Section 4- Coastal Hazards and Their Management

Question 1

What is a coastline?

Answer 1

is the boundary where land meets the sea

Question 2

What is vulnerability ?

Answer 2

the potential to be harmed by a natural hazard.

Question 3

What are the 4 physical factors that increases the vulnerability ?

Answer 3

Magnitude - the stronger the hazard, the more severe the impacts
Duration - the longer the hazard lasts, the more severe the impacts are
Predictability - hazards that hit without warning will have more serious results
Regularity - if hazards often and in quick succession, so the communities dont have the capacity to recover before the next storm hitd

Question 4

What is Magnitude?

Answer 4

a quantitative measure of the size of a natural event

Question 5

What is Capacity?

Answer 5

the ability if a country or region to react to recover from a natural hazard

Question 6

What are the social and economic factors that increase vulnerability ?

Answer 6

Wealth : poor people are less able to afford housing that can withstand extreme events and are less likely to have the money or insurance that can help recover
Education : when population are literate, messages can be used to spread information either before the event or to issue warning and give advice during

Question 7

What is a storm surge?

Answer 7

a rapid rise in sea level caused by storms forcing water into narrow sea area

Question 8

What is isostatic change?

Answer 8

change in the height of land relative to the sea, often because of the melting ice from the last ice age

Question 9

How are coastlines managed (HARD) ?

Answer 9

• sea walls
• groynes
• rip rap
• gabions
• revetments

Question 10

How are coastlines managed (SOFT) ?

Answer 10

• beach nourishment

- managed retreat

Question 11

What are the advantages and disadvantages of sea walls ?

Answer 11

\+ provide excellent defence where wave energy is high
\+ have a long life span
- expensive 
- affect access to the beach
- can increase erosion of beach material

Question 12

What are the advantages and disadvantages of groynes ?

Answer 12

+ relatively cheap
+ retain a wide sandy beach
- beaches further along the beach dont get as much beach material

Question 13

What are the advantages and disadvantages of rip rap?

Answer 13

\+ relatively cheap
\+ effective
- unattractive
- access to beach becomes difficult 
- costs increase when rocks is imported

Question 14

What are the advantages and disadvantages of gabions ?

Answer 14

+ cheap
+ effective
- visually unattractive
- shorter life span than sea wall

Question 15

What are the advantages and disadvantages of revetments ?

Answer 15

\+ cheaper 
\+ less intrusive than sea walls
\+ cause less erosion of beach material
- short life span 
- unsuitable where wave energy is high

Question 16

What are the advantages and disadvantages of beach nourishment ?

Answer 16

+ relatively cheap
+ it retains the natural look of the beach
- offshore dredging of sand and shingle increases erosion in other areas and affects ecosystems
- beach replenishment is necessary on a regular basis, increasing costs

Question 17

What are the advantages and disadvantages of managed retreat ?

Answer 17

+ it retains the natural balance of the coastal system
+ eroded material encourages the development of beaches and salt marshes
- the costs depends on the amount of compensation that needs to be paid to landowners and homeowners
- people lose their livelihoods and homes

Question 18

What is soft engineering ?

Answer 18

works with natural systems, using natural materials and processes. Less expensive and low impact on the environment and is more sustainable

Question 19

What is hard engineering?

Answer 19

building artificial structures to control coastal processes. Usually expensive and has high impacts on the environment and is unsustainable

Question 20

What is managed retreat?

Answer 20

allowing the sea to breach sea defences and flood the land behind it

Question 21

What is beach nourishment ?

Answer 21

sand and shingle are added to the beach to make it higher and wider

Question 22

What is hold the line ?

Answer 22

where existing coastal defences are maintained but no new ones built. Hard and soft engineering is used to keep the coastline in the same place

Question 23

What happens in managed retreat ?

Answer 23

people move out of danger zones and let the coastline move inland.

Question 24

What is cliff regrading ?

Answer 24

reducing the angle of a cliff to reduce mass movement

Question 25

For the Holderness Coastline why does it have high erosion rates?

Answer 25

• rocks are weak boulder clay
• tides and winds from north-east
• beaches are narrow and offer little protection

Question 26

What are the risks for the Holderness Coastline ?

Answer 26

• fertile farmland will be lost to the sea
• more villages will disappear
• major roads will disappear into the sea

Question 27

What are the management strategies for the Holderness Coastline?

Answer 27

• Hornsea has been protected by groynes, a sea wall and rip rap
• Mappleton has been protected by groynes, rip rap and cliff regrading

Question 28

How can the community be protected by a hazard?

Answer 28

monitoring - being able to predict extreme weather
hazard mapping - being able to know which areas will be affected by the hazard
emergency services - having the resources and training to react to the hazard

Question 29

What are hazard maps?

Answer 29

a map that highlights are that are affected by, or vulnerable to a particular hazard.

Question 30

Why are some coastlines at greater risk than others?

Answer 30

• some coasts are sinking or subsiding
• rocks which make the coast soft or hard
• coastal storms affect some coastlines more than others

Question 31

What are the effects on the Maldives and the sea rising

Answer 31

• threaten the existence of the Maldives
• flooding od beach resorts, damaging tourism that the economy depend on
• more intense tropical storms
• damage to coral reefs due to warmer sea temperatures.
• agricultural land is lost and fishing industry is disrupted

Question 32

How can the Maldives manage the risk of the sea level rising?

Answer 32

• a 3m high wall has been built in Male the capital, cost $63 million funded by Japan
• the smaller islands could be evacuated.
• dyke could be built to hold back the sea.
• the height of the islands could be increased, requires a lot of sand
• the population could be relocated in Australia