Coasts Case Studies

Question 1

Example of concordance coastline ?

Answer 1

Purbeck coast in Dorset

Where layers of differing rock types are folded into ridges that run parallel to the coast

Question 2

Example of a bay ?

Answer 2

Lulworth cove Dorset
Formed when easily eroded rocks such as clay and and chalk are found backed by more resilient rock, more resistant to erosion, hard rocks= more jutting out coastline = caves and headlands, waves detract off headlands and dissipate energy in circular motion eroding a spherical bay, further development of a bay is due to sub-Ariel erosion

Question 3

Example of a headland ?

Answer 3

Peveril point Dorset

Form on discordant coastlines where hard and soft rocks layers run perpendicular to the coast, hard rocks erodes slowly and soft erodes fast, alternating rate of erosion of hard and soft rock is called differential erosion, can form on concordance coastline too but only when hard rock has been previously weakened by e.g ice age- Lulworth Cove

Question 4

Example of caves stacks and stumps ?

Answer 4

Old harry rocks in Dorset

Waves force way into crack in cliff face, sand and shingle in water grinds away rock until cave formed (hydraulic action = predominant process) on headland it may break through= arch, arch may collapse = stack, stack erodes at base and collapses = stump

Question 5

Example of a spit

Answer 5

Spurn head- holderness coat
Formed when coast suddenly changes direction e.g across a river mouth LSD continues to deposit across mouth of river = formation of long bank of sand and shingle forming
Reccurved end spit occurs when change in prevailing wind and wave direction occur

Question 6

Tombolo example?

Answer 6

Chesil beach

Where a spit links the main land and and island

Question 7

Bar example ?

Answer 7

Slapton Ley, Devon

Spit that joins together two headlands which may for a lagoon behind it

Question 8

Salt marsh example ?

Answer 8

Spurn point- Humber estuary

Often occur in sheltered river estuaries behind spits, vegetation develops in intertidal mud flats found in these areas

Question 9

Sand dunes example

Answer 9

Daymer bay- North Cornwall
- large supply of sediment needed
- source of sediment is best from large tidal flat so lots of sand is exposed to the wind and ready to be transported
- string continuous wind
Obstacles such as rocks or human rubbish are deposited on the strandline (essentially high water mark)
Obstacle obstruct deposition of sand and build to from small embryo dunes
Pioneer species of plants grow on embryo dune and bind sand together increasing stability of the dune and traps sand
It will grow to become a foredune and another embryo dune will form in front creating a dune succession

Question 10

Example of barrier island ?

Answer 10

North Carolina USA
Several conditions needed
- source of sand that may come from coastal deposits or offshore deposits called shoals
- topography of of coastline must have abroad gene slope
- finally forces of waves, tides and currents must be strong enough to move sand, waves mid be the dominant force

Question 11

Submerge then landform associated with sea level change,

Rise example ?

Answer 11

Silva, Pembrokeshire,South Wales

• coastal formation once a river valley, found along unglaciated land
• today the river valleys are open to the sea
• flooding caused by one of two reasons, world sea levels rising- eustatic change, or land has sunk below sea level- isostatic
• these coastal features contribute to uniquely showed coastlines, often marked by the presence of scattered islands

Question 12

Example of a fjord ?

Answer 12

Songe, west coast Norway

• flooded U shaped valleys,
• glaciers erode U shaped valleys during ice age eroded below sea level
• valleys flooded during eustatic post glacial sea level rise
• deep narrow inlets, common Norway

Question 13

Dalmatian coastline example ?

Answer 13

• croatia
• where mountains run parallel to the coast
• mountains run parallel to the coast
• submergence if coastline due to eustatic sea level rise leaves tips of valleys running parallel to the coast exposed at the surface of the sea and displaying a series of islands running parallel to the coast

Question 14

Example of emergent landforms, raised beaches ?

Answer 14

Portland, Dorset

When sea level falls more coastline is revealed, beaches no longer combed by waves forming raised beaches displaying material on higher beaches as rounded flint

Question 15

Marine platforms example of emergent landforms ?

Answer 15

Wave-cut platforms left behind during isostatic uplift, landforms created as result of land rising relative to sea level e.g raised beaches

Question 16

Odisha ? - case study of a contrasting coastal landscape beyond UK to illustrate and analyse how it presents risks and opportunities for human occupation and development ?

Answer 16

• 9th largest state by area
• coastline 480km
• 6 large deltas running through( hexadeltaic region )
• population 68million
• mangroves being uprooted to make way for the development of fisheries, 50 years ago average width of mangrove sin a village was 5.1 km now it’s 1.2km, they’re needed as they protect people from harsh weather conditions, associated with accretion and low death rates

-1400km2 mangrove forest
-home to Chilika lake, a saline lagoon known for bird wildlife and boost over 150 species of migratory and resident bird species
- lakes become less bio diverse during monsoon season as the lakes become less saline
Coast is heavily eroded in south and heavily deposited in south
- fishing = Odishas third largest revenue

Occupation

• people offered incentive to maintain high quality of mangrove plantation as mangroves act as a barrier to erosion and holds sediment in place
• 35% coastline laden with metals and sediment deposits and also offshore oil and natural gas seabed mining
• locals involved in shrimp farming, 0.3 million hectares of land found suitable for aquaculture purposes
• golden triangle (networks of rail/ road services that interlink major attractions

Erosion
Rates of erosion increased due to natural processes and humans
- 14% stable
- most erosion occurring in south where we find major structures protection infrastructure

Coastal management
- Odisha officials attempting to stop huge rates of erosion with hard structures which only shifts the problem down the coast, worsen problem ?
- ICZM, integrated coastal zone management project promotes sustainable use of coasts naturals resources whilst maintaining natural environment
- key figure in protection of coastline; world bank, Indian Government and government of Odisha
- their aims- establish sustainable levels of social ad economic activity and protect the coast
Major issues identified
- pollution, coastal erosion, livelihood and security
Hard management
South, sea walls and breakwaters protecting local fishing ports
- 17.5 km long sea wall Kendrapara

NGOs

• Wetlands international with India’s ICZM planting mangroves along the coastline
• communities trained to plant mangroves + given inscentives, 200 hectares already developed
• eco cottages near Chilika lake made with bamboo and mud thatched roofs

Mitigation and adaption 
Tropical cyclone (Phailin) 2013
- 1 million evacuated and 40 died 
- 700,000USD economic losses 
- mangroves destroyed in Chilika Lake and ecosystems disturbed= years to recover

Question 17

Coastal management at Lyme Regis ?

Answer 17

Physical processes

• strong winds
• LSD east to west
• mass movement on cliff due to geology
• rising sea levels

Why manage ?

• natural world heritage site
• located in centre or Jurassic costs in Dorset
• exposed to south westerly waves in Atlantic
• stand son some of most unstable cliffs in Uk (clays and green sand) prone to landslide
• sea undermines base of cliffs
• suffers frequent landslides
• important tourist town
• 214 beach front properties

Hard engineering

Why was a phased approach used ?
To make coats look appealing