This document provides an overview of coastal environments and processes. It begins with key thinking questions about coasts and their value. It then defines coasts and describes their main zones or parts. Two main factors that affect the coastal environment are tides and sea level changes. The document also discusses coastal erosion processes like abrasion and hydraulic action. Finally, it introduces coastal landforms like cliffs, shore platforms, headlands and bays that result from erosion.

1. Chapter 1: Coasts
Chong Boon Secondary School
Pure Geography
Physical Geography

2. Lesson 1

3. Key thinking questions
• Should coastal environments matter?
• How and why are coastal environments
different and dynamic?
• Why are coastal areas valuable?
• How can we manage coastal areas in a
sustainable manner?

4. What are coasts?
• The area where land meets the sea
• Affected by various agents – waves,
tides and currents
• Divided into various zones –
offshore, nearshore, foreshore and
backshore
• There are various types of coastal
environments (pg 5)

5. Parts of a coast (pg 5)
• Offshore – submerged region extending
out to the sea
• Nearshore – always submerged below
the low-tide level, area where breakers
start forming
• Foreshore – submerged during high-tide
but exposed during low-tide
• Backshore – where the berm is usually
found

6. Factors that affect the coast
• Tides – daily alternate rise and fall in the
sea level caused by gravitational pull of
the moon and sun
• Sea level changes – change in sea
levels due to ending of ice age or climate
change
• Currents – large scale and continuous
movements in the oceans and seas
Watch the videos on the FB page on how tides and
currents work.

7. Factors that affect the coast
• Geology – refers to the
composition and also the
arrangement of rocks found at
the coastal area
• Ecosystems – affects the rate of
coastal changes by reducing the
impact of waves

8. Evaluation
• You have 5 minutes to relook at the
information.
• After 5 minutes, you will attempt the
mini test.
• You have 10 minutes to complete the
test.

9. Mini Test
In Progress

10. Group activity 1
• What is a coast? Select a suitable cross section
diagram that will show the parts of the coast.
• List down what your team feels are the 2 main
factors that affect the coastal environment.
– 15 minutes, discuss and put down what your team
feels is correct.
– Point form.
– Put up your answers once you are ready.
– Assign your presenter(s).

11. Presentation Time
• Presenters please stand by your
answers.
• Present your answer.
• 2 minutes maximum!

12. Individual activity
(use the blank side of the minitest)
• Copy the questions and answer it in the blank
space.
Q1 Using only a fully labelled diagram, show
what the parts of a coast. (4m)
Q2 List and explain two factors that affect the
coastal environment (4m)
Optional

13. Homework reminder
• Read up pg 9 to 16.
• Focus on the Coastal
Erosional Processes &
Waves.

14. Lesson 2
Wk 2

15. Let’s take a look at
your 1st mini test
Please take out your
worksheet

16. Self
Evaluation
• Let’s look at the key thinking
questions for this part of the chapter.

17. Key thinking questions
• What affects a wave’s speed and energy?
• What are the parts of a wave?
• What is a swash / backwash?
• Why do waves break near the coast?
• What is the difference between
Destructive and Constructive waves?

18. Factors that affect waves
• Wind speed
• Duration of wind
• Fetch – refers to the distance of
open sea that is exposed to effects
of wind
How does each factor affect
wave energy?

19. Waves in general…
• As waves approach the coasts, the
depth of the water becomes
shallower
• When the depth is about half of the
wavelength, the wave starts to
change
• The base of the wave starts to slow
down due to friction
• Wave height increases and
wavelength decreases

20. Waves in general…
• When the base of the wave stops,
the wave crest becomes steeper
and topples over
• This causes the wave to “break”
over the coast and releasing the
wave energy
• Surfers are always in search of
these breaking waves to ride over
them
• *breakers, breaking waves

21. Waves in general…
• Swash: water moving up the shore,
brings sediments in
• Backwash: water moving down the
shore, carries sediments away
• Constructive waves: waves with
swash more powerful than the
backwash
• Destructive waves: waves with
backwash more powerful than the
swash

22. Wave refraction
• Refers to a process where waves
change direction as they approach
the coast
• *** Refraction occurs because wave
energy will always approach the
coast perpendicularly
• Refraction therefore causes wave
energy to concentrate on headlands
and spread out at bay areas

23. Group activity 1
• Using only a diagram, show the various parts
of the wave. (Crest, Trough, Wave height,
Wave length)
• Explain how any 2 given factors affect the size
and energy of waves.
• With the aid of a suitable diagram, describe
what are constructive waves.
– 10/20 minutes, discuss and put down what your
team feels is correct.
– Point form.
– Put up your answers once you are ready.
– Assign your presenter(s).

24. Gallery Walk Time
• Please put up your presentations on the
given space.
• Let’s do a gallery walk.
• You are to award stars to the
presentations that you feel are the best.
• Each person has 2 stars only.
• You should not give both to the same
group.

25. Homework
• Take a detailed look at the Investigation Task
(pg 10 & 11)
• Refer to Pg 253-254 on how to construct a
scatter graph.
• Refer to Pg 265 on how to annotate maps
• Refer to Pg 264 on how to take and annotate
photographs.

26. Homework reminder
• Memorise the 4 coastal processes
on pg 15.
• We will be looking at these on
Lesson 3.

27. Lesson 3

28. Individual activity
• Look at the exercise given,
complete it to your best ability.
• You have 8 minutes.

29. What is C.A.S.H ?

30. COAStal erosion (c*A*S*H)
• Corrasion (Abrasion): when
sediments such as sand and
rocks scrape against the coast
and breaks down the coast
• Attrition: when sediments rub or
hit against one another and
become smaller and more
rounded

31. COAStal erosion (c*A*S*H)
• Solution (Corrosion): when seawater
chemically reacts with the minerals in
coastal rocks and dissolves them, e.g.
limestone rocks are easily eroded by
carbonic acid
• Hydraulic action: when the coast is
struck by action of water, air within the
joints are compressed and exert
pressure, which weakens the rock
structure

32. Group Activity
• In your groups, discuss and come up
with a simple way to explain any 3
erosional processes.
–It can be in the form of a dance/rap/song/
diagram/ skit / etc.
–Your presentation must not be more than 3
minutes long.
–You have 20 minutes to prepare.

33. Lesson 4

34. Individual activity corrections
• Look at the exercises I’ve
returned.
• Let’s do corrections
• File it in!

35. Prep for next lesson
• Read Pg 16 carefully.
• Watch the prescribed video on
Long shore drift
• Practice drawing the diagram

36. Lesson 5

37. Key thinking questions
• What affects the transport of sediments
on a coast?
• How does a piece of sediment move
along the coast?
• What are longshore currents?
• What is longshore drift?

38. Sediment transport
• Refers to the movement of sediments
along the beach
• Beach drift: zigzag movement of
sediments along the beach
• Sediments move up the beach at an
angle as swash
• Sediments move down the beach
perpendicularly as backwash

39. Sediment transport
• Longshore currents: ocean
currents flowing parallel to the
coastline
• Moves sediments along the
shore
• Combine effect of transportation
by longshore currents and
beach drift is longshore drift.
diagram

40. Sediment deposition
• Refers to the process where
sediments are let go and no longer
carried by the waves due to loss of
wave energy
• Usually larger sediments get
deposited first (WHY?)
• Sheltered coasts with calmer waters
have fine sediments
• Small bays tend to have coarser
sediments

41. Self
Evaluation
• Complete the timed exercise now.
• You have 10 minutes.

42. Group activity 1
• Using only a diagram, show how a sand
particle is moved along the beach.
• List and explain the four ways in which coastal
erosion can occur.
• With the suitable diagrams, compare
constructive waves and destructive waves
– 30 minutes, discuss and put down what your team
feels is correct.
– Point form.

43. Gallery Walk Time
• Please put up your presentations on the
given space.
• Let’s do a gallery walk.
• You are to award stars to the
presentations that you feel are the best.
• Each person has 2 stars only.
• You should not give both to the same
group.

44. Homework
• Take a detailed look at the
Investigation Task (pg 17)
• Read Pg 17to 29.

45. Lesson 6

46. Key thinking questions
• What are the landforms that are caused
by waves?
• What coastal landforms are linked and
related?
• Besides the force of water, what other
materials are used to form the coast?

47. Sediment deposition
• Refers to the process where sediments
are let go and no longer carried by the
waves due to loss of wave energy
• Usually larger sediments get deposited
first (WHY?)
• Sheltered coasts with calmer waters
have fine sediments
• Small bays tend to have coarser
sediments

48. Coastal features
• Various landforms and
features can be found at
coasts
• The types of features found
tend to be due to factors such
as type of waves, type of
rocks (geology), the location,
and human activities

49. Cliff and shore platforms
• Cliff: A steep or near-vertical
rock face found along coasts
• Shore platform (or wave-cut
platform): gently sloping
platform usually found at the
base of a cliff and submerged
during high tides

50. Cliff and shore platforms
• Due to hydraulic action and abrasion,
a joint or crack in the rocks may be
enlarged to form a notch, usually
found between the high and low tide
mark
• The notch may be further eroded and
enlarged to form a cave
• Further erosion and gravity eventually
causes the roof of the cave to
collapse

51. Cliff and shore platforms
• This results in the formation of a
steep rock face, or cliff
• With further erosion, undercutting
occurs at the base of the new cliff
face
• As the overhang collapses, the cliff
retreats inland
• The gentle slope at the base of the
cliff where previous cliffs used to be
is the shore platform

52. Headlands and bays
• Occurs due to the uneven rates
of erosion of different rock types
• Usually found in locations where
there are bands of alternating
resistant and less resistant
rocks
• What is an example of less
resistant rock?

53. Headlands and bays
• As the less resistant rocks are
more easily eroded, they give
rise to bays
• The resistant rocks will stand out
as headlands
• The formation of headlands and
bays gives an indented coastline

54. Homework
•Revise the entire set of
content we’ve covered so
far.
•Next lesson we will do a
mini test