Please enable JavaScript.
Coggle requires JavaScript to display documents.
Coast LDQ: Protection measures of coast (Laws and Regulations (Limiting…
Coast LDQ:
Protection measures of coast
Engineering Measures
Soft Engineering measures
Beach Nourishment
E1:
Beach nourishment
slows down
erosion as
depleted
beach is
replenished
constantly with sand from
another beach
or
dredged
\picked up from the sea floor.
E2:
For example, in
Sentosa
, Singapore, fine sand was brought in to replenish
Siloso
,
Palawan and Tanjong
beaches and these beaches became
aesthetically pleasing
L:
However, trucking or
piping
sand can be expensive and
time consuming
. Moreover, the sand that is
washed out
to the sea can
suffocate
the coral reefs
Planting vegetation (mangrove)
E:
Mangroves have prop roots that anchor the trees firmly in the muddy soil and
bind loose soil
to prevent erosion. Mangroves protect the coast from damages caused by
strong waves and winds
.
E2:
For example, mangroves have protected the entire
4800km Malaysian
coastline against strong winds and waves, and have successfully prevented erosion.
L:
However, not all places are suitable fir mangroves to grow. They can only grow in
tropical region
. Moreover, mangroves may take
a number of years
to be established before it can resist natural elements such as
storms
and human elements such as
trampling
.
Stabilizing sand dunes
E1:
Vegetations such as
marram grass
are planted to
trap and bind
sand together. At the same time, the authority fenced off the sand.dunes and build access path to the beach
E2:
For example,
marram grass
is planted at
Omaha Beach
in
New Zealand
and has effectively
stabilised sand dunes
and
prevented erosion
.
L:
However, the fences on the sand dunes make the beach less attractive and do not allow visitors and residents access to all parts of the beach.
Grow coral reefs
E1:
Coral reefs reduce the speed of the waves. When waves approach the beach, energy is lost. Therefore, erosion is weaker.
E2:
For example,
Maldives
has been operating a
coral-growing programme
to help curb sever
beach erosion
on its
many islands
. Solar-generated electricity structure is placed off the coast to speed up coral reef.
L:
However, coral reefs cannot be grown in all coastal areas. Coral can only grow in
warm area,
and at a
specific depth
of water so that the corals can still
absorb sunlight.
Moreover, as they can only grow in
clean water
, large amount of money will be spent to
clear up
the coastal area before the programme is implemented.
Hard engineering measures
Seawall
P:
A seawall is a concrete structure built
along and parallel
to the coastline
E1:
Seawalls
reflects
the energy of waves away from the coast. It is effective as it reduces coastal erosion and
protects low-lying land
E2:
For example, Singapore has built seawall along
Esplanade Park
, near the
mouth of Singapore river
and has successfully reduced erosion.
L:
However, the reflected wave energy is
directed
to the base of the seawall, causing it to
collapse
eventually.
Moreover, it is
expensive
to build seawalls along the entire coastline and
constant maintenance
is required. Therefore, the less developed countries are not able to afford it.
Also, building such a large physical structure may
disrupt
the natural
coastal process
and natural
environment
.
Breakwater
P:
Breakwaters are granite structures built with
one end attached to the beach
, or at
some distance
from the beach.
E1:
Breakwaters
break
the
force of the oncoming waves
at some distance from the coast. As a result, a
quiet zone
of water is created behind the breakwaters, allowing
deposition
to build up the beach.
E2:
For example, breakwaters have been successfully built up in east coast park, and Siloso beach at Sentosa, in singapore.
L:
However, breakwaters protect the coast
unevenly
. Parts of coast that are not protected by breakwaters subjects to erosion.
Moreover, breakwaters are
aesthetically unappealing
.
Large amount of money is also needed for
maintenance
as they are constantly hit by waves.
Gryone
P:
Gryones are
low walls
built
perpendicular
to the coast to trap beach sediments
E1:
Gryones
interrupt
the
longshore drift
and cause materials to be
deposited
on the side of the gryone that is facing the longshore drift. (updrift side)
E2:
For example, gryones are built in
Sussex, United Kingdom
, to stop the removal of beach sediments due to longshore drift.
L:
However, unprotected part(downdrift side) of the coast is
deprived of depositional materials
and is subjected to even greater erosion. Gryones also spoilt the natural beauty of the coast.
Gabion
P:
Gabions are
wire cages
containing
small rocks
that are built to form a
wall
to protect the coast.
E1:
Gabion
conform
movement of the ground and
dissipate
the wave energy
more easily
as the gaps between rocks
allow water
to flow through.
E2:
For example, gabions in
North Norfolk
,
United Kingdom
, weaker wave energy and help to reduce the rate of erosion.
L:
However, gabions are
easily destroyed
by strong waves during storms and the
wires rust
easily. If not maintained constantly, wire cages may be
unsightly and dangerous
.
Limitation for all:
Disrupt the natural environment and spoil the natural beauty of the coast
Expensive as maintenance is needed
Laws and Regulations
Limiting damaging activities
P:
Government limits damaging activities as they
interrupt
the functioning of
natural systems
. These activities include
blasting coral reefs
for
channels of ships
and
clearing mangroves for fish farm
E1:
This is done through government bodies who
align
the needs and
demands of people
with the
nature of the coastal environment.
E2:
For example, sand dunes in
Port Philip, Melbourne
are often
trampled
by visitors. To protect the dune
vegetations
and prevent
erosion
, the government
fenced off
the sand dunes and built access path to the beach.
L:
However, these fences make the coast
less attractive
and do not allow residents and visitors to
access
to parts of the beach.
Protect coastal resources
P:
Government protect coastal resources from being exploited or
depleted
.
Marine reserves marke off
area close to the coastline and prevent
commercial fishing*
.
E1:
Establishment of
marine reserve
protects marine
ecosystems
and allow
fish and endangered species
to
breed
and
thrive
.
E2:
For example,
Goat island
in
New Zealand
is now a tourist attraction because of its
plentiful fish
. This indicates the
positive management impact
of protecting coastal resources
L:
However, there is strong objective from the local
fishermen
as their
access
to valuable
resources
and
food
has been denied. The
long term benefit
of a marine reserve threatens the
mean survival
of local fishermen
Deal with natural hazards
P:
Government manage the coastal areas by dealing with natural hazards
E1:
The government
plans
and
enforces management policies
to protect the coastal area from natural hazards.
E2:
For example, in
Indonesia
, there are laws that restricts
new residence
from being built on
low-lying coastal areas.
L:
However, despite the
occurrence
and
unpredictability
of natural hazards, people are still
attracted
to coasts as many coasts provide resources such as food and building materials
substantial build services
such as ports,
housing
and
recreational facilities.