Humans and Coasts: Flooding and Coastal Recession

Humans and Coasts

Effects of Human Activities on Coasts:

• Coastal areas are subject to urbanisation for many reasons, including fishing and trading opportunities.
• Effects:
• Original wetland areas were drained to prevent settlements from flooding, creating habitat loss.
• Developments in farming in lowland areas meant further draining of wetlands.
• Harbours were built to shelter fishing boats.
• Large ports had a large visual impact on the area.
• Tourist activity at the coast led to further changing of the landscape.
• Many of these developments interfere with natural processes such as longshore drift.
• Modern human activities are vastly changing the climate, which is effecting coastal processes and species.

Coastal Recession

• Coastal recession is the wearing away of the coastline, posing great risk to areas of settlement in particular.
• Loss of land is also an important factor. For example, National Trust area, Golden Cap, will not be under protection from 2025 onward, meaning there will be significant habitat loss.
• Example: Happisburgh, North Norfolk
• In 1995, the local council stopped maintaining coastal defences in the area, causing the rate of erosion to accelerate.
• Since then, many properties and the the village's lifeboat launching station have been washed away.
• Houses in the vicinity which were valued at £80,000 have now devalued to £1.
• Beach Road, which was once relatively busy, is now cut off by the sea.

What is causing coastal flooding?

• Sea Level Rise
• Storm Surges
• Tsunamis

Effects of coastal flooding

• 
• Damage to homes and property
• Deaths
• Contamination of fresh water supplies
• Damage to infrastructure
• Disruption to gas and electricity supplies

Coastal Realignment

• Coastal realignment is a major form of coastal engineering.
• This involves creating an engineered new position of a coastline.
• This method aims to reduce the effects of coastal flooding.
• Medmerry in West Sussex is the largest managed coastal realignment scheme in Europe.

Managed retreat

• Managed retreat allows an area that was not previously exposed to flooding by the sea to become flooded by removing coastal protection.
• People and infrastructure are moved out, coastal protection is removed, and the area is allowed to flood.
• In low-lying areas, inland embankments are built to protect the area.
• Further defences may be installed at a later date if necessary.
• Coastal realignment of this variety creates a sustainable solution to rising sea levels and climate change.

Managed retreat: Benefits and Costs

• Benefits:
• This method can help take pressure off areas further along the coast to reduce risk of flooding.
• It is cheaper in the long term compared to the upkeep of hard engineering methods.
• Managed retreat is designed to conserve and enhance the natural environment.
• Costs:
• Relocation of homes and infrastructure can cause great distress and could split up entire communities.
• Short term costs are high, as relocation costs have to be paid.
• Large areas of agricultural land are lost.
• Short term decline in bird numbers.

Coastal realignment in Medmerry

• 
• The Environment Agency deemed the area around Medmerry at high risk of flooding due to climate change.
• Mitigation measures, namely beach reprofiling, were becoming unsustainable.

What strategy was used?

• Work began in 2011 and was completed in 2014 and was achieved by the following:
• Building a new embankment 2km inshore.
• Building a channel behind the embankment to drain water.
• Rock armour was placed at the seaward edges of the embankment.
• Once these measures were in place, a 110m breach was made in the existing shingle bank to flood the land, creating an intertidal area.

Results:

• Positive Effects:
• Lowered vulnerability to flooding
• Creation of new cycling and walking paths along the embankment
• Expected tourism increase, particularly bird watchers
• The area has become an important fishing nursery to boost the local fishing industry
• Increased measures to protect local species
• Formation of new habitats
• Negative Effects:
• Residents believe that other options should have been sought for
• Some non-residents were angered by the large investment in a sparsely populated area
• The scheme was very expensive
• Loss of good agricultural land
• Existing badger habitats have been disturbed