Coastal Management Flashcards Preview

CGP Geography > Coastal Management > Flashcards

Flashcards in Coastal Management Deck (28)
Loading flashcards...
1
Q

What are some parts of the coast defended

A

The aim of coastal management is 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.

All coastal settlements want to be defended, but the amount of money available is limited so not everywhere can be defended. Choosing which places are defended and how is based on a Cost benefit analysis. The money available is usually used to protect large settlements and important industrial sites, rather than isolated or small settlements.

2
Q

List the four options for coastal management

A

Hold the line
Advance the line
Do nothing
Managed realignment

3
Q

What is the hold the line option

A

Maintain the existing coastal defences

4
Q

What is advance the line option

A

Build new coastal defences further out to sea than the existing line of defence

5
Q

What’s the do nothing option

A

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

6
Q

What’s the managed realignment option

A

Allow the shoreline to move, but manage retreat so it causes least damage

Eg. Flooding farmland rather than towns

7
Q

List hard engineering defences

A
Sea wall
Revetment 
Gabions 
Riprap
Groynes 
Breakwaters
Earth bank
Tidal barrier
Tidal barrage 

SRGRGBETT

8
Q

Tell me about sea walls

A

The wall reflects waves back out to sea, preventing erosion of the coast. It also acts as a barrier to prevent flooding.

Expensive to build and maintain

It creates a strong backwash, which erodes under the wall

9
Q

Tell me about revetments

A

Revetments are slanted structures built at the foot of the cliff. They can be made from concrete, wood or rocks. Waves break against the revetments, which absorb the wave energy and so prevent cliff erosion

Expensive to build, but relatively cheap to maintain

They create a strong backwash which erodes under the wall and may also remove sediment from any beach in front

10
Q

Tell me about gabions

A

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.

Cheap

Ugly
^subjective ¿? I think u r not 🤩

11
Q

Tell me about Riprap

A

Boulders piled up along the coast are called riprap
The boulders absorb wave energy and so reduce wave energy

Fairly cheap

Can shift in storms

12
Q

Tell me about groynes

A

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.

Quite cheap

They starve down drift beaches of sand. Thinner beaches don’t protect the coast as well, leading to greater erosion and flooding.

13
Q

Tell me about breakwaters

A

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.

Expensive

Can be damaged in storms

14
Q

Tell me about earth banks

A

Mounds of earth act as a barrier to prevent flooding.

Quite expensive

Can be eroded

15
Q

Tell me about tidal barriers

A

Tidal barriers are built across river estuaries. They contain retractable flood gates that can be raised to prevent flooding from storm surges

VERY expensive
Really very expensive !

16
Q

Tell me about tidal barrages

A

Tidal barrages are dams built across river estuaries. Their main purpose is to generate electricity. Water is trapped behind the dam at high tide. Controlled release of water through turbines in the dam at low tide generates electricity. They also prevent flooding from storm surges.

VERY expensive

They disrupt sediment flow, which may cause increased erosion elsewhere in the estuary

17
Q

What do soft engineering processes involve

A

They involve coaxing natural processes along

18
Q

List the different soft engineering strategies

A
Beach nourishment 
Beach stabilisation
Dune regeneration
Land use management 
Creating Marshland
Coastal realignment 

BBDLCC

19
Q

What is beach nourishment

A

Beach nourishment is where sand and shingle are added to beaches from elsewhere (eg dredged from offshore). This creates wide beaches, which reduce erosion of cliffs more than thin beaches

20
Q

What is beach stabilisation

A

Can be done by reducing the slope angle and planting vegetation, or by sticking stakes and old tree trunks in the beach to stabilise the sand. It also creates wide beaches, which reduce erosion of cliffs.

21
Q

Tell me about dune regeneration

A

Dune regeneration is where sand dunes are created or restored by either nourishment or stabilisation of the sand. And dunes provide a barrier between land and sea, absorbing wave energy and preventing flooding and erosion.

22
Q

Tell me about land use management

A

Land use management is important 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 cars from gaining access to the dunes, all reduce vegetation loss.

23
Q

What is creating marshland

A

Creating marshland from mudflats can be encouraged by planting appropriate vegetation eg grassworts. 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.

24
Q

What is coastal realignment soft engineering management strategy

A

Also known as managed retreat

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

25
Q

How should coastal management be sustainable

A

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

Hard engineering is often expensive, and disrupts natural processes

Soft engineering schemes tend to be cheaper and require less time and money to maintain. Soft engineering is designed to integrate with the natural environment and it creates areas like marshland and sand dunes, which are important habitats.

Soft engineering is more sustainable because it has lower environmental impact and economic cost.

26
Q

What are the two important ideas involved in deciding how to manage coastal areas sustainably

A

Shoreline management plan

Integrated coastal zone management

27
Q

Tell me about shoreline management plans

A

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(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 in coming up with an SMP.

28
Q

Tell me about integrated coastal zone management

A

Integrated coastal zone management (ICZM) considers all elements of the coastal system (eg. 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 develop it in different ways.

It is integrated in various ways:
The environment is viewed as a whole - the land and the water are interdependent
Different uses are considered, eg fishing, industry, tourism
Local, regional and national levels of authority all have an input into the plan

It is a dynamic (constantly changing) strategy, decisions are re-evaluated if the environment or demands on the area change.