Case Study: Christchurch Bay - AQA Geography

Case Study: Christchurch Bay - AQA Geography

Case Study: Christchurch Bay An extended stretch of coast. Overview to Christchurch Bay Christchurch bay is located on the South Coast of England. It is formed between the headlandHegistbury Head near Christchurch, Dorset and a spit at Hurst, Keyhaven close to the town of Lymington in Hampshire. Christchurch Christchurch bay bay is is located located within

within cell cell 55 of of the the England England and and wales wales sediment sediment cells cells however however this this stretch stretch of of coast coast acts acts as as aa

sub sub cell cell on on its its own own with with little little sediment sediment leaving leaving this this area area and and coming coming into into the the area.

area. Christchurch Bay comprises a 16km section of open coastline exposed to dominant waves from the south-west. This area of coast erodes at between 1-3m/ year Geology

The rocks and clays forming the Christchurch Bay and Solent coasts include materials laid down when the Solent was an estuarine river that drained the Hampshire Basin. These were never subjected to the great pressures that formed the harder rocks to the west. With rising sea levels after the last Ice Age, the chalk ridge that formerly linked the Purbecks with the Isle of Wight was breached, and the former river valley became the new coast, and started to erode. This led to the formation of Poole Bay. The land to the east was protected initially by the ironstone outcrop at Hengistbury Head, but in due course this too eroded and, as sea levels continued to rise, Christchurch Bay began to develop. The dominant south-westerly wind and waves created a littoral drift of shingle and sand along the coast in an easterly direction, initially forming the Shingles Bank which lies between the mainland and the Isle of Wight, and subsequently forming Hurst Spit.

Fetch Wind action generates waves that impinge on the shore from various directions. The longer its fetch (the distance the wind travels without interruption), The more powerful are the waves that it generates. Around the Districts coast, winds are strongest in Christchurch Bay, where the fetch varies from 10 km for winds from the north to many thousands of kilometres for those from the south-west, extending across the Atlantic Ocean to the coast of South America. Sediment Cell 5 LSD wi nd

T U P IN WEST TO EAST Hegistbury Head Mudeford Quay Mudeford/Avon Beach Site 1

Highcliffe Cliffs site 2 Barton on sea site 3 Milford on sea Site 4 Hurst spit site 5 Hegistbury Head Hegistbury Head is a sandstone headland located in Dorset on the south coast close to Christchurch between Southampton and Bournemouth. The headland on the west side of the bay. HH is a SSSI The groyne that sticks out into the sea makes sure that sediment from Bournemouth bay doesnt spread into that of

Christchurch bay. Mudeford Quay Mudeford is where the Avon and Stour flow out of Christchurch harbour into the sea this flow stops Hegistbury head connecting with Mudeford spit. Hegistbury Head Christchurch Harbour Mudeford Spit Mudeford Mudeford/ Avon Beach Site 1 Avon beach groyne Mudeford

quay Mudeford spit Avon beach is located to the east of the quay. This is one of the sandiest beaches in the bay . This is due to the coastal defences in the area but also due to artificial dredging. embankment Sea wall Highcliffe site 2 Friars cliff Site 2 Highcliffe castle beach

LSD takes away material from these beaches. And takes it to Hurst The HH long groyne stops these beaches looking like those at Bournemouth. As less sediment is transferred to this bay. Highcliffe site 2A To Barton TO HH In this picture you can make out the coastal slump due

to the recent bad weather. Naish holiday village sits on top of this cliff. The cliff is retreating at roughly 1m per year. Barton-on-sea Site 3 Barton beach -Coastal management: Groynes, Rock armour, Each stone costs roughly 5000 - Erosion toward the middle of this picture you can see mass movement at Bartonrotational slip - this is due to cliff collapse due to a permeable rock sitting on an impermeable rock Milford On Sea Site 4

Milford - sea wall rock armour Cliff is very close to sea this is eroding very quickly up to 3m per year rocks have been moved by current storms The fetch here comes all the way from Brazil, this coast gets battered by storms. Hurst Spit site 5

Currently there is Less material than usual at the spit is due to the recent storms. Therefore emergency work is in place to rebuild the spit without this spit Lymington and surrounding area would be under water! Hurst spit it the headland at the most eastern part of the bay. Hurst spit is formed due to a change in direction on the coast and a river mouth, this creates the spit with Hurst castle on the end of it and Keyhaven salt marshes. Case study Erosion and Destruction JAN/FEB storm 2014 nB Avo e ac h t gis

He Mu def ord Highcliffe Barton r bu uts ta h s h

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M t n a ur Hurst Spit d ea Sources Ian West - Southampton University New Milton Advertiser Google Maps

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