2. Overpopulation and Development 1. 2. 3. 4. Learning Objectives Explain the term overpopulation Describe the causes of overpopulation Describe the effects of overpopulation on resources, income and society Describe how technology can influence population growth Outline of work 1. Causes of overpopulation • • Case study 1: Overuse of resources e.g. Aral Sea Region Case Study 2: Effects of overpopulation on resources e.g. Sahal region Africa Case Study 3: Influence of society and culture e.g. India Case Study 4: Impact of income levels e.g. Mezzogiorno Case Study 5: Impact of technology on Population growth e.g. agriculture and medical • • • 2. Impact of population growth on rates of development. Overpopulation Definition • Overpopulation occurs when the number of people in a region is greater than the ability of the land to support them. • I.e. there are more people than there are resources to support them. Carrying Capacity • The number of people that a region can support with its basic resources is called its carrying capacity. • Basic resources = land, food, water, fuel and shelter. Example: if a region contains 10 people but only have enough resources for 9 then it is overpopulated. If it contains 10 people and has resources for 20 then it is not overpopulated. Carrying Capacity • What factors would increase the carrying capacity? • What factors would decrease the carrying capacity? The best or optimum population of an area is one which can exist in a region and enjoy a good quality of life without destroying the resources or landscape. Cause of Overpopulation 1. High birth rates 2. Migration 3. Overuse of depletion of resources Each of these have a case study. In your answer You can write about all three or one in detail. You could be asked for a cause or causes 1. High Birth Rates • An increase in population increases the demand for basic resources such as food, fuel and water. If these are not available the area will become overpopulated 2. Migration • Migration can raise the population. People choose to leave their homes for many reasons. • Sometimes they may move to areas that are already under stress due to soil erosion and overgrazing. • Rural – urban migration also plays a part. Shanty towns have to be built. Homelessness, congestion and crime are also symptoms of an overpopulated city region. 3. Overuse or depletion of resources • If resources are overused they can not support the population with a decent standard of living. • When this happens many people have to leave the area e.g Aral Sea in central Asia has become depleted due to overuse of its water resources. Cause of overpopulation: Overuse or depletion of resources The Aral Sea Aral Sea • Activity: Read the photocopy of the Aral Sea in central Asia case study. • Summarise the most important parts into your copies for eg the cause and the effects. • http://www.youtube.com/watch?v=Z0Pi61SyV SM&feature=related Effect of overpopulation on resources: Sahel Region of Africa • Sahel region of Africa stretches across the African continent. • Sudan (largest country in Africa) is a country where high birth rates, migration and environmental degradation have combined to make parts of the country overpopulated. • (Also cause of overpopulation – high birth rates ) Factors contributing to overpopulation and overuse of soil resources 1. Birth Rates: • Increasing population but the economic development of Sudan has not kept up. • It is in stage 2 of the demographic transition model. • Sudan has a population of 43 million years. • On average women have 5 children. Infant mortality rate is high. Life expectancy is 58 years. • Half the population is under 18 so there is a high dependency ratio. Key Idea! Population growth has led to overgrazing, deforestation, and over cultivation. In groups discuss some reasons for overgrazing, deforestation and over cultivation Some possible reasons…. • Cattle are a symbol of wealth and rank within society. • There are now more families and each family needs more cattle to survive. The increase in cattle leads people into poverty as they overgraze the soil. The soil eventually becomes damaged and useless for farming. • Increased demand for fuel has led to deforestation and land clearance. • International debt has caused plantation owners to plant huge areas of land under cash crops e.g. cotton and beans. The land is not being left to rest between crops. This results in overcultivation 2. Migration and Conflict • Civil war and famine have caused movements of people around Sudan. • Many people hav being killed and up to four million are at risk of attack. This internal migration has affected the population distribution, producing overpopulation in areas that can not provide services or employment. • Also more than one million refugees from Ethopia have entered the country. 3. Environmental Degradation • Droughts over the last 30 years have reduced Sudan’s food production. They occur most often and last longer and longer. • To provide water for people and cattle wells have been dug.. This lowers the water table and dries the soil even more. The influence of Society and Culture on Overpopulation • We are going to use India as the case study for this topic. You should know about India from regional geography • In groups read page 301 of your text book. Find out how India’s culture and society have led to overpopulation. Activity • Write your findings into your notes copy Impact of Income Levels • Can be broken into two parts - Effects of rising incomes - Effects of low incomes e.g. Mezzogiorno Italy Activity Read page 301 and 302 of your books. Impact of technology on Population Growth (Agriculture) • Increased food supply leads to population growth. • More food = healthier lifestyle and life expectancy increases. • We now have the technology to grow enough food to feed 1,000 people for a year on an area the size of a soccer pitch. • Biotechnology has created and developed new varieties of crop that can survive drought nd produce more seeds. • Chemicals control pests. • Irrigation methods. • Computer controlled systems are used to water, heat and light the greenhouses Impact of technology on population growth (Medical) • 1. 2. 3. 4. Advances in medicine has decreased the rate of population growth this is because People living longer because of access to immunisation, primary healthcare and disease eradication programmes. Family planning Status of women As health conditions improve more children are likely to survive so they are choosing to have fewer babies Case Study: HIV/AID treatment in South America. Activity: Read the case study and answer the following questions. 1. Why will the population in some areas of the world decrease over the next 40 years? 2. Why is there a delay in the use of effective medicines in South Africa? 3. Pick out three facts about Aids and South America that surprised you. 4. Summarise the governments influence on the use of HIV/AIDS medicines 5. Summarise the influence of multinational companies on HIV/AIDs treatment in South Africia Impact of Popuation Growth on Development • Population growth and developed countries • Population growth and developing countries Population growth and developed countries 1. Developed countries need population growth to provide a labour force for industry and services. 2. Population growth provided a market for products such as textiles 3. Rising population moved from rural to urban areas. Fewer farms were needed to feed the urban population because of increases in food. 4. Industrialisation was encouraged by the creation of trading systems 5. Tax revenue allowed for investment in education, health and services such as sanitation. This led to an incerease in life expectancy and lowered birth rates. 6. As a result these countries passed through the demographic transition model faster than other countries Population Growth and Developing Countries 1. Increased population = increased need for food, infrastructure and services. 2. Developing countries are benefiting from better healthcare but are not experiencing economic development and industrialisation that Europe did. 3. Few jobs to support the population. Lower incomes and cannot afford to provide education, healthcare or state support. Large families are needed to provide economic security. 4. Developing countries have a very young age dependency ratio and there will be an increase in demand for services and jobs. They will need financial help Chapter Summary • Traffic light your learning objectives. • Are you typical?