Topic 8 Human Populations and Urban Systems

At the end of this subtopic 8.1 you should know:

• Births and immigration are inputs to a human population. (8.1.1) 

• Deaths and emigration are outputs from a human population. (8.1.2)

• Population dynamics can be quantified and analysed by calculating total fertility rate, life expectancy, doubling time and natural increase. (8.1.3)

• The global human population has followed a rapid growth curve. Models are used to predict the growth of the future global human population. (8.1.4)

• The demographic transition model (DTM) describes the changing levels of births and deaths in a human population through different stages of development over time. (8.1.8)

• The composition of human populations can be modelled and compared using age-sex pyramids. (8.1.7)

• Population and migration policies can be employed to directly manage growth rates of human populations. (8.1.5)

• Human population growth can also be managed indirectly through economic, social, health, development and other policies that have an impact on births, deaths or migration. (8.1.6)

At the end of this subtopic 8.2 you should know:

• An urban area is a built-up area with a high population density, buildings and infrastructure. (8.2.2)

• An urban area works as a system. (8.2.3)

• Urbanisation is the population shift from rural to urban areas. (8.2.4) 

• Due to rural-urban migration, a greater proportion of the human population now live in urban rather than rural systems, and this proportion is increasing. (8.2.5)

• Suburbanization is due to the movement of people from dense central urban areas to lower density peripheral areas. (8.2.6)

• The expansion of urban and suburban systems results in changes to the environment. (8.2.7)

• Urban areas contain urban ecosystems. (8.2.1)

• Urban planning helps decide on the best way to use land and buildings. (8.2.8) 

• Modern urban planning may involve considering the sustainability of the urban system. (8.2.9)

• Ecological urban planning is a more holistic approach that treats the urban system as an ecosystem, understanding the complex relationships between its biotic and abiotic components. (8.2.10)

At the end of this subtopic 8.3  you should understand:

• Sources of primary pollutants are both natural and anthropogenic. (8.3.2)

• Urban air pollution is caused by inputs from human activities to atmospheric systems, including nitrogen oxides (NOx), sulfur dioxide, carbon monoxide and particulate matter. (8.3.1)

• Most common air pollutants in the urban environment are either derived directly or indirectly from combustion of fossil fuels. (8.3.3)

• NOx and sulfur dioxide react with water and oxygen in the air to produce nitric and sulfuric acid, resulting in acid rain. (8.3.5)

• Acid rain has impacts on ecology, humans and buildings. (8.3.6)

• A range of different management and intervention strategies can be used to reduce urban air pollution. (8.3.4)

• Management and intervention strategies are used to reduce the impact of sulfur dioxide and NOx on ecosystems and to minimise their effects. (8.3.7)