4.3. Population–resource relationships Flashcards

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1
Q

Overpopulation

A

A situation where the population exceeds the available resources of a country

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2
Q

Under Population

A

A situation where the population is too small relative to the available resources in a country

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3
Q

Carrying Capacity

A

The number of individuals an environment can support, taking into account the resources available, without significant negative impacts to individuals and the environment

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4
Q

Population Ceiling

A

First suggested by Malthus, it is a saturation level where the population equals the carrying capacity of the environment.

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5
Q

Optimum Population

A

the size of a population that produces the best results according to chosen end targets

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6
Q

The J-Curve

A

J curves start at a fast exponential growth and then collapses / crashes (diebacks). This happens from overpopulation, where the population can no longer be supported. Where the population exceeds carrying capacity it is called as an overshoot.

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7
Q

The S-Curve

A

The S-curve starts with exponential growth but after a certain amount of population the growth halts at a constant population amount due to the effect of a limiting factor (in this case the carrying capacity of the environment).

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8
Q

Malthus’ Theory Core Principles

A
  • Population if unchecked, grows at a geometric rate
  • Food only increases at an arithmetic rate, land is finite
  • The effect of these 2 powers must be kept equal
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9
Q

Malthus’ Theory: “Checks”

A

Malthus suggested once this ceiling (catastrophe) has been reached, further growth in population would be prevented by negative and positive checks. He saw checks as a natural method of population control. They can be split up into 2 groups

1) Negative Checks were used to limit the population growth. It included abstinence / postponement of marriage which lowered fertility rate
2) Positive Checks were ways to reduce population size by events such as famine, disease, war- increasing the mortality rate and reducing life expectancy.

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10
Q

Malthus’ Theory was right

A
  • There has been a world population explosion
  • Africa - repeated famines, wars, food crisis, environmental degradation, soil erosion, crop failure, disastrous floods (positive checks)
  • Rwanda - genocidal massacre of 800,000 Rwandans in 1994 was due in part to ethnic hatred but also to population. Too many farmers dividing same amount of land into increasingly smaller pieces that became inadequate to support the farmers family
  • China’s one child policy - an example of a negative check. The government was concerned that people soon wouldn’t have enough food to feed themselves and adopted the policy to reduce birth rates.
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11
Q

Malthus’ Theory was wrong

A
  • Technological improvements which he could not foreseen
  • The increased amount of cropland due to irrigation
  • Reduced population growth as countries move through the Demographic Transition Model. By early 1970s fertility rates around the world dropping and the population growth has fallen since then by over 40%
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12
Q

Boserup’s Theory

A

Boserup believed that people have the resources of knowledge and technology to increase food supplies. Her theory is opposite to Malthus’s - she suggested that population growth has enabled agricultural development to occur.

  • “Necessity is the mother invention” - When we have to, we find a way to increase food production and stay alive
  • She assumes that people knew of the techniques required by more intensive systems and used them when the population grew
  • Demographic pressure (population density) promotes innovation and higher productivity in use of land (irrigation, weeding, crop intensification, better seeds) and labour (tools, better techniques).
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13
Q

Boserup’s Theory was right

A
  • Boserup argued that the changes in technology allowed for improved crop strains and increased yields
  • GM crops
  • ‘Green revolution’ - (e.g. High yielding varieties of crop. Example = IR-8 rice)
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14
Q

Boserup’s Theory was wrong

A
  • Some agricultural processes have been proved to be unsustainable in the long run
  • Aspects of ‘Green revolution’ (e.g. HYV require lots of water
  • Land degradation from intensive farming (e.g. Sahel and desertification, salt marsh reclamation)
  • Migration - people move away from over populated areas
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15
Q

Natural Causes of food shortages

A
  • Soil exhaustion
  • Drought
  • Floods
  • Tropical Cyclones
  • Pests and Disease
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16
Q

Human Causes of food shortages

A
  • Low capital investment
  • Rapidly rising populations
  • Poor distribution / transport difficulties
  • Conflict situations
17
Q

Problems caused by food shortages

A

Malnutrition (poor health that results from something missing in the daily diet)

  • Beri Beri (vitamin B1 deficiency)
  • Rickets (vitamin D deficiency)
  • Kwashiorkor (eating too much carbs, not enough protein)
18
Q

The Green Revolution

A

Countries in Asia and Central America experienced rapid increases in food production through the introduction of new technology between 1968 and 1983. This was known was the Green Revolution. Yields of the staple crops of wheat, rice and maize increased by using the land available more intensively rather than by a large-scale increase in the area cultivated. These technologies were:

  • Hybrid seeds producing higher crop yields (high-yielding varieties or HYVs)
  • Irrigation facilities
  • Machinery to replace manpower and animal labour
  • Chemical fertilizers and pesticide
19
Q

Criticisms of the Green Revolution

A
  • Green revolution is not sustainable. It destroys resource base on which agriculture depends on
  • Agrochemicals are bad for health and the environment
  • Rural people are displaced from land and replaced by machines, because the wealthy own the land. Rural people have a high food insecurity.
  • Only benefits wealthy. There is more hunger and more food at the same time
20
Q

History of South Sudan

A

Civil war lasted 21 years in Sudan - between the Muslim government in the north of the country and the rebels in the South and west of the country (mainly Christian and Animist). Due to the conflict, thousands of farmers have been moved off their land (displaced) and many became refugees in neighboring countries.
2011 - South Sudan becomes an independent country, after over 20 years of guerilla warfare, which claimed the lives of at least 1.5 million people and more than 4 million were displaced
2012 - Disagreements with Sudan over the oil-rich region of Abyei erupt into fighting, known as the Heglig Crisis. A peace deal was reached in June 2012 that helped resume South Sudan’s oil exports and created a 10km demilitarized zone along the border
2013 - Civil war breaks out after the president, Salva Kiir Mayardiit, sacks that cabinet and accuses Vice-President Riek Machar of planning a failed coup. Over 2.2 million people are displaced by the fighting and severe famine puts the lives of thousands at risk.
2015 - Warring sides sign a peace deal to end the civil war but the conflict continues
2017 - This is when famine occured. Around 100,000 people starved and 5.5 million on the brink of food security. Transport of food aid blocked by the government to starve the rebels. People fled to marshland to avoid fighting, but there is no food there. Many people evacuated South Sudan to neighboring countries like Uganda. There is no food security as most of the people rely on UN food supply; this reliance isn’t good as the government loyalist have started a blockade not allowing any UN food to reach rebel held territory.

21
Q

Factors causing food shortages in South Sudan

A

Social Factors
- An estimated 85% of the population is illiterate
Physical Factors
- Long term drop in rainfall in South Sudan has caused annual droughts and left land infertile
- Increased rainfall variability
- Increased use of marginal land leading to degration
Flooding
- most of South Sudan is marsh and swamps creating a problem for agriculture; since there is limited land there is competition for arable and grazable land for crops and livestock.
Economic Factors
- High dependency on farming (70% of labour force)
- The country is in massive debt so limited money to spend on social and economic spending
- A lot of state money has been spent on military equiptment
- Dependency on food imports (13% of consumption 1998-2000 while exporting non-food goods e.g. cotton).