iGCSE Coasts/Rivers/Natural Vegetation - Case Studies

Location

India and Bangladesh - Ganges River

• 400 million people live on the floodplains

Uses of the floodplain

• Fertile farmland
• Irrigation
• Holy river by Hindus
• Flat land for building
• Transportation

Causes of the flooding

• Monsoon climate - prolong heavy rain
• Spring snow melt from the Himalayas
• Flat flood plain/deltas
• Deforestation

Effects - Social

• 1100 deaths
• 1 million home were damaged
• 13 million people affected
• Spread of diseases

Effects - Economic

• 2 million acres of crops were destroyed
• Factories closed down
• Economic loss of $7 billion

Effects - Environmental

• Contamination of clean water
• 40% of the country was flooded
• Habitats were destroyed

Solutions

• Early warning system in place to predict heavy rainfall
• 8000kms of embankments to control the flooding of the flood plains
• Flood shelters built for people to use when their homes are destroyed from flooding. 

Background

• Occured during the winter of 2013/14
• 350mm of rain fell 
• Affected S.W England
• Area of coastal plain and wetlands in Central Somerset (650km2)
• Flatland lying close to sea level
• Mainly agricultural, crop and grazing land
• Important habitats for birds and plants
• River Parrett and Sowy River was involved

Impacts

• Damage to homes
• Farmland was destroyed
• Unable to get to work
• Lost a large amount of business
• Some villages were cut off
• Major roads blocked
• Many dairy cows were evacuated or sold due to no grass to graze on.

Responses

• Rescue boats were deployed 
• Extra police patrols
• A 20 year flood action plan has been drawn up
• UK government gave £30 million to help with repairs
• Royal Marines were deployed to help
• Environment Agency installed giant pumps to lower water levels
• Embankments along the main rivers (River Parrett and Sowy River)
• Pumping stations
• Dredged up the river bed to lower water levels

Location

• Source - Swiss Apls
• Passes through S.E France
• Mouth - Mediterranean Sea
• Delta is found at the mouth 

Rivers that form the Delta

• Major confluence at Lyons with the River Saone

How is it formed?

• The river carries a large load of sediment
• There is no strong tides or currents which would wash away the sediment faster than they could build up to form a delta
• The river's flow is slowed down by entering the sea depositing sediment
• The river's flow is blocked so much by deposition that it is forced to divide up into distributaries
• Sediment is deposited aling the distributaries and extends into the sea

Background

• Located in Yorkshire
• 50km stretch of coastline
• Impressive chalk headlands and cliffs near Flamborough
• Retreating clay cliffs at Holderness Bay
• 6km spit at Spurn Point

Problems

• Increasing populaion due to retirement
• Development of leisure and holiday facilities (Bridlington and Hornsea)
• Groynes at Hornsea and Mappleton means there isn't a build up of beaches elsewhere
• Rapid erosion
• Cliff not protected from wave erosion

Solutions

• Groynes at Hornsea were repaired
• Groynes and sea walls were placed at Withernsea
• Gabion cages at Skipsea

Facts/Figures

Largest coral reef in the world

Made up of nearly 3000 reefs and 900 islands

1500 species of fish live there

Can be seen from space

World’s largest living structure

Threats

• Tourism - Tourists breaking of coral or standing on it.

• Overfishing

• Boats - Boat anchors damaging the coral. Boats releasing oil into the water.

• Climate Change - Rising sea temperatures are causing bleaching to the reef which destroys it. 

• Agriculture - Run of chemicals from sugar cane farms can pollute the water killing cora

• Acidification - As more carbon dioxide is released into the atmosphere it dissolves in sea making it more acidic. This dissolves the coral made of calcium

• Crown of thorns Starfish - This is an invasive species which kills the coral. 

Solutions

• Creation of a Great Barrier Reef National Park
• Charge tourists to visit
• Try to control Crown of Thorns Starfish population
• Reduce the fertilizers used by farmers.
• Try to reduce climate change.
• Zoning - to stop people from over using the areas so they can recover
• Restrict diving in certain areas

Key Facts:

• 23-31st August, 2005
• Category 3 (when it hit land)
• 1,800 deaths
• $110 billion damage

Impacts - Social

1800 deaths

800,000 homes destroyed

New Orleans was the worst affected city

Hospitals and schools badly damaged

People sought refuge in the Superdome

Shortage of food

Rise in looting and crime

Economic

- $111 billion of damage. The most costly Hurricane in US history

- Oil facilities damaged so the oil price rose

Environmental

- Pollution of waterways with oil

- Uncollected bodies spread disease

Response

- The US government was heavily criticised for its response.

- Many people were evacuated but many of the poor and vulnerable were left behind.

- $50 billion given by the US government

 - National guard was mobilised to restore order.

Background

• Struck May 2008
• 28th April - Category 1
• 29th April - Category 2
• 2nd May - Category 4 (135mph winds)
• Landfall 2nd May at Myanmar

Impacts

Economic

$10 billion worth of damage

Majority of the population worked on the flooded rice fields therefore they lost their harvest and income

75% of buildings collapsed but on the delta 95% collapsed

1,163 temples were destroyed

Environmental

Rice fields were flooded on the Irrawaddy Delta

The 2008 and 2009 harvests of rice were destroyed - The UN’s Food and Agricultural Organization (FAO) estimated that Nargis impacted 65% of the country's paddies.

Strong winds up to 135mph

• Storm surge of 7.6m

• Heavy rainfall

Floodwaters penetrated an estimated 40-50 km (24-31 mi) inland from the coast. Farmland, livestock, and fisheries were all destroyed

Social

There was a lack of food, water for survivors

Many children were orphaned

Diseases spread with many survivors dying from disease

50,000 people are still missing

A death toil of at least 138 000 people has been quoted, but estimates vary widely, it is thought that 80,000 people could have died in the town of Labutta alone, making the 84,000people death toll seem unrealistic

It is estimated that at least 2.4 million people were severely affected by this cyclone. Structural damage throughout Myanmar was extensive, causing over a million to become homeless after the event.

Responses

Initially the response of the Military government was appalling.  The military Junta did not want foreign people coming into the country and destabilising their political oppression, so they refused aid despite the scale of the disaster.  A full 6 days after the storm made landfall and with the government woefully underprepared and unable to cope, the Myanmar government representation from the United States formally asked the United Nations (UN) for help.

Even then, the Myanmar government did not endorse international aid and placed harsh restrictions on even the most basic forms of assistance. It was not until 9 May, a full week after the cyclone made landfall, that the Junta finally gave into international pressure to accept outside aid. However, this aid was limited to food, medicine and basic supplies, and foreign aid workers remained banned from the country.

Finally, on 19 May, Myanmar granted members of the Association of South-East Asian Nations admittance into the country to deliver aid. After negotiations between Ban and the Myanmar head of state, Than Shwe, it was declared on 23 May that other international aid workers would be let into the country - a full 3 weeks after the cyclone struck.

Reasons for Deserts

Some or all of the following:

- Areas of High Pressure

- Descending air from the Hadley Cell

- Rain Shadow from mountains e.g. Andes

- Coast has cold ocean currents which give little rain e.g Peru and the Humboldt Current

- Centre of continent - long way from the sea e.g. Centre of Australia.

Plants with adaptations which allow them to live in hot and dry conditions are called xerophytic. The following adaptations allow plants to survive in the hot desert environment:

Small leaves - these ensure that less water is lost from the plant by transpirationbecause the leaf has a smaller surface area.

Tap roots - these are long roots (7-10 metres long) that reach deep under the ground to access water supplies. The tap roots are much longer and bigger than the plant which is visible at the surface.

Spines - some plants have spines instead of leaves, eg cactuses. Spines lose less water than leaves so are very efficient in a hot climate. Spines also prevent animals from eating the plant.

• Waxy skin - some leaves have a thick, waxy skin on their surface. This reduces water loss by transpiration.
• Water storage - some plants, known as succulents, store water in their stems, leaves, roots or even fruits. Plants which store water in their leaves and stems also have a thick waxy skin so that they lose less water by transpiration.

Location 

The Sahel part of Africa includes from west to east parts of northern Senegal, southern Mauritania, central Mali, northern Burkina Faso, the extreme south of Algeria, Niger, the extreme north of Nigeria, parts of Cameroon and Central African Republic, central Chad, central and southern Sudan, the extreme north of South Sudan, Eritrea, and the extreme north of Ethiopia.

Causes

Decrease in Rainfall - in many North African countries

Rapid population growth - has put pressure on the land. Many families in the Sahel have 6 or more children. Niger’s population is predicted to climb to over 500 million in just 80 years.

Deforestation. Cutting down trees for fuelwood has reduced the amount of rainfall (less transpiration) and allowed the soil to blow away.

Overgrazing. Too many animals eat all the vegetation and destroy the topsoil.

Overuse of fertilisers and pesticides destroys the soil making it easier to blow away. 

Solution

The Great Wall

The objective is to plant a wall of trees across the Sahel and to stop the Sahara expanding into the region. 

Benefits:

• Stops desert expanding
• Helps create fertile soil
• Provides wood
• Increases biodiversity
• Harvest fruits from the trees. 

Key facts

• Largest Rainforest
• 30x larger than the UK
• 40,000 plant species
• Produces 20% of the world’s oxygen.

Location 

The Amazon Rainforest is located in 9 different countries but the majority of it (around 60%) is located in Brazil. The rest of it can be found in Peru, Colombia, Ecuador, Bolivia, Venezuela, Guyana, Suriname and French Guiana (which is technically an overseas territory)

The layers of a rainforest, from the highest to the lowest, are:

• Emergent layer (the tops of the highest trees)
• Canopy layer (the branches and leaves of most of the rainforest’s trees. This is the layer in which the largest number of rainforest species are found)
• Undercanopy layer (small trees and shrubs that are able to live in low-light conditions)
• Forest Floor layer (the dark, damp ground layer, where the rainforest’s largest animals are found)

Adaptations

Lianas:Woody vines that climb up other trees to try and get into the canopy layer to capture sunlight.

Strangler Figs: Strangler figs grow around the outside of other trees taking their light and nutrients and slowly killing the host tree. However, when the host tree collapses so does the strangler fig.

Buttress Roots: Very long roots that support tall trees and absorb the maximum amount of nutrients.

Humus Layer:Rainforest soils are fairly infertile and dependent on the humus layer (decaying biological matter), so that the soil does not degrade quickly.

Walking Palms: Grow new roots to move towards the sunlight.

Drip tip leaves:  Leaves allow rainfall to travel over them and drip to the ground because of their special design, so that the vegetation is not damaged by the large quantities of wáter.

Threats

Illegal Gold mining - Mining destroys the forest. Mercury is used to process the gold, poisoning fish and rivers. It can enter the human population making people sick and reducing brain function.

Road Construction - A new Highway has been built from Brazil to Peru. This highway creates traffic but also other people to access the rainforest. The red line is the road, notice all the new road which people have built off it in order to exploit the forest.

Wildlife Trafficking - Animals such as Parrots and tortoises are smuggled out the rainforest for sale in Lima. 

Logging - Cutting down of trees for timber especially valuable trees such as Mahogany. 

Farming - Poor farmers have invaded the forest and established farms on the land.

Problem of Rainforest destruction:

- Soil Erosion. Without trees soil is at risk of washing away                               

- Flooding. Trees absorb water so without the rainforest more surface runoff will enter rivers.

- Biodiversity. Destruction of the rainforest will mean many plants and animals will become extinct like the Giant River Otter

- Oxygen. The amazon supplies 20% of the World’s oxygen and absorbs large quantities of CO2.

Protecting the Rainforest

Eco-tourism -  Tourist lodges designed with eco-friendly materials and built around protecting the forest.

Extractive reserves - Encourage farmers to use the forest to extract natural products to sell such as Brazil nuts.

 Law enforcement - Use the police and army to control illegal practices such as gold mining and arrest those involved.