Consequences of Urbanisation and Urban Growth (AQA A-Level Geography): Revision Notes

Consequences of Urbanisation and Urban Growth

Urban areas worldwide face similar challenges regardless of their economic status, including housing problems, traffic congestion, waste management difficulties, crime, and pollution. However, the specific nature and severity of these issues often relate to the geographical characteristics of each city, such as its topography, climate, and function. This section explores the major consequences that result from rapid urbanisation and urban growth.

Urban sprawl

Urban sprawl creates numerous negative impacts on both the environment and urban functionality:

Infrastructure and economic costs

Expanding urban areas require extensive infrastructure networks. New roads, water pipes, electricity cables, and telecommunications wires must be installed across low-density rural areas. This is economically inefficient compared to serving compact urban developments with the same number of households. The costs of providing services to sprawling suburbs are significantly higher per person.

Environmental damage

The spread of urban development into rural areas is recognised as one of the primary causes of wildlife habitat destruction. Natural ecosystems are fragmented or completely destroyed as concrete and asphalt replace green spaces. This biodiversity loss has long-term ecological consequences.

Transport and pollution impacts

Urban sprawl increases commuting distances between suburbs and city centres, leading to greater fuel consumption and traffic congestion. The car-dependent lifestyle associated with sprawl results in increased fossil fuel consumption and higher emissions of greenhouse gases. These areas also tend to experience elevated temperatures due to the urban heat island effect, where built-up areas retain more heat than natural landscapes.

Loss of agricultural land

As cities expand outwards, valuable farmland and open spaces disappear. This reduces local food production sources and increases food miles – the distance food must travel from production to consumption. Communities become more dependent on food transported from distant locations.

Water management problems

Covering the countryside with impermeable surfaces such as concrete and tarmac prevents rainwater from naturally soaking into the ground and replenishing groundwater aquifers. Instead, water runs off quickly, which can lead to increased flood risk in both urban and downstream rural areas. The natural water cycle is disrupted.

Decentralisation and homogenisation

An important consequence of sprawl has been the movement of people, industry, and retail businesses outward from city centres. This process, known as decentralisation, has been blamed for the decline of traditional retail in many city centres. As businesses relocate to suburban areas and edge locations, cities become increasingly similar to one another, resulting in what geographers call homogenisation of the landscape.

Edge cities

In many urban areas, particularly in the United States, large edge-of-city complexes have developed containing shopping centres and leisure facilities. In some cases, completely new self-contained settlements have emerged beyond the original city boundary. These are known as edge cities – they function as cities in their own right with their own employment, retail, and residential areas.

Shortage of housing in lower-income countries

Population density in urban areas tends to be high, and one major consequence is a shortage of accommodation. This leads to the presence of extensive areas of informal and often inadequate housing. These settlements typically develop on the edge of cities or in areas of low land value that are vulnerable to environmental hazards such as flooding or landslides. They may also be found adjacent to transport networks or in areas experiencing high levels of air, noise, or water pollution.

These settlements generally have limited access to basic infrastructure including water supply, electricity, and waste disposal systems. They also lack essential services such as health centres and schools.

Global statistics on slum populations

Projections indicate the problem is worsening. By 2030, it is estimated that one in four people globally will live in a slum or other informal settlement. The scale of the challenge is immense – Mumbai alone had more than 41 million slum dwellers in 2020. Throughout India, the number of people residing in slums is estimated to be 104 million, representing nine per cent of the total population.

The bar chart above demonstrates how the proportion of people living in urban slums has changed across different world regions between 1990 and 2014. The patterns vary significantly by region. For example, in Sub-Saharan Africa, slum populations continued to grow at an increasing rate, whilst in other regions the rate slowed down or even declined (such as in Northern Africa). These changes should be viewed positively in the context of the Millennium Development Goal 7 (Ensure environmental sustainability), which aimed to improve the lives of slum dwellers.

One of the targets in the post-2015 sustainable development goals is to 'ensure access for all to adequate, safe and affordable housing and basic services, and upgrade slums by 2030.'

Terminology for informal settlements

Informal settlements are known by different terms depending on their location:

• In the hills of Rio de Janeiro, Brazil, they are called favelas
• In parts of India, they are known as bustees
• In West Africa, they are called bidonvilles

The term 'slum housing' itself has been criticised by some as a political label. In Mumbai, for example, settlements such as Shivaji Nagar and Dharavi are referred to by some residents as 'homegrown neighbourhoods'. The argument is that these areas developed gradually by the people who live there, with help from local construction artisans, and usually with minimal or no support from government authorities.

Approaches to addressing informal settlements

Historically, the most extreme strategy adopted by authorities was to eradicate slums completely. However, this approach simply relocated the problem elsewhere rather than solving it. A more common and constructive approach has been to acknowledge the existence of slums and provide assistance in the form of building materials or basic services.

These 'self-help' or 'site and service' schemes have proved remarkably successful in some cities. However, the quantity and quality of housing remains inadequate in most urban areas around the world.

One notable organisation is Shack/Slum Dwellers International (SDI), which gives a voice to those living in informal settlements and links up poor communities across Africa, Asia, and Latin America. The organisation's philosophy is that slum dwellers should share their knowledge and expertise so they are not excluded from the economic and political processes happening in their cities.

Case study: Dharavi, Mumbai, India

Shortage of affordable housing in higher-income cities

Whilst lower-income countries struggle with slums and informal settlements, higher-income cities face a different housing crisis – affordability. The shortage of affordable housing has become a critical problem in many wealthy cities as rising demand for accommodation has led to dramatic increases in both house prices and rental costs.

The London example

Lack of urban services and waste disposal

Financial constraints in lower-income countries often result in a shortage of basic urban services such as clean water and reliable electricity. The maintenance of essential infrastructure such as roads, sewers, and drainage systems is also limited. This infrastructure deficit can result in traffic congestion, polluted watercourses, flooding, and the rapid spread of disease.

Water and electricity shortages

Waste disposal challenges

Waste disposal poses a further significant problem. The amount of waste increases year-on-year, but there are economic, physical, and environmental constraints on its disposal.

In Addis Ababa, Ethiopia, the city authority is only able to deal with two-thirds of the rubbish created by the rapidly growing urban population. The remainder is either left to private contractors to collect or is simply dumped on streets and in rivers, creating a huge health hazard.

At Koshe, a huge landfill site on the edge of the city, families live in makeshift housing and search for anything they can use for themselves, or resell.

Informal recycling economy

In other cities, refuse is seen as an opportunity to generate income. In Nairobi, recycling forms an important part of the everyday economy:

• Old car tyres are cut up and used to make cheap sandals
• Washing machine doors are repurposed as kitchen bowls, and the drums serve as storage units
• Glass bottles are collected and returned to stores for refilling
• Food waste is collected and fed to animals or composted for use on vegetable plots
• Tin cans and old oil drums are used to make charcoal stoves, lamps, buckets, and metal tips for ploughs

Unemployment and under-employment

Since a high proportion of the people who move to cities are relatively young, there is considerable pressure on urban economies to create sufficient employment opportunities. Unemployment rates in cities are typically high, although official statistics are difficult to obtain. Many migrants eventually find employment in informal work such as street hawking or selling goods from small stalls.

Under-employment represents wasted human potential and can lead to social problems including poverty, frustration, and inequality.

Transport issues

The processes of urbanisation and suburbanisation have led to increased traffic in cities across the world. This has created more congestion and pollution, which damages human health and results in billions of pounds in lost productivity.

The spread of houses into the suburbs and beyond has created surges of morning and evening commuters. Traffic flows increase during peak hours for shopping, entertainment, and other commercial services, adding to the congestion problem.

Failed solutions

During the car boom of the 1960s, city planners built more and wider roads as a solution to traffic problems. However, this approach did not work as intended. The more roads that were created, the more cars they attracted.

Health and economic impacts

Traffic congestion has serious consequences:

• Air pollution from vehicle emissions damages respiratory health
• Noise pollution affects mental wellbeing
• Lost productivity costs billions annually
• Fuel is wasted whilst vehicles sit in traffic
• Stress levels increase for commuters

Contemporary urban processes

Higher-income countries have experienced a much slower rate of urbanisation in recent decades, and some cities have even witnessed a decline in population numbers. Rather than moving into urban areas as was typical during the industrial periods, a more significant trend has been the movement outwards from city centres.

Historical development in the UK

The towns and cities of the UK demonstrate the effects of past suburbanisation patterns. Different periods have left distinctive marks on the urban landscape:

1930s: Ribbon development

In the 1930s, there were few planning controls and urban growth took place alongside main roads. This was known as ribbon development. By the 1940s, this uncontrolled growth between the 'ribbons' became a cause for concern.

1940s: Green belts

Concern about unchecked urban sprawl led to the creation of green belts – designated areas of open space and low-density land use around towns where further development was strictly controlled. The purpose was to prevent towns from merging into one continuous urban area and to preserve countryside for recreation and agriculture.

1950s and 1960s: Council housing expansion

Large-scale construction of council housing took place on the only land available at the time – the suburban fringe. This period saw significant expansion of suburban areas.

1970s onwards: Home ownership growth

From the 1970s, there was a move towards home ownership. This led to private housing estates being built, also on the urban fringe. Building in these areas allowed houses to have more land for gardens and provided more public open space compared to dense inner-city development.

Recent developments: Edge cities

As car ownership grew, the edge of towns, where more land was available for car parking and expansion, became the favoured location for new offices, factories, and shopping outlets. In a number of cases, strict control of green belt development was ignored, leading to the emergence of edge cities.

In recent years, new housing estates have been built in suburban areas, along with local shopping centres and other amenities, continuing the pattern of outward urban growth.

Key terms

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