Topic Overview Flashcards
What is the world population?
7.9 billion
What is the global fertility rate?
2.3
Population density
The number of people living in an area, usually given as people per km2.
Population
All the inhabitants of a particular place
The Fertile Crescent
This is a band of densely populated area with very fertile soil
What areas are densely populated?
- the Fertile Crescent
- South-East Asia
- Asia Pacific Rim
- coastlines
What areas are sparsely populated?
- deserts
- rainforests
- where it is too cold - e.g., in the Arctic Circle
What were infant mortality rates like pre-1950?
They were really high. People would have around 6 children, but 3 or 4 of them would die before becoming parents themselves
What did the Industrial Revolution lead to?
- better wages
- more food
- tapped water
- better sanitation
- soap
- medical advances
What is the minimum fertility rate needed for population to grow?
2.1
What does population growth look like for the future?
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.
What was the UK population in mid-2020?
67.2 million
Give some physical factors affecting population density
- topography / relief of the land
- climate
- hazards
- water supply
- distribution of / access to resources
- quality of the soil
Why are there more people where the soil is fertile?
You can grow lots of crops, creating lots of food, therefore attracting people to the area.
How does climate affect population density?
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.
Why is a water source essential to an area?
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.
Why is Bhutan sparsely populated?
Because it is mountainous
What is something that has allowed rapid industrialisation?
Access to resources
An advantage of flooding
Floods fertilise soil, so you can grow more
What is the fertility rate like in Niger and why?
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.
Where are climate-related diseases often found?
In between the tropics
Where are most major cities?
On a coast or river
Population distribution
The pattern of where people live
Crude birth rate
The number of births per 1000 people (CBR)
Crude death rate
The number of deaths per 1000 people (CDR)
Natural increase
The difference between the CBR and the CDR usually expressed as a % per year. Natural increase (%) = CBR - CDR
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
What is the world’s most crowded city?
Dhaka, Bangladesh
What is the population density of Dhaka, Bangladesh?
44,500
What was the annual population growth rate from 2011-2015 for the UK?
0.6
Where will population grow the most in the future?
Africa
What is the minimum temperature many crops need in order to grow?
5ºC
Give two types of soil prone to hazards
Rich volcanic or alluvial soils (e.g., because of volcanic eruptions or floods)
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)
What are population numbers recorded by?
Census data
How often is census data collected in most countries?
Every 5 or 10 years
What is the expected world population in 2050?
9.7 billion
What percentage of the world’s population live in Asia?
Around 60%
What are the most densely populated areas?
- coastal areas + seaboards
- major river basins
- areas of industrialisation + urbanisation
What is projected to happen to the population of Sub-Saharan Africa by 2050?
It is projected to double
What is projected to happen to the population of north and west Africa by 2050?
A 46% increase in population
What was the population in 1700?
1 billion
How has the population in Sub-Saharan Africa increased?
From 10% in 1950 to more than 25%
In 1850, how much of Britain’s population lived in towns and cities?
More than half
What is Nigeria’s population set to rise to by the end of the century?
800 million
What is Malthusianism?
The idea that population growth is potentially exponential
What is demographic transition?
A process allowing the population to stabilise at a higher level.
What is the world’s most populated country?
China
What was the average global food supply in the 1960s?
About 2300 calories/person/day
What was the average global food supply in the 1960s for those in HICs?
3080 calories/person/day
What was the average global food supply in the 1960s for those in LICs?
2000 calories/person/day
Has the average global food supply calories/person/day risen or fallen?
It has risen
What was the average global food supply in 2010?
2800 calories/person/day
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
What type of system does agriculture work as?
An open system
Inputs to agricultural systems
Physical, human + economic factors that determine the type of farming in the area
Processes in agricultural systems
The activities carried out to turn inputs into outputs
Outputs in agricultural systems
The products from the farm
Are wealth and calorie intake linked?
Yes
Is high population density and high calorie consumption linked?
No
What is calorie intake like between the tropics?
There is less calorie intake, due to these countries being mainly LICs
Why might calorie intake be higher where it is colder?
Because you need to eat more to stay warm
Where are the most calories consumed?
In Western countries in the Northern Hemisphere
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.
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
Undernourishment
The status of people whose food intake does not include enough calories (energy) to meet minimum physiological needs
Over-nourishment
The excessive consumption of food which can increase the risk of developing health problems
Approximately how much of the ‘usable’ land on the planet is used to grow food?
Around half
How much of food produced worldwide is wasted?
Around 1/3
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
Is there enough food worldwide?
There is enough food, it is just in the wrong places
What is an arable farm?
A farm that grows crops
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
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
Processes in the agricultural system
- harvesting
- spraying
- irrigation
- planting
- ploughing
- feeding
- milking
- threshing
- calving / birthing
Possible physical changes to the agricultural system
- climatic conditions (climate change)
- hazards
- spread of disease
- fires
- droughts
Possible human changes to the agricultural system
- climate change
- fluctuations in prices
Positive outputs to the agricultural system
- crops and animal produce
- meat / milk / other animal produce
- food
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
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.
Tropical monsoon climates: location
Asia, the Indian subcontinent and other areas around the Pacific Ocean
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
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
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.
Polar tundra climates: location
Above the Arctic circle. Polar and tundra climates cover more than 20% of the Earth.
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?
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.
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
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.
Semi-arid climates: location
Found near the equator, between the tropics of cancer and Capricorn.
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.
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
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.
Mediterranean climates: location
Warm, coastal regions found between 30º and 45º in latitude. This climate is mostly found in the Mediterranean Sea.
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.
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
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.
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
Give some different causes of climate change that will effect agriculture
- increase of temperature
- floods
- droughts
- sea level rises
What does CCAP stand for?
Climate Change Adaptation Project
Give an example of a Climate Change Adaptation Project (CCAP)
Indian state of Haryana, Mewat (south of Delhi)
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
What is likely to be the hardest hit sector as a result of climate change?
Agriculture
Why is agriculture likely to be the hardest hit sector as a result of climate change?
Because of its dependence on the weather
What is the monthly mean temperature in tropical monsoon climates?
Above 18ºC in every month of the year
Around how many people’s lives are threatened by desertification?
1 billion people in around 100 countries
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.
What are the 4 dimensions of food security?
- food availability
- food access
- food utilisation
- food stability
Food availability
Where food is made to exist for consumption at local levels where needed foods can be located without striving
Food access
Access by individuals to adequate resources (entitlements) for acquiring appropriate foods for a nutritious diet
Food utilisation
Being able to eat and properly metabolise foods that meet nutritional needs
Food stability
Access, availability and utilisation of food remains relatively stable over time
What is the GAFSP?
The Global Agriculture and Food Security Programme
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
Where is there lots of food security?
In Western parts of the world where countries are more secure economically
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.
Why is there lots of food insecurity risk in Asia?
Because of the very high population
Why is there lots of food insecurity risk in Africa?
Because of financial insecurities
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
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
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.
What is the ‘gene revolution’?
The gene revolution is the application of bio-technology in food production (Genetically Modified (GM) crops).
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.
Gene flow
GM crops could mix with traditional crops and introduce unwanted, new characteristics into them.
What was the world population in 1960?
3 billion
How can we stop population growth?
By improving child survival to 90%
What factors affect farming type?
- temperature
- rainfall
- soil type
- money / capital
- sunlight hours
- wind
- relief / topography
What types of farms are there?
- arable farm
- pastoral farm
- mixed farm
Arable farm
One which grows crops
Pastoral farm
One which has animals
Mixed farm
One which has both crops and livestock
Where does arable farming usually take place?
On flatter land where soils are of a higher quality
What is the most common form of agriculture in the UK?
Mixed farming
What does intensive farming involve?
High investment in labour and/or capital such as machinery, glasshouses and irrigation systems
What does commercial farming involve?
Farmers and agribusinesses maximising profits by specialising in single crops (monoculture) or raising one type of animal.
Extensive farming
This uses low inputs of labour, machinery and capital, but usually involves large areas of land; yields per hectare are consequently low
What is the opposite of intensive farming?
Extensive farming
Subsistence farming
Involves the direct production of sufficient food to feed the family or community involved, with any excess produce sold or bartered.
Different types of farm
- sedentary
- nomadic
- subsistence
- commercial
- arable
- pastoral
- mixed
- extensive
- intensive
Sedentary farm: definition
A farm that is static (doesn’t move)
Sedentary farm: example
UK
Nomadic farm: definition
A farm which moves around (set up in one area then moves to the next)
Nomadic farm: example
- West Africa
- Rainforests
- Desert areas / semi-desert regions
Subsistence farm: definition
A farm which produces just enough food to survive, involves growing what you need
Subsistence farm: example
- nomadic pastoralism
- slash-and-burn
Commercial farm: definition
Large-scale, grow food to sell
Commercial farm: example
Potato cultivation in the UK
Arable farm: definition
A farm which grows crops
Arable farm: example
Slash-and-burn cultivation technique in Latin America
Pastoral farm: definition
A farm which involves animal rearing
Pastoral farm: example
Herding of cattle, sheep, goats and camels in semi-desert regions of West Africa
Mixed farm: definition
A farm which grows crops and rears animals
Mixed farm: example
Mixed farming in Fife takes advantage of some of the most productive, easily worked soils in Scotland.
Extensive farm: definition
Farming over a massive area
Extensive farm: example
- hill sheep farming in upland regions of the UK
- the Lake District sheep farming
Intensive farm: definition
Farming a small area, but getting a lot out of that small area
Intensive farm: example
South-west England
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.
Zonal soils
Those that have been forming for long periods of time under the influence of climate and vegetation
What are the different bands of soil known as?
Horizons
What are the different letters for the horizons of zonal soils?
O, A, B, C and R
Zonal soil layer: O
Organic, humus, rotting vegetation, where leaves are broken down
Zonal soil layer: A
Topsoil, good for growing crops
Zonal soil layer: B
Subsoil, rich in minerals
Zonal soil layer: C
The rock that is being weathered
Zonal soil layer: R
Bedrock, rock layer at the bottom, solid rock, not yet weathered
What can be seen when you put the different soil horizons together?
They form a soil profile
What are the 3 major horizons that most soils have?
A,B,C
Give two key zonal soils
- Tropical Red Latosol
- Podsols
What are the seasons like in rainforests?
Rainforests don’t really have seasons and have leaves falling off trees all year round.
Tropical Red Latosol: location
Found 5º either side of the Equator in the rainforest biome
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
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
Tropical red latosol: characteristics
- red
- infertile
- found in hot, wet, humid climates
- can become quickly exhausted of stored nutrients
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.
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
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.
Podsols: nutrient cycling
Poor nutrient cycle, no calcium, magnesium and potassium, leading to a poor mor (acidic) humus
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
Podsols: human activity
Burning heather and managed logging (?)
What factors speed up nutrient cycling?
Hot, wet conditions
Leaching
Nutrients are washed out of the soil
What is soil mainly made up of?
- mineral particles
- organic materials
- air
- water
- living organisms
What is the very top layer of the Earth’s surface?
Soil
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
Is soil finite or infinite?
Soil is finite
What does soil being finite mean?
When soil is finite, it means it has the potential to run out, making it invaluable
Biota
The animal and plant life of a particular region, habitat or geological period
Humus
The organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms
Nutrient Cycle
A repeated pathway of a particular nutrient or element from the environment through one or more organisms and back to the environment
Gully
Make deep channels in (land)
What is rainforest soil like?
Very infertile
Tropical equatorial rainforest biome conditions
Hot, wet, humid and without seasons
Deciduous trees
Trees that lose their leaves
Coniferous trees
Trees that do not lose their leaves
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
Zonal soil simple definition
Fully developed soil
Where do podzols occur?
In cool, temperate climates in the northern hemisphere, where there is more precipitation than evapotranspiration
Are tropical red latosols or podzols acidic?
Podzols are acidic
Are podzols good for agriculture?
No
Is the O horizon quite thick in tropical red latosols or podzols?
Tropical red latosols
Why is the O horizon quite thick in tropical red latosols?
Because of the year-round plant growth
What is higher in rainforests - rainfall or evapotranspiration?
Rainfall is higher than evapotranspiration in rainforests
What gives the tropical red latosols their colour?
Iron compounds within it
Are tropical red latosols good for agriculture?
No
Why are tropical red latosols poor for agriculture?
Because of their low nutrient content
What does burning vegetation to clear a plot of land add to the soil?
Nutrients
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.
Waterlogging
Waterlogging is excess water in the root zone accompanied by anaerobic conditions, which is the saturation of soil with water
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.
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).
Soil degradation
This describes what happens when the quality of soil declines, lessening its capacity to support animals and plants.
How much food is produced from the soil?
About 99%
How much carbon does soil contain?
The world’s soil contains 2-3 times more carbon than the atmosphere
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
Give an insect which makes and sustains soil
Earthworms
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.
How long does it take us to build up soil?
It takes more than 100 years to build up just 5 mm of soil.
Give some ways in which we are destroying soil
- chemical contamination
- urbanisation
- landslides
- erosion
How old is our soil in the UK?
Around 15,000 years old
When did our soil form in the UK?
After the last ice age
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.
What percentage of soil is thought to be unhealthy in Europe?
60-70% of soils
What is soil management?
About the conservation of soil
Give some ways in which we can manage soil erosion
- afforestation
- terracing
- direct drilling
- controlled grazing
- improved drainage
- strip cropping
- contour ploughing
- shelter belts
Contour ploughing: advantage
Takes advantage of the natural slopes and stops water from building up
Contour ploughing: disadvantage
Not sufficient when there is really heavy rain
Terracing and bunds: advantages
- maximises the use + potential of the land
- really good in tropical monsoon climates
Terracing and bunds: disadvantage
- doesn’t do anything to help against wind erosion, which is one of the two types of soil erosion
How can soil be eroded?
By wind and by water
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
Give two places suffering from soil erosion
- Africa
- the USA
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
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
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
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
What percentage of the soil used for agriculture is classed as degraded?
40%
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
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
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)
What are the two main categories of soil deterioration?
- loss of organic matter in the topsoil
- compaction
Attack rate
The number of cases of a disease diagnosed in an area, divided by the total population, over the period of an epidemic
Mortality
The death of people. It is measured by a number of indices, including death rate, infant mortality, case mortality and attack rate
Crude death rate
The number of deaths per 1000 people in one year
Health
A state of complete physical, mental and social well-being and not merely the absence of diseases and infirmity
Morbidity
Illness and the reporting of disease
Case mortality
The number of people dying from a disease divided by the number of those diagnosed as having the disease
Infant mortality
The number of deaths of children under the age of one expressed as 1000 live births a year
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
Pandemic
An epidemic occurring worldwide, or over a very wide area, crossing international boundaries and usually affecting a large number of people
Endemic
The constant presence of a disease or infectious agent in a certain geographic area or population group
Where is life expectancy highest?
Japan with 81 years and 6 months
What is the life expectancy in Zambia, Africa?
32 years and 6 months
What percentage of the world’s doctors do the poorest 1/5 of the world have?
2%
What percentage of the world’s doctors do the richest 1/5 of the world have?
50%
How many of the world’s deaths from AIDS are in sub-saharan Africa?
80%
What percentage of Malaria deaths are in Africa?
94%
Where do most people die of cancer?
In richer countries
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.
What is the biggest cause of death globally?
Heart disease
What do increases in food productivity, supply and transport ensure?
A more well-nourished population
What do improvements in sanitation and hygiene standards reduce the spread of?
Water-bourne diseases
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
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
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
When does overpopulation occur?
When a species’ population becomes larger than the carrying capacity of its environment
In what year was the day of 7 billion people reached?
2012
Physical factors that influence health and wellbeing
- pollution, can lead to respiratory illness
- clean water source
- climate
- level of development
- resources
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
What does ETM stand for?
Epidemiological Transition Model
Who was the Epidemiological Transition Model proposed by?
Abel Omran
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
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
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
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
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
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
Which stage of the Epidemiological Transition Model was added after the original model was made?
Stage 4
Ebola symptoms
- sudden fever
- vomiting
- internal bleeding
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.
Where did the West Africa Ebola pandemic begin?
Guinea
Between 2013 and 2016, how many people died in the West Africa Ebola pandemic?
More than 11,000
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
Is Ebola an airborne disease?
No
What disease can the first symptoms of Ebola resemble?
Malaria
What type of disease is Malaria?
A tropical disease
How is Malaria transmitted?
By mosquitoes
What areas are most at risk from Malaria?
Areas of poverty
What is the simplest and most effective way to prevent Malaria?
Mosquito nets
How many deaths does Malaria cause every year?
660,000
Who are the most Malaria deaths in?
Children - 70% of Malaria deaths are in children under 5 years old
How often does a child die from Malaria?
1 child dies every minute from Malaria
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
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
How much have Malaria mortality rates declined by?
60% since the year 2000
How many children are not protected by mosquito nets in Africa?
1 in 4
How much are the WHO looking to invest annually into reducing Malaria cases?
$8.7 billion annually by 2030
Give an NGO helping to reduce Malaria infections
The Bill and Melinda Gates Foundation
How much has the Bill and Melinda Gates Foundation contributed to combating Malaria?
$3.6 billion
How is Malaria treated?
Malaria is treated with prescription drugs to kill the parasite
