Lesson 1
• Check equipment list
• ‘Semester 1 Planner’ and Course Outline
• Reflect on Transition exercises
• Introduction to Coasts unit
(see page 74 of New Perspectives)
Year 11 VCE Geography – 2010 Semester 1 Planner
Week
1
Term 1
2
Introduction to Coastal Environments
Characteristics of a coastal environment
Coastal erosion features and processes
College swim sports Thu 11 Feb
3
4
Coastal deposition features and processes
5
Changes on coastal environments
Senior Sport Mon 22 Feb
Impacts of human activity on coasts
College X Country Run Tue 2 Mar
Coastal Environments Fieldtrip Tue 9 Mar
Coastal Environment Fieldwork analysis
Labour Day Mon 8 Mar VET Camp Phillip Island
Wed 10 Mar
SAC – Fieldwork Report and Test
Submission date Thur 18 Mar
Introduction to Volcanic Environments
Earth structure and plate tectonics
6
7
8
9
Term 2
Characteristics of a volcanic environment
College Athletics Wed 14 Apr
Eruptions and volcanic features
Summarising volcanic characteristics
Changes in a volcanic environment
Anzac Day Mon 26 Apr
Changes in a volcanic environment
Volcanic Case Study analysis
Volcanic Environment Research Report
District X Country Mon 10 May
SAC - Research Report completion
Senior Sport Tue 18 May
SAC – Research report
Submission date Mon 24 May
Mid Year Exam revision
Yr 11 Mid Year Exams
Introduction to Urban Environments
10
Central Australia Tour departs Thu 17 June
11
Unit 1 – Natural Environments
This unit investigates the geographic characteristics of natural environments and
landforms and the natural processes that shape and change the earth’s surface. It
investigates how the interactions between natural processes and human activities can
also change natural environments.
Students must investigate at least two natural environments in each area of study
Term 1 – Coasts
Area of study 1
Area of study 2
Term 2 – Volcanic environments
Characteristics of natural environments
Changes in natural environments
Task 1 – Define a coast. Write a definition in your folder
What is a coast?
‘A coast is the link between the sea and the land, and there is a strong spatial
interaction between these two zones. What happens on land affects the sea and
what happens in the sea affects the land’.
(Taken from Place and Change by Pask. R et al, 2002)
Technically, the term refers to the region that stretches from the shallow water
of the continental shelf to the furthest extent of wave and tide influence on the
land.
Coasts are not static, they are dynamic places. They quickly change shape and
location in response to natural processes and human activities. For example, sand
and other materials are moved onto and off beaches by currents and waves.
During major storms, huge waves can move large amounts of coastal sediment,
and can flood vast areas in hours.
Task 2 – Familiarise yourself with the coastal zones on Pg. 75
of ‘New Perspectives’ and label the photograph handout. Put
completed photo annotation in your folder.
Annotate this photo using the coastal
zones diagram on page 75 of NP.
Lesson 2
Task 3 – Discuss as a class, different types of coasts and
copy descriptions of coast types into folder.
Talk to each other about which coastal regions you have been
to and identify which coast type they characterise.
Task 4 – Trace the Victorian coastline onto tracing paper,
using the satellite image provided. Add a key and label
different coast types. Then discuss in a group, how
swell/wave direction impacts on the Victorian coastline. Use
Pg.77 of ‘New Perspectives’ to help you.
Task 5 – Even though the sea and wind conditions vary daily,
the Victorian coastline is usually subjected to waves from
the south west. Explain why this is the case.
Task 6 – Describe the distribution of different types of coast
within Victoria. Give some reasons for these variations.
Lesson 3 - How coasts are formed
Next we will be looking at how waves are formed and ways in which they can shape the
land.
Open two text resources to help you – New Perspectives pg 78-79 and Jacaranda essentials
Geography 2, page 82 and 83
You will also need to load the Coasts Interactive PowerPoint and refer to slides 1-7 an 27-28
to assist you in completing this task.
Task 7 - Please write down a definition for each of the following terms and also draw a
simple diagram to illustrate the term. You may use the diagrams in the books and on the
PowerPoint to assist you.
•
•
•
•
•
•
Swash
Backwash
Destructive wave
Constructive wave
Fetch
Longshore drift
Task 8 - Once you have finished your definition of ‘longshore drift’, attempt Activity 6,
7a,b,c and d, on Page 83 of Jacaranda Geography 2 to test your understanding of the
longshore drift process.
Lesson 4 - Coastal features
caused by erosion
Today we will be looking at types of coastal erosion and features or landforms
that are caused by coastal erosion.
Types of coastal erosion
Abrasion, hydraulic action, attrition, corrosion, sub-aerial erosion
(also could look at mass movement and dune blowouts)
Coastal features/landforms caused by erosion
• Headlands and bays
• The influence of wave refraction and wave reflection
• Wave-cut notch and wave-cut platform
• Caves, arches, stacks and stumps.
Types of coastal erosion
Abrasion, hydraulic action, attrition, corrosion, sub-aerial erosion
(please see New Perspectives page 78 for definitions)
Abrasion
Corrosion
Hydraulic Action
Sub-aerial erosion
Headlands and bays form on coasts where bands of rock of alternating
resistance run perpendicular (at right angles) to the coast.
Bays form where weak/less resistant rocks (such as sandstone or clay) are
eroded, leaving bands of stronger/more resistant rocks (such as chalk,
limestone or granite) forming a headland.
Wave refraction:
is the bending of waves as they
reach shallow water. This causes
the curving of wave crests around
the headland.
Wave energy is concentrated
around the headland , causing
eroded landforms such as wavecut notches, stacks, and arches.
Wave reflection:
The reflecting of wave energy back
towards the sea, usually occurring
where a wave strikes a solid surface
such as a cliff or sea wall.
This causes the erosion and
transportation of sediment back into
the sea.
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography and only
for non commercial use in schools
14
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
15
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
16
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
17
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
18
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
19
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
20
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
21
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
22
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
23
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
24
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
25
Shallow
water
Shallow
water
Tom Abbott, Biddulph High School
and made available through
www.sln.org.uk/geography
and only
wave
for non commercial use in schools
26
Wave cut platform
A wave-cut notch forms after
destructive waves hit against the cliff
face, causing undercutting between the
high and low water marks.
Wave cut platform
Over time, a wave-cut notch enlarges into a
cave. The waves undercut this portion until
the roof of the cave cannot hold due to the
pressure, and it collapses, resulting in the cliff
retreating landward. The base of the cave
forms the wave-cut platform as attrition
causes the collapsed material to be broken
down into smaller pieces and transported by
waves as sand sediment.
Cave
Caves form when the sea attacks small cracks in a headland
and opens them. The cracks then gradually get larger and
turn into a small cave.
Arch
An arch is formed when a sea cave is eroded away on
both sides of the headland.
Sea stack
Continued erosion of an arch causes the arch to collapse,
leaving the pillar of hard rock standing away from the
coast called a stack.
Sea stump
Eventually, erosion will cause the stack to
collapse, leaving a stump. This stump is usually a
small rock island; small enough to be submerged
by high tide.
Task – photo annotation
Each photograph provided includes
examples of a variety of coastal
processes and coastal features formed
by erosion.
• Cut out each photo and stick it in
your folder.
• Annotate each photograph, using
arrows, terms and explanations .
Explain each coastal feature or process
you can identify.
• Include: headland, bay, wave-cut
notch, wave-cut platform, arch, cave,
stack, stump, wave refraction, wave
reflection, abrasion, sub-aerial erosion
and hydraulic action.
Lesson 5 - Coastal features
caused by deposition
Today we will be looking at types of coastal features or landforms that are
caused by coastal deposition.
Constructive waves are responsible for building up coastlines by transporting
sediments to the shore and depositing them.
Coastal deposition features/landforms
• Beach
• Sand dune
• Sand spit
• Tombolo
Beach
A beach usually consists of loose particles which are often composed of rock,
such as sand, gravel, shingle or pebbles. Beaches can sometimes have biological
origins, such as shell fragments.
Beaches are formed when sand or other loose sediments are transported by wave
action. Beach materials come from erosion of rocks offshore, as well as from
headland erosion and slumping (collapsing).
Sand dunes
Dunes occur in different forms and sizes,
formed by interaction with the wind, when
dry sand is blown to the black of the
beach(transportation). Most dunes are
longer on the windward side where the
sand is pushed up the dune and have a
shorter slip face in the lee of the wind.
Task
Study the information and diagram on
sand dunes on page 89 of Jacaranda
Geography 2.
1. Describe the conditions with which dune
vegetation needs to cope.
2. List some adaptations that help plants to
survive in dune environments.
3. What might be the consequences of
removing vegetation from sand dunes?
Sand Spit
A sand spit is one of the most common coastal landforms. A sand spit is a linear
accumulation of sediment (a build up of sand in a line) that is attached to land at
one end.
How it is formed
Sand is carried parallel to the shore by longshore drift. The transportation of sand
may eventually extend across a bay or between headlands especially where water
is relatively calm. Spits are typically elongated, narrow features built to several
dozen feet by wind and waves.
Spits often form when wave energy
decreases as a result of wave refraction
(see notes to remind yourself what this
means) in a bay. When a coastline turns
abruptly, wave energy is reduced by a
divergence of wave trajectories. This
reduction in wave energy causes the
deposition of sediment (mainly sand). In
other words, sand accumulates as the
water loses its ability to transport material.
Spits grow in size as sand is continually deposited in the direction determined by
prevailing winds (longshore drift). As spits grow, the sheltered area behind them
often develops into a marshland, where plant and animal species can thrive.
In a case where a sand spit forms near the mouth of a river (such as in the two
diagrams below), the fast currents from the river mouth (estuary) erode the sand
accumulating in the river channel, preventing it from depositing sand all the way
across the river to the next headland.
In cases where a river estuary is not present, wave energy levels will determine the
length of the sand spit. Sand will only accumulate where deposition occurs; not
erosion.
Examples
Two sand spits formed by longshore drift occurring in opposite directions.
A - right to left
Revel Island, Virginia, USA
B - left to right
Dawlish Warren, Dorset, England
Sand spit formation
This photo shows Dawlish Warren sand spit in England.
Task
4. Using your notes on sand spits and your knowledge of coastal processes of
erosion, transportation and deposition, describe the processes that are occurring at
each point (a,b,c,d) and explain the causes.
5. Identify which coastal
management strategies are
being used at E & F, and
explain how they work.
6. State which of the
following is occurring at
each point: erosion,
transportation or deposition
7. State what the wave
energy level is likely to be at
each point.
8. Draw an annotated diagram in your folder of the photo, include answers to
tasks 2,3 & 4.
9. The Dawlish coastal management agency wishes to widen the estuary to allow
larger vessels to enter the river. Design a coastal management plan to solve this
issue.
You will need to:
• Draw 3 diagrams
Diagram 1 – current situation
Diagram 2 – coastal features altered
Diagram 3 – final coastal layout
• Annotate each diagram with
explanations of coastal processes
occurring and management
strategies to control these
processes.
Tombolo
A tombolo is a deposition landform such
as a spit or bar which forms a narrow piece
of land between an island or offshore rock
and a mainland shore, or between two
islands or offshore rocks. They usually
form because the island causes wave
refraction, depositing sand and shingle
moved by longshore drift in each direction
around the island where the waves meet.
Task
10. Describe the difference between a spit
and a tombolo.
Lesson 6 – Coastal management
In future lessons, we will explore human impacts in the coastal environment; positive
and negative. Firstly, let’s use our knowledge of coastal erosion, transportation and
deposition to explore the techniques used to protect this vulnerable and dynamic
environment.
Today we will be looking at ways to protect the coastline through human
intervention.
Coastal protection techniques
Hard construction
Soft construction
• Groynes
• Beach nourishment
• Revetments
• Sand dune stabilisation
• Riprap
• Gabions
• Breakwaters
Groynes
Groynes are wooden, concrete or rock barriers (walls)
perpendicular to the sea. Beach material builds up on the up drift
side, where littoral drift (longshore drift) is predominantly in one
direction, creating a wider and a more plentiful beach.
The groyne structure enhances the protection of the coast
because the retained sand material filters and absorbs the wave
energy.
There is a loss of beach material on the down drift side, requiring
that another groyne to be built there. This is why groynes are
often laid in groups, not on their own.
Positives
• Groynes are extremely common, cost-effective coastal
defence measures, requiring little maintenance.
Negatives
• Groynes do not protect the beach against storm waves and
if placed too close together will create currents, which will
carry sand material offshore.
• Groynes are increasingly viewed as detrimental to the
aesthetics of the coastline, and face strong opposition in
many coastal communities.
Revetments
Revetments consist of wooden slanted or
upright blockades, built parallel to the sea on
the coast, usually towards the back of the beach
to protect the cliff or settlement beyond. The
most basic revetments consist of timber slants
with a possible rock infill
Riprap
Riprap is made from a variety of rock types, commonly
granite, limestone or occasionally concrete rubble from
building and paving demolition.
Riprap works by absorbing and deflecting the impact of
a wave before the wave reaches the defended structure.
The size and mass of the riprap material absorbs the
impact energy of waves, while the gaps between the
riprap traps and slows the flow of water, lessening its
ability to erode soil or structures.
Gabions
Gabions consist of boulders and rocks contained in a wired mesh cages and usually
placed in front of areas vulnerable to heavy to moderate erosion: sometimes at
cliffs edges . They may also be placed to jag out at a right angle to the beach like a
large groyne. When the seawater breaks on the gabion, the water drains through
leaving sediments, also the rocks and boulders absorb a moderate amount of the
wave energy
Offshore breakwater
An offshore breakwater is constructed using large concrete
blocks and natural boulders. These materials are sunk offshore
to alter wave direction and to filter the energy of waves and
tides. The waves break further offshore and therefore reduce
their erosive power. This often leads to wider beaches, which
absorb the reduced wave energy, protecting cliff and
settlements behind.
Aerial photo
Breakwaters can also be attached to the land. This is very common adjacent to a
marina. In the case below left, two breakwaters protect the coast and provide shelter
for the local marina.
Port Taranaki, NZ.
Plymouth Breakwater, UK.
Beach nourishment
Beach nourishment or replenishment is one of the
most popular soft engineering techniques of coastal
defence management schemes. This involves
importing alien sand off the beach and piling it on top
of the existing sand. The imported sand must be of a
similar quality to the existing beach material so it can
integrate with the natural processes occurring there,
without causing any adverse effects. Beach
nourishment can be used alongside the groyne
schemes.
Sand dune stabilisation
Vegetation can be used to encourage dune growth by
trapping and stabilising blown sand. A common form
of planting in the foredunes is Ammophila.
These grasses include Marram Grass, Bent Grass, and
Beach Grass. Their extensive systems of creeping
underground stems allow them to thrive under
conditions of shifting sands and high winds.