Human Geography
Globalisation
Regenerating Places
Superpowers
Health, Human Rights and Interventions
Physical Geography
Tectonic Process and Hazards
Coastal Landscapes and Change
- Milankovitch cycles: 100,000 year cycle -> 90,000 years glacials (cold, + ice), 10,000 interglacial (warm, -ice)
- Rocky coasts - 1,000 km of the UK's coastline, mainly in the north and west
- 427m Conachair Cliff on the Isle of Hirta in the Isle of Hebrides
- 3m cliffs Chapel Porth Cornwall
- South Dorset Coast
- A concordant coastline with resistant Portland limestone forming a protective stratum parallel to the sea. Behind it are less resistant Purbeck limestone and Wealden clay, which eroded very quickly when the portland limestone goes (producing Lulworth Cove and Stair Hole).
- Lateral widening of coves may produce a single bay, again parallel to the coastline, such as Bull's Head in St Oswald's Bay.
- Sognefjord
- 80% of residents of the Seychelles live and work at the coast.
- The Maldives have an average height of 1.5 m above sea level, but its population of 400,000 is too large to be easily accommodated elsewhere. It's highest point is 2.3 m above sea level, and a 50 cm rise would flood 77% of it.
- New Zealand courts grant residence to 75 Tuvalu citizens each year as rising sea levels decrease its land area. In 2014, the Alesana family were granted permanent residence as 'climate change refugees'
- Groynes cost £150-250 per metre
- Rip-rap costs £1300-6000 per metre
- Sea walls cost £3000-10,000 per metre
- Beach nourishment typically costs more than £2000 per metre,but ongoing costs are high
- Cliff regrading and drainage commonly costs £10,000 per metre
- Dune fencing costs £4-20 per metre
- Dune replanting costs about £10 per metre
- Integrated Coastal Zone Management dates from the 1992 Rio Earth Summit - manages the entire coastal zone, recognises the importance of the coastal zone to people's livelihoods, management must be sustainable. It's over the long term, involves all the stakeholders and uses 'adaptive management' - changing plans as threats change. Works on the concept of littoral cells.
- DEFRA policies: No active intervention; Hold the line; Strategic (Managed) Realignment; Advance the Line
- Strategic Realignment - allowing to recede, but directing to certain areas
- Advance the line (seaward side)
- Happisburgh, North Norfolk - No active intervention (managed realignment in the longer term)
- To defend the whole village would have an impact on the wider coastal management plan. Happisburgh would end up as a promontory, blocking longshore drift and causing further erosion downdrift.
- Costs of erosion: Grade 1 listed St Mary's Church and Grade 2 listed Manor House would be lost. £160,000 available to the Manor Caravan Park to assist in relocating to a new site. £2000 per resident - £40,000-£70,000. Social costs.
- Benefits of protection: by 2105, 20-35 houses would be 'saved' from erosion with a combined value of £4-7 million. 45 hectares of farmland. Manor Caravan Park - local jobs.
- The cost of building sea defences is about £6 million, very close to the value of property saved and much higher than the compensation costs to residents. Context of whole SMP.
- Carry out an environmental impact assessment. Identifies short and long term impacts.
- Losers are the poorest, who lack a formal land title. No insurance so lose everything.
- Blackwater Estuary, Essex
- An area of tidal salt marsh and low-lying farmland.
- It's prone to flooding and coastal erosion -> so traditionally protected by flood embankments and revetments. Not sustainable to just continue building higher and higher coastal defences.
- In 2000 Essex Wildlife Trust purchased Abbots Hall Farm on Blackwater Estuary.
- A 4000 ha managed realignment scheme was created by breaching the sea wall in five places in 2002, allowing new salt marsh to form inland.
- The owners of Abbots Hall farm received the market price for their farmland, water quality in the estuary improved because of the expansion of reed beds that filter water quality. Income from ecotourism and wildlife watching. Dunlin, redshank, bass and herring nurseries were enhanced.
The Water Cycle
- 1385 million km cubed
- Only 2.5% of water is freshwater. Only 1% of freshwater is easily accessible freshwater. 96.9% of total water is found in the oceans. Rivers only hold 0.007% of total water - but are the main water source for humans.
- Ocean<->atmosphere: evaporation: 400,000; precipitation: 370,000
- land<->atmosphere: evaporation: 60,000; precipitation 90,000
- ocean<->land: surface runoff: 30,000
- Amazon: less humidity, less precipitation, more surface run off, infiltration, soil being fed into rivers.
- Water budget: annual balance between inputs and outputs. National - amount of water available for human use. Local, available soil water. A drainage basin water budget is calculated as precipitation = discharge + evapotranspiration +/- change in storage.
- River regimes:
- European mountain rivers have a high water period when glaciers feeding them melt rapidly (July-August) e.g. the Rhone
- In oceanic areas of Europe, rainfall is evenly distributed throughout the year, but there is low run off in the summer due to high evaporation. Thames.
- In tropical areas, evapotranspiration tends to be high and stable, but a peak in the summer. (Blue Nile)
- Snowmelt in early spring or summer in mountainaous areas, e.g. the Great Plains of the USA. River Durance.
- River regime - annual discharge, measured in cumecs.