AQA A level geography COASTS - HOLDERNESS CASE STUDY

location and nature of coastline

- the coast is 60km long, runs from Flamborough head to Spurn point

- The Holderness coastline is in the North-East coast of England

- fastest eroding coastline in Europe, 2m/year

- Approximately, 3 miles of land has been lost since Roman times, including 23 towns/ villages.

- made up of weak permeable clay and harder chalk at Flamborough head

Waves

- strong NE prevailing winds create destructive waves

- destructive waves erode beaches and attach foot of cliffs

- LSD then carries material southward

- tides and the lower energy environment of the Humber estuary allow sediment to collect formung a spit, mudflats and sand dunes near Spurn head

--> however this has been interrupted by hard engineering

Geology

- this coastline is mostly made from chalk and boulder clay

- the more resistant rock have created coastal features such as the Flamborough head

- the boulder clay cliffs are easier to erode so it has caused retreat and formed the bay of Holderness

- Soft boulder clay is being eroded by waves at 10m a year

Spurn head

- 5.5km long reaching across mouth of Humber

- narrow ridge of land projecting into sea from land

- sediments are deposited by winds, waves and river estuary

- these have created a fragile recurved spit which is growing by 10cm a year

- it also proves shelter for mudflats

Holderness cliffs

- these boulder clay cliffs are formed from material left by ice sheets

- they are retreating by 1.8 metres per year

- rainwater sometimes enters the clay and the weight of it causes material to slide towards the sea

Human factors effecting the Holderness coast

1) interfering with natural processes/hard engineering

- groynes at Hornsea, Mappleton and Withernsea mean sediment is being prevented from building beaches elsewhere = sediment starvation

- in 1999, £2 million was spent on rock armour to protect the gas terminal just south of Mappleton groynes (where they experienced sediment starvation)

2) Global warming: short term changes in climate, an indirect human impact

- eustatic sea level rise due to increased water temps so thermal expansion = larger volume of water

- sea level rise could reach 8mm/year in next 50 years

- Spurn head and the shoreline of Humber estuary are at great risk of flooding and erosion

- increased storm frequency and intensity

sea level rise at the Holderness coast

- climate change is occurring due to both human and natural factors

- global average sea levels have risen at a rate of 1.8 mm a year over the period of 1961 to 2003

- Flamborough head to Gibraltar Point sea level rise is over 1.1 mm a year

- Holderness could be underwater by 2050

Why does the Holderness Coast need to be managed?

- retreated by 4km over past 2000 years

- 30 villages have been lost

- 80,000m2 of farmland is lost a year

- gas terminal at Eastington is only 25m from cliff edge

How are coastal management decisions made?

1) cost benefit analysis: considers social and economic aspects of strategy. By looking at costs of building and maintaining it

2) environmental impact assessments: assessing the effects of a strategy in an area. It is also important that the attractive scenery is maintained

3) risk assessment

4) shoreline management plans: try to decide upon the most appropriate scheme for each cell

5) feasibility study: looking at if the engineering plan suits the geology and coastal processes

Hard engineering

- nearly 12km kg 61km of coastline ha being protected by hard engineering

- bridlingnton protected by 4.7km sea wall and groynes

- concrete sea wall, groynes and riprap at Hornsea

- 500m revetment at Mappleton for £2 million

- easington gas terminal protected by revetment.

Exsisting schemes are not sustainable

- groynes trap sediment locally e.g. in Hornsea, Bridlington but cause terminal groynes syndrome further up coastline e.g., Mappleton which has seen increases in erosion

- most sediment used to flow into Humber estuary where it helped form mudflats but this isn't occurring now which is increasing risk of flooding

- it's leading to formation of bays between protected areas which can create wave refraction and therefor lead to increase in cost to protect them

Sustainable management

SMP for holderbess recommends

holding the line at either sea, Hornsea and Mappleton

doing nothing along less populated areas

- however this has been unpopular for owners of land where nothing is being done

- managed realignment is being suggested e.g. relocating caravan pens further inland and allowing land to erode which allows coast to undergo normal processes without businesses being effected however relocation isn't always possible

- 1995 council stopped protecting spurn head which saved money and allowed natural process to occur

Withernsea management

- another resort further south

- there are groynes and a sea wall

- to prevent wave erosion a new wave return wall has been built and it's further protected by rip rap and rock armour + some beach nourishment

- but the natural beach has disappeared leaving a wave cut platform in the clay beneath

- this costed £6.3 million

ADVANTAGES: this will hold the line, calm concerns of local residents

DISADVANTAGES: costs have limited the length of the sea wall, the rocks have reduced access to the beach and views are restricted

How successful are the schemes?

- Mappleton shows the benefits of coastal defence

- in 1987 the village was right next to the sea and houses were nearly falling into the sea

- in 1992 a scheme was implemented at a cost of £2.1 million supported by EU funding

- the features of scheme included rock groynes to trap sediment, a rock revetments to prevent erosion of the cliffs

- there was also some beach nourishment

with reference to a coastal environment at a local scale, assess the predicted impact of climate change upon the landscape [20 marks]

INTRODUCTION: to a great extent climate change is impacting the landscape at the Holderness coastline in Holderness coastline. located in the North of England and runs between the Humber Estuary in the South and a Flamborough head, and impacts such as flooding, increased erosion and increase in storm events, but human impacts also are creating changes on local landscape

PARAGRAPH ONE: as a result of climate change global average sea levels have risen at a rate of 1.8 mm a year over the period of 1961 to 2003, Holderness could be underwater by 2050, Flamborough head is made from resistant chalk but is eroding at a rate of 0.4m a year and this is set to increase as temps will increase by 1.5 degrees

PARAGRAPH TWO: global warming is also increasing precipitation rates by 10% which is so areas of coast such as Holderness cliffs which are made of boulder clay will be at risk of mudflows due to water becoming trapped within rock which increases pore water pressure which will force rocks apart and lead to slope failure.

PARAGRAPH THREE: But human impacts such as unsustainable management are interfering with natural processes and thus the landscape. groynes at Hornsea, Mappleton and Withernsea to reduce LSD, further up the coastline in Great Cowdenbeath it has led to terminal groyne syndrome because less sediment is being deposited there so landforms such as the beach and the spit at spurn point are declining rapidly