coastal flooding and coastal management

how is climate change increasing the likelihood of coastal flooding

1. rising sea levels

2. storm frequency

impact of rising sea levels on coastal flooding

- causes higher tides which would flood coastal areas more frequently

- rising sea levels could expose more of the coastline to erosion, beaches could become narrower as the sea will be able to move further inland

impacts of increase in storm frequency on coastal flooding

- storms give the sea more erosional power so areas of hard rock will be more vulnerable to erosion and areas of soft rock will erode quicker

- storms surges could become more frequent and sea level rises could cause storm surges to reach areas further inland

- the sea will have more energy to transport material due to high winds from storms, meaning that high energy waves can move more material for greater distances so some areas may be starved of material

coastal flooding and its threats to people

- low lying areas could become permanently flooded so impossible to inhabit

- coastal industries may be shut down

- damage to infrastructure affects economy

- there's a booming tourism in coastal areas, flooding can put people off from it, so fewer tourism means that businesses that rely on tourism may close leading to a loss in livelihoods

coastal flooding and its threats to the environment

- seawater has a high salt content, increased salt levels due to coastal flooding can damage or kill organisms in an ecosystem and reduce soil fertility and so affect agricultural land

- the force of sea water can uproot trees and plants

- conservation areas such as lagoons destroyed

What is hard engineering?

man made structures built to control the flow off the sea and reduce flooding and erosion

what is soft engineering

schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion

what is a sea wall (hard engineering)

A wall made out of hard material like concrete that reflects waves back to sea.

benefits of a sea wall

- prevents erosion of the coast

- acts as a barrier to prevent flooding

costs of a sea wall

-social : can restrict access to beach and can cause flooding if not high enough

-economic : it is expensive to build and maintain as it creates strong backwash which erodes under the wall

-environmental : concrete wall can be ugly and destroy habitats

what is a groyne (hard engineering)

A wooden barrier built at right angles to the beach they trap material transported by longshore drift

benefits of a groyne

- creates wider beaches which slow the waves

- cheap

costs of groynes

- impedes walking along a beach

- they starve beaches further down the coast of sand making them narrower

- narrower beaches don't protect the coast as well, leading to greater coastal erosion and floods

What is beach replenishment? (soft engineering)

sand and shingle from elsewhere or from lower down the beach are added to the upper part of beaches

benefits of beach replenishment

1) looks natural

2) provides a beach for tourists

3) beach absorbs wave energy, protecting the land and buildings behind

4) creates wider beaches which slow the waves

costs of beach replenishment

1) sea continues eroding it away, so it has to be replaced every few years, so expensive

2) taking material from the seabed can kill organisms

what is slope stabilisation ( soft engineering)

slopes are reinforced by inserting concrete nails into the ground and covering the slope with metal netting

benefits of slope stabilisation

prevents mass movement by increasing the strength of the slope

costs of slope stabilisation

very expensive and difficult to install

what is strategic realignment (soft engineering)

Removing an existing defence and allowing the land behind it to flood

benefits of strategic realignment

Over time the land will become marshland, creating new habitats. Flooding and erosion are reduced behind the marshland

costs of strategic realignment

people may disagree over which land should be allowed to flood

What is rock armour/rip-rap?

Large boulders placed at the foot of a cliff. They break the waves and absorb their energy.

advantages to rock armour

Cheaper than a sea wall and easy to maintain

disadvantages to rock armour

- not very attractive

- not easy for people to get over the beach, can cause broken ankles

- rats may live in spaces

what is another option to manage coastal flooding other than hard and soft engineering?

- do nothing and erosion and floosing are dealt with as they happen

it doesn't cost anything to let the coast retreat naturally but infrastructure eg. tourism may be lost

people may also move away from the area because of the risk of flooding

what does it mean for coastal management strategies to be sustainable

making sure erosion and flooding is controlled without causing more problems elsewhere

- eg. - erosion further down the coast

- affecting people who live or work at the coast eg. farmers

- also need to be cheap to avoid conflicts about the spending of public money

what is the ICZM and how is it sustainable

Integrated Coastal Zone Management.

It is a coastal management process that uses an integrated approach, regarding all aspects of the coastal zone, taking everyone's interest into account.

It is sustainable because it can be adapted to any future needs or changes along the coastline so it can be used long term