Coasts Flashcards
Guinea, West Africa
700m erosion in 40 years, 10cm SLR since 1950, 1m by 2100,
Urbanisation high along the coast: fishing, tourism, commerce
Trinidad Coastline
Small island developing state (SID) - low lying and susceptible
70% of population live or work on coast
Winter storms from Atlantic have higher swell waves
NE-SW wind direction means east coast beaches are subject to southerly LSD
Coastal Flooding along 20km of Manzanilla Beach in 2014 cut off routes to SE
Geology is a mix of low grade metamorphic rocks and weak sandstone
Guayaguayare vital site of oil industry
What do we already know at New Guinea
Rock Hardness - softer and uncemented sediment and rock are vulnerable
Igneous rocks - stronger crystalline structure
Geological orientation - discordant coasts have different rates of erosion resulting in headlands and bays
Wave type/energy - water is driven into cracks in rocks creating blast
Wave-cut erosion - worn back cliffs leave a wave-cut platform which is covered by sea at low tide
Economic Losses ?
T&T is 3rd largest economy in America - dependent on Petrochemical Industry
All major natural gas pipelines come ashore at Guayaguayare site
Manzilla beach flood 2014 destroyed 300m of road access
Manyluxury beach front home in Mayaro valued at £600k
400,000 tourists
Social losses ?
Potential loss of coconut plantations - home to many crops
Transport access severely affected by road damage
Value of luxury coastal property declines
Potential damage to existing hotel & tourist industry
Environmental losses?
Nesting sites for endangered turtles - also contribute to ecotourism industry
16000 acre Wildlife Sanctuary & Reserve
New York City
Hurricane Sandy 2012
Winds of 90mph
Coastal flooding 14ft high
53 killed, $32bn damage
NY Stock Exchange closed, subways flooded, hospitals without power
Local factors for NY
US Eastern sea board- populated coastlines and low lying
Sea level-rise, storm surges, subsidence (sediment deposition)
Low lying because: Coastal plains, estuaries, deltas
Do people matter - cause isostatic sinking, land exists below sea level
Human activities - Mangrove deforestation, groundwater extraction, river straightening
Bangladesh, Bay of Bengal
Country most at risk from storm surges linked to tropical cyclones
40% of all recorded storm surges have occurred within Bangladesh
55cm by 2100 = 40% farmland lost
Much of the country is low lying - only 9m above sea level
Much of the coastline is unsaturated so easily eroded
Deforestation has removed vegetation = less stability
Triangular shape coastline = acts as funnel for tides
Intense rainfall = flooding
Tropical cyclone: ones create localised areas where the atmospheric pressure is lower -> SLR
less mangroves -> wave energy isn’t absorbed so more powerful waves during flooding
Population pressure meaning hard to live inland
The Netherlands
Very low lying
SLR of 19cm sinc e1900
Subsidence of 8mm/year
Feb 1953 Great Flood combined with high tides
Sea inundated 17% of Hollands land area
Vulnerable Population - projected increase in flood
Economic cost of 1 billion Dutch Guilders
1836 confirmed deaths
10% of farmland destroyed - 200,000 animal deaths
50,000 buildings damaged
72,000 displaced
Government to set aside 1 billion euros yearly of coastal defence
Deliberately flood farmland to lower water river level and relocate farmers
Pump water using windmills/turbines
Build a 9km storm surge barrier
Male, Maldives
1190 islands - 600,000 tourists each year
Main stresses: storm surges, lack of freshwater, SLR of 1.5ft by 2100
Key points about The Maldives
97% of country threatened by SLR
Money is spent protected Male
Urban areas and tourism given priority
Traditional income and mangroves are given low priority
Security for women and children is a requirement for refugees
Salt-water incursion is making subsistence agriculture impossible
High density of population creates drugs and crime problems
Maldives removed itself from the Commonwealth, led to 20% cut In sea defences
Some migrants moved to Canada -> Brain Drain impacting R&D
Should be promoting resilience
Solutions for Maldives ?
Mangroves for the future - helping community maintain swamps to act as defences
Global Environment Facility (GEF) Grants - small grants for islanders to develop farming
Only protect the most populated islands
Slapton Sands, Devon
Major Barrier Beach - shingle ridge
Protects Slapton Ley - a freshwater lagoon and National Nature Reserve
Significant storms and damage in 2001 cut off A3790
Followed by beach realignment
Key Points about Slapton
Shoreline Management Plan - Divides coastline into littoral cells and sub cells
4 key decisions - not active intervention, hold the line, managed realignment, advance the line
How to decide ? - economic value of assets. technical feasibility of engineering solutions, cultural and ecological value of land, political pressure
Shingle ridge naturally migrates inland at 0.3m/year
Need to sustain shingle ridge freshwater lagoon - but want natural processes to occur
Can’t lose the A379 - important transport and emergency route, builds tourism and creates accessible coastline
Cost = £300,000 to align and £50,000 to maintain
