located at the top of the waterfall.
2. There are 2 layers of rock involved in the formation
3. Niagara falls is located on the border of Canada and
the USA.
4. The water plunges down a 50m cliff at Niagara Falls
5. The soft rock is located on top of the Whinstone rock
6. Waterfalls can be used for hydroelectric power
Niagara Falls,
New York State
USA / Ontario
Canada
CASE STUDY: A landform formed by water action that
attracts people
Name a landform formed by water that attracts people.
Describe what attracts people to the landform.
Explain how people’s use of the landform brings
advantages
Describe what attracts people to the landform.
1. Often shown in films e.g. Niagara 1953,
Superman II 1980, Pirates of the Caribbean – At
World’s End 2006
2. Close to major populations with great transport
3. Use for hydroelectricity
4. Lots of attractions – Maid of the Mist, nightly
illuminations, winter light festival, journey
behind the falls, the aero cable car, speed boat
down the gorge, regular stunts etc.
http://www.niagarafallslive.com/daredevils_of_niagara_falls.htm
http://www.youtube.com/watch?v=A5ggG8PP7_U&safe=active
Explain how people’s use of the landform
brings advantages
The big benefit is money. Niagara Falls tourist
industry serves approximately 28 million visitors
each year.
The hydroelectric plant not only supplies 4.4 gig
watts of energy cleanly, the plants also lead to a
contract being drawn up which guarantees to
protect the falls and keep them flowing and clean.