Humans and Coasts: Flooding and Coastal Recession

Humans and Coasts

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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 RiseStorm Surges Tsunamis

Effects of coastal flooding

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Damage to homes and propertyDeathsContamination of fresh water suppliesDamage to infrastructureDisruption 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

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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