Abstract
Trends in Urbanization and Land Cover Changes
Over 56% of the world’s population now lives in cities, and the world is still urbanizing fast especially in Africa and Asia, with the urban population expected to reach 60% by 2030 (United Nations, 2019). Urbanization is widely seen as a main innovative and transformative driving force for economic development, social progress and political and societal change (UN-Habitat, 2020). Most cities included in the UK Research and Innovation supported Global Challenge Research Fund (GCRF) project on Sustainable, Healthy and Learning Cities and Neighbourhoods (SHLC) have experienced continuous and large-scale economic development, population growth, land use changes and sprawl since the turn of the century. In this process, larger cities and national capitals received more migrants and experienced faster economic transformation. Delhi, for example, saw its population increased by 3.4 million to 16.3 million between 2001 and 2011, a 2.4% increase per annum; the city experienced an even faster annual population growth of 4.2% in the previous decade. 1 A similar growth trend was found in other cities. Population in Cape Town increased from 2.6 million in 1996 to an estimated 4 million in 2016, although the annual growth rate has fallen from 3.3% between 2000 and 2010 to 1.5% since 2010. In Johannesburg, the population growth has remained high since 1996, ranging between 2.6% and 3.2% per annum in recent years, with the total population now at 5 million. Dar es Salaam, a city with approximately 10% of the Tanzanian population, saw an increase from 4.4 million residents in 2012 to a current estimate of 6 million.
Unplanned urban sprawl was once associated mainly with the boom years of development in land-rich developed countries such as the USA, Canada and Australia, but it is now occurring in cities all over the developing world. In Africa and Asia, urban population growth has consumed large areas of land around major cities. Of the cities covered by SHLC project, suburban sprawl and fragmented land development and transformation have created new sub-centres and industrial districts, as well as ribbon development of residential areas along major roads. The city of Chongqing, for example, has transformed from a regional industrial centre in inland China to a large metropolitan area of national significance in a period of 20 years. Its built-up area has enlarged more than five times so that almost all the developable flat ground around the city has been built on. Delhi’s population growth also has been accompanied by urban sprawl; its built-up area expanded by 65% in the two decades preceding 2018. Kigali is another of our study cities that has seen a dramatic increase in its built-up area, from around 25 to 115 square kilometres in the last 30 years.
Migration and population growth have also led to infill development, intensifying land use in existing built-up areas and causing the loss of green spaces and water bodies within cities. The City of Manila, with its fixed boundaries and finite land resource, saw its population density increase to 71,000 inhabitants per square kilometre, with a residential population of 1.7 million in a land area of 25 square kilometres. During the daytime, its population density is even higher as more than 1 million people commute from surrounding districts into the city for work. In Dhaka, the population density increased from 14,000 per square kilometre in 1991, to 28,900 in 2011 and 31,800 in 2015. Currently, 40% of the residential areas in the city have a density of over 99,000 people per square kilometre. In Africa, urban population density is low in comparison with these Asian cities, but densification is rising. In Johannesburg, the density increased from 2,055 to 3,281 people per square kilometre between 2002 and 2017, and Kigali’s new master plan aims to bring its overall population density up to 5,198 persons per square kilometre.
Urban Expansion and Informal Development
In a previous World City Report, UN-Habitat argued that ‘the current urbanization model is unsustainable in many respects, puts many people at risk, creates unnecessary costs, negatively affects the environment, and is intrinsically unfair’ (UN-Habitat, 2016, p. iv). Fast urban expansion and sprawl indeed often results in more inequality, informality, insecurity and unsustainable forms of urban community. As the SHLC case cities show, alongside of new industrial developments, various types of neighbourhoods are emerging in peripheral areas of large cities, including commercially constructed housing estates of various standards, gated or semi-gated communities for the rich, tenement and high-rise apartments for the middle class and civil servants and state-supported low-income settlements. However, informal settlements such as urban villages, townships, relocation settlements as well as various slum settlements are growing at a much large scale than the various types of planned or semi-planned residential areas.
Despite the major efforts made in poverty reduction during first 15 years of the twenty-first century under the UN Millennium Development Goals (MDGs) programme, urban slums still house a significant proportion of population. The six SHLC countries for which data are available have all seen a decline in the slum population between 2000 and 2018, and some countries have made very significant progress (Table 1), a large proportion of urban population still lives in slums, and many new residential developments are informal and spontaneous. In Johannesburg, for example, by 2018, informal land use had grown to the equivalent of almost a third of the entire built-up area.
Urban Population Living in Slum Areas in SHLC Case Countries (% of population)
In all cities, most informal residential areas lack formal legal recognition; they are often disconnected from the infrastructural grids for drinking water, gas, electricity and sanitation. Public services, including basic services such as refuse collection and also healthcare and education, in these informal districts either do not exist or are very poor quality. In Manila, for example, in some low-income neighbourhoods, children can only attend school on a half time basis due to limited classroom space. Where there are services available, the private sector often plays a major role and the cost for residents tends to be high. These slums tend to locate at marginal places such as riverbanks, along railway lines, beaches, stripe land left over by industrial facilities, under bridges and other environmentally hazardous places. Slums and informal housing areas are always poorly connected by paved road and transport, further limiting their job and employment opportunities.
Challenges for Urban Planning
To realize the full potential of the urban transformative power and address the social and economic problems caused by urban sprawl and expansion, the international community has adopted several agreements to guide urban development, with the assumption that well-planned cities and urban extensions can curb excessive land consumption. The UN 2030 Agenda for Sustainable Development and the Sustainable Development Goals (SDGs) aim for an accelerated sustainable solution (United Nations, 2015). The related document The New Urban Agenda (NUA) provides a spatial framework intended to achieve better urban outcomes. The NUA aims, by readdressing the way cities and human settlements are planned, designed, financed, developed, governed and managed, to end poverty and hunger in all its forms and dimensions; reduce inequalities; promote sustained, inclusive and sustainable economic growth; achieve gender equality; improve human health and wellbeing; foster resilience; and protect the environment (United Nations, 2017). The World Cities Report 2020 makes the case that sustainable urbanization is essential to the global effort to ‘build back better’ from the impacts of the COVID-19 pandemic and get the world back on track to achieve the SDGs and meet the ambitious targets of the Paris Agreement on climate change (UN-Habitat, 2020).
These global policies and targets are very ambitious and maybe not very realistic. There are only 10 years left to achieve the SDGs, and the global COVID-19 pandemic has made the task even more challenging. SHLC fieldwork shows that there was no wide spread of practice of urban planning, especially at local and neighbourhood levels in African and Asian cities. Only in the two case study cities in China—Chongqing and Datong, due to their state ownership of urban land and strong public control of the development process—the effect of urban planning on the built environment was very clearly shown; most of new areas and neighbourhoods there, including large high-rise social housing and relocation estates, were planned and professionally constructed. The impact of planning in other cities tends to be more piecemeal and fragmented. The City of Kigali, for example, launched a new master plan in 2020 that allows more flexibility for residents to know what and where to invest their resources and to enhance social inclusion (Sabiiti, 2020). At the city level, planning practice tends to focus on infrastructure improvement in general and slum upgrading. At local level, professional planning of new residential areas was concentrated at sites of demonstration, such as the Vision City. In other areas, planning means very simple drawing of street patterns and the division of land into family blocks. Housing development often starts without proper infrastructure on the ground. Delhi’s urban planning brought a significant improvement of the urban infrastructure, such as the metro system; planning of the residential areas tends to focus on the rich quarter of the population.
Professional planned housing developments are marketed at a high price in all cities, often out of the reach of the low-income people and urban poor. SHLC fieldwork found that most new residential areas in African and Asian cities are mainly the result of a process of uncontrolled or minimally regulated concentration of low-rise family houses in the style familiar in rural areas, rather than large-scale construction of well-planned housing estates. It is the wealthy and upper-middle-income residents that benefit most from planned spaces and neighbourhoods, as they can afford homes that are built in a regulated way, meeting ‘planning’ standards of construction, layouts, scheme design, technical standards for building services, etc. Only these planned wealthy neighbourhoods were supported by modern infrastructure with good road network links, adequate local amenities and clear and running tap water, sanitation and electricity.
‘Planning’ of infrastructure fails to benefit the wider set of neighbourhoods in the city. In addition, good quality public services (schools and healthcare) for reasons of history, politics and demand are not evenly distributed spatially and, in fact, deliberately skewed towards areas where rich and middle-class people live. There is, therefore, a continuing disconnect between the standards that planners think they ought to set for urban development in line with international standards and the ability of both public authorities and residents to afford those standards. Therefore, UN Habitat’s repeated calls for better planning in pursuit of urban sustainability often gets little reaction beyond an expression of aspirations in formal plans that are seldom realized in practice.
The Need for Innovative Research
Two major processes of urban land use changes can be observed in Africa and Asia—fast expansion and sprawl in suburban areas and infill developments and increases in population and building densities in the existing built-up areas. Thanks to the geospatial technologies and remote sensing methodology, many researchers have carried out city-level analysis of land use changes in their cities (e.g., Patra et al., 2018; Rizk et al., 2015). The articles included in this issue provide some further examples of research in these areas and reveal the common trend and unique characteristics of these eight cities. To achieve sustainable urbanization and SDGs, apart from the practice of planning and the city-level analysis, we will need further innovative research to help us to understand the local land use changes and associated social and economic processes. The next stage of SHLC work focuses on the neighbourhood level analysis and examination of the spatial, social, economic and environmental inequalities in detail in relation to land use changes.
Footnotes
Acknowledgements
We would like to thank all SHLC partner teams and researchers for their excellent works over the last three years and their interesting research findings on which this short summary is based on.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
Funding
This paper and the whole SHLC project are funded by UKRI/ESRC’s Global Challenge Research Fund (GCRF). Grant Ref: ES/P011020/1.