(i) Define the term suburbanization. 

(ii) Briefly outline two possible population changes in an urban area where suburbanization is occurring.

Referring to one or more named cities, explain two ways in which humans affect urban air pollution.

Examine the effects of the movement of services and manufacturing activities to new locations in cities.

(i) Suburbanization is the outward growth of towns or cities [1] that leads to former villages or rural areas becoming urban [1], or the movement of people to the rural–urban fringe [1].

(ii) Award [1] for each outlined population change (either to suburban or other affected area):

• more people arrive in suburbs (newer housing)
• fewer people might be left in city centre
• lower density left in city centre
• older people in particular may move to (quieter) suburbs
• families in particular may move to (spacious) suburbs.

There are many other possibilities that can be credited.

Possible ways humans affect air pollution in urban areas include through transport emissions, burning of fossil fuels for energy production/domestic heating/commercial enterprises.

Equally, it is possible that human activities may reduce air pollution in urban areas, eg Beijing’s relocation of iron and steel plants before the 2008 Olympics, the use of park and rides, Clean Air Acts, etc.

In each case, award [1] either for the identification of a specific source of urban pollution in a named city or for a located pollution reduction strategy. In each case award up to [2] for the description and explanation of what the effect (positive or negative) has been.

Only award [2] in each case if no city named.

For example: In Los Angeles, vehicles release nitrogen oxides [1]. NOx react in sunlight to form ground level ozone [1]. High levels of ground-level ozone form photochemical smog pollution [1].

For example: In Paris 2014 the authorities introduced a policy to reduce the number of cars in the central area [1]. Cars with an odd-numbered number plate were allowed in certain days of the week whereas those with an even numbered-number plate were allowed in on the other days of the week [1]. This has reduced emissions of NOx, improving air quality [1].

(Vehicle pollution includes NOx, CO, particulates and hydrocarbons; NOT carbon dioxide.)

Responses could consider the movement of economic activities into cities in developing/emerging economies; or the relocation movement from central areas to out of town/edge of town locations for well-established cities. There are also redevelopments in inner urban areas and some central areas of older cities, as a result of regeneration schemes. The movement of services (accept retailing) and manufacturing to new locations can have many effects: environmental, economic and social.

Socio-economic effects could be discussed, for instance changes in employment and social class structure, and associated neighbourhood changes.

Negative environmental effects may include increase in impermeable surface, poorer air quality due to the volume of people traveling to the new location. Effects may be highly damaging in newly-industrializing areas eg Pearl River Delta.

On the other hand, new business developments in post-industrial cities increasingly include landscaping, creation of new environments and a more varied habitat. There may also be environmental impacts in the post-industrial area which industry has left – at first dereliction and visual pollution of the environment; then urban succession; but longer-term improvements/landscaping may also occur.

Good answers may do more than explain/list different, unconnected effects. They may additionally examine the interrelations or the timescale of different effects, for instance by showing how economic impacts and social effects are linked. Another approach might be to examine what the effects are for cities at different stages of development, or for areas gaining/losing activity.

At band D, expect a description of some effects of relocations, or new economic activities, within one or more recognizable cities/types of city.

At band E, there should be either an explanation of a wider range of effects/movements or some critical examination of how cities/places/people are affected.

At band F, expect both.

Marks should be allocated according to the markbands.