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

1. 1
   China introduced a one-child policy around 1980, relaxed it to two children in 2015 and to three children in 2021. Its total fertility rate (TFR) fell from about 2.7 children per woman in 1980 to about 1.2 in recent years, one of the lowest in the world. China's population peaked in 2021 and began to fall in 2022. Life expectancy has risen to about 78 years, so the proportion of people over 65 is growing.

   (a)

   Which of the following is a direct population policy?

   [1 mark]

   • AA law limiting the number of children a couple may have
   • BImproving the education of girls
   • CRaising average incomes through economic growth
   • DExpanding access to healthcare

   (b)

   Which of the following is an indirect way of managing population growth?

   [1 mark]

   • ASetting a maximum number of births per couple
   • BSetting a limit on the number of immigrants allowed each year
   • CFining couples who have more children than allowed
   • DExpanding education and job opportunities for women, which tends to lower birth rates

   (c)

   Explain why a TFR far below the replacement level leads to a falling population.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Country K has a crude birth rate of 38 births per 1 000 people per year and a crude death rate of 10 deaths per 1 000 people per year. Migration into and out of the country is negligible. Nearly 45% of its people are under 15 years old. The government has opened family-planning clinics and started a programme to keep girls in school for longer.

   (a)

   What is the rate of natural increase in Country K?

   [1 mark]

   • A0.28%
   • B2.8%
   • C28%
   • D3.8%

   (b)

   Using the rule of 70, what is the approximate doubling time of Country K's population?

   [1 mark]

   • A10 years
   • B28 years
   • C25 years
   • D70 years

   (c)

   (HL) Explain why Country K's population is likely to keep growing for decades even if its TFR fell to replacement level tomorrow.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   City X is a hypothetical city. In 1990 it had a population of 2 million people living in a built-up area of 150 square kilometres. By 2020 its population had risen to 5 million and its built-up area had grown to 420 square kilometres, as new housing estates, shopping centres and roads spread out into surrounding farmland and woodland. Many people now commute into the centre by car.

   (a)

   Calculate the population density of City X in 2020 and compare it with that in 1990.

   [3 marks]

   (b)

   Explain how the expansion of City X may change the environment.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Vauban, a district of Freiburg in Germany built from the 1990s on a former military site, is home to about 5 000 people. Most streets are car-free and car ownership is much lower than in most German neighbourhoods. The homes are built to very high energy standards, many with solar panels, thick insulation and triple-glazed windows, and some are built with timber from local forests. Shops, a school, nurseries, offices and both rented and owner-occupied apartments are all within a short walk, and a tram line connects the district to the city centre.

   (a)

   (HL) Explain how the three principles of urban compactness, mixed land use and social mix are shown in Vauban.

   [6 marks]

   (b)

   (HL) Explain how green architecture, as used in the homes in Vauban, reduces harmful effects on human health and the environment.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   In winter, the air in Delhi often contains fine particles (PM2.5) at concentrations many times higher than the World Health Organization guideline. Sources include millions of vehicles, coal-fired power stations and industry, the burning of waste and cooking fuels, and smoke from crop stubble burnt in neighbouring states after the harvest. In winter, cold, still air near the ground holds the pollutants over the city.

   (a)

   Which of the following is a particulate pollutant?

   [1 mark]

   • ACarbon monoxide gas
   • BSulfur dioxide gas
   • CFine particles of soot and dust smaller than 2.5 micrometres (PM2.5)
   • DNitrogen gas

   (b)

   Which is an example of a primary pollutant from the combustion of fossil fuels?

   [1 mark]

   • ACarbon monoxide from vehicle exhausts
   • BOzone formed by sunlight acting on other pollutants
   • CNitric acid in acid rain
   • DNitrogen gas in the air

   (c)

   Outline two strategies that could reduce urban air pollution in Delhi.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   Before the 2008 Olympic Games, Beijing had frequent days of heavy air pollution caused by traffic, coal burning and industry. For the Games, the authorities allowed cars on the roads only on alternate days according to their number plates, closed or moved factories and power plants, and stopped most building work. Air quality improved sharply during the Games, but pollution levels rose again after the restrictions were lifted. On hot, sunny days, high levels of tropospheric ozone were still recorded in the city.

   (a)

   (HL) How is photochemical smog formed?

   [1 mark]

   • ACold air traps smoke from coal fires on windless nights
   • BAcid rain reacts with limestone buildings
   • CCarbon dioxide absorbs ultraviolet radiation in the stratosphere
   • DSunlight acts on primary pollutants, such as nitrogen oxides and volatile organic compounds, forming secondary pollutants

   (b)

   (HL) Which is an indirect impact of tropospheric ozone?

   [1 mark]

   • ADamage to lung tissue
   • BSocietal costs and lost economic output, for example through illness and lost work days
   • CBleaching and damage to leaves
   • DCracking of rubber

   (c)

   Using the information, outline two management strategies that can reduce urban air pollution.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   Country B has a population of 80 million people. Its age structure is 12 million aged 0 to 14 years, 50 million aged 15 to 64 years and 18 million aged 65 years and over. Its total fertility rate is 1.3 and its working-age population is shrinking. The government is worried about the cost of pensions and healthcare and about a shortage of workers.

   (a)

   (HL) Calculate the dependency ratio for Country B.

   [3 marks]

   (b)

   Explain how the government of Country B could use direct and indirect policies to manage its shrinking working population.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   Dhaka, the capital of Bangladesh, has grown from about 3 million people in 1980 to over 20 million today. Many of the migrants come from coastal and riverside areas of southern Bangladesh, where cyclones, floods, river-bank erosion and salt water entering the soil have destroyed farmland and homes. Many settle in informal settlements on low-lying land with poor sanitation, and demand for housing, water, transport and jobs has grown faster than the city can provide them.

   (a)

   (HL) Explain how environmental problems have contributed to migration to Dhaka and how this migration affects the urban system.

   [6 marks]

   (b)

   Evaluate strategies that the government of Bangladesh could use to manage the rapid growth of Dhaka.

   [6 marks]

   Total for question 8: 12 marks

End of questions