Human populations and urban systemsIB Environmental Systems and Societies SL: Topic test

1. 1
   In the 1980s the total fertility rate (TFR) in Iran was about 6.5 children per woman. In the following years the government started a national family planning programme, which provided free contraception and health clinics in towns and villages. At the same time, there was a large increase in girls' education and in the number of women attending university. By the early 2000s the TFR had fallen to about 2.

   (a)

   What does the total fertility rate measure?

   [1 mark]

   • AThe average number of children that a woman would have in her lifetime
   • BThe number of births per 1000 people in a year
   • CThe number of children that survive to adulthood in a country
   • DThe proportion of women in the population who are pregnant

   (b)

   Which of these is an indirect policy to manage population growth?

   [1 mark]

   • AFining families that have more than two children
   • BLimiting the number of immigrants
   • CIncreasing girls' education
   • DPaying couples to have more children

   (c)

   Explain how increasing the education of women can lead to a lower birth rate.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Niger, in West Africa, has one of the fastest-growing populations in the world. Its total fertility rate is above 6, and the median age is about 15 years. Its age–sex pyramid has a very wide base and narrows rapidly towards the top. In the past 70 years improved health care, vaccination and clean water have reduced the death rate considerably, but the birth rate has stayed high, and most families depend on farming.

   (a)

   What does the wide base of Niger's age–sex pyramid show?

   [1 mark]

   • AA large proportion of the population is elderly
   • BA large proportion of the population is young because of a high birth rate
   • CThe death rate is higher than the birth rate
   • DImmigration is much higher than emigration

   (b)

   In which stage of the demographic transition model is a country such as Niger?

   [1 mark]

   • AStage 1, with a high death rate and a high birth rate
   • BStage 3, with a rapidly falling birth rate
   • CStage 4, with a low birth rate and a low death rate
   • DStage 2, with a falling death rate and a high birth rate

   (c)

   Explain why the rate of natural increase is high in a country such as Niger.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Country V has no significant migration. In one year its crude birth rate was 36 per 1000 people and its crude death rate was 8 per 1000 people. The government is worried that the population will double too quickly for its schools, housing and food supplies to cope. It is considering introducing policies to slow the growth of the population.

   (a)

   Calculate the natural increase rate of Country V as a percentage, and the doubling time of its population using the rule of 70.

   [3 marks]

   (b)

   Discuss the ways in which the government of Country V could manage the growth of its population.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Singapore is a city-state of about 5.9 million people on an island of roughly 730 square kilometres. It has very little land, no large rivers and few natural resources, so it imports most of its food and a large share of its energy. It recycles wastewater to make a product called NEWater and uses desalination and imported water. Planners have required developers to include parks, rooftop gardens and green walls, and the city has built an extensive network of public transport. Gardens by the Bay includes tall artificial structures called Supertrees, covered in climbing plants.

   (a)

   Explain how an urban area such as Singapore works as a system.

   [6 marks]

   (b)

   Evaluate Singapore's approach to ecological urban planning.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   Dhaka, the capital of Bangladesh, is one of the most densely populated cities in the world, and hundreds of thousands of people move there every year from the countryside. Many migrants come from rural areas where farmland has been lost to river erosion, where farm incomes are low and where there are few jobs. In Dhaka they hope to find work in the many garment factories and in construction, and to have access to schools and hospitals. The city has expanded over farmland and wetlands, and many paved surfaces now cover areas that once absorbed rainwater.

   (a)

   Which term describes the movement of people from rural areas to cities?

   [1 mark]

   • ASuburbanisation
   • BCounter-urbanisation
   • CUrbanisation
   • DNatural increase

   (b)

   Which of these is a pull factor for migrants to Dhaka?

   [1 mark]

   • AOpportunities for work in the garment industry
   • BLoss of farmland to river erosion
   • CLow farm incomes
   • DA lack of jobs in rural areas

   (c)

   Explain two ways in which the expansion of an urban area such as Dhaka changes the environment.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   In 2013 the annual mean concentration of fine particulate matter (PM2.5) in Beijing was about 90 micrograms per cubic metre of air. The city's government then began a major air pollution action plan. Coal-fired boilers in homes and factories were replaced with gas or electric heating, the most polluting factories were closed or moved away, and older vehicles were taken off the roads. By 2023 the annual mean concentration of PM2.5 had fallen to about 30 micrograms per cubic metre.

   (a)

   Which of these is a primary pollutant produced by burning fossil fuels?

   [1 mark]

   • AOzone formed from sunlight acting on pollutants
   • BAcid rain
   • CPhotochemical smog
   • DParticulate matter

   (b)

   Which strategy reduces air pollution at its source?

   [1 mark]

   • APlanting trees along roads to absorb pollutants
   • BReplacing coal-fired boilers with cleaner heating
   • CAdvising people to stay indoors on polluted days
   • DUsing filters at the exit of a chimney after pollutants are formed

   (c)

   Explain how replacing coal-fired boilers with gas or electric heating reduces urban air pollution.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   In the United States, sulfur dioxide from coal-burning power stations caused acid rain, which damaged forests and lakes in the north-east of the country. A law passed in 1990 set a limit on total sulfur dioxide emissions from power stations and required many of them to fit equipment to remove sulfur from their waste gases. In 1990 power stations emitted about 16 million tonnes of sulfur dioxide. By 2010 this had fallen to 5.1 million tonnes and by 2020 to 1.4 million tonnes (simplified figures).

   (a)

   Calculate the percentage fall in sulfur dioxide emissions from 1990 to 2010, and the percentage fall from 2010 to 2020.

   [3 marks]

   (b)

   Explain the effects of acid rain on ecosystems, human health and buildings.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   The United Arab Emirates has a population of about 10 million, of whom roughly 88% are migrants who came to work. Most are young adults, and about two-thirds of the population is male. Many live in cities such as Dubai, which grew quickly from a small trading town. Dubai has built a metro, which opened in 2009, but most people still travel by car. Traffic, construction dust, and the burning of fuel in power stations and for air conditioning contribute to air pollution, which is often worst in the hot summer months.

   (a)

   Explain how migration affects the population dynamics of the United Arab Emirates and how this is shown in its age–sex pyramid.

   [6 marks]

   (b)

   Evaluate the strategies that could be used to reduce urban air pollution in a city such as Dubai.

   [6 marks]

   Total for question 8: 12 marks

End of questions