COASTSAL LANDSCAPES AND CHANGE CASE STUDIES Flashcards
(10 cards)
Coastal Management Strategies: US East Coast Barrier Islands
Characteristics:
* The East coast of the USA is dominated by barrier islands. These barrier islands can be found from
Florida in the South all the way up to Connecticut in the North.
* Made of sand, there are 23 shifting barrier islands which each create lagoons behind them.
* There is currently ongoing debate about how these islands have formed.
Conservation:
Barrier islands are a form of defence as they dissipate wave energy and lead to waves breaking
further out and so the waves hitting land are less destructive. Since the East Coast is repeatedly hit
by hurricanes (forming in the Atlantic Ocean), the barrier islands are an important natural defence
against storm surges.
* Most islands are open for low-impact tourism activities – hiking, fishing, bird watching. However,
many restrictions are put into place to protect the nesting birds and shellfish.
* No permanent residence is permitted on the barrier islands. A previous beach resort and
settlements have all been washed away, due to the shifting nature of the barrier islands.
Coastal Management Strategies: Tuvalu
Tuvalu is a low-lying Pacific Island, which is becoming increasingly vulnerable as eustatic sea level rise
continues. Most areas in Tuvalu are only 1-2m above sea level with the highest point only 4.5m above sea level. Its population have had to mitigate to the changing coastal environment or forced to migrate to New
Zealand.
Problems and Mitigation Solutions:
* More tropical cyclones are occurring, due to an increase in sea temperatures
Residents must construct cyclone shelters to avoid injury
* Flooding of low-lying settlements has resulted in the drowning of cattle
Farmers are forced to move further inland. May consider importing food to avoid hunger.
* Salt water encroachment has led to crop failures and loss of local water sources
Residents grow staple crops in concrete plots and must travel further inland to access a
freshwater supply to drink from and water their crops.
Migration: Some cannot afford to mitigate or are fed up of losing cattle, crops and economic assets. Therefore, there
is a growing number of environmental refugees from Tuvalu who must live in New Zealand to survive. This can result in a better standard of living, but cultural tensions can arise between the migrants and locals.
Coastal Management Strategies: The Maldives
97% of inhabited islands in the Maldives are experiencing erosion and, as sea levels rise, an increased risk
of flooding. For some time, any coastal management by the local government has not been sustainable
since:
* Isolated islands are ignored as most money is spent on the capital city Male
* Sustainable management of traditional income sources (e.g. fishing) are overlooked in favour of
protecting tourist and urban developments.
NGO Intervention:
* NGOs have encouraged sustainable living and educated locals to change The Maldives’ situation.
They have been more successful than the government because they have involved and centred
their efforts around the locals, rather than tourists (public participation).
* The organisation Mangroves for the Future (MMF) is educating communities about the
importance of coastal mangroves as a defence against erosion and flooding, hence reducing their
deforestation.
* The Global Environment Facility (GEF) has provided small grants to locals on the islands in order
for them to help develop sustainable and organic farming.
Coastal Management Strategies: Deltawerken Project - Netherlands
This is a hard engineering project which began following the 1953 Storm Surge drastically damaged the Netherlands. 1800 people died during the storm surge as well as the flooding of 10% of the Netherlands’ farmland, 40000 building were damaged and a further 10,000 destroyed.
The Scheme:
* A series of dams and gates constructed along rivers to control the flow of water during a storm
surge.
* It also aims to reduce the length of the coastline exposed to the sea whilst maintaining safe access
to the North Sea for shipping.
Sustainability and Longevity:
* The cost of the project was $5 billion. However, due to sea level rise, the Dutch will need to spend
more than $1 billion annually to maintain and improve defences against the rising sea levels.
* It has allowed for 4 million people to live below normal sea level, hence easing the Netherlands’
population growth.
* The dams have allowed for new roads and transport connections, which drastically reduce journey
times and reduce isolation for settlements.
* A number of nature reserves were lost during construction, though some have been replaced
during the project.
Dorset Coastline
Dorset has become famous for its Jurassic Coastline – a world heritage site protected because of its
extensive rocks and fossils, some dating back 185 million years. It is an example of both a discordant
and concordant coast, as well as many different distinct coastal features.
- Chesil Beach
* It’s a barrier beach connecting the mainland
to the Isle of Portland.
* The barrier beach has also created Fleet
Lagoon, which is saline (salty).
* The beach is 18 miles long and maximum
height of 15m. It is made of pebbles. - Weymouth Spit
* A spit formed as the mainland behind
changes direction sharply.
* A recent change in the prevailing wind’s
direction has caused the spit to curve.
* A salt marsh has formed behind, as the spit
offers protection from the sea’s currents. - Lulworth Cove
* Formation began after an Ice Age, where a
river running to sea became swollen with
glacier meltwater.
* Erosion of the river banks and marine
erosion at the mouth widens the river.
* Now the sea can access soft rock behind
the cliff face, and erosion accelerates to
form a cove. - Durlston Point
* Durlston Point is receding due to erosion.
* Weathering on the top of the cliff and
marine erosion creating a wave cut notch
causes the cliff to weaken.
* Eventually, the cliff will collapse and fall
under mass movement, leaving a shallow
wave cut platform and new cliff face
(further back) for erosion to act upon. - Old Harry & His Wife
* Old Harry & His Wide are an example of a
Cave-Arch-Stack-Stump Sequence
* Old Harry is a stack, left separated from
the mainland as the arch connecting them
collapsed.
* Old Harry’s Wife is a stump, which would
have previously been a stack that has
eroded, weathered and collapsed.
* The cliffs are made of Cretaceous Chalk,
which is strong enough to support itself as
a vertical stack.
East Anglia Coastline
East Anglia is sediment cell 3 of the UK coastal system. Running geographically from the Wash to the
Thames are eight towns of interest:
Blackney Point
* 4 mile spit, curving due to a recent change in prevailing wind direction
* Made of 97% flint
* The spit has cut off Clay-next-the-sea from
the sea, causing the loss of their harbour
and migration of fishermen families away
Weybourne
* Suffers from rapid erosion, due to its cliffs. They’re made from unconsolidated sands and its base consists of chalk with flint nodules.
* The permeable sand absorbs rainwater, making them unstable and causing
Sheringham
* Experiences waves of travelled 4100km
from the North Pole and 600km from
Denmark.
* Due to their large fetch, waves have high
energy and so high eroding capacity.
* Sheringham has bull nose sea walls to
reduce erosion and hold the coastline.
Happisburgh
* Cliffs consist of glacial till, which is permeable and so absorbs rainwater,
causing it to slump. Its base is clay, which
is vulnerable to marine erosion.
* Since wave fetch is long and Happisburgh
beach is narrow, output > input.
* Wooden revetments (built 1959) became
easily damaged due to frequent storms. They were going to be replaced by a sea wall in 1990s, but the value of land wasn’t high enough for DEFRAs Cost-Benefit Analysis. Now, rock armour is used, but is ineffective in reducing
erosion.
Sea Palling
* Installed 9 artificial reefs (costing £350 million) and 2 million cubic metres of beach nourishment.
* This has increased Sea Palling’s beach, adding to its tourist attraction.
* Some would say it’s a sustainable approach,
since:
Economically – high initial cost, but minimal
maintenance costs after.
Socially – Tourists and Locals happy for a
long time, after beach created.
Environmentally – no damage caused to
coast, maybe increased sea life at reefs.
Great Yarnmouth
* 128m long sea wall installed to stop the
land receding and prevent flooding.
* Wooden groynes used to trap sediment and create a beach in front of wall.
However, there is little sediment to trap.
* Costs £7.6 million. Area is seen as high value to DEFRA, hence expensive
management used.
Lowestoff and Southwolde
* Lowestoff & Southwolde are being negatively impacted by the management schemes
used by northern towns.
* Groynes, artificial reefs and sea walls are reducing sediment available further along the
sediment cell. With little sediment in front the cliffs are exposed to more marine erosion.
* Known as Terminal Groyne Syndrome.
Holderness Coast
Overview
- The Holderness Coast in East Yorkshire is one of the fastest-eroding coastlines in north-west Europe, losing around 1.7 meters per year.
- The coast stretches about 50 km, from Flamborough Head to Spurn Point.
Geology and Erosion
- Made of boulder clay, deposited during the last ice age – very soft and easily eroded.
- Erosion and longshore drift move material southwards.
- Erosion is intensified by northeast storms and rising sea levels.
Coastal Management
- Managed under the Shoreline Management Plan (SMP) led by DEFRA and local authorities.
- Four management options: do nothing, hold the line, advance the line, managed retreat.
- Policy: “Hold the line” in key areas; “do nothing” in less valuable stretches.
Protected Areas
- Bridlington: 3.6 km of sea walls and groynes to protect the fishing port.
- Hornsea: 1.86 km of concrete sea walls and rock armour.
- Withernsea: 2.26 km of mixed defences including a small offshore reef.
- Mappleton: Defended in 1991 due to a threatened road; uses rock armour and groynes.
- Easington: Gas terminal protected with a 1 km revetment to avoid disrupting nearby SSSIs (protected areas).
Spurn Point & Natural Changes
- A spit formed by sediment from Holderness. Has a natural 250-year cycle of destruction and regrowth.
- Protection was abandoned in 1961, and it’s now left to natural processes.
Monitoring & Planning
- Over 110 monitoring sites using GPS and other tech for erosion tracking.
- Roll-back policy for caravan parks: relocate inland beyond 400 meters over time.
Conflict of Interest
Local stakeholders are divided:
- Some demand stronger protections for homes, farms, and tourism.
- Others support natural processes, fearing sediment loss elsewhere (like Lincolnshire and Humber estuary ESAs).
- Climate change may worsen the issue with more severe storms and sea level rise.
Storm Surges and Cyclones: 2013 North Sea Storm Surge
In December 2013, there was a large depression which moves South East from the North Sea.
Characteristics
* Wind speeds over 140 mph were recorded in parts of Scotland
* Gale force northerly winds led to a storm surge reaching 5.8m in Lincolnshire
* There was significant flooding in North Eastern England and Eastern Scotland
* Scotland’s rail network had to be closed and 100,000 homes lost their electricity
* 15 fatalities across the UK, Holland, Germany and Belgium.
Factors Increasing Vulnerability
* North Sea becomes shallower in Southern England, which leads to higher wave heights in the
South
* The North Sea is open to the Atlantic and the coastline is funnel shaped, therefore low lying
coastal settlements (such as Norfolk) are at a greater risk of flooding.
Storm Surges and Cyclones: Cyclone Sidr
In November 2007, a storm surge hit the Bay of Bengal due to a tropical cyclone formed in the Indian
Ocean. This had huge social, economic and environmental costs.
Key Facts
* Storm surges were 6 metres high, due to the extreme gales reaching 223km/h.
* 3500 fatalities caused due to drowning
* Houses, bridges, road and infrastructure were destroyed. Electricity and communications
networks were damaged, leaving homes unconnected.
* Drinking water was contaminated with salt water and debris and sanitation infrastructure
was destroyed. This increased the risk of diseases spreading in the aftermath of the cyclone.
Factors Affecting Bangladesh’s Vulnerability
* Most of the country is very low lying, most places are only 1-3 metres above sea level. In
addition, there are many bays and rivers running far inland. These can allow storm surges to
travel further inland, hence increasing the area affected.
* The coastline consists of mainly unconsolidated sediment which is easily eroded, therefore
there are few cliffs and natural coastal defences against cyclones
* Deforestation of mangroves means there is little to dissipate wave energy when it initially
hits land.
* Bay of Bengal is triangular/ funnelled which concentrates waves and increases their destructive power for the countries surrounding.
* Bangladesh is one of the world’s most densely populated country (population = 169m in
2015)
Storm Surges and Cyclones: Hurricane Katrina
Hurricane Katrina, which struck the U.S. Gulf Coast in August 2005, had catastrophic and wide-ranging impacts on the coastal regions, particularly in Louisiana, Mississippi, and Alabama. Here’s a breakdown of the key impacts on the coast:
Physical and Environmental Impacts
Storm Surge:
- Surge reached over 27 feet (8.2 meters) in parts of Mississippi.
- Massive coastal flooding inundated cities like Biloxi, Gulfport, and New Orleans.
Erosion and Land Loss:
- Severe coastal erosion occurred, washing away entire stretches of beach and barrier islands.
- Louisiana’s already fragile wetlands suffered accelerated loss, with more than 200 square miles of land turned to open water.
Destruction of Natural Habitats:
- Saltwater intrusion and flooding damaged marshes, forests, and estuaries.
- Disruption of ecosystems affected fish, birds, and marine life.
Infrastructure and Community Damage
Widespread Structural Damage:
- Coastal cities saw entire neighborhoods destroyed, especially low-lying areas.
- Buildings, roads, bridges, ports, and oil rigs were heavily damaged or destroyed.
Levee Failures in New Orleans:
- Though not directly on the coast, the city’s failure of levees led to 80% of New Orleans flooding, with some areas under 10–15 feet of water.
Power Outages & Utility Disruption:
- Coastal power grids and water systems were knocked out, sometimes for weeks or months.
