Key Terminology• Overpopulation = when there are too many people in an area for the resources of that area

to maintain an adequate standard of living.

• in 1990, Ireland was overpopulated – only had population of 3.5 million but 70,000 emigrated due to unemployment.

• Calabria in the Mezzogiorno only has a population density of 137 people per km square, but is OVERPOPULATED.

• Underpopulation = when there are more resources in a region than can be exploited by the people living there.

• before the Celtic Tiger period in mid 1990s Ireland was underpopulated and the government had to search abroad for workers.

• Optimum Population = the optimum number of people that can live a high standard of living in a region given the resources available for them.

• Carrying Capacity = the number of people that can live a sustainable lifestyle in a region using the resources available to them.

• Japan has population density of 336 people per km square and is not overpopulated!

Very Important Topics

• Dharavi, Mumbai.

• The Sahel – Desertification.

What do you think can effect the carrying capacity of a region?

Increases carrying

capacity

Decreases carrying

capacity

Decreasing population Population growth

Fertilizers Soil erosion

New farming methods Deforestation

Irrigation Flooding

Better crops/animals Overgrazing/overcropping

Land reclamation Urbanisation

Climate change

The Sahel

The Role of Society and Culture on Population Growth

The status of women. The desire for sons. The role of religion (Christianity and Islam).

The Role of Income Levels on Population Growth

• South Korea • Kenya

The influence of Income Levels and

Technology on Population Growth

To do list!1. Bangladesh

Use pages 34/35 to create a bank of SRPs that could be useful for Human Elective essays.

2. The impact of population growth on DEVELOPMENT

pg 41 to 43.

3. Fill in BOOKLET information tables for section 5.2.

4. The positive and negative impacts of migration pg49 to 52.

Urban Growth Problems in a Developing World City

This information can be adapted to answer a variety of questions e.g.

• Discuss the effects of rural to urban migration in the developing world.

• Discuss the effects of high population density on an area.• Discuss the impact of rapid population growth in the developing

world.• Name and explain two socio-economic problems associated with

migration in the developing world.• Name and explain the effects of overpopulation in area that you

have studied.• Be sure that you revise the impact of migration on the donor and

rural areas.• Be sure that you revise the impact of rural to urban migration in

the developed world.

You should know the causes and effects ofoverpopulation in relation to the:

• development of resources (e.g. The Sahel).

• influence of society and culture (e.g. role of women,religion, desire for sons).

• impact of income levels (e.g. South Korea v Kenya).

• impact of technology (e.g. Industrialrevolution/Medical and Agricultural Revolution)

• You should also know the impact populationgrowth has on development.

Overpopulation in the Sahel

• Overpopulation occurs when there are not enough resources to supportthe population of the region.

• These basic resources include clean water, food, shelter, fuel and farmland.• Overpopulation has several causes which include high birth rates,

migration, the overuse (depletion) of resources, the influence of society andculture, income levels and the advancement of technology.

• The effects of overpopulation can include the lack of food, poverty,degradation of the environment, low life expectancy, migration and conflict.

• In my answer I will discuss high birth rates as a cause and lack of food thatcan result in famine as an effect of overpopulation.

• I will look closely at the Sahel region of Africa, which runs along thesouthern edge of the Sahara Desert.

• This region includes many African countries including Mali, Sudan, Nigeriaand Chad.

Cause of overpopulation: high birth rates.

• Overpopulation in this region has happened due to high birth rates.• Mali has a very high birth rate of 41.2 per 1,000 and Sudan has a very high birth rate of 38.6

per 1,000.• These countries are in Stage 2 of the Demographic Transition Model.• This means that there is a large increase in population at this stage which puts a huge strain

on natural resources, therefore eventually leading to overpopulation.• The role of society and culture contribute to the population growth of the region as women

in Mali and Sudan have very low social status and do not have easy access to education.• The lack of education for women means that the adult literacy rate for women in Mali is

only 34%.• This lack of education disempowers women, and they become the property of their

husbands and are tied to traditional roles of motherhood and homemaking.• This combined with the lack of contraception, family planning education and poor health

services has lead to high fertility rates of 6.3 babies per mother in Mali.• This means that 63 babies are born for every 10 mothers in the country!• The governments of these countries have not been able to provide enough housing,

employment, education or healthcare services for their growing populations.• As a result Mali and Sudan and other countries in the Sahel are poor and have very low life

expectancies and standards of living.• The people of Mali have a life expectancy of 42 years and the infant mortality rate is 120

per 1,000!• These are evidence of overpopulation in the region.

Effect of overpopulation: lack of food and famine

• (remember – this could be adapted to use as CAUSE 2 – the unwise development of a natural resource)

• The lack of food is an effect of overpopulation in the Sahel region, which includes Mali and Sudan.

• The natural resource in this region is soil. Soil in the Sahel is made up of sand and laterite.

• Because it doesn’t hold water as well as clay soil, it is easily eroded by the wind.

• The high birth rates and population growth has caused overpopulation in the Sahel region which in turn has led to the unwise development of this natural resource.

• The effect of this overpopulation which has been desertification and reduced food supplies.

• The rising population depends on wood fuel for cooking which has led to increased deforestation in the area.

• 90% of the people in the Sahel rely on wood as their energy source.

• Cattle numbers amongst the nomadic tribes in the Sahel define individual wealth and importance.

• This along with the population growth has led more animals to graze than the land can potentially sustain. This means the carrying capacity of the land has been exceeded.

• This has led to overgrazing in the Sahel.

• Deforestation and overgrazing has therefore stripped the area of it’s protective vegetation cover, reducing the fertility of the land, increasing soil erosion by the wind and therefore making it very difficult to grow food.

• Overcultivation of the land due to population growth has also led to damage to soil structure and fertility that leads to less food being able to be produced.

• Because wood is now scarce, cattle dung is burned as fuel. This deprives the soil of valuable nutrients, again reducing soil fertility and leads to soil erosion.

• The degradation of this natural resource of soil, has therefore led to food shortages and famine.

• Millions of people have died of hunger and hunger related diseases in the Sahel region due to this.

• Experts estimate that desertification caused by the unwise development of this resource and drought has allowed the Sahara Desert to spread southwards at the rate of 10 km per year!

Effect 2: Rural to Urban migration

• Overpopulation in the Sahel region has led to rural to urban migration.

• Many cities of the Sahel experience rapid population growth as people leave the countryside in the hope of a better quality of life in the cities such as Bamako in Mali.

• This has had led to many socio-economic effects on both the rural and urban regions.

• In the urban regions, migrants have very few skills and are forced to live in shanty towns on the outskirts of vast cities like Bamako.

• Shanty towns are filled with handmade shelters in which people live. People build their own shelter from any scrap materials they can find, and pose a serious health and safety issue.

• Shanty towns are built on any spare unused land in the city, but most are found on the edge of the city.

• Conditions in these areas are extremely poor and have in turn become overpopulated themselves.

• The rapid population growth in the shanty towns has led to the lack infrastructure and services.

• Sewerage, water and electricity supplies are absent or extremely limited.

• Rubbish is dumped onto the streets and open drains run down the small alleyways between shelters.

• Death rates and infant mortality rates are much higher than average in these shanty towns. Children and adults die from diseases such as dysentery caused by drinking dirty water and from playing in the unhygienic living conditions.

• There have been impacts in the rural communities also.

• The migration of males in particular to the urban areas in search of work has led to an imbalance of males to females in the rural communities, resulting in low marriage rates.

• Young able professionals leave the rural areas and results in brain drain, leaving an older, often physically incapable generation behind to sustain the community and land.

• This has led to abandonment of agricultural land and the closure of the few services that were available.

• This has lastly caused these regions of the Sahel to become politically and economically isolated, with the road infrastructure being so poor, the economic development of the region is prevented.