1. Overpopulation and development

2. Overpopulation
The number of people in a region is greater than the ability of the land to support them
Carrying capacity= no. of people a region can support with its basic resources

3. Optimum Population – no of people in a region with high standard of living given regions level of development and natural resources at any time
Under population – no of people living in area cannot exploit fully the natural resources
Inward migration improves SOL for all
Ireland – labour shortages

4. Causes of overpopulation
High birth rates: demand on basic resources increase ie. The Sahel
Migration: people forced to leave areas puts new areas under pressure ie. Darfur in Sudan
Overuse of sources: resources that the population depend on becoming overused leading to overpopulation ie. Cod banks in the north atlantic

5. Factors to increase carrying capacity
How these factors work
1. Decreasing population
Reduces demand for basic resources
2. Fertilisers
Increase food supply and feed more people
3. New farming methods
Feed more people
4. Irrigation
Raises crop yields, more water
5. Better crops/ animals
6. Land reclamation
Provides new land for settlement and farming

6. Factors to decrease carrying capacity
How these factors work
1. Population growth
Raises demand for basic resources
2. Soil erosion
Reduces food supply
3. Deforestation
Reduces fuel supply/ increases soil erosion
4. Flooding
Destroys living space and farmland
5. Overgrazing/ over cropping
Damages soil and reduces food supply
6. Urbanisation
Raises demand for resources/ reduces farmland
7. Climate change
Makes land areas uninhabitable

7. Case study: The Sahel An area stretching across northern Africa
5,0000km long and 300km wide
a semiarid zone
extends from Senegal (west) through Mauritania, Mali, Burkino Faso, Niger, Northern Nigeria, Sudan to Ethopia.

8. Case study Focus on Sudan Same size as France Barren land
33% of population live in 7% of land
Capitol city Khartoum
Stage 2

9. Factors contributing to overpopulation and overuse of soils
1. Birth rate:
birth rate = 33 per thousand
death rate = per thousand
Population 43million
Infant mortality rates= 81 per thousand
½ population under 18= HDR
Led to a number of problems:
Overgrazing: status of cattle
Deforestation: need of fuel, manure often used (no natural fertilizer in the soil)
over cultivation: use of cash crops to pay debt

10. Factors contributing to overpopulation and overuse of soils
2. Migration and conflict:
Civil war and famine led to internal migration
Since 2003 Darfur has become a human rights crisis region
120,000+ fled to Chad or to area at the east of Sudan
Suffering brain drain
Influx of 1milliion+ from Ethiopia

11. Factors contributing to overpopulation and overuse of soils
3. Environmental degradation:
Global warming: increased temp and evaporation
Droughts reduces food production
Rainfall levels decreased by 30% over 20 yrs leading to drying of soil triggering erosion
Wells drying up and droughts , , dug lower which lowers the water table
Desertification caused by deforestation and drought cause the Sahara desert to spread southward by 10km a year

12. Unsustainable Farming Methods
CAUSE
EFFECT
OVERGRAZING
Cattle exceed carrying capacity
Indication of wealth and importance
GRASS CANNOT REGROW
SOIL EROSION
DESERTIFICTION
OVERCULTIVATION. FARMERS ARE FORCED TO GROW CROPS ON POOR LAND
THE CONTINUAL USE OF THE SOIL LEADS TO LOSS OF SOIL STRUCTURE. THE SOIL IS EASILY BLOWN AWAY BY DESERT WINDS
DESERTIFICATION
DEFORESTATION. TREES ARE REMOVED FOR FUEL AND TO CLEAR LAND FOR CROPS
REDUCED TRANSPIRATION OF MOISTURE FROM PALNTS LEADS TO LESS RAINFALL
ANIMAL MANURE USED AS FUEL INSTEAD OF WOOD. NO LONGER USED TO FERTILIZE THE GROUND
REDUCED CROP COVER

13. OVERPOPULATION AND INCOME
Areas with highest birth rates and highest levels of population growth
poorer countries have a higher birth rate
UN Development Programme:
1.3 billion live on less than .77 cent a day
800 million people do not get enough to eat
500 million are chronically malnourished

14. Effects of overpopulation
Socio-economic
Soil degradation
Cash crops on valuable land
Increasing population
Farmers more sedentary
Refugees not self reliant
Environmental
Change in rainfall patterns
Conflict over water

15. Impact of Income levels on development
UN development programme: 500 million + malnourished
Poor people = larger families, economic asset
High population density not sole indicator of poverty & population
High income families – children an economic liability
Education of women central to decline in birth rate

16. Income levels and development
Kenya
poor, mainly rural
Stage 2
Population growing rapidly (fertility rates high)
42% of pop= 1-14age group
Low incomes
Women low social status
Low quality education and health services
Infrastructure poor
Foreign investment weak
Underemployment and unemployment high
Low pop density but is overpopulated
South Korea
Successful economy, exports orientated
Stage 4
Population growing slowly
Economy developed per capita income improved
High quality education and health
Densely populated
Modern lifestyle and a good standard of living
Unemployment remains low
High pop density but it is not overpopulated

17. Impact of technology on population: medical technology
Improved access to family planning
Vaccinations have been developed to cure/prevent infections ie. Measles etc
Infant mortality rates decreased
Some are cheap and administrated in primitive conditions by use of syringe
better education more women starting families later
Rate of increase not as rapid as a result

18. Impact of technology on population: agricultural technology Increase in food supply leads to longer life expectancy
Advance
Results
1. Improved fertilisers
Increased yields
2. New strains of plants
Able to grow and thrive in strained conditions
3. Chemicals
New pesticides and herbicides allow food to thrive
4. Glasshouses
Able to grow plants in artificial conditions all year round
5. Machinery
Harvesters, planters, pickers gather more crops increasing yields
6. Selective animal breeding
Increased meat and milk yields from each animal
7. Irrigation
Brings formerly dry land into production

19. Ecological footprint and sustainability
Ecological footprint Area of land required to feed, clothe, house
Sustainability is based on the recognition that when a resource is consumed faster that it is produced or renewed the source runs out
Technology can make a positive difference

20. GM foods & The Green Revolution
Increase in food production, technology & research, 1960’s
Modified for desired traits e.g. Salt tolerance
Disadvantages:
Expensive products and equipment
Oil derived fertilisers- non renewable resource
Genetic diversity reduced

21. Population growth and developed countries
Developed countries are in stage 4 and 5
Agricultural and industrial revolution caused economic growth in Europe
Tax revenue allowed for continued investment in health and education
Increase in life expectancy and lower birth rate
Today high standards of living , aging population and high GNP

22. Population growth and developing countries
Stage 2 many countries experiencing high population growth
30% under the age of 14yrs
Increase need of food, infrastructure, education and services
Civil wars, corrupts leadership and MNC’s
Not experiencing economic development in the same way that Europe did as due to unfair trading systems
Migration to shanty towns – cities pop can double in 15yrs
Low incomes cannot afford to invest in education and health
Large families needed to provide economic security
Very young age dependency ratio
Population growth increase in rural-urban migration
Brain drain: leave to find well paid work else where
Loss slows down economic progress in country of origin

23. Over population impacts on society and culture in Bangladesh
Poor country
Primary economic activity: agriculture
Population: 158 million+
28% urban areas
1100 per km squared
Causes of over population
Risk of flooding
Low lying delta
Annual monsoon season, typhoons
1m of water floods 20% of Bangladesh land
Sterilises agri land and contanimates water
Infection: typhoid and cholera

24. Social Factors: Stage 3 Birth Rates declining with family planning
4 births per mother in 1990 but only 2.6 in 2011
Muslim: Marry young, desire for sons
Adult literacy rate only 47%

25. Effects of overpopulation Bangladesh
Migration
Land scarce
Rural to urban migration, lack skills, live in shanty towns
Overcrowding
Both rural and urban areas
Shanty towns= high mortality rates
Domestic servants- remittance