2.3.1 Coastal Management

Question 1

Aim of coastal management

Answer 1

To protect homes, businesses and the environment from erosion and flooding.

This is because flooding and erosion of the coastline can have severe social, economic and environmental impacts.

Question 2

How do local authorities choose which (and how) places are defended?

Answer 2

Using a cost-benefit analysis.

The money available is usually used to protect large settlements and important industrial sites, rather than isolated or small settlements.

Question 3

Four main options for coastal management

Answer 3

• Hold the line
• Advance the line
• Managed retreat
• No active intervention (do nothing)

Question 4

Hold the line

Answer 4

Maintain the current location of the coast usually by using hard engineering.

Question 5

Advance the line

Answer 5

Extending the coastline further out to sea by reclaiming land or encouraging the build up of material.

Question 6

Managed retreat

Answer 6

Allow the coast to retreat, but manage the retreat so that is causes least damage (typically by sacrificing low value land).

Question 7

No active intervention (do nothing)

Answer 7

Build no coastal defences at all, and deal with erosion and flooding as it happens.

Question 8

Soft engineering

Answer 8

Soft engineering encouraging natural processes to manage (but not necessarily prevent) erosion.

Question 9

Soft engineering techniques

Answer 9

• Beach nourishment
• Beach stabilisation
• Dune regeneration
• Lane use management
• Creating marshland
• Coastal realignment (managed retreat)

Question 10

Hard engineering techniques

Answer 10

• Sea wall
• Revetment
• Gabions
• Riprap
• Groynes
• Breakwaters
• Tidal barriers

Question 11

[Soft engineering]

Beach nourishment

Answer 11

Where sand and shingle are added to breaches from elsewhere (e.g. dredged from offshore). This creates wide beaches, which reduce erosion of cliffs more than thin beaches

Question 12

[Soft engineering]

Beach stabilisation

Answer 12

This is done by reducing the slope angle and planting vegetation. It also creates wide beaches, which reduce erosion of cliffs.

Question 13

[Soft engineering]

Dune regeneration

Answer 13

Where sand dunes are created or restored by either nourishment or stabilisation of the sand.

Dune provide a barrier between land and sea, absorbing wave energy and preventing flooding and erosion.

Question 14

[Soft engineering]

Lane use management

Answer 14

This is used for dune regeneration.

The vegetation needed to stabilise the dune can easily be trampled and destroyed, leaving the dune vulnerable to erosion.

Wooden walkways across dunes, and fenced-off areas that prevent walkers, cyclists or 4x4 drivers from gaining access to the dunes, all reducing vegetation loss.

Question 15

[Soft engineering]

Creating marshland

Answer 15

Creating marshland from mudflats can be encouraged by planting appropriate vegetation. The vegetation stabilises the sediment, and the stems and leaves help reduce the speed of the waves. This reduces their erosive power and how far the waves reach inland, leading to less flooding of the area around the marsh.

Question 16

[Soft engineering]

Coastal realignment (managed retreat)

Answer 16

This involves breaching an existing defence and allowing the sea to flood the land behind. Over time, vegetation will colonise the land and it will become marshland.

Question 17

Hard engineering

Answer 17

Involves building strucures to prtoect the coastline.

Question 18

[Hard engineering]

Sea wall

Answer 18

• The wall reflects energy back out to sea, preventing erosion of the coast. It also acts as a barrier to prevent flooding.
• Cost: Expensive to build and maintain.
• Disadvantage: It creates a strong backwash, which erodes under the wall.

Question 19

[Hard engineering]

Revetment

Answer 19

• Revetments are slanted structures built at the foot of cliffs. They can be made from concrete, wood or rocks. Waves break against the revetments, which absorb the wave energy and so prevent cliff erosion.
• Cost: Expensive to build, but relatively cheap to maintain.
• Disadvantage: They create a strong backwash, as above.

Question 20

[Hard engineering]

Gabions

Answer 20

• Gabions are rock-filled cages. A wall of gabions is usually built at the foot of cliffs. The gabions absorb wave energy and so reduce erosion.
• Cost: Cheap
• Disadvantage: Ugly

Question 21

[Hard engineering]

Riprap

Answer 21

• Boulders piled up along the coast are called riprap. The boulders absorb wave energy and so reduce erosion.
• Cost: Fairly cheap
• Disadvantage: They can shift in storms

Question 22

[Hard engineering]

Groynes

Answer 22

• Groynes are fences built at right angles to the coast. They trap beach material transported by longshore drift. This creates wider beaches, which slow the waves (reducing their energy) and so gives greater protection from flooding and erosion.
• Cost: Quite cheap
• Disadvantage: They starve down-drift beaches of sand. Thinner beaches don’t protect the coast as well, leading to greater erosion and flooding.

Question 23

[Hard engineering]

Breakwaters

Answer 23

• Breakwaters are usually concrete blocks or boulders deposited off the coast. They force waves to break offshore. The waves’ energy and erosive power are reduced before they reach the shore.
• Cost: Expensive
• Disadvantage: Can be damaged in storms

Question 24

[Hard engineering]

Tidal barrier

Answer 24

• Tidal barriers are built across river estuaries. They contain retractable floodgates that can be raised to prevent flooding from storm surges.
• Cost: Very expensive
• Disadvantage: Very expensive!

Question 25

Sustainable coastal management strategies

Answer 25

Coastal management has to be sustainable – this means that strategies shouldn’t cause too must damage to the environment or to people’s homes and livelihoods, and shouldn’t cost too much.

There are two important ideas involved in deciding how to manage coastal areas sustainably:
- Shoreline Management Plans (SMP)
- Intergrated Coastal Zone Management (ICZM)

Question 26

Is hard or soft engineering more sustainable?

Answer 26

• Hard engineering is often expensive, and it disrupts natural processes.
• Soft engineering schemes tend to be cheaper and require less time and money to maintain than hard engineering schemes. Soft engineering is designed to integrate with the natural environment and it creates areas like marshland and sand dunes, which are important habitats.
• So soft engineering is a more sustainable management strategy than hard engineering because it has a lower environmental impact and economic costs.

Question 27

Shoreline Management Plans

Answer 27

• The Coastline is split into stretches by sediment cells. For each cell, a plan is devised for how to manage different areas with the aim of protecting important sites without causing problems elsewhere in the sediment cell (e.g. starving an adjacent area of sediment could increase erosion).
• For each area within a cell, authorities can decide to hold, advance or retreat the line – or to do nothing.
• The overall plan for each sediment cell is called a Shoreline Management Plan (SMP). All the local authorities in one sediment cell co-operate alongside local stakeholders to create an SMP.

Question 28

Stakeholders in the Holderness SMP

Answer 28

For Holderness - The SMP is led by The East Riding of Yorkshire council, but has over 80 stakeholders, including:
- The environment agency
- Local government
- The NFU (economic stakeholder)
- English Heritage (environmental stakeholder)

Question 29

What does the Holderness SMP set out?

Answer 29

The SMP in this region sets out to address coastal erosion and flood risk over the next 100 years.

It includes:
- The protection of critical infrastructure at Mappleton
- Strategic energy protection, as seen in Easington Gas Terminal.
- Protection of major settlements through hard and soft engineering techniques. This is done in Bridlington, Hornsea and Withernsea.
- Designated areas of ‘No Active Intervention’ along areas of the coastline with no population.

Question 30

Integrated Coastal Zone Management (ICZM)

Answer 30

ICZM considers all elements of the coastal system (e.g. land, water, people, the economy) when coming up with a management strategy.

It aims to protect the coastal zone in a relatively natural state, whilst allowing people to use it and developed it in different ways.

• It is a dynamic strategy – decisions are re-evaluated if the environment or demands on the area change.

Question 31

How are ICZMs integrated?

Answer 31

• The environment is viewed as a whole – the land and the water are interdependent.
• Different uses are considered, e.g. fishing, industry and tourism.
• Local, regional and national levels of authority all have an input into the plan.

Question 32

Case study: Coastal management in the developing world

Answer 32

Odisha, India

Question 33

Where is Odisha?

Answer 33

Odisha is a region of North-East India. Management is required for coastal recession and coastal flooding.

Question 34

Challenges of managing Odisha

Answer 34

• Tourism means some players (e.g. business owners and local governments) are keen to preserve a natural appearance and limit hard engineering to prevent loss of profits.
• The local government has limited money to spend. Large scale hard engineering strategies might be too expensive.
• Rapid urban industrialisation creates an argument about the environment vs the economy.
• Odisha is a petroleum producing state. This fossil fuel consumption exacerbates the issue of climate change and flooding.
• Increased intensity and frequency of tropical storms is a key issue as Odisha is at a high risk of tropical storms. - Temperature of Indian Ocean is increasing. 26oC+ is where tropical storms form.

Question 35

Mangrove forests

Answer 35

• Mangrove swamps (which are good natural flood defences) are being deforested for economic purposes. 50 years ago, villages in Odisha had an average width of 5.2km of mangroves protecting them. Today the width is only 1.2km.
• 25% of mangroves have been deforested to make room for shrimp farms.

Question 36

Key players and stakeholders in Odisha’s ICZM

Answer 36

• Government departments, including the water resource department, department for culture and archaeology, and fishing department.
• Odisha Tourism Development Corporation
• Paradeep (a sea-port city) Municipality
• Odisha State Pollution Control Board
• Odisha State Disaster Management Authority

An Integrated Coastal Zone Management (ICZM) project was implemented in 2010 which aims to manage the coast and its resources in a sustainable way. It is the first of its kind in India and relies on funding from the World Bank to protect 480km of coastline.

Question 37

Suggestions of Odisha’s ICZM

Answer 37

• Reforestation of mangrove trees. – These act as natural flood defences.
• Clean environment around Paradeep (a large coastal port) by promoting awareness among urban communities -> maintains economic activity.
• Sea wall construction to protect highly populated areas.
• Regulation of motor boat traffic, to reduce pollution and protect local ecosystems.
• Building multi-purpose disaster shelters to provide future protection against natural disasters.
• Educate fishermen on how to prevent injuring/killing turtles. This improves the local ecosystem and promotes tourism.
• Promoting eco-tourism.

Question 38

Mitigation of coastal erosion

Answer 38

Making efforts to reduce the severity of coastal erosion to lessen impacts.

Question 39

Adaptation of coastal erosion

Answer 39

Adjusting to the current and future effects of coastal erosion by preparing for the changes it’ll bring.