Urbanization in sub-Saharan Africa: Trends and implications for development and urban riskDavid Satterthwaite
In 2015, sub-Saharan Africa’s urban population reached 396 million. This was distributed among thousands of urban centres that included two mega-cities (with more than 10 million inhabitants), as well as three cities with populations of 5 – 10 million and another 41 with populations of 1 – 5 million. But it is worth noting that there are also a very large number of urban centres with less than 20,000 inhabitants and more than 1,000 urban centres with populations of 20,000-50,000, and these smaller urban centres include a significant share of the urban population in most nations in the region.
The region’s urban population doubled between 2000 and 2015. Much of it lives in poor quality and overcrowded housing that lacks access to the infrastructure and services that urban centres need and that reduce ‘everyday’ risks – including safe, regular water supplies and good provision for sanitation, drainage, roads, traffic management and health care. These also have relevance for disaster risk and, increasingly, for the threats that arise from or are exacerbated by the direct and indirect impacts of climate change.
The everyday, disaster and climate change risks to which urban populations are exposed have severe implications for the development of urban areas, as well as the health and welfare of their populations. In many cities, these are concentrated in particular districts or settlements with ‘development deficits’ in relation to risk-reducing infrastructure and services. This is also generally where urban governments lack the resources and capacities to address these deficits. In addition, there is often little in the way of local government accountability to citizens, posing a major obstacle to the great potential of urban areas to support improved health outcomes, better living conditions and stronger economies.
Urban Africa Risk Knowledge (Urban ARK) is a three-year research and capacity building programme (funded by DFID and ESRC) that is examining the processes that define and shape urban risk in sub-Saharan Africa. This is to allow a better understanding of the ways in which Africa’s urbanization can lead to improved life chances and better health, but also to avoid the accumulation of disaster risk. Addressing disaster risk is central to building resilience in sub-Saharan cities and towns. Drawing on available studies, some general points can be raised that have relevance to this:
1. It is common for between a third and two-thirds of an urban centre’s population to live in housing of poor quality, with high levels of overcrowding in terms of indoor space per person and number of persons per room.
2. A perhaps surprisingly large proportion of urban dwellers in sub-Saharan Africa still use dirty fuels for cooking and heating, resulting in high levels of indoor air pollution and severe health impacts. Over half the region’s urban population cooks on open fires or inefficient stoves using fuel wood, charcoal or dung. The two most common implications of poverty for energy use among urban populations in sub-Saharan Africa are, first, no access to electricity, and second, use of the cheapest and often most polluting fuels and energy-using equipment, including stoves.
3. Much of the urban population lacks safe, regular, convenient supplies of water and provision for sanitation – far more so than the official statistics suggest. In 2015, 66% of the region’s urban population did not have water piped on premises, up from 57% in 1990. Most nations in the region have missed the MDG targets for water (when assessed by who has water piped on premises) and for sanitation in urban areas. Generally, provision for water and sanitation is worse in smaller urban centres, although there are many large cities too where provision is comparably poor. Most of the region’s urban centres, large and small, lack sewers.
4. Much of the urban population lack regular (or even irregular) services to collect household waste. The environmental health implications of non-existent garbage collection services in urban areas are obvious – most households dispose of their wastes on any available empty site, into nearby ditches or lakes, or simply along streets. The problems associated with this include smells, disease vectors and pests attracted by rubbish, as well as drainage channels blocked with waste.
5. There are very large health burdens relating primarily to infectious and parasitic diseases, indoor air pollution and accidents. This includes large health burdens arising from unsafe working conditions for low income urban dwellers, with exposure to diseases, chemical pollutants and physical hazards in the workplace being a significant contributor to premature death, injury and illness – all of which have obvious economic consequences.
6. In many urban locations, there are also large and often growing health burdens from non-communicable diseases. For instance, cancer, diabetes and strokes are often creating ‘a double burden’ as low-income urban dwellers face the increasing incidence of both communicable and non-communicable diseases. Much more work is needed on understanding the health problems that impact on urban populations, especially low-income groups, and disaggregated by age, sex and occupation. This should include research on the relative roles of communicable and non-communicable diseases, as well as further investigations to identify which diseases are most significant.
7. Physical hazards evident in the home and its surroundings are likely to be among the most common causes of serious injury and premature death in informal settlements and other housing types used by low-income urban dwellers – for example, burns, scalds and accidental fires, cuts and injuries from falls. The risks from accidental fires are particularly acute in areas with high levels of overcrowding, housing made of flammable materials, and the widespread use of open fires, candles, kerosene lamps and dangerous stoves.
8. Road traffic accidents are among the most serious physical hazards in urban areas – although there are no data that separate rural from urban. The World Health Organization (WHO) reports that about 1.3 million people die each year as a result of road traffic crashes, with over 90% of these fatalities occuring in low- and middle-income countries – even though these have less than half of the world’s vehicles. Children and young people under the age of 25 years account for over 30% of those killed and injured.
9. There are also many cities and smaller urban centres, or particular settlements within cities, where levels of outdoor air pollution considerably exceed WHO guidelines – for example, certain centres of heavy industry, mining or quarrying, or cities with high concentrations of motor vehicles with elevated levels of polluting emissions. But there is little or no data on the pollutants that can have the most serious health consequences for cities in sub-Saharan Africa.
10. But there are also the urban centres where conditions are even worse than the generalizations noted above. Hundreds of millions of people live in urban areas where, at least in terms of public and environmental health, there is in effect no functioning government – no public provision for piped water, sewers (or other excreta disposal systems that meet health standards), drains and solid waste collection, no land-use management to encourage and support good quality housing, no pollution control. Furthermore, there is often little or no available education or health care for large sections of the urban population. There are in fact thousands of small urban centres across the region for which there is almost no documentation.
11. In the absence of data available in each city or smaller urban centres to ascertain the most serious environmental health problems and who is most at risk, it is obviously difficult to set priorities – both for action and for research. When this is combined with research and action agendas strongly influenced by external funding and the preferences of external professionals, it can lead to inappropriate choices.
12. It is important to consider the impact of disasters on urban populations in the region and who is most likely to be impacted. There is also a need to consider how climate change has already affected, or will affect in the near future, the scale and range of extreme weather events and other changes that impact on urban populations and economies. The consequences, which will be felt hardest by low-income groups and could have the effect of puhing many others into poverty as well, have been greatly under-estimated. In part, this is because most disasters go unrecorded in national and international disaster databases. Another factor is that the metrics used to assess disaster impacts do not include many of those most relevant to low-income groups – for instance, damage to housing, injury, disrupted livelihoods and loss of assets.
Thus, we are confronted with very significant gaps in data to allow comparison and discussion across Urban ARK’s focus cities, each of which presents different development and hazard contexts: Ibadan in Nigeria, Karonga in Malawi, Mombasa and Nairobi in Kenya, Niamey in Niger, and Dakar in Senegal. Moreover, the core generalisations noted above provide important entry points for the Urban ARK programme, emphasising the need for more detailed and nuanced understandings of urban risk in sub-Saharan Africa and the ways these risks are evolving in the context of persistent poverty, urban growth and climate change.