1
Q
What are the different factors which affect climate?
A
Latitude, distance from sea, prevailing winds, ocean currents, altitude
2
Q
How does latitude affect the climate?
A
- Places near the Equator are much warmer than places nearer the poles
- this is due to the curvature of the Earth and the angle of the sun
- at the equator the Sun is always high in the sky
- when it is overhead it shines directly downwards concentrating its heat into a small area which will become very hot
- in contrast the Sun is always low in the sky towards the poles
- this means that its heat is spread over a wider area and so temperatures remain lower
- the lower the angle of the sun the greater the amount of atmosphere through which the rays have to pass.
- This means that more heat will be lost to gases dust and cloud in the atmosphere
- this is why places in the south of Britain can expect to be warmer, especially in summer, than places further north.
3
Q
How does distance from sea affect the climate?
A
- The sea (a liquid) is less dense than the land (a solid) and can be heated to a greater depth
- this means that the sea takes much longer to heat up in summer than does the land, but once warmed, however, the sea retains its heat for much longer and cools down more slowly than the land in winter
- this is why places that are inland are warmer in the summer but cooler in winter than places on the coast
- a country surrounded by sea tends to get cold summers and mild winters
4
Q
How does prevailing winds affect the climate?
A
- prevailing winds will bring warm weather if they pass over a warm surface (land in summer, the sea in winter) and cold weather if they blow across cold surfaces (the land in winter, the sea in summer)
- as Britain’s prevailing winds blow from the south-west, they are cool in summer but mild in winter
5
Q
How do ocean currents affect the climate?
A
- Many coastal areas are affected by ocean currents
- the North Atlantic drift (Gulfstream) is a warm current of water which originates in the Gulf of Mexico. it keeps the west coast of Britain much warmer in the winter than other places in similar attitudes
- IMPORTANT EXAMPLE: The Benguela current causes coastal fog along the coast of the Namib desert in Namibia, however as the foggy air moves inland the water droplets quickly evaporate. daytime warming, as the air passes over the land, reduces its relative humidity and chance of precipitation
6
Q
How does altitude affect the climate?
A
- Temperatures decrease on average by 1°C for every 100 m in height
- as many parts of the Scottish highlands are over 1000 m, they will be at least 10°C cooler than coastal places
- in fact, the wind chill factor will make them colder, and enable snow to lie for long periods during the winter
7
Q
Draw and label a Hadley cell
A
Include :
- Wet warm air rises -low-pressure
- condensation on the tropopause
- dry air moves towards the poles
- air cools
- dry cold air sinks - clear skies and direct sunlight
- air warms - deserts form
- trade winds push air towards the Equator
- air is heated
8
Q
What are the different opportunities for human activity in the rainforest?
A
Farming, Transport, Resources, Settlement
9
Q
Explain how farming is an opportunity for human activity in the rainforest
A
Land is cleared for three types of farming:
- ‘Slash and burn’ is the traditional method used by Amerindians in the rainforest. although this is the most sustainable of the three types, it nevertheless causes considerable areas to be cleared, even if only temporarily each year
- Subsistence farming -has increased as a result of the government providing land to some of Brazil’s 25 million landless people. in places, 10 km strips of land were cleared alongside highways and settlers were brought in from places that were even poorer, like the drought areas in the north-east
- Commercial cattle ranching - is run by large transnational companies which sell beef mainly to fast food chains in developed countries. these companies burn the forest, replacing trees with grass
10
Q
Explain how transport is an opportunity for human activity in the rainforest
A
- Over 12,000 km of new roads have been built across the rainforest, the largest being the 5300 km trans-Amazonian highway
- these roads were built to develop the region and transport timber, minerals, farm produce and people
- a 900 km railway has been built in carajas to the coast and numerous small airstrips have been constructed
11
Q
Explain how resources is an opportunity for human activity in the rainforest
A
The main types of resources are:
- timber- mainly hardwoods are obtained by logging companies which fell trees for markets in developed countries. While timber is a valuable source of income for Brazil, little attempt has been made to replant deforested areas
- Minerals- provide the region with a vast natural resource. they include: iron ore, bauxite, manganese, diamonds, gold and silver
- Hydroelectricity- is an important renewable source of energy but the building of dams and the creation of large lakes has led to large areas of forest being flooded
12
Q
Explain how settlement is an opportunity for human activity in the rainforest
A
- The development of Amazonia has led to an increase in population from 2,000,000 to over 30,000,000
- large tracts of forest have been cleared for the development of such new settlements, as Maraba (150,000) and Carajas
13
Q
What are the different impacts of human activity?
A
Reduction of species diversity, impact on soils and nutrient cycle, rivers, reduction in number of Ameridians, climatic change
14
Q
How does human activity have an impact on the reduction of species diversity?
A
- A typical patch of rainforest 10 km Square could obtain as many as 1500 species of flowering plant, 750 species of tree, 400 types of bird, 150 varieties of butterfly, 100 different reptiles and 60 types of amphibian.
- deforestation has destroyed many of these species, some of which have proved to be of considerable value
- we already get over half of our medicines from the rainforest -one of these recently discovered was the periwinkle -has reduced deaths from child leukaemia from 80 to 20%
15
Q
How does human activity have an impact on soils and nutrient cycle?
A
- The clearance of trees means that there is no canopy to protect the soil from heavy afternoon rain or roots to bind it together
- the result is less interception and infiltration and more surface run-off and soil erosion
- deforestation also breaks the nutrient cycle and existing nutrients are rapidly washed out of the soil, leaving it infertile
- this loss infertility has already caused as some of the new subsistence farms and the larger cattle ranches to be abandoned
16
Q
How does human activity have an impact on rivers?
A
Many rivers has been polluted due to mining operations
17
Q
How does human activity have an impact on the reduction of number of Ameridians
A
- There has been a huge reduction in the number of the Amerindians (from 6 million when the Europeans arrived to the present number of 200,000) and destruction of their traditional culture and way of life
- those remaining such as the Kayapo are forced to live on reservations
18
Q
How does human activity have an impact on climatic change
A
- Deforestation is causing climatic change into ways:
- with fewer trees there is less evapotranspiration and therefore less water vapour in the air. with less moisture in the hydrological cycle there is already evidence of reduced rainfall totals together with the threat of a possible increase in local droughts
- at the same time the burning of the forest is accelerating global warming by releasing huge amounts of carbon dioxide ,the main greenhouse gas.
- it is possible that there already changes in the composition of the atmosphere.
- scientists already claim that over one third of the worlds fresh oxygen supply comes from the tropical rainforest- this would be lost of the region was completely deforested
19
Q
How much precipitation does a desert receive every year
A
Less than 250mm
20
Q
How hot are hot deserts
A
They can have very high daytime temperatures often over 50°C and low nighttime temperatures below 20°C with clear skies.
21
Q
Describe the global distribution of hot deserts
A
- Most are located at latitude is from 15° to 30° on the western side of continents (e.g South Africa,Central Australia, mid-east, Sahara)
- however the Mojave, Mexican, Iranian and Thar deserts line north of the Tropic of Cancer, extending 40°N
- Hot deserts are found in subtropical and tropical latitudes
22
Q
How does lack of cloud cover affect desert climate?
A
-Desert air has a very low relative humidity, so little clouds form. -this causes extreme to daily (diurnal) temperatures and very large daily temperatures ranges all year round
23
Q
Why is rainfall so rare in deserts?
A
-high pressure (explained on handles cell) means convection is seldom strong enough to rise through the descending air
24
Q
Draw a diagram showing how relief rainfall
A
Include:
- vegetation on left
- warm, moist air is pushed up mountain
- dew point temperature on mountain causes condensation
- rain clouds form
- dry air passes over mountain
- air descends and warms
- dry conditions known as rain shadow (deserts)
25
What is an example of a rain shadow?
-The rain shadow effect of the Drakensberg Mountains forms the Namib desert
26
For a named area of hot desert, you have studied, (Nabib desert) explain why the climate is hot and dry. (7 marks)
* The Namib desert can be found 30 degrees north of the equator in a high pressure belt. This is an area of dry sinking air. As the air is not rising there is no cooling or condensation and this produces cloudless skies.
* The absence of cloud cover means that no rain can fall, the sun’s heating is intense throughout daylight hours and night temperatures fall rapidly.
* Although the prevailing winds blow from the ocean, it has to cross a mountain barrier, this creates a rain shadow effect on the Drakensberg Mountains. Much of the rain falls on the windward side of the mountain so there is little rain on the leeward side. Much of the Namib desert is in the rainshadow.
* The cold Benguela ocean current leads to the formation of fog on the coast of Namibia. These fogs are soon dissipated as they move inland when the temperatures rise and the air can hold more water vapour.
27
What are the impacts of deforestation on people who live in the rainforest?
- loss of traditional culture
- lack of fuel wood
- lack of drinking water
- floods
- landslides
- soil erosion
- loss of species used for food
28
What is a biome?
A Large scale ecosystem (A biological community of interacting organisms and their physical environment)
29
What are some plants and animals which have adapted to the rainforest?
Lianas (woody vine like plants), epiphytes, bark, buttress roots, drip tip leaves, sloths, spider monkeys, flying frogs, toucans
30
How are lianas adapted to the rainforest?
Have their roots in the ground, climb up trees to reach sunlight
31
How are epiphytes adapted to the rainforest?
Plants which live on branches high up on the canopy, get nutrients from air and water, receive lots of sunlight
32
How is the bark adapted to the rainforest?
Smooth to allow water to flow to roots
33
How are buttress roots adapted to the rainforest?
Large with ridges for larger surface area to support larger trees
34
How are drip tip leaves adapted to the rainforest?
Plants have leaves with points to allow water to run off quickly without damaging the leaf
35
What are the four rainforest layers?
The shrub layer, under canopy, main canopy and emergents
36
Why do rainforests form on the equator?
- Rainforests are located in Brazil, Congo, Indonesia
- high in temperature because of higher concentration of solar radiation.
- higher concentration of solar radiation because the position of the equator on the globe causes the sun to have to heat only a small area of land. In other areas (mainly the Northern Hemisphere), latitudes are higher so they are spread out across more land, meaning the climate is cooler.
- rainy environment due to strong sunlight, which causes conventional rainfall.
37
What is the nutrients cycle like before deforestation?
1. Leaves, branches and trees fall and decay rapidly to form humus
2. This adds nutrients to the soil
3. The nutrient rich soil results in rich tree growth. Trees protect the ground from heavy rainfall which would wash out the nutrients.
4. The cycle continues
38
What is the nutrients cycle like after deforestation?
1. Fewer leaves and plants, so less humus
2. With less humus, few nutrients are added to the soil and any nutrients is leached and infiltrated downwards because no interception from trees of the rain (direct rainfall) and there is more surface runoff ans soil erosion
3. The soil becomes less fertile and there is poorer-quality vegetation and soil erosion. This loss in fertility has already caused some of the new subsistence farms and larger cattle ranches to be abandoned
4. Animals have no habitat\>animals find new habitat\>creates competition\>fights,death
39
What is conventional rainfall?
- sun rises high in sky by midday and heats up ground
- the air next to the ground is heated and starts to rise
- as the warm air rises up through the trees, transpiration occurs
- the warm air carries on rising up, past the trees until it’s so high in the sky that is starts to cool and condense
- the condensation forms white, cumulus clouds
- the cumulus clouds merge and form a cumulonimbus storm cloud
- the cumulonimbus storm cloud results in heavy rain
- the cycle continues
40
What is transpiration?
The evaporation of water on trees and leaves
41
What is the climate of the rainforest like?
- hot, humid (perfect for photosynthesis, vegetation growth)
- temperatures over 20 degrees Celsius most of the year
- diverse range and high volume of plant and animal life (high biodiversity)
- high rainfall
- long hours of daylight and sunshine
42
What are the global values of the rainforest?
- strongly affects world’s environment:
Trees give off water into the atmosphere and help regulate water cycle. Trees absorb CO2, reducing global warming. Trees give out O2 which is needed for human’s survival.
- important for medicine around the globe:
1/4 of all cancer treating drugs are found in the rainforest. St Johns Wort (a plant found in the rainforest) can help treat depression. The periwinkle plant is used to treat leukaemia. Quinine is used as a painkiller and malaria treatment.
43
What are the national values of the rainforest?
- income tax from exported goods leads to an improvement in infrastructure (hospitals, schools, roads)
- valuable goods (wood pup for paper, rubber and latex for tyres) can be used by citizens or exported
- variety of goods means there are more jobs available, leading to an improvement in infrastructure
44
What are local values of the rainforest?
- nuts, berries, gold etc. can be used by locals or exported
- exported goods are taxed, so locals have to pay tax, leading to a stronger infrastructure
- trees absorb water before it reaches the ground, reducing the risk of flooding
- rainforests have spiritual values for tribes
- provide a nutrients cycle, resulting in rich soil (perfect for farming)
45
What are the different reasons for why deforestation is happening in the rainforest?
Farming (Cattle farming, soya farming), settlement, Resources (Logging, Mining, Hydroelectricity), Transport
46
What is logging doing to the rainforest?
-Logging is the cutting down of trees and expensive woods (mainly hardwoods) such as mahogany. This wood is made into furniture, flooring and paper, then exported to countries in Europe (HICs)
- the timber industry is helping Brazil become an economically strong country (the GDP has grown by 5% due to logging)
- the country is trying to make specific areas for logging.
- They use a method called selective logging to help the rainforest
regrow
-while timber is a valuable income source for Brazil, little effort has been made to regrow deforested areas
47
What is mining doing to the rainforest?
- Brazil clears forests to mine iron ore, bauxite, gold, silver, manganese, diamonds and copper.
- Since the country lies on the World’s largest rainforest and has the most iron ore, 45 million tons are harvested annually which provides many much needed jobs
- the mines activities are constantly monitored by an environmental policy who aim to conserve and recuperate the Amazon’s ecosystem
48
What is cattle farming doing to the rainforest?
- huge areas of rainforest are cleared to make room for animal farming.
- between 1990 and 2001 the percentage of Europe’s meat imports from Brazil rose from 40 to 74 percent.
- Brazil earns 2.5 billion from overseas sales of beef
49
What is settlement doing to the rainforest?
- tribes in Brazil live in the rainforest and use the land for farming and building houses
- the number of people living Brazil was once 6,000,000 but has increased to just over 30 million.
50
What is Soya Farming doing to the rainforest?
- soya farming is where people clear land to grow soya beans
- soya farming is effective because the soil is fertile and the climate is perfect as there is enough sunlight and rainfall.
- Soya beans are used to feed cattle and pigs
51
How can we develop the rainforest sustainably?
- create environmental laws to protect it
- set up national parks and nature reserves where damaging activities are restricted
- teach locals of negative impacts of deforestation and other ways to make money
- selective logging: only some trees (e.g the oldest) are felled and the rest are left standing
- reduce the amount of money that poor countries owe richer countries so that poorer countries don’t need to allow logging,farming or mining
- teaching international communities about deforestation so that there is lead demand for products that cause it
- ecotourism: benefits locals by providing a source of income without affecting the environment
- reducing the demand for hardwood : high taxes are put on the wood so that less people buy it
- replanting/reforestation : new trees are planted to replace those cut down by deforestation
52
What are the goods and services that come from the rainforest?
Services:
- trees are a flood defence: trees absorb water before it reaches the ground
- O2 is given out which is needed for humans to survive
- nutrient cycling: dead leaves and plants add nutrients to the soil
- rainforests provide spiritual value for the tribes who live there
- trees give off water (transpire) into the atmosphere which helps regulate the water cycle.
- CO2 is absorbed by trees from the atmosphere, reducing global warming.
- the rainforest provides a habitat for animals
Goods:
- nuts, berries, timber, fish, meat
- bamboo (used for scaffolding in Hong Kong)
- Rubber and latex comes from trees and makes tires
- Quinine comes from bark and is used as a painkiller and for malaria treatment
- The periwinkle plant is used to treat leukaemia
- st. Johns wort is a plant that may help to treat depression
- 1/4 of all cancer treating drugs are found in the rainforest
- lots of minerals: gold, iron ore
53
In which countries are rainforests found in?
Brazil, Congo, Indonesia
54
What is Transport doing to the rainforest?
- Over 12,000km of roads have been built into the rainforest, the largest being the 5300km Trans-Amazonian highway.
- These roads were built to develop the religion and transport timber, minerals, farm produce and people
- A 900km railway has been built and numerous small airstrips have been constructed
55
What are the three types of farming?
- slash and burn
- subsistence farming
- commercial cattle ranching
56
What is ‘Slash and Burn’ farming?
- traditional method used by Ameridians in the rainforest
- although this is the most sustainable farming method, it nevertheless causes significant areas to be cleared, even if only temporarily each year
57
What is Subsistence farming?
- farming for self/family. Any spare produce is sold at the market
- associated with LICs
- has increased as a result of the government providing land to some of Brazil’s 25 million landless people
- in places, 10km strips of land were cleared alongside highways and settlers were brought in from places that were even poorer, such as drought areas in the northeast
58
What is commercial cattle ranch farming?
- run by large transnational companies which sell beef mainly to fast food chains in developed countries
- these companies burn the forest, replacing trees with grass
- commercial farming= large scale farming, run by businesses (associated with HICs)
59
What is Hydro-electricity doing to the rainforest?
-an important renewable source of energy but the building of dams and creation of large lakes has led to large areas of forest becoming flooded
60
What are the different impacts of human activity?
reduction of species diversity, impact on soils and nutrient cycle, rivers, reduction in number of Ameridians, climatic change
61
What is the reduction of species diversity?
- a typical patch of rainforest 10km square could contain as many as 1500 species of flowering plant, 750 species of tree, 400 types of birds, 150 varieties of butterflies, 100 different reptiles and 60 types of amphibian
- deforestation has destroyed many of these species; some of which have proven to significant value
- we already get over half our medicines from the rainforest- one of these being the periwinkle (which has reduced deaths of child leukaemia from 80 to 20 percent)
62
What is the impact of human activity on rivers?
-many rivers have been polluted due to mining operations
63
What is the impact of human activity of reduction of number of Ameridians?
- huge reduction: 6 million to 200,000
- big destruction of their traditional culture and way of life
- those remaining, such as the kayapo, are forced to live in reservations
64
What are the impacts of human activity on climate change?
- two ways it is affecting climate
- with fewer trees there is less evapotranspiration and therefore, less water vapour in the air
- with less moisture in the hydrological cycle there is already evidence of reduced rainfall totals together with the threat of possible increase in local droughts
- at the same time, burning the forest is accelerating global warming by releasing huge amounts of CO2 into the atmosphere
- it is possible that there are already changes in the composition of the atmosphere
- scientists claim that already over one-third of the world’s fresh oxygen supply comes from the rainforest. This could be lost if the area is completely deforested
65
Draw and label a diagram of a rain gauge
Include:
Outer canister, funnel, measuring bottle, ground level, inner canister
66
What does a rain gauge measure?
Rainfall
67
What are the site requirements of a rain gauge and explain why
- on grass not hard surface to avoid splashes entering
- part buried to prevent evaporation and for stability
- rim 30cm above ground to avoid splashes and surface runoff entering
- no overhanging roofs and trees to avoid shelter and too little rain entering
- away from buildings, trees and other objects to avoid drips from entering
- standing vertically upright to keep the gauge diameter
GCSE Geography
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