Presentation Transcript
COPING WITH ENVIRONMENTAL CHANGE :COPING WITH ENVIRONMENTAL CHANGE CORE UNIT
A3
ORFORD NESS TO WALTON-ON-THE-NAZE :ORFORD NESS TO WALTON-ON-THE-NAZE Having completed our studies of visitor pressure on the Daintree World Heritage Coast in Australia we turn to a part of East Anglia Coast to complete our coastal studies.
Our objective is to look at the issues of both human and physical origin that shape the landscape and create management challenges of one kind or another.
What processes create management concerns? :What processes create management concerns? What physical processes operate at the coast?
What is the impact of these processes?
Why do the physical processes need management?
Slide 4:Orford Ness Walton-on-the-Naze
We study two contrasting sites :We study two contrasting sites Orford Ness – a low lying coastal spit formed by deposition. This site is in Suffolk at the northern end of the stretch of coast we study.
Walton-on-the-Naze – a cliff headland in north Essex that is a popular tourist destination but one where the coastline is retreating at a rapid rate.
Slide 6:Walton-on-the-Naze Aldeburgh & Orford Ness Walton-on-the-Naze
WHAT PROCESSES AREOPERATING? :WHAT PROCESSES AREOPERATING? marine erosion
sub-aerial processes
hydrological processes
cliff retreat
longshore drift
Slide 8:Orford Ness is one of four major shingle landforms in Britain, and important on a world scale as an example of a shingle spit and foreland ness. It is a Special Areas of Conservation site This site is also a Special Protection Area (SPA) and is designated a Site of Special Scientific Interest (SSSI).
Slide 9:Direction of LSD Original mouth of the River Alde Distal end of the spit These marshes have formed on the landward side of the spit where the waters are calm and deposits from the river are common Shingle has been moved down from the north by longshore drift to form the spit so that the river has had to change its direction continuously The spit formation
Slide 10:Can you locate Shingle Street, King’s Marshes, the River Ore, Orford spit (Ness) and Havergate Island?
Can you roughly make out where Aldeburgh and Slaughden are?
What direction is the photographer facing?
What is the direction of the longshore drift?
Salt marshes develop on the landward side of the spit. Silt from the river and the sea accumulate in the calm waters there. :Salt marshes develop on the landward side of the spit. Silt from the river and the sea accumulate in the calm waters there.
Slide 12:Aldeburgh - Town Centre
Slide 13:The ness of Orford Ness has a number of key issues requiring careful management:
shingle extraction for beach recharge
managed realignment at Lantern Marsh
Former military use including atomic weapons research, testing ordnance and building the ‘Cobra mist’
presence of a large gull colony on the shingle towards the south of the site
Slide 14:There is a constant threat of breaching here (Slaughden) where the spit is at its narrowest due to coastal and river erosion. The spit is having to be recharged to protect it. Concrete and rock armour, together with wooden groynes, are used as protection as well as an artificially created shingle sea wall. It is having to be regularly maintained. For example in the winter of 1997 it was eroded from its normal 13 metres width down to only 1.5 metres. Top secret military installations research unit built during the height of the Cold War in the early 1960s along with the Anglo-American development of a sophisticated radar system – ‘Cobra Mist’ Physical and human pressures on the spit
Walton-on-the-Naze presents a different set of problems to those at Orford :North of the town of Walton the cliffs at the Naze are under constant attack by the weather and waves. A small stretch of the coast there is managed to prevent erosion but nearby the land is left to fall into the sea. We will study why and consider what effect this has. Walton-on-the-Naze presents a different set of problems to those at Orford Check out the photos at http://www.stacey.peak-media.co.uk/Walton/WaltonJune2004/WaltonJun2004.htm
Slide 16:Can you find the sewage works, farmer’s fields, wooded part of the nature reserve, the nature reserve’s lagoon, Walton town and the Tower? And approximately what direction is the photographer facing? Walton-on-the-Naze
Slide 17:What direction is the arrow facing? Check out locations of the pier, centre of town, the Naze and the low lying land and mudflats behind the Naze.
Slide 18:What direction is the photographer facing? Describe the landscape in the foreground? Where is the nature reserve? Can you spot the Tower?
Slide 19:What’s the evidence that these cliffs get attacked by the sea?
Slide 20:What’s going on here?
Slide 21:Sept 1990 July 1991 Early Aug 1991 Oct 1991
Slide 22:Describe the processes at work in each of these three scenes
Slide 23:Which direction is the longshore drift? How do you know?
Why have they managed the area to the left (south) and not the right (north)?
Slide 24:Can you describe what is happening here?
Slide 25:Why manage this section? What do the waves do to the coast here? Do groynes work?
Slide 26:What processes have shaped the cliff profile here?
Slide 27:The unmanaged coast at the Naze …
Slide 28:The managed coast at the Naze …