Indian, global megacities growing at unprecedented rate: UK study
The researchers at universities of Birmingham and Sheffield say rapid and large-scale urban growth can cause major problems – as recognised in the UN’s New Urban Agenda – in areas such as housing, infrastructure, basic services, food security, health and education.Updated: Jan 26, 2020 20:27 IST
The world’s biggest cities are growing at an unprecedented rate – particularly in India and the global South – with 11 of the planet’s 30 biggest cities each adding more than 10 million citizens over the last four decades, according to a new study.
The researchers at universities of Birmingham and Sheffield say rapid and large-scale urban growth can cause major problems – as recognised in the UN’s New Urban Agenda – in areas such as housing, infrastructure, basic services, food security, health and education.
The study published in journal ‘Town Planning Review’ uses ‘big data’ techniques to analyse Global Human Settlement Layer (GHSL) data to focus on population growth and density in 30 major urban areas around the world since 1975, including Delhi, Kolkata, Mumbai and Chennai.
In 2014, the 30 ‘megacities’ – urban agglomerations with a population of more than 10 million - analysed contained a total of more than 558 million people or 8.2 per cent of the world’s population.
In 1975, however, they contained less than half this total at 261 million or 6.4 per cent of the then global population.
The analysis shows that Tokyo was the most populous city in 1975 with 23 million people, followed by Kolkata at 17 million. By 2014, there were 12 megacities of 20 million or more, the most populous being Guangzhou–Shenzhen, in China, with over 46 million people.
Guangzhou–Shenzhen added over 10 million people from 1975 to 1990 and again from 2000 to 2014, while Jakarta added over 10 million people between 2000 and 2014, while Dhaka, Manila and Shanghai all more than trebled in size between 1975 and 1990, with Bengaluru and Beijing quadrupling their populations.
Dhaka had a maximum population density of 200,000 people per km2 whilst Cairo, Kolkata, Guangzhou–Shenzhen, Manila and Shanghai had maximum population densities of 200,000 people per km2.
Report author Charlotte Hoole based in the University of Birmingham says: “There are some particularly striking findings that demonstrate a rate of urbanisation which is often seen as neither sustainable nor desirable, yet it is the lived reality for residents and policy makers in many large cities across the global South”.
“Whilst high population density in itself is not necessarily problematic – the affluent urban centres of Seoul, Hong Kong and Tokyo are good examples of high-density megacity living – it requires infrastructure, long-term planning and significant capital investment; none of which are available to the required level in cities such as Kolkata.”