Topic Overview Flashcards
(300 cards)
1
Q
What is the world population?
A
7.9 billion
2
Q
What is the global fertility rate?
A
2.3
3
Q
Population density
A
The number of people living in an area, usually given as people per km2.
4
Q
Population
A
All the inhabitants of a particular place
5
Q
The Fertile Crescent
A
This is a band of densely populated area with very fertile soil
6
Q
What areas are densely populated?
A
- the Fertile Crescent
- South-East Asia
- Asia Pacific Rim
- coastlines
7
Q
What areas are sparsely populated?
A
- deserts
- rainforests
- where it is too cold - e.g., in the Arctic Circle
8
Q
What were infant mortality rates like pre-1950?
A
They were really high. People would have around 6 children, but 3 or 4 of them would die before becoming parents themselves
9
Q
What did the Industrial Revolution lead to?
A
- better wages
- more food
- tapped water
- better sanitation
- soap
- medical advances
10
Q
What is the minimum fertility rate needed for population to grow?
A
2.1
11
Q
What does population growth look like for the future?
A
We are expecting a slowing down in the next 100 years - the population will reach about 11 billion and then start to flatten. Although, this is only a projection, so there is some uncertainty.
12
Q
What was the UK population in mid-2020?
A
67.2 million
13
Q
Give some physical factors affecting population density
A
- topography / relief of the land
- climate
- hazards
- water supply
- distribution of / access to resources
- quality of the soil
14
Q
Why are there more people where the soil is fertile?
A
You can grow lots of crops, creating lots of food, therefore attracting people to the area.
15
Q
How does climate affect population density?
A
In cold areas, such as Greenland, where there are low levels of sunlight, there is low photosynthesis, meaning that barely any crops can be grown and so, not many people will live here for there is not a reliable food supply. Moreover, climate can also affect diseases - for example, Malaria occurs in tropical climates, which can put people off visiting / living in a particular area.
16
Q
Why is a water source essential to an area?
A
Water is needed for irrigation, meaning that crops can be grown and a population sustained through this food. People need water as an essential to live and drink, so without a reliable supply, the population will be very small.
17
Q
Why is Bhutan sparsely populated?
A
Because it is mountainous
18
Q
What is something that has allowed rapid industrialisation?
A
Access to resources
19
Q
An advantage of flooding
A
Floods fertilise soil, so you can grow more
20
Q
What is the fertility rate like in Niger and why?
A
Niger is one of the poorest countries in the world. It has a total fertility rate of 7, because the infant mortality rate is so high.
21
Q
Where are climate-related diseases often found?
A
In between the tropics
22
Q
Where are most major cities?
A
On a coast or river
23
Q
Population distribution
A
The pattern of where people live
24
Q
Crude birth rate
A
The number of births per 1000 people (CBR)
25
Crude death rate
The number of deaths per 1000 people (CDR)
26
Natural increase
The difference between the CBR and the CDR usually expressed as a % per year. Natural increase (%) = CBR - CDR
27
Fertility rate
Sometimes called the Total Fertility Rate (TFR), this is the average number of children that are born to a woman during her lifetime
28
What is the world's most crowded city?
Dhaka, Bangladesh
29
What is the population density of Dhaka, Bangladesh?
44,500
30
What was the annual population growth rate from 2011-2015 for the UK?
0.6
31
Where will population grow the most in the future?
Africa
32
What is the minimum temperature many crops need in order to grow?
5ºC
33
Give two types of soil prone to hazards
Rich volcanic or alluvial soils (e.g., because of volcanic eruptions or floods)
34
What is the population distribution like in Egypt?
95% of the population live on about 4% of the country's land (around the River Nile, demonstrating the importance of water supply in determining population distribution)
35
What are population numbers recorded by?
Census data
36
How often is census data collected in most countries?
Every 5 or 10 years
37
What is the expected world population in 2050?
9.7 billion
38
What percentage of the world's population live in Asia?
Around 60%
39
What are the most densely populated areas?
- coastal areas + seaboards
- major river basins
- areas of industrialisation + urbanisation
40
What is projected to happen to the population of Sub-Saharan Africa by 2050?
It is projected to double
41
What is projected to happen to the population of north and west Africa by 2050?
A 46% increase in population
42
What was the population in 1700?
1 billion
43
How has the population in Sub-Saharan Africa increased?
From 10% in 1950 to more than 25%
44
In 1850, how much of Britain's population lived in towns and cities?
More than half
45
What is Nigeria's population set to rise to by the end of the century?
800 million
46
What is Malthusianism?
The idea that population growth is potentially exponential
47
What is demographic transition?
A process allowing the population to stabilise at a higher level.
48
What is the world's most populated country?
China
49
What was the average global food supply in the 1960s?
About 2300 calories/person/day
50
What was the average global food supply in the 1960s for those in HICs?
3080 calories/person/day
51
What was the average global food supply in the 1960s for those in LICs?
2000 calories/person/day
52
Has the average global food supply calories/person/day risen or fallen?
It has risen
53
What was the average global food supply in 2010?
2800 calories/person/day
54
Why has the average global food supply calories/person/day increased, given that population has risen?
By 2010, even though global population had increased by 2.5 times, increases in agricultural production have meant that the world produces enough food to provide 2800 calories/person/day
55
What type of system does agriculture work as?
An open system
56
Inputs to agricultural systems
Physical, human + economic factors that determine the type of farming in the area
57
Processes in agricultural systems
The activities carried out to turn inputs into outputs
58
Outputs in agricultural systems
The products from the farm
59
Are wealth and calorie intake linked?
Yes
60
Is high population density and high calorie consumption linked?
No
61
What is calorie intake like between the tropics?
There is less calorie intake, due to these countries being mainly LICs
62
Why might calorie intake be higher where it is colder?
Because you need to eat more to stay warm
63
Where are the most calories consumed?
In Western countries in the Northern Hemisphere
64
Periodic famine
The regional failure of food production or distribution systems, leading to increased mortality due to starvation and associated disease. E.g., if you get a drought - this is triggered by a human or physical cause.
65
Malnutrition
Develops when the body doesn't get the right amount of the vitamins, minerals and other nutrients it needs to maintain healthy tissues and organ function
66
Undernourishment
The status of people whose food intake does not include enough calories (energy) to meet minimum physiological needs
67
Over-nourishment
The excessive consumption of food which can increase the risk of developing health problems
68
Approximately how much of the 'usable' land on the planet is used to grow food?
Around half
69
How much of food produced worldwide is wasted?
Around 1/3
70
How has food production changed over the years?
Food production has increased steadily at a rate higher than population has increased - we are producing more food than there is people
71
Is there enough food worldwide?
There is enough food, it is just in the wrong places
72
What is an arable farm?
A farm that grows crops
73
Give some physical inputs to the agricultural system
- seeds
- irrigation
- sunlight
- temperature (needs to be reasonably warm)
- nutrients
- land
- wind
- rain
- soil
- food for the animals
- feed
- breeding stock
74
Give some human inputs to the agricultural system
- labour and capital
- money (being spent on machinery etc)
- irrigation
- fertiliser
- pesticides
- storage
- transport
- farmer needs knowledge + skills
75
Processes in the agricultural system
- harvesting
- spraying
- irrigation
- planting
- ploughing
- feeding
- milking
- threshing
- calving / birthing
76
Possible physical changes to the agricultural system
- climatic conditions (climate change)
- hazards
- spread of disease
- fires
- droughts
77
Possible human changes to the agricultural system
- climate change
| - fluctuations in prices
78
Positive outputs to the agricultural system
- crops and animal produce
- meat / milk / other animal produce
- food
79
Negative outputs to the agricultural system
- gas emissions (methane, greenhouse gases) - this leads us to possible changes in the farming system
- chemicals in soils could harm animals. Some chemicals on plants can get washed off into the soil. Eutrophication
- soil erosion
- pollution
80
Eutrophication
Excessive richness of nutrients in a lake or other body of water, frequently due to run-off from the land, which causes a dense growth of plant life.
81
Tropical monsoon climates: location
Asia, the Indian subcontinent and other areas around the Pacific Ocean
82
Tropical monsoon climates: characteristics of climate zone and vegetation
- distinguished by wet and dry seasons
- summer wet season May - October, lots of heavy rain
- by November, wind directions are reversed
- in winter, cool and dry winds blow from the Asian interior to the sea
83
Tropical monsoon climate: importance and type of agriculture
- rice is cultivated during the monsoon season
- none of the rice is wasted. Not only is it a staple food, the 'waste' from when the rice is threshed and winnowed is used as fodder for animals, kindling for fires and even woven into hats, mats, screens and baskets
- as long as there is sufficient water for irrigation, even the paddies can be reused during the dry season for second rice crops, or for beans, lentils and wheat
84
Tropical monsoon climate: threats to this region
Weak monsoon rains result in crop failure, which affects the economy in a negative manner, due to lower production. Later on, this translates into rising prices, low industrial output and other issues.
85
Polar tundra climates: location
Above the Arctic circle. Polar and tundra climates cover more than 20% of the Earth.
86
Polar tundra climates: characteristics of climate zone and vegetation
- the tundra climate is very cold
| - hours of summer sunshine may be long, but temperatures rarely exceed 0ºC?
87
Polar tundra climates: importance and type of agriculture
- the harsh climate and associated tundra vegetation have supported indigenous people sustainably, albeit at substance levels, for thousands of years.
- for example, the Inuit in northern Canada and Greenland have hunted caribou and seals in winter and fished in summer, but always sustainably.
- the Sami of Northern Europe have followed the seasonal movements of reindeer northwards to the treeless tundra in summer and southwards to the boreal (coniferous) forests in winter. Their hunting has long provided most of their food and material needs - sustainably because of their low population density.
88
Polar tundra climates: threats to this region
- human activities are restricted and characterised by fishing, adventure tourism and particularly mineral exploitation, rather than land-based agriculture
- climate change
- air pollution
- industrial activity
- invasive and migrating species
89
Invasive species
An organism that is not indigenous or native to a particular area. It harms its new environment, because they change habitats and starve native animals of food and resources, for example.
90
Semi-arid climates: location
Found near the equator, between the tropics of cancer and Capricorn.
91
Semi-arid climates: characteristics of climate zone and vegetation
- characterised by savanna vegetation, which consists of tall grasses and occasional woody trees
- they are an area of transition between wet, tropical rainforests and dry, hot deserts
- can receive plenty of rain or long periods of drought
- rainfall is seasonal and averages 25 - 50 cm per year, depending on the location
- vegetation growth does take place within the wet season, but water levels are insufficient to sustain many plants other than grass.
- temperatures are determined by latitude. The semi-arid regions of North America are much cooler than those found in Africa.
92
Semi-arid climates: importance and type of agriculture
- agriculture is the most important form of economic activity for African countries such as Niger and Senegal. Agriculture consists of 3 systems of farming: pastoral, rainfed mixed and irrigated mixed.
- crops produced include millet, cowpea, sorghum, cotton and groundnut
- livestock involves rearing cattle, sheep, goats and camels
93
Semi-arid climates: threats to this region
- farming is unreliable in this region, because of the climate. As a result, food insecurity is widespread and many suffer malnutrition.
- population growth is outstripping food supply. Population across the Sahel as a whole is expected to triple in the space of just 40 years.
- climate change is making rainfall levels less reliable and therefore, agriculture is becoming more difficult. In the Sahel between 1970 and 1993, there were 20 years of widespread and severe drought.
94
Mediterranean climates: location
Warm, coastal regions found between 30º and 45º in latitude. This climate is mostly found in the Mediterranean Sea.
95
Mediterranean climates: characteristics of climate zone and vegetation
- characterised by shrubs, thorny bushes and small trees
- there are summer and winter seasons
- summers: warm to hot and very dry
- winters: mild to cool and wet
- mediterranean climates receive around 50 cm of rainfall a year
- vegetation found in this climate type tends to be small and drought resistant
- there are many fruit trees, grape vines, figs, olives and citrus fruits that grow well in this region.
96
Mediterranean climates: importance and type of agriculture
- intensive viticulture (grape cultivation) takes place and supports the wine, sherry and port industries
- citrus fruits, olives and figs are also cultivated here - their long roots, sparse foliage and waxy-skinned fruits grow well in this type of climate
- pastoral farming is not as common, because grass has shallow roots and does not grow well here, so grazing land is scarce
- farming is reliable in this region and food security is high, so large numbers of people can be supported
97
Mediterranean climates: threats to this region
- the biggest threats come from development, as these areas are in warm, coastal locations that are desirable for accommodation and tourism
- climate change is shifting climate belts and a warming of just 2ºC could lead to arid and semi-arid climate belts encroaching on the Mediterranean Basin, resulting in an increasingly dry climate.
- the Mediterranean Sea is warming at a faster rate than other bodies of water, which is affecting marine life, such as sea grass and dolphins.
- rainfall levels have been decreasing during the winter months, which means that groundwater aquifers are not being recharged, and therefore, less water is available for the growth of crops during the summer months. These trends mean that greater levels of irrigation are required for agriculture to continue at current levels in the Mediterranean Basin.
98
What affect is climate change having on agriculture?
- there is a concern that climate change will result in less predictable weather conditions, which would jeopardise traditional rice production and has led to research into less water-intensive methods of cultivation, in which the grain is sown directly into the soil.
- warmer temperatures will increase the length of growing seasons and may increase production of crops such as sugar beet and leafy vegetables. Although, crops such as autumn-sown cereals may yield less than their potential if they mature earlier
- the increasing concentration of CO2 in the atmosphere will continue to increase plant growth generally
- reduced availability of water will likely result in drier soil conditions, reducing growth in crops, pasture and trees
- summer drought likely to become more frequent
- sea level rise will result in increased flooding = can lead to substantial losses in crop production in low-lying agricultural areas and may contribute to compaction, water logging and erosion of soil.
- pests and diseases will be found in more areas geographically
99
Give some different causes of climate change that will effect agriculture
- increase of temperature
- floods
- droughts
- sea level rises
100
What does CCAP stand for?
Climate Change Adaptation Project
101
Give an example of a Climate Change Adaptation Project (CCAP)
Indian state of Haryana, Mewat (south of Delhi)
102
Give some strategies being introduced in the CCAP of Haryana, India
- heat-stress tolerant varieties of wheat introduced to increase yields by 12-18%
- integrated soil and pest management programmes
- farmland was levelled to improve water efficiency by 15-20%
- underground pipelines to deliver drip irrigation, leading to 40% water saving
- greater crop diversity encouraged
103
What is likely to be the hardest hit sector as a result of climate change?
Agriculture
104
Why is agriculture likely to be the hardest hit sector as a result of climate change?
Because of its dependence on the weather
105
What is the monthly mean temperature in tropical monsoon climates?
Above 18ºC in every month of the year
106
Around how many people's lives are threatened by desertification?
1 billion people in around 100 countries
107
Food security
According to the United Nations, this is when all people at all times have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life.
108
What are the 4 dimensions of food security?
- food availability
- food access
- food utilisation
- food stability
109
Food availability
Where food is made to exist for consumption at local levels where needed foods can be located without striving
110
Food access
Access by individuals to adequate resources (entitlements) for acquiring appropriate foods for a nutritious diet
111
Food utilisation
Being able to eat and properly metabolise foods that meet nutritional needs
112
Food stability
Access, availability and utilisation of food remains relatively stable over time
113
What is the GAFSP?
The Global Agriculture and Food Security Programme
114
What is the goal of the GAFSP?
To increase the incomes, food and nutrition security of those in low-income countries through productivity improvements in agriculture, building their resilience and helping them adapt to climate change
115
Where is there lots of food security?
In Western parts of the world where countries are more secure economically
116
Where is there lots of food security risk?
In the Southern Hemisphere, with the continents of Asia and Africa facing the largest food security risk.
117
Why is there lots of food insecurity risk in Asia?
Because of the very high population
118
Why is there lots of food insecurity risk in Africa?
Because of financial insecurities
119
Give some ways that global food security can be improved
- using science and technology
- we must do a better job at distributing the food we have got - there is enough food for everyone, we just don't distribute it well
- if we want to avoid a hungry future, we need to make sure we keep a healthy population of farms and farmers around our cities - we need to support local food systems
- we need stronger regulation and proactive government policy - need to promote more sustainable farming
120
What was the 'green revolution'?
The green revolution was a great increase in the production of food grains, especially wheat and rice, that resulted in large part from the introduction into developing countries of new, high-yielding varieties, beginning in the mid-20th century
121
How did the 'green revolution' help food security?
The increased grain yields caused by it meant more income for poor farmers, helping them to climb out of poverty and, more food means less hunger. Increase in crops means there is more food for locals and there is less pressure on importing things, which also means there are less financial concerns attached and money can be used in other ways.
122
What is the 'gene revolution'?
The gene revolution is the application of bio-technology in food production (Genetically Modified (GM) crops).
123
How is the 'gene revolution' helping food security?
Genetically modified crops possessing genes from different species could possibly relieve global food shortages. GM crops will be able to grow in difficult climatic conditions and are resistant to the pests and disease. This will mean more food can be produced in areas that previously couldn't support the growth of crops, providing locals with food and there is less reliance on inputs (which have economic strains). Less pests and disease also means that more of the crops are safe for human consumption, so more food is available, reducing food insecurity.
124
Gene flow
GM crops could mix with traditional crops and introduce unwanted, new characteristics into them.
125
What was the world population in 1960?
3 billion
126
How can we stop population growth?
By improving child survival to 90%
127
What factors affect farming type?
- temperature
- rainfall
- soil type
- money / capital
- sunlight hours
- wind
- relief / topography
128
What types of farms are there?
- arable farm
- pastoral farm
- mixed farm
129
Arable farm
One which grows crops
130
Pastoral farm
One which has animals
131
Mixed farm
One which has both crops and livestock
132
Where does arable farming usually take place?
On flatter land where soils are of a higher quality
133
What is the most common form of agriculture in the UK?
Mixed farming
134
What does intensive farming involve?
High investment in labour and/or capital such as machinery, glasshouses and irrigation systems
135
What does commercial farming involve?
Farmers and agribusinesses maximising profits by specialising in single crops (monoculture) or raising one type of animal.
136
Extensive farming
This uses low inputs of labour, machinery and capital, but usually involves large areas of land; yields per hectare are consequently low
137
What is the opposite of intensive farming?
Extensive farming
138
Subsistence farming
Involves the direct production of sufficient food to feed the family or community involved, with any excess produce sold or bartered.
139
Different types of farm
- sedentary
- nomadic
- subsistence
- commercial
- arable
- pastoral
- mixed
- extensive
- intensive
140
Sedentary farm: definition
A farm that is static (doesn't move)
141
Sedentary farm: example
UK
142
Nomadic farm: definition
A farm which moves around (set up in one area then moves to the next)
143
Nomadic farm: example
- West Africa
- Rainforests
- Desert areas / semi-desert regions
144
Subsistence farm: definition
A farm which produces just enough food to survive, involves growing what you need
145
Subsistence farm: example
- nomadic pastoralism
| - slash-and-burn
146
Commercial farm: definition
Large-scale, grow food to sell
147
Commercial farm: example
Potato cultivation in the UK
148
Arable farm: definition
A farm which grows crops
149
Arable farm: example
Slash-and-burn cultivation technique in Latin America
150
Pastoral farm: definition
A farm which involves animal rearing
151
Pastoral farm: example
Herding of cattle, sheep, goats and camels in semi-desert regions of West Africa
152
Mixed farm: definition
A farm which grows crops and rears animals
153
Mixed farm: example
Mixed farming in Fife takes advantage of some of the most productive, easily worked soils in Scotland.
154
Extensive farm: definition
Farming over a massive area
155
Extensive farm: example
- hill sheep farming in upland regions of the UK
| - the Lake District sheep farming
156
Intensive farm: definition
Farming a small area, but getting a lot out of that small area
157
Intensive farm: example
South-west England
158
Soil
The unconsolidated mineral or organic material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants.
159
Zonal soils
Those that have been forming for long periods of time under the influence of climate and vegetation
160
What are the different bands of soil known as?
Horizons
161
What are the different letters for the horizons of zonal soils?
O, A, B, C and R
162
Zonal soil layer: O
Organic, humus, rotting vegetation, where leaves are broken down
163
Zonal soil layer: A
Topsoil, good for growing crops
164
Zonal soil layer: B
Subsoil, rich in minerals
165
Zonal soil layer: C
The rock that is being weathered
166
Zonal soil layer: R
Bedrock, rock layer at the bottom, solid rock, not yet weathered
167
What can be seen when you put the different soil horizons together?
They form a soil profile
168
What are the 3 major horizons that most soils have?
A,B,C
169
Give two key zonal soils
- Tropical Red Latosol
| - Podsols
170
What are the seasons like in rainforests?
Rainforests don't really have seasons and have leaves falling off trees all year round.
171
Tropical Red Latosol: location
Found 5º either side of the Equator in the rainforest biome
172
Tropical red latosol: vegetation
- very biodiverse
- there is a year-round growing season, meaning that deciduous tropical equatorial rainforest trees can shed their leaves at any time of the year
- constant supply of leaf litter
173
Tropical red latosol: nutrient cycling
- rapid nutrient cycling
- the year-round growing season provides a constant supply of leaf litter, which decomposes with other biota into humus, supplying nutrients to support sustainable new growth
- leaves fall all year round
- for things to rot, it needs to be hot and damp. The rainforest has these conditions
174
Tropical red latosol: characteristics
- red
- infertile
- found in hot, wet, humid climates
- can become quickly exhausted of stored nutrients
175
Tropical red latosol: human activity
Recent decades have seen deforestation on a massive scale, by felling, bulldozing and burning. Population growth and economic development are considered reasons for this deforestation.
176
Podsols: location
- sub-Arctic and Arctic
- there is a cold climate with little rainfall
- no leaching here
- not a lot of evaporation happening in the Arctic
- get very waterlogged soil
177
Podsols: vegetation
Coniferous trees (don't lose their leaves, don't require many nutrients, can grow in poor soil). Boreal coniferous forest. Evergreen trees like fir, spruce and pine.
178
Podsols: nutrient cycling
Poor nutrient cycle, no calcium, magnesium and potassium, leading to a poor mor (acidic) humus
179
Podsols: characteristics
- Accumulation of a hard pan of iron beneath the zone of leaching, marking the highest point of the water table.
- Clear differentiation of horizon, few mixing agents like earthworms and ants
180
Podsols: human activity
Burning heather and managed logging (?)
181
What factors speed up nutrient cycling?
Hot, wet conditions
182
Leaching
Nutrients are washed out of the soil
183
What is soil mainly made up of?
- mineral particles
- organic materials
- air
- water
- living organisms
184
What is the very top layer of the Earth's surface?
Soil
185
Why is soil important?
- soil is needed for food
- soil sustains biodiversity, as everything has to grow in soil
- soil is important for stability and support for things to be built on
- soil is a habitat; things, such as worms, live in the soil
186
Is soil finite or infinite?
Soil is finite
187
What does soil being finite mean?
When soil is finite, it means it has the potential to run out, making it invaluable
188
Biota
The animal and plant life of a particular region, habitat or geological period
189
Humus
The organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms
190
Nutrient Cycle
A repeated pathway of a particular nutrient or element from the environment through one or more organisms and back to the environment
191
Gully
Make deep channels in (land)
192
What is rainforest soil like?
Very infertile
193
Tropical equatorial rainforest biome conditions
Hot, wet, humid and without seasons
194
Deciduous trees
Trees that lose their leaves
195
Coniferous trees
Trees that do not lose their leaves
196
Why is urbanisation bad for soil?
Urbanisation involves building impermeable surfaces (such as concrete) over soil = we lose access to this soil and this creates other problems, such as increased runoff
197
Zonal soil simple definition
Fully developed soil
198
Where do podzols occur?
In cool, temperate climates in the northern hemisphere, where there is more precipitation than evapotranspiration
199
Are tropical red latosols or podzols acidic?
Podzols are acidic
200
Are podzols good for agriculture?
No
201
Is the O horizon quite thick in tropical red latosols or podzols?
Tropical red latosols
202
Why is the O horizon quite thick in tropical red latosols?
Because of the year-round plant growth
203
What is higher in rainforests - rainfall or evapotranspiration?
Rainfall is higher than evapotranspiration in rainforests
204
What gives the tropical red latosols their colour?
Iron compounds within it
205
Are tropical red latosols good for agriculture?
No
206
Why are tropical red latosols poor for agriculture?
Because of their low nutrient content
207
What does burning vegetation to clear a plot of land add to the soil?
Nutrients
208
Soil erosion
Soil erosion is a gradual process, occurring when the impact of water or wind detaches and removes soil particles, causing the soil to deteriorate.
209
Waterlogging
Waterlogging is excess water in the root zone accompanied by anaerobic conditions, which is the saturation of soil with water
210
Salinisation
The process of increasing the salt content in soil is known as salinisation. It is the process by which water-soluble salts accumulate in the soil.
211
Structural deterioration
This is any change to the material or the geometric properties affecting the structural performance. Structural deterioration in soil most commonly refers to compaction (the compression of soil particles so that the space between them is diminished).
212
Soil degradation
This describes what happens when the quality of soil declines, lessening its capacity to support animals and plants.
213
How much food is produced from the soil?
About 99%
214
How much carbon does soil contain?
The world's soil contains 2-3 times more carbon than the atmosphere
215
How many microorganisms are in one teaspoon of soil?
In one teaspoon of soil, there are more microorganisms than there are people on the Earth
216
Give an insect which makes and sustains soil
Earthworms
217
What do earthworms do to the soil?
They create small channels in the soil (they create breathing holes), which are like lungs in the soil. This creates space for plant roots to grow and keeps the soil alive.
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How long does it take us to build up soil?
It takes more than 100 years to build up just 5 mm of soil.
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Give some ways in which we are destroying soil
- chemical contamination
- urbanisation
- landslides
- erosion
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How old is our soil in the UK?
Around 15,000 years old
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When did our soil form in the UK?
After the last ice age
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How much are we losing soil faster than it's able to rebuild?
We're losing soil 50-100 times faster than it's able to rebuild.
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What percentage of soil is thought to be unhealthy in Europe?
60-70% of soils
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What is soil management?
About the conservation of soil
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Give some ways in which we can manage soil erosion
- afforestation
- terracing
- direct drilling
- controlled grazing
- improved drainage
- strip cropping
- contour ploughing
- shelter belts
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Contour ploughing: advantage
Takes advantage of the natural slopes and stops water from building up
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Contour ploughing: disadvantage
Not sufficient when there is really heavy rain
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Terracing and bunds: advantages
- maximises the use + potential of the land
| - really good in tropical monsoon climates
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Terracing and bunds: disadvantage
- doesn't do anything to help against wind erosion, which is one of the two types of soil erosion
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How can soil be eroded?
By wind and by water
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When does soil erosion become a problem?
When the rate of removal of soil by water and/or wind exceeds the rate of soil formation
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Give two places suffering from soil erosion
- Africa
| - the USA
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Causes of soil erosion in Africa
- using short-sighted farming methods are ineffective and often degrade the fragile soil
- rapid population growth has increased the pressure
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Impacts of soil erosion in Africa
- unless current trends are reversed, Africa will be unable to feed 2/3 of a projected 1 billion population in 2025
- already 2.2 million km squared is classified as degraded land
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Causes of soil erosion in the USA
- The Great Plains lose 30 million ha of land to damage from the wind per year
- blowing soil reduces seedling survival
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Impacts of soil erosion in the USA
- most of the eroded soil enters the atmospheric dust load, where it pollutes the air, damaging human and animal health
- wind erosion is a threat to the sustainability of the land
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What percentage of the soil used for agriculture is classed as degraded?
40%
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Causes of soil erosion
- removal of trees in an area = no roots to bind the soil together, soil washed away easier. Deforestation is a cause.
- wide, open fields = no hedges to act as windbreaks
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Solutions to soil erosion
- plant fast-growing trees amongst the crops
- build terraces (steps) and small dams. Terraces mean there is a little bit of flat land, so the water won't rush down.
- plant new trees as windbreaks
- planting different crops between the trees
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When are changes in soil structure common?
When agriculture is practiced (e.g., compaction by heavy machinery can compress the soil, making it almost impenetrable to water and roots)
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What are the two main categories of soil deterioration?
- loss of organic matter in the topsoil
| - compaction
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Attack rate
The number of cases of a disease diagnosed in an area, divided by the total population, over the period of an epidemic
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Mortality
The death of people. It is measured by a number of indices, including death rate, infant mortality, case mortality and attack rate
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Crude death rate
The number of deaths per 1000 people in one year
245
Health
A state of complete physical, mental and social well-being and not merely the absence of diseases and infirmity
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Morbidity
Illness and the reporting of disease
247
Case mortality
The number of people dying from a disease divided by the number of those diagnosed as having the disease
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Infant mortality
The number of deaths of children under the age of one expressed as 1000 live births a year
249
Epidemic
The rapid spread of infectious disease to a large number of people in a given population within a short period of time, usually 2 weeks or less
250
Pandemic
An epidemic occurring worldwide, or over a very wide area, crossing international boundaries and usually affecting a large number of people
251
Endemic
The constant presence of a disease or infectious agent in a certain geographic area or population group
252
Where is life expectancy highest?
Japan with 81 years and 6 months
253
What is the life expectancy in Zambia, Africa?
32 years and 6 months
254
What percentage of the world's doctors do the poorest 1/5 of the world have?
2%
255
What percentage of the world's doctors do the richest 1/5 of the world have?
50%
256
How many of the world's deaths from AIDS are in sub-saharan Africa?
80%
257
What percentage of Malaria deaths are in Africa?
94%
258
Where do most people die of cancer?
In richer countries
259
Why do most people die of cancer in richer countries?
Because it has been diagnosed. Also, people in richer countries live longer, so there is more time for them to contract the disease.
260
What is the biggest cause of death globally?
Heart disease
261
What do increases in food productivity, supply and transport ensure?
A more well-nourished population
262
What do improvements in sanitation and hygiene standards reduce the spread of?
Water-bourne diseases
263
Economic factors affecting health around the world
- investment in drainage and sewage systems, especially in urban areas
- trading of manufactured resources and goods in exchange for a wider variety of foods and medicines
- technology to improve food productivity (the green revolution, aeroponics etc)
- better training for doctors, nurses and midwives
264
Social factors affecting health around the world
- improved sanitation
- better education about sanitation and disease transmissions
- Aid programmes from the UN or from NGOs which provide healthcare resources
- advances in medical technology, such as vaccines and antibiotics
- improved transport infrastructure to distribute food and medical supplies
- improvements to housing quality so heating / air conditioning is more commonplace and over-crowding is reduced
265
How much has the population increased in the last 50 years?
There has been more than a 50% increase in population in the last 50 years
266
When does overpopulation occur?
When a species' population becomes larger than the carrying capacity of its environment
267
In what year was the day of 7 billion people reached?
2012
268
Physical factors that influence health and wellbeing
- pollution, can lead to respiratory illness
- clean water source
- climate
- level of development
- resources
269
Socio-economic factors that influence health and wellbeing
- money for medicine
- access to healthcare / number of doctors
- drainage and sewage systems
- access to food production
- aid programmes
270
What does ETM stand for?
Epidemiological Transition Model
271
Who was the Epidemiological Transition Model proposed by?
Abel Omran
272
What are the stages in the Epidemiological Transition Model?
- stage 1: the age of pestilence (infection) and famine
- stage 2: the age of receding pandemics
- stage 3: the age of degenerative and man-made diseases
- stage 4: the age of delayed degenerative diseases
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What does the Epidemiological Transition Model show?
How as a country develops, the greatest number of deaths progresses from being the result of communicable disease to lifestyle-related diseases
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Stage 1 of the Epidemiological Transition Model
- low life expectancy probable (about 20-40 years)
- poor sanitation
- unreliable food supply
- more infections
- e.g., Zambia
275
Stage 2 of the Epidemiological Transition Model
- life expectancy about 30-50 years
- improved sanitation
- better diet
- reduced number of infections
- e.g., rural India
276
Stage 3 of the Epidemiological Transition Model
- life expectancy 50-60 years
- increased agein
- rise in lifestyle-related diseases
- e.g., more developed NEEs, such as urban India and China
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Stage 4 of the Epidemiological Transition Model
- life expectancy = 70+
- lots more lifestyle-related diseases
- dementia and ageing diseases are starting to occur more
- e.g., HICs such as the UK
278
Which stage of the Epidemiological Transition Model was added after the original model was made?
Stage 4
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Ebola symptoms
- sudden fever
- vomiting
- internal bleeding
280
How do people become infected with Ebola?
When they have direct contact through broken skin, or the mouth and nose, with the blood, vomit, faeces or bodily fluids of someone with Ebola.
281
Where did the West Africa Ebola pandemic begin?
Guinea
282
Between 2013 and 2016, how many people died in the West Africa Ebola pandemic?
More than 11,000
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Factors influencing the fast spread of Ebola
- dysfunctional health systems
- high population mobility across state borders
- densely populated capitals
- lack of trust in authorities
- fear: people were afraid to go to hospital, because they thought it could be the source of infection
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Is Ebola an airborne disease?
No
285
What disease can the first symptoms of Ebola resemble?
Malaria
286
What type of disease is Malaria?
A tropical disease
287
How is Malaria transmitted?
By mosquitoes
288
What areas are most at risk from Malaria?
Areas of poverty
289
What is the simplest and most effective way to prevent Malaria?
Mosquito nets
290
How many deaths does Malaria cause every year?
660,000
291
Who are the most Malaria deaths in?
Children - 70% of Malaria deaths are in children under 5 years old
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How often does a child die from Malaria?
1 child dies every minute from Malaria
293
Factors linking to the physical environment affecting the spread of Malaria
- mosquitoes breed in stagnant water
- transmission of Malaria is greatest in areas during or just after the rainy season
- the disease is largely concentrated in the tropics and subtropics
- the parasites require temperatures of between 16ºC and 32ºC to develop inside the mosquito
- studies in India show those living in close proximity to forested areas are more susceptible to infection
294
Factors linking to the socio-economic environment affecting the spread of Malaria
- densely clustered housing in built-up areas or overcrowded rooms increase risk of infection
- unsanitary conditions - areas surrounding houses were dirty and polluted by rubbish and waste (including human), increase risk
- young children are most at risk as they lack the immunity levels of older generations
- distance and accessibility to clinics or hospitals affects deaths from Malaria
295
How much have Malaria mortality rates declined by?
60% since the year 2000
296
How many children are not protected by mosquito nets in Africa?
1 in 4
297
How much are the WHO looking to invest annually into reducing Malaria cases?
$8.7 billion annually by 2030
298
Give an NGO helping to reduce Malaria infections
The Bill and Melinda Gates Foundation
299
How much has the Bill and Melinda Gates Foundation contributed to combating Malaria?
$3.6 billion
300
How is Malaria treated?
Malaria is treated with prescription drugs to kill the parasite
