How does costal erosion and sea level change alter the physical characteristics of the coastline and increase risk

Question 1

What are the 2 types of sea level change called and explain

Answer 1

Eustatic change - When the sea level itself rises or falls (Global change)

Isostatic change- When the land rises or falls relative to the sea (local change)

Question 2

What is marine regression and transgression

Answer 2

Marine regression - Where the sea level drops and produces and emergent coast

Marine transgression - Where the coastline is flooded and produces a submergent coast

Question 3

What type of sea level change is Marine regression and explain

Answer 3

Eustatic fall in sea level (global) - During glacial times, when ice sheets formed on land in high altitudes (far north and south) water evaporated is locked up on the and as ice. Resulting in global sea level fall.

Isostatic fall in sea level - During the build up of ice sheets the weight of the ice causes the earths crust to sink (Isostatic subsidence). As it melts it causes the earth to rebound (Called post-glacial adjustment or isostatic recovery) . Land lifts out of the sea

Question 4

What is an emergent and submergent coastline

Answer 4

Emergent - Land rising (land being exposed out of the sea)

Submergent - Land sinking

Question 5

What parts of the UK have been effected by sea level changes

Answer 5

Land in the north west (which was covered by ice) is rising as a result of isostatic recovery

Land in the south east (which was not covered by ice) is sinking. Sediment deposition is causing the crust to sink and relative sea levels to rise

Question 6

What are the landforms on and emergent coastlines by sea level change and how are they formed

Is it isostatic or eustatic changes

Answer 6

Isostatic changes
Raised beaches - As land rose as a result of isostatic recovery former shorelines and beaches were raised above sea levels
Fossil cliffs can occur behind

Fossil cliffs Cliffs are exposed as a result of isostatic recovery. Often have old wave cut notches and causes evidence of past marine erosion

Question 7

What are the landforms on submergent coastlines caused by sea level change and explain

Is it an isostatic change or a eustatic change

Answer 7

Eustatic changes
Rias - When valleys in dissect upland areas are flooded due to water being forced back up the mouth of the river during sea level rise they drown lower parts of rivers and their tributaries.

Fjords - Deep glacial troughs are flooded by rise in sea level. Long steep sided with a U shaped cross section. Deeper when inland compared to on the coast

Dalmatian coast - Similar to rias. Rivers flow almost parallel to the coast (not a right angle)

Question 8

Where is Kiritimati and what challenges is it facing

Answer 8

It is located in the Mid pacific and is apart of the Republic of Kiribati which is a group of 33 islands that straddle the equator

• Raised no more than 2 meters above sea level
• Half of households have already been affected by sea level rise
• LIDC country
• People who have become climate refugees

Question 9

What are the responses to Kiritimati being under threat by sea level rise

Answer 9

• “migration with dignity” scheme where they aim to create a skilled work force so they residents can find good jobs abroad
• New Zealand has created a lottery where 75 Kiribati citizens can resettle in New Zealand
• Plant Mangrow trees to reduce flooding
• They have low carbon admissions (little to none)
• President have stopped countries tuna hunting in Kiribati waters due to admissions

Question 10

Why is the Netherlands under threat to sea level rise

Answer 10

• Low lying coasts as 1/4 of the total territory lies below sea level
• Without Dykes this parts of the country would be permanently flooded
• Sea levels in the Netherlands rose about 20cm within 100 years

AC example

Question 11

Why did the Netherlands start managing flooding
What did they do

Answer 11

31st January 1953 as huge storm happened which killed 1,900 people in the Netherlands and 300 on the English east coast

The built a network of Dams, dykes and storm barriers that is unmatched work wide

Number of people killed by flooding since 1953 is zero

Question 12

Why is China under threat for sea level rise?

Answer 12

• The sea has rose by 3.3 mm per year since 1993 in China
• Sea levels could rise by 2 meters by the end of the century which is enough to flood Chinas megacity Shanghai
• Worlds largest population living at low altitudes as 126,000 are 10 meters above sea level or below
• If global temperatures keep rising 64 million Chinese people will be flooded
• Low-lying shanghai is in population terms the worlds at most risk from rising sea waters

Question 13

What type of sea level change is marine transgression and explain

Answer 13

Eustatic rise in sea level - At the end of a glacial period melting ice returns water to the sea causing sea levels to rise globally. The thermal expansion of water causes sea level rise

Isostatic rise in sea level - Land can sink at the coast due to the deposition of sediment. This can happen especially in large river deltas where the weight of sediment deposition causes delta subsistence

Question 14

Where is the Nile Delta and what is the population like

Answer 14

North Eastern Africa in Eastern Egypt. North of the river Nile where the river splits into two rivers

Home to 41% of Egypt’s population (95 million people)

Question 15

What are the physical causes of erosion on the Nile Delta

Answer 15

• 270 Km of coastline is at a dangerously low elevation (many parts are 0 - 1m above sea level)
• A 1m rise in sea level that is predicted in the next 100 years will cause 20% of the Delta to become flooded
• A 2m rise in sea level would see 8789km^2 flooded (43.9% of the delta)

Question 16

How has the Aswan high Dan contributed to erosion on the Nile Delta

Answer 16

• Has disrupted the normal flooding of the delta
• Discharge fell from about 35 billion m^3/year to 10 billion
• Sediment volume fell from 130 million tonnes to 15 million
• The sediment is trapped by the dam + reservoir so less reaches the delta
• In 1965-1970 the erosion rates were 225 m/year

Question 17

What are the human impacts of erosion on the Nile delta

Answer 17

• Water withdrawals from lake Nasser (behind the dam) that supports industries, cities etc significantly reduced water discharge to the delta
• Removal of coastal sand dunes contributing to the submergence across the Delta coast
• Egypt became Africa’s 2nd largest producer of natural gases, most are extracted from thick layers of sand and shale underlying the delta exacerbating subsidence

Question 18

How was extraction of ground water played a part in the erosion of the delta

Answer 18

• Over the past 30 years ground water pumping for agricultural, urban and industrial use has been at an exceptional rate causing large areas to subside

Question 19

What does subside mean

Answer 19

subside means to fall/sink

Question 20

What are the main factors making Bangladesh even more vulnerable to flooding

Answer 20

• Population density
• Land height
• Location
• Himalayas/rivers
• storm surges
• Monsoon climate

Question 21

How does Population density and Land height make Bangladesh more vulnerable to flooding

Answer 21

. Population density - Have the highest population density in the world.
This could mean many are living in informal sector housing and slums and many more people will be effected
. Land hight - Low lying land especially around costal areas (2-3m above sea level)
46% of the countries population lives 10 meters above sea level

Question 22

How does location and the Himalayas/rivers make Bangladesh more vulnerable to flooding?

Answer 22

. Location - Bangladesh lies on the flood plains of 3 major rivers (Brahmaputra, Meghana and Ganges). The 3 converge in Bangladesh and flow to the bay of Bengal
. Himalayas/rivers - Bangladesh lies below Nepal. As an increase of snow melting (due to global warming) flows into the rivers, meaning more water is flowing through Bangladesh so more likely to flood the watershed

Question 23

How do Storm surges and Monsoon climates make Bangladesh more vulnerable to flooding

Answer 23

. Storm surges - Bangladesh is prone to tropical cyclones which bring regular storm surges to the coast
40% of all storm surges recorded have occurred in Bangladesh
. Monsoon climate - The majority of rain fall occurs between June and October which can bring over 50mm of rain per day to some regions

Question 24

What is watershed

Answer 24

The max water a river can hold

Question 25

What human factors increase flood risk in Bangladesh

Answer 25

- Rapid urbanisation - Deforestation - Fresh water demands

Question 26

How does rapid urbanisation/population increase flood risk in Bangladesh

Answer 26

Bangladesh has had a drastic growth in population. The population increased from 1.8 million to 30 million between 1951 and 1991. The population is now at 163 million Rapid growth means a higher rate of urbanisation therefore building of infrastructure. It can impact the drainage basin and flooding in the watershed. It allows more water to enter the area 60% of land is covered in Highways and buildings so there's less agricultural land with plants to uptake water for processes such as photosynthesis etc

Question 27

How does deforestation increased flood risk in Bangladesh

Answer 27

Deforestation has increased due to demand in food and fuel. The deforestation of the Himalayan foothills has allowed more rainwater into the Ganges and the 2 other rivers increasing the magnitude of water flow. Also the deforestation of mangroves reduces the protection and shelter they provide against extreme weather events. 71% of mangroves are retreating by up to 200m per year

Question 28

What are storm surges and how are they created

Answer 28

Changes in sea level caused by intense Low-pressure systems and high wind speeds - For every drop in air pressure of 10mb, the sea level rises by 10cm. During tropical cyclones the air pressure can drop by 100mb or more causing a sea level rise of 1m or more - The forwards motion of the storms towards coastlines pushes the surge forwards onto land - Rise in sea level is intensified in areas where the coastline is funnel-shaped

Question 29

What factors can contribute to impacts of storm surges

Answer 29

- Wind speed and height of storm surge - Nature of coast - Rivers - Rainfall - Debris in the water

Question 30

In which LIDC and AC countries did 2 storm surges hit which we studied

Answer 30

LIDC - Bangladesh AC - Neverlands/UK

Question 31

What is the background for the Storm surge in Bangladesh

Answer 31

- LIDC - The tropical cyclone Sidr was a category 4 cyclone, Air pressure reached a low of 944mb, this brought 150 mph winds and a 6m storm surge - Worsened by the funnel shape of the bay of Bengal focussing water on Bangladesh at the bay apex - 60% of Bangladesh is less than 3m above sea level - Prior deforestation of mangroves - Flood action plan that included 5000 flood shelters, forecasting system, Building of Dams etc

Question 32

What are the social, economic and environmental impacts of the Bangladesh storm surge

Answer 32

. Social - 15,000 people killed and 550,000 injured (Low for an LIDC country) - 1.6 million homes destroyed and 30 million displaced from their homes . Economic - Total damage estimated $1.7 billion - 8000km of roads 700km of electricity lines and 900 fresh water wells all destroyed . Environmental - Loss of farm land - Crops destroyed on 600,00 acres of agricultural land

Question 33

What is the background of the storm surge hitting the UK/Netherlands

Answer 33

- Netherlands has 20% of land bellow mean sea level and 50% less than 1 meter above mean sea level - A combination of high spring tide, a severe wind storm and low pressure systems led to a storm surge of more than 5.6 m above mean sea level in some locations - Overwhelmed sea defences in East UK and Netherlands causing extensive flooding - Many people were underprepared due to local radio stations and small weather stations not operating at night

Question 34

What are the social impacts of the storm surge that hit the UK/Netherlands

Answer 34

- 1836 deaths in the Netherlands and the emergency evacuation of 70,000 - 307 killed in England and 19 in Scotland - Flooding forced 30,000 people to be evacuated from their homes and 24,000 properties destroyed in the UK

Question 35

What are the economic and environmental impacts of the storm surge that hit the UK/Netherlands

Answer 35

. Economic - The ferry MV princess Victoria was lost at sea in the north channel of Belfast. 133 fatalities and many fishing trawlers sank - 47,300 buildings were damaged and 10,000 of which were destroyed in Netherlands. Total damage estimated 1 billion Dutch Guilders . Environmental - Floods covered 9% of Dutch farm land and Sea water flooded 1,365 km^2 of land - An estimated 30,000 animals drowned

Question 36

What are the climate change projections and who are responsible for predicating this

Answer 36

The IPCC - Intergovernmental panel of climate change are responsible for predicting and researching changes in climate change 'It is very likely sea level will rise in more than about 95%' 'It is virtually certain that global mean sea level rise will continue for centuries beyond 2100'

Question 37

What will climate change do to hurricanes

Answer 37

They will not cause the frequency of them but having warmer and higher oceans are expected to make them more intense

Question 38

What are the future storm predictions

Answer 38

- Wind speed will be 2-11% stronger - Rainfall will increase by around 20% - Storm damage will increase loss of life and property

Question 39

What were the causes of Hurricane Katrina 2005

Answer 39

- Category 5 storm - Winds reached up to 185 mph - 2005 produced 3 of the 6 most powerful hurricanes ever recorded - Caused a 28ft high storm surge along the Mississippi coastline

Question 40

What were the impacts of hurricane Katrina 2005

Answer 40

- Costliest US disaster in history - cost $106 billion worth of damage - 1836 people died (After the hurricane hit) - Levees burst causing the low-lying city of New Orleans to burst - $30 billion of damage and 22 deaths (immediately)

Question 41

Why is New Orleans so vulnerable to flooding

Answer 41

- 50 miles from the gulf of Mexico - Built on a swamp - Majority of the city is bellow sea level - Wetlands/mangroves are disappearing - If water is pushed over the levees there's no way to get it out

Question 42

Why is the vulnerability in New Orleans increasing

Answer 42

- 25 million US residents live in areas vulnerable to costal flooding - Coastal activities such a marine transportation of goods, resource extraction and tourism etc is vital to the US economy. Generate 58% of the GDP - Trump is anti-climate change as he has removed memberships etc and he has put major tariffs on goods from other countries

Question 43

Why as a HIC wasn't the impact of hurricane Katrina mitigated against better

Answer 43

- Many false evacuation alarms prior so people were fed up of evacuating so didn't - Hard to predict the path of hurricanes

Question 44

What is the change in sea level like in America

Answer 44

It is shown the Eastern coast of America are experiencing an increase in sea level rise. For example in New York some areas may experience up to 8 inches of sea level rise. Also, the southern coast of America such a Texas and Florida are showing major sea level rise. However the western coast of America is shown to be predicted minimal sea level rise but also Alaska in the North is predicted to experience a drop in sea level

Question 45

What is hard and soft engineering

Answer 45

Hard engineering - Man made structures to reduce the rates of erosion Soft engineering - Natural, Sustainable methods to manage erosion

Question 46

What is a Tangible and Intangible cost

Answer 46

Tangible - Where costs and benefits are known and can be assigned monetary value (Costs of buildings) Intangible - Where costs may be difficult to assess but are important (e.g. social impacts)

Question 47

What are the costal management strategies and explain

Answer 47

- Hold the line = This involves maintaining the current position of the coastline - Advance the line = This involves extending the coastline out to sea - Managed retreat/strategic realignment = This involves allowing the coast to retreat but in a managed way (e.g. to create salt marshes) - Do nothing/no active intervention = This involves letting nature take its course and allowing the sea to erode cliffs and flood low-lying areas

Question 48

Who manages costal management in the UK and what did they introduce

Answer 48

Defra They introduced shoreline management plans (SMPs) in 1995 where only 4 polices (hold the line, Advance the line, manage retreat and do nothing) are used for costal management

Question 49

What are the different types of Hard and soft engineering

Answer 49

Hard engineering = - Groynes - Sea walls - Rip rap/rock armour - Revetments - offshore breakwater/bars Soft engineering = - Beach nourishment - Cliff drainage - Dune stabilisation - Marsh creation

Question 50

What are - groynes - Sea walls and what are the advantages and disadvantages and cost of them

Answer 50

. Groynes(£5000 each) - Rock or wooden conducted at 90 degree angles to hold beach material threatened by LSD + Low capital costs, repaired relatively easy - Need regular maintenance, have impacts on beaches down shore . Sea walls(can cost millions) - Made of rocks or concrete. Often recurved and used to absorb wave power + long life span, excellent in high energy storms, don't disrupt sediment movement - costly to construct/ maintain, do not look attractive

Question 51

What are - Rip Raps/Rock armour - Revetments and what are the advantages, disadvantages and cost

Answer 51

Rip raps/ rock armour (£1000/3000) - Barriers of large rocks/boulders before a sea wall or cliff to absorb wave power and reduce backwash + Effective, Quick and easy to construct (weeks), can last a long time if well maintained - May be moved in strong weather, cost is increased if it needs importing - Revetments (£2000) - Slatted barriers of wood or concrete to reflect rather than resist waves + cheaper and less intrusive as a sea wall - short life span, unsuitable in high wave energy, do not look attractive

Question 52

What is a offshore breakwater/bar and what are the advantages ,disadvantages and costs

Answer 52

1.5 million a bar Large concrete blocks to reduce the power of waves and redirect them + mimic natural bars and reefs, natural appearance - Difficult to maintain, may not work at large scale

Question 53

What is - Beach nourishment/regeneration - Cliff drainage and what are the advantages, disadvantages and cost

Answer 53

Beach nourishment/regeneration (£20 per cu/m) - Sand pumped or transported to areas/beaches lost by LSD. The beaches are bad higher and wider + Natural looking process, better for tourism - May soon be eroded by the sea/people so needs continuous management Cliff drainage (cheap) - removal of water preventing landslides/slumping + cost effective - Drained cliffs can dry out and lead to collapse

Question 54

What is - Dune stabilisation/regeneration - Marsh creation and what are the advantages disadvantages and costs

Answer 54

Dune stabilisation/regeneration (cheap £3000 per km) - Taking action to build up dunes and increase vegetation. Mariam grass is often planted to hold dunes together + provides barrier between land and sea, natural looking, can increase biodiversity - Trampling from people so needs to be closely managed, Strom waves can damage dunes Marsh creation (depends on value of land £5000-10,000 per hectare) - Low-lying coastal areas to be flooded by the sea to become salt marshes. Salt marshes are barriers to the sea + Cheap option compared to hard engineering, creates habitats for wildlife - Land will be lost as it is flooded by sea water, Farmers or landowners will need to be paid for this loss of land

Question 55

What coastal management strategies are being conducted at different parts of the Holderness coast

Answer 55

- Chalk cliffs (Flamborough head) . Do nothing - as the intent is to allow natural processes to continue - Holderness cliffs . Do nothing - to allow natural processes to take place however . Hold the line - At Bridlington, Hornsea and Withernsea as they are viable towns and seaside resorts so need sustaining - Mappleton . Hold the line to sustain Mappleton and a strategic north-south transport link - Dimlington and Easington . Hold the line - Due to gas terminals - Spurn head . manage retreat - To maintain access to key facilities but to not disrupt the natural environment

Question 56

What is CBA (Cost benefit analysis) and why is it controversial

Answer 56

CBA is a tool used to help decide whether defending a coastline from erosion and/or flooding is 'worth it' Often controversial because: - The value of the property is dependent on how at risk it is (e.g. An identical house at the risk of erosion will cost less than one inland) - Some human and environmental costs are very hard to quantify in financial terms

Question 57

What does the environmental impact assessment (EIA) aim to identify

Answer 57

- Short term impacts on coastal environment of construction - Long term impacts of building new sea defences of changing a policy form hold the line to no active intervention or managed realignment

Question 58

Where is the blackwater estuary and what was the problem there

Answer 58

located in south west England in Essex Increase rapid erosion of the salt marsh which is prone to flooding. Shown that responding to flooding/erosion by costal defences is not always sustainable due to 'costal squeeze'. This effects the blackwater estuary

Question 59

What is costal squeeze

Answer 59

When sea levels rise estuary salt marshes naturally migrate inland. Defences would stop this so the salt marsh is squeezed would eventually disappear removing natural protection from the sea

Question 60

What action was taken to combat costal squeeze in the blackwater estuary

Answer 60

Abbots farm linking over 1,200 hectares was brought by the Essex wildlife trust. A 400 hectare managed realignment scheme was implemented They created 5 breaches in the sea wall in 2002 allowing new salt marshes to form in-land

Question 61

Who were the main winners and loser of the blackwater estuary scheme

Answer 61

Winners : - Local government - high hold the line costs avoided but flooding was still reduced - Environment - The water quality increased due to reed beds which filter and clean the water - Tourists and local residence - The land safe from flooding and New paths and waterways created for leisure activities - RSPB - important bird habitats enhanced losers : Abbots hall farm owners received market value for their threatened farm and it was lost to the sea

Question 62

Who are winners and losers

Answer 62

Winners - People who have gained form the decision either economically, socially or environmentally losers - People who are likely to lose property, or sea the coastline as un-natural etc

Question 63

What are the rates of erosion like in some places in Asia

Answer 63

- Around 30% of Malaysia's coast is eroding - In Jiangsu China there's erosion of 80m at year - Southern Vietnam 50m per year - West Bengal India 6m per year

Question 64

What are the causes of erosion in parts of Asia

Answer 64

- Construction of dams on major rivers (near Himalayas) e.g. three gorges dam. They have reduced sediment supply to the coast and have disrupted local sediment cells - Rapid coastal development, urbanisation and development of tourist resorts have led to haphazard construction with no defences or plans - Destruction of mangroves forests for fuelwood and shrimp ponds has exposed soft delta sediments to rapid erosion

Question 65

What is happening in Bangladesh in regards to costal erosion and where in Bangladesh

Answer 65

Chittagong A costal climate resilient infrastructure project supported by the Asian development bank (ADB) aims to climate proof the area

Question 66

What does the costal climate resilient infrastructure project in Bangladesh involve

Answer 66

- Improving road connections while raising embankments to 60cm above normal flood levels plus making them resistant to coastal erosion - Creating new market areas raised on platforms above the 2050 expected sea level - Constructing, improving or extending 25 tropical cyclone centres - Training in climate resilience and adaptation measures

Question 67

What were the positives and negatives of the Coastal climate resilience infrastructure project in Bangladesh

Answer 67

Positives - Poverty decreased by 10% as income opportunities for locals - Adapting to climate change and reducing disaster risk and enhancing the environment such as planting trees Negatives - The forceful relocation of 200 people due to road realignment - permeant removal of natural vegetation - Government had to borrow $60 million from IFAD (international fund for agricultural development) - Project only rated satisfactory