CASE STUDY-HOLDERNESS COAST Flashcards
how fast is the coast eroding every year?
around 2m per year.
what is the Geology like?
at Flamborough head-boulder clay overlying chalk cliffs.
alluvium- loose clay, silt, sand, or gravel that has been deposited
boulder clay is structurally weak and has little resistant to erosion
what is the fetch like on the coast?
-exposed to wind and waves from the North-East with a fetch of 500-800km across the North Sea
how does the weather affect the coast?
winter storms in North sea are often intense and the low pressure raises the sea level, producing higher tides than normal and the storms add energy to the waves
what kind of mass movement is common along the coast?
rotational slumps and major landslides
what happens regarding longshore drift?
boulder clay erodes easily and produces very small, fine clay particles which are easily transported by longshore drift along the coast an is deposited elsewhere.
what is the sediment cell of Holderness?
Flamborough head-source region
Holderness coast-transfer region
Spurn head-sink region
a sediment cell is a linked system of sources transfers and sinks of sediment along a section of coastline
how is equilibrium upset on the Holderness coast?
can be upset by natural vents and human actions e.g. the rock groynes at Mappleton which cost £2 million and starved other places of sediment
what are the social effects of processes?
- 30 villages lost since the roman times.
- difficult to get insurance/mortgage
- property prices along the coast fallen sharply
- loss of homes and a dairy farm
what are the economical effects of processes?
- 80,000m² of good quality farmland is lost each year
- tourist number is Bridlington dropped by over 30% between 1998-2006
- loss of jobs in the area is resulting in internal migration of young people.
- Gas terminal at Easington at risk as its 25m away form cliff edge and it provides 25% of Britain’s gas supply
what are the environmental effects of processes?
SSSIs(sites of special scientific interest) are threatened -the lagoons near Easington
-the Lagoon is separated from the sea by a narrow strip of sand and shingle and if eroded lagoon would be lost
what is the future threat?
if sea levels continue to rise by a couple meters due to climate change by the end of the century all settlements will be lost.
what is the strategy at Hornsea?
- holiday resort, hotels
defences: sea walls, rock armour, groynes
impact: groynes maintain the beach but down the coast Mappleton has been starved of sediment as a result
what is the strategy at Mappleton?
- settlement
defences: 2 rock groynes (£2million,1991), Rock armour
impact: At Great Cowden 3km south of Mappleton sediment starvation has occurred causing increased erosion of the cliffs
what is the strategy at Withernsea?
defences: straight sea wall (1875)over time base of the wall was eroded and it collapsed and in 1990 the wall was replaced by a curved wall(£6.3 million)
impact: waves are noisier when breaking against walls. Views from sea front hotels are restricted and some find the rip-rap at the base of sea wall unattractive