Coasts CS by EQ

• EQ1: Cliff Profiles - Northumberland Heritage Coast

  Folding can produce interesting coastal landcapes

  Cliffs made of sedimentary sandstone: micro features like horizontal bedding planes, vertical joints and small caves can be seen within the layers of limestone

  Erosion has removed relatively soft rock strata, exposing hard layers of grey limestone
• EQ1: Geological Structure - Glamorgan Heritage Coast

  14 mile stretch of coast from Ogmore-by-Sea to St-Athan, lying between Aberthaw and Porthcaw

  Glamorgan Heritage Coast made the news when coastal erosion left a towering stack of limestone separated from the main cliffs near Dunraven Bay

  Blue lias: geological formation in southern, eastern and western England and part of South Wales; consists of a sequence of limestone and shale/mudstone layers (sedimentary rocktypes)
• EQ1: Differential erosion of strata inn rock - Flamborough Head [Chalk Cliffs](Holderness)

  Sedimentary rock e.g chalk cliffs located at Flamborough, Holderness Coast, are more resistant to erosion. They are typically made up of bedding planes (layers) with joints (vertical cracks)

  Cracks are regularly formed in more resistant rock forming headlands

  Over time, crack erodes further as a result of erosional processes like hydraulic action

  Chalk bedding planes (layers) with joints (vertical cracks) and erosion taking place at base of the cliff
• EQ1: Vegetation and Sand Dune Successional Development/Salt Marsh Successional Development - Scotland

  Eden Estuary, Fife, Scotland

  Lots of bare mud —> host to species of algae and beyond this there are pioneer plants which are first to colonise the mudflats

  Taller plant species from later serial stages can be seen and after this, the salt marsh gradually slopes upwards towards the shore as plants trap sediment on incoming tides which is deposited

  Slowly increases salt marsh height so flooding is less frequent
• EQ2: Wave types and their coastlines - The North Sea

  Located in NE of England —> Windiest part of country due to large fetch —> destructive waves/high energy coastline

  Seasonality impacts this as in winter there are more frequent/severe storms which increases wind energy and thus creates more erosion along Holderness coast - fastest eroding coastline in Europe e.g North Sea Storm Surge (2013) which was 5.8 m tall and flooded 2500 coastal homes
• EQ2: Sediment Cells and LSD - Holderness

  Source (Hornsea boulder clay + Flamborough Head Chalk):

  • Sediment eroded from cliffs, contributing to the store (during storms, size of store can increase which disturbs equilibrium, but this always restores itself)
• EQ2: Sediment Cells and LSD - Holderness

  Transfer Zone (Humber Estuary):

  • Places where sediment moves along the coast through LSD and offshore currents, sand dunes and salt marshes perform this function
• EQ2: Sediment Cells and LSD - Holderness

  Sinks (Spurn Head):

  • Locations where dominant process is deposition, creating depositional landforms including spits. Some coastal features may act as sinks and sources depending on which process (erosion or deposition) dominates
• EQ3: Isostatic Sea Level Change - Norway and Scotland

  Norway:

  • Land in Norway rising via glacial isostatic adjustment, where land rebounds from weight of glaciers disappearing after last ice age, causing it to rise ~ 20 inches per century
  • Isostatic rebound is outpacing sea level rise in area, which has been happening at a rate of around 8 inches per century

  Fife and Ayrshire, Scotland:

  • Evidence of raised beaches and fossil cliffs, and the head vegetation of fossil cliff shows it isn’t still eroding
• EQ3: Eustatic Sea Level Change - Croatia and Dalmatian Coastline

  Eustatic sea level rise has lead to creation of a Dalmatian coastline where valleys parallel to the coastline are submerged, creating small islands
• EQ3: Influence of human activity on coastal erosion - Nile Delta, Egypt (Aswan Dam)

  Delta is a depositional landform created by sediment brought down Nile by annual floods

  Aswan Dam was built in 60s and both river and sediment discharged fell drastically, caused by:

  • Water withdrawal for industry, cities, and farming from Lake Nasser (reservoir behind dam)
  • Sediment being trapped by reservoir and dam
  • Significantly impacted erosion rates at Rosetta where the main branch of Delta meets sea, where the rate of erosion jumped from 20/25 m/yr to > 200 m/yr as delta was starved of sediment
• EQ3: Influence of human activity on coastal erosion - Ghana (Akosombo Dam)

  Construction of dam reduced flow of sediment down river Volta from around 50 mn m^3/yr to less than 7 mil m^3

  Major implications on longhorn drift and coastal erosion in Ghana and even neighbouring countries
• EQ3: Physical Factors in Flood Risk - Hurricane Ayla

  Hurricane Ayla, Bangladesh (2009)

  • 190 dead
  • Hit southern Bangladesh and also parts of Eastern India, and was aggravated by the fact that it hit at high tide
• EQ3: Physical Factors in Flood Risk - Hurricane Ayla Economic Impacts/Causes

  • Developing country with low GDP, differential spread of weather warnings, EWS insufficient although evacuation was partially successful
  • Destruction of fishing industry and loss of livelihoods exacerbated difficulty of recovery as it was both a large source of income for country and local people; widespread poverty
  • Damaged crops via salinisation from sea water which affected the agricultural industry relied on by both subsistence farmers and country as a whole
• EQ3: Physical Factors in Flood Risk - Hurricane Ayla Social Impacts/Causes


  • People in rural areas or areas outside the capital often have much less access to television, internet or radio meaning there is differential reception of weather warnings
  • 200,000 people living in temporary accommodation a year after the hurricane
  • 1 mn people lost access to clean drinking water and sanitary systems were washed away, leading to spread of disease and health risks
  • 750,000 made homeless
• EQ3: Physical Factors in Flood Risks - Hurricane Ayla Environmental Impacts/Causes

  • Incoming storm surges meet river discharge from Ganges river so river flooding and coastal flooding combine
  • Almost entire coastline is unconsolidated delta sediment which is very susceptible to erosion
  • 3 meter storm surge exacerbated flooding but 85% country < 1 meter above sea level
  • Salination of crops means they can not grow —> less defences
  • Deforestation of coastal mangrove forests help protect coastal flooding by dissipating wave energy during tropical storms
  • Relief rainfall created by Himalayas
• EQ3: Physical Factors in Flood Risk - Hurricane Sandy, USA, 2012

  • Affected 24 US states and Caribbean
  • 223 deaths caused
  • Category 1 hurricane when it made landfall in the US
  • Generated a large storm surge which coincided with high spring tide, sea level 3 meters higher
• EQ3: Physical Factors in Flood Risk - Hurricane Sandy, USA 2012 Economic Impacts/Causes

  • 2nd costliest hurricane in history
  • > $71 bn in damages
  • Closed NY stock exchange for 2 days
  • Loss of crops damaging the agricultural industry
  • > 180,000 flights were cancelled —> disruptions in business, tourism and trade
• EQ3: Physical Factors in Flood Risk - Hurricane Sandy, USA 2012 Social Impacts/Causes

  • 147 direct deaths: 72 in USA, rest mainly in Caribbean (54 in Haiti and 11 in Cuba)
  • Power failure at New York University Langone Medical Center = evacuation of all 215 patients to other hospitals
  • Long term: many affected psychologically (loss of family and friends)
  • > 8.5 mn homes and businesses left without power
  • Washington DC: many supermarkets ran out of essentials e.g bottled water and batteries as people prepared for the worst
  • NYC marathon cancelled resulting in loss of income for many businesses
• EQ3: Physical factors in Flood Risk - Hurricane Sandy, USA 2012 Environmental Impacts/Causes

  • One factor contributing to storm’s strength: abnormally warm sea surface temperatures offshore the East Coast of the US - > 3 degrees Celsius above normal (linked to global warming)
  • In areas e.g New York and New Jersey, untreated sewage washed into public drinking water, threatening human health
• EQ3: Sea Level Rise and Flood Risk - Maldives and Tuvalu

  Maldives:

  • Population of 400,000 across 1200 islands and highest point in whole country is only 2.3 m above sea level
  • Sea level rise of 50 cm by 2100 = loss of 77% of land area
  • Very vulnerable to storm surges and smallest changes to sea level can have adverse effects on land and topography
• EQ3: Sea Level Rise and Flood Risk - Maldives and Tuvalu

  How has the Maldives attempted to mitigate flood risk?

  • There have been aims to create new habitable spaces and protect against rising sea levels
  • Male is ringed by a 3 meter high sea wall
  • Hulhumale is a new artificial island built from coral and sediment dredged from seabed between 1997 and 2002 at a cost of $32 mn. It is a full meter higher than Male, which may be useful in decades to come
• EQ3: Storm Surges - North Sea Storm, 2013

  • Worst storm surge event since 1953
  • Very low air pressure and winds > 140 mph in some parts of Scotland
  • Coincided with high tide in many locations which exacerbated severity of storm surges
  • Storm surge of > 5.8 m in some areas
  • Significant coastal flooding in Boston, Hull, Skegness, Rhyl and Whitby
  • Scotland’s rail network was shut down and 100,000 homes lost power
  • ~ 2500 coasal homes and businesses flooded
  • Hemsby, Norfolk: erosion -> several homes collapsing into sea
  • 15 deaths across all countries affected
• EQ4: Impacts of Coastal Recession - Skipsea (Holderness)

  Skipsea, East Yorkshire

  • Lies on soft boulder clay and experiences fastest rate of erosion in Europe
  • Combination of stormy weather and rising sea levels caused more than 10 m of cliff to disappear from a 2 mile stretch of coast in just 9 months
• EQ4: Impacts of Coastal Recession - Skipsea (Holderness), Social

  • Anger in village as towns on either side of Skipsea are protected by sea defences but due to its small population of around 700, it remains unprotected
  • Until recently, 19 properties sat adjacent to coast and now there are 16, and it has been suggested that the remaining residents will need to move out in next couple of years, but with increasing erosion risk, it is suggested that erosion events could put the houses at imminent risks within a year
• EQ4: Impacts of Coastal Recession - Skipsea (Holderness), Economic

  • Sea defences decided on cost-benefit analysis where larger urban areas and important industries are prioritised over farmland and smaller villages/individual houses, meaning Skipsea will remain unprotected in the future
• EQ4: Economic and Social Impacts of Storm Surges - Haiyan and Netherlands

  The Netherlands, 1953:

  • Cause - Mid-latitude depression moving south through the North Sea generating a 5 m storm surges, a lot of the country is low-lying
  • Economic costs - close to 10% Dutch farmland flooded; 40,000 buildings damaged and 10,000 destroyed
  • Social costs - 1800 deaths

  Typhoon Haiyan, Philippines, 2013

  • Cause - one of most powerful tropical storms ever with a 4-5 m storm surges
  • Economic costs - damages of ~ $2 bn, centred on city of Tacloban
  • Social costs - At least 6,300 deaths and 300,000 injured
• EQ4: Soft Engineering - Holderness: Reasons for Management

  Coastline rapidly eroding at an average of 1.8 m/yr

  Caused by:

  • Rock type - cliffs are made from less-resistant boulder clay (made from sands and clays) which slumps when wet
  • Naturally narrow beaches - give less protection to coast as it does not reduce the power of waves
  • Man- made structures: Groynes have been installed to stop longshore drift; narrows unprotected beaches elsewhere even more
  • Powerful waves - waves at Holderness travel long distances over the North Sea (so have a long fetch) which means they increase in energy
• EQ4: Soft Engineering - Holderness: Management Strategies

  • Bridlington is protected by a 4.7 km long sea wall
  • Hornsea is protected by a sea wall, Groynes and rock armour
  • Coastal management at Withersea has tried to make the beach wider by using Groynes, and also uses a sea wall to protect the coast
  • Mappleton is protected by rock groynes
  • Spurn Head is protected with Groynes and rock armour
• EQ4: Soft Engineering - Holderness: Conflicts

  • There has been an increase in erosion at Great Cowden caused by groynes in Mappleton which led to farms being destroyed by erosion and loss of 100 chalets at Golden Sands Holiday Park
  • Some people disagree with where the sea defences are located, especially if it means the land in their community is not protected
  • Some sea defences negatively impact tourism and reduce amount of money coming in to area
• EQ4: Hard Engineering - Deltawerken, Netherlands - Aim of Project

  • Begun less than 3 weeks after devastation of 1953 storm, and sought to reduce flood risk in low-lying Eastern Scheldt area, where much of land was below sea level
  • Shorten length of coastline exposed to sea by 700 m
  • Control flow of all major rivers in country to reduce flood risk
  • Maintain safe access to North Sea for trade and shipping from important ports
• EQ4: Hard Engineering - Deltawerken, Netherlands - means of achieving aims

  • Designed to protect from a 1-in-2000 year coastal flood and 1-in-250 year river flood
  • Series of dams and sluices were built between the islands that make up Eastern scheldt area to control flow of water which can be closed to shut sea out
  • Embankments (ring-dykes) built to act as flood walls around the islands and along the coast
• EQ4: Hard Engineering - Deltawerken, Netherlands - costs and futures

  • Cost of entire project: > $5 bn
  • Risk of rising sea level due to global warming means dutch will need to continue to raise and strengthen their flood defences
  • 2008: Dutch government report concluded that the country should assume a sea level rise of 1.3 m by 2100, so $1.5 bn would need to be spent each year on new flood defences up to 2100
• EQ4: Sustainable Coastal Management - The Maldives

  Attempts to mitigate coastal erosion have been large, but are unlikely to benefit the whole population and most of the land experiencing coastal erosion is uninhabitable

  There is the risk that:

  • Money spent protecting the capital city Male and building new islands leads to more isolated islands being ignored
  • Sustainable management of traditional income sources e.g fishing, and resources e.g mangroves are overlooked in favour of protecting urban and tourism development from coastal threats
• EQ4: Sustainable Coastal Management - Maldives

  • Risk that conflict could occur surrounding the differential protection of coastlines, and so sustainable management has been a focus in these areas
  • Mangroves for Future (MFF) works with Maldivian communities to educate on the importance of maintaining coastal mangrove swamps as a natural defence against coastal erosion
  • Global Environment Facility (GEF) has provided small grants to islanders to help develop sustainable organic farming as an alternative food and income source to coral reef fish (threatened by both overfishing and global warming)
• EQ4: ICMZ Strategies for Coastal Management - Hornsea (Holderness)

  Hornsea:

  • Impact of policy decisions can clearly be seen in use of ICZM where in Hornsea they adopt a ‘Hold the Line’ policy due to:
  • Regional economic center with population of ~ 8500 people
  • Important historic sites in town and at Southorpe medieval village
  • Inland is Hornsea mere (very important lake habitat for Birds designated as an SSSI)
• EQ4: ICMZ Strategies for Coastal Management - Mappleton (Holderness)

  Mappleton:

  • Decision in 90s to protect Mappleton ensure it was saved from erosion and if that decision was revised today, it may not be as well protected
  • 2010: study showed economic case for protecting Mappleton was ‘marginal’
  • In ‘No active intervention’ areas, up to 400 m of land could be lost to erosion by 2150
  • North Cliff area of Hornsea, some coastal properties could be at risk by 2025
  • By 2055, around 200 hectares of farmland and 32 properties are likely to have been lost to erosion
• EQ4: Conflicts Surrounding Coastal Management - Happisburgh

  • Coastline eroding at rate of 2 m/yr
  • Populated town with many homes along coastline that are at risk
  • UK’s entire 11,000 mile long coastline can’t be protected so old defences may not be restored if they no longer meet the cost-benefit analysis of the area
• EQ4: Conflicts Surrounding Coastal Management - Happisburgh - Management Strategies Used

  • Sea defences have impacts elsewhere along coastline so people may disagree with where they are located
  • Protected by wooden groynes, wooden revetments (now badly damaged) and rock armour
  • Policy was to hold the line, but in 2012, this changed to managed realignment
  • Unsightly sea defences negatively impact tourism, harming the local economy
  • Plan for local council to buy small number of Happisburgh’s most at-risk homes along Beach Road and demolish them so owners can buy another home elsewhere
• EQ4: Conflicts Surrounding Coastal Management - Happisburgh - Conflicts, Costs, and Futures

  • Homes that surveyors estimated has 150 years left in 2000 are now said to have < 25 years left
  • If land value is low and there are few people living there, government may put sea defences elsewhere due to their high cost
  • Managed realignment will create conflict between government and locals as it seems unfair that other places are protected. Requires little to no investment and so gives impression that people’s attachment to place and property is less valuable than making money