CASE STUDIES Flashcards
Isle of Purbecks southern coast is a concordant or discordant coastline
CONCORDANT
what is the geology of the isle of purbeck
The geology of the isle of Purbeck varies between the harder more resistant Purbeck limestone and less resistant clays and sands
how did lulworth cove form in the Isle of Purbeck
the sea gradually eroded the resistant Purbeck limestone at the entrance to lulworth cove. Then, rapid coastal recession occurred due to the less-resistant unconsolidated sediment, clay behind the limestone which led to the formation of the cove
lulworth cove led to the formation of a bay which leads to increased what
increased inland erosion
how do bays affect the ways that waves enter the bay
The waves energy is dissipated and reduced. This leads to the deposition of sediment forming a beach
Isle of Purbecks eastern coast is a concordant or discordant coastline
DISCORDANT
where is a dalmatian coast
The dalmatian coast in Croatia
what is the dalmatian coast
It is composed of long, narrow islands running parallel to the coastline and separated by narrow sea channels. These sea channels are also called sounds. They are produced by rising sea-level flooding the shoreline with the geological structure of folds aligned parallel to the coast.
what is a haff coast named after
Named after the Haffs, or lagoons of the southern shore of the baltic sea, which are enclosed by sand spits or dunes.
where is a discordant coastline
West cork coast, Ireland
what are discordant coastlines feature
Discordant coastlines are dominated by headlands with resistant rock and bays that have less resistant rock
what is the morphology of west cork coast and how has it led to the formation of headlands and bays
In the west cork coast in Ireland there are rock strata that meet the coast at 90 degrees in parallel bands. Weaker rocks have been eroded, whereas the more-resistant rocks form headlands.
what type of rock has led to the formation of the clear island in west cork
It has particularly resistant areas that are detached islands such as the clear island formed by old red sandstone.
boxing day earthquake caused the sea level to rise or fall
rise
raised the seabed reducing the capacity of the entire Indian Ocean by 0.1mm
what are islands at risk of coastal flooding due to height
The Maldives in the Indian Ocean, and Tuvalu and Vanuatu in the Pacific
describe the maldives population
The Maldives has a population of 340,000 people spread out across 1200 islands
what is the highest height of the maldives islands
The highest point in the country is a mere 2.3m above sea level.
A sea level rise of 50cm by 2100 would lead to the Maldives losing .%.?.. of its land
losing 77% of its land.
where has subsidence occured
Bangladesh’s estuarine islands have sunk as much as 1.5m in the last 50 years
what has led to subsidence within Bangledesh
Isostatic readjustment is partly responsible, but the main reason is clearance and drainage of more than 50 large islands in the ganges-brahmaputra river delta
why have the islands been cleared in the ganges river
islands used to be forested but are now cleared to grow rice and fed the countries population
what did bangladesh do in the 1960s to try protect the islands from further flooding
large embankments of earth were built around these islands to protect them against tidal and storm surge flooding
what was a problem with protecting the islands from flooding in Bangladesh using embankments
prevents natural deposition of sediment that used to maintain the islands height, now they’re quickly submerging and millions of people living on them are at risk of flooding
Bangladesh is particularly vulnerable to the impacts of tropical cyclones for a number of reasons can you list them
Much of the country is a very low-lying river delta, only 1-3m above the sea level
Incoming storm surges often meet the river ganges discharge causing river and coastal flooding
Intense rainfall occurs contributing to the flooding
Almost all the coastline consists of unconsolidated delta sediment, which is very prone to erosion
Deforestation of the coastal mangrove forests has removed vegetation which once stabilised coastal swamps and dissipated wave energy during tropical cyclones
The funnel shape of the bay of bengal concentrates the cyclones storm surge towards bangladesh and increasings its height as it travels towards the land
what factors have led to fallen death tolls within Bangladesh when cyclones occur
the death tolls have fallen due to improved warning systems, construction of cyclone shelters and better aid response.
what are the physical impacts of cyclones on the bangladesh coastline
The physical impacts are that cyclones in bangladesh cause many metres of coastal erosion eroding farmland and reshaping the coastline.
what are the social impacts of cyclones
cyclones and storm surges force millions of people away from their homes and farms in the densely populated coastal regions
where did cyclone sidr form
Cyclone Sidr came from the bay of Bengal on 15 November 2007
what height cyclones sidr’s storm surge get to
bringing with it a storm surge which reached heights of 6 metres.
how did the coastal topography of bangladesh worsen the storm surges effect
This rise in sea level is intensified in areas where the coastline is funnel shaped.
death toll of cyclone sidr
Cyclone Sidr killing 3363 people.
what category storm was cyclone sidr
4
what caused the North Sea storm surge in 2013
The combination of low pressure and strong winds led to a significant storm surge across the east coast of scotland and england as well as the southern coasts of belgium
what was the highest point of the north sea storm surge
5.8 metres!!
what cyclone caused the North Sea storm surges
Cyclone Xaver was what resulted in the North sea storm surges.
death count of cyclone xaver
15 people
social costs of cyclone xaver
Thousands of people were evacuated from their homes.
Emergency services were under severe pressure.
The cost of repair ran over one billion pounds.
100,00 homes lost power.
About 2500 coastal homes and businesses in the UK was flooded.
physical impacts of cyclone xaver
There was significant coastal flooding in Boston, Hull, Skegness, Rhyl and Whitby
Scotland’s rail network was shut down
where are they building storm surge barriers
netherlands
the UK
why did the netherlands build storm surge barrier
The Netherlands constructed a series of delta works in response to the 1953 storm surge
what are the delta works in the netherlands made up of and what is it designed to protect the country from
Delta works consist of a series of dams and storm surge barriers, designed to protect the country from flooding by the North Sea
what is the cost of the netherlands eastern scheldt storm barrier
it cost 2.5 billion euros to build and 17 million euros a year to operate
why have london built a storm surge barrier
Its built to protect the flood plain of most of greater london from high tides and storm surges moving up from the north sea
what has the storm surge barrier allowed london to become
The barrier has prevented flooding and helped london to grow into a capital city
the cost of the london storm surge barrier
It cost £583 million to build in 1982
what is the first nation that have protected all their mangrove forests
SRI LANKA
how many hectares of mangrove forests do sri lanka protect
Its scheme will protect all 8800 hectares of remaining forest
Which UK coastline is the fastest eroding coastline in europe
Holderness Coastline
what towns are impacted by the erosion that takes place on the holderness coastline
Hornsea
Mappleton
Withernsea
Easington
Spurn point
Hull
what physical factors cause the erosion of the holderness coastline
geology
fetch
longshore drift and beach material
sub aerial processes
coastal erosion
what are the human factors that cause the erosion of the holderness coastline
economic and social loss
coastal management
what is the main geology of holderness coastline that contributes to the rapid erosion
boulder clay, a mixture of fine clays and sands, its unconsolidated sediment
what is one of the main factors effecting erosion rate on the holderness coastline
wave energy which depends on the FETCH (how far the wave travelled)
TRUE OR FALSE is holderness boulder clay structurally weak and produces shallow sloping cliffs
TRUE
lacks resistance to erosion which produces shallow, sloping cliffs
Flamborough head is made out of ….?… which has lead to the formation of ….?…..
chalk bands
cliffs, arches, stacks
where are the winds from that impact the holderness coastline
the north sea
yoohoo
does the north sea have a large or small fetch in comparison to other oceans
SMALL FETCH
what 4 factors influence the north seas fetch
currents
weather systems
size of north sea
depth of the north sea
where does the UK current circulate from
the atlantic to the north sea
how does the atlantic ocean influence the fetch of the north sea
the atlantics fetch is 5000 km more so its currents increase wave energy in the north sea leading to powerful destructive waves
what type of weather systems pass over the north sea
Low pressure weather systems and storms are intense when passing over the north sea
what do low pressure weather systems produce when passing over the north sea
strong winds and waves.
what does low air pressure create within the north sea
low pressure air weighs less, rising sea levels, which in turn create higher tides
how does the size of the north sea influence erosion
Its small and enclosed creating huge waves during storms, waves move within the sea, but cannot disperse their energy
how does the depth of the sea floor influence erosion of the holderness coastline
Its relatively deep, so waves reach the cliffs without first being weakened by friction with shallow beaches
why are the beaches an issue along the holderness coast
The boulder clay erodes to produce mainly clay particles, which are transported by suspension instead of accumulating on-shore as beach sand. there is never enough sand to stop the waves reaching the cliffs at high tide as the beach offer little friction to absorb wave energy,
how is material transported by longshore drift along the holderness coast
southwards so the holderness cliffs are poorly protected.
how has longshore drift impacted the erosion rate of the holderness coastline
Beaches south of Hornsea have reduced in width because of an imbalance between the input of sand (deposited by the swash) and the removal of sand (backswash)
where is the only place along the holderness coastline that chemical weathering is effective
the chalk cliffs at Flamborough Head
what is the main type of mechanical weathering and its effects
main type is freeze thaw weathering and wetting and drying of boulder clay which makes it crumbly in dry periods
how does slumping occur due to the mechanical processes that happen to the boulder clay at holderness coastline
The wetting and drying of the clay causes expansion and shrinkage — producing cracks during long, dry periods. Rain then enters the cracked clay and percolates into the cliff, becoming heavier. The weakened cliff cannot support the extra weight causing the clay to slump under gravity
what are some of the economic and social costs of the erosion at holderness coastline
-Golden sands holiday park, south of Withernsea, has lost 100 chalets to the sea in 15 years — the owner believes if she hadn’t lost the chalets an extra 400 tourists would have visited Withernsea helping the local economy
-It’s also predicted that 200 homes and several roads will fall into the sea between Flamborough Head and Spurn Point by 2100
-Individuals lose out both socially and financially due to coastal erosion, as there’s no compensation for loss of private property caused by coastal erosion
-2010-2012 the Yorkshire council used £1.2 million to assist those households along the coast learning to adapt. They gave financial assistance to 36 households, supported 16 relocations and 43 property demolitions
-The remainder of the money was used to help residents through the relocation and adaptation packages
how has coastal management impacted the holderness coastlines
The sea wall, groynes and rock armour at Hornsea protected parts of the coast but they interrupt the flow of beach material by LSD
The beaches after Hornsea, such as Mappleton, is then starved of material and its cliffs are exposed to wave attack — known as terminal groyne syndrome
how much of holderness’ coastline is protected using hard engineering structures
9.2 km is protected by hard engineering structures maintained by East Riding of Yorkshire’s Council
examples of hard engineering structures along the holderness coastline
sea walls at hortsea and withernsea
groynes at mappleton
what was the impact of building a sea wall at Hornsea
groynes trap and build up sediment along hornseas beaches but starve beaches downdrift at mappleton of sediment
what was the impact of building a sea wall at withernsea
-the waves are now noisier when they break
-views from sea front hotels have bee restricted
-people find the rip rap at the base visually unappealing
what was the impact of building groynes at mappleton
cowden, 3km south of mappleton, experienced sediment starvation which resulted in increased erosion
who developed an ICZM for the holderness coastline
East riding of yorkshire council developed an ICZM in 2002
what was the ICZM for the holderness coastline used to develop
An SMP from flamborough head to gibraltar point
where has the ‘hold the line’ coastal management policy been implemented along the holderness coast
bridlington
hornsea
mappleton
withernsea
easington
where has the ‘strategic realignment’ coastal management policy been implemented along the holderness coast
Spurn point
where has the ‘no active intervention’ coastal management policy been implemented along the holderness coast
everywhere but the places listed
bridlington
hornsea
mappleton
withernsea
easington
spurn point
who are the stakeholders that are involved when developing the SMP for the holderness coast
National government agencies
local governments
stakeholders in the economy
environmental stakeholders
what did the CBA of the Holderness coastline conclude
-the parts of the coast that have the ‘no active intervention policy’ has no costs but there will be some economic loses (land, buildings etc)
-the benefits outweigh the costs of continuing to protect Bridlington, Hornsea and Withernsea
-the economic benefit of ‘holding the line’ at mappleton is similar to the cost
-the importance of dimlington and Easington due to the gas terminal means the benefits clearly outweigh the costs
-spurn point will be allowed to evolve – requiring minimal costs
when managing the holderness coastline what are the issues with environmental sensitivity
flamborough head and spurn point are both defined as heritage coasts because of the value of their landscape.
hornsea mere is a SSSI (site of special scientific interest)
flamborough head is a special area of conservation
when managing holderness coastline what are the issues with land use and value
the holderness coastline consists of agricultural land which is rated on grades 1-5 (1 fab 5 very bad) 160 hectares of grade 3/4 will be lost to erosion
when managing holderness coastline what are issues with the impact on coastal processes
no active intervention to flamborough head means sediment continues to be supplied
holding the line at bridlington, hornsea, withernsea etc means erosion is prevented but this interrupts the sediment supply further south
defended areas are likely to become promontories and beaches may narrow
when managing holderness coastline what are the issues with the impact on coastal processes
-agriculture is a key employer in the area many jobs depend on it
-tourism is another key industry along the coast and is a major contributor to the economy
-approx. 37 homes are at risk of disappearing into the sea by 2025
-politically costs must be accepted and the ‘no active intervention policy’ may be reasonable but its rarely accepted by those affected
TRUE or FALSE is there conflict when developing a SMP
TRUE there will always be winners and losers
