Lessons from the World’s Largest Megacity​

How to confront the challenges facing China’s ​Pearl River Delta

A view above Shenzhen, China. Photo © Zhu Difeng

The United Nations has named October 31st as World Cities Day, with the goal to promote international cooperation to meet the challenges of 21st-century urbanization. This initiative is founded on the idea that cities around the world are facing similar issues, and have much to learn from each other.

In the spirit of international exchange, Peter Kindel, director of SOM’s City Design Practice in Asia, considers the state of the world’s densest urban area: the Pearl River Delta. This emerging megacity in southern China is a phenomenon without precedent — but one that holds important lessons for the future of our rapidly urbanizing world.


If a product says “Made in China,” chances are that product, or parts of it, came from the Pearl River Delta. This region in southern China is the world’s largest megacity: eight major urbanized zones with a combined population of 55 million people, spread in a horseshoe-shaped ring around a complex watershed ecosystem. Hong Kong, Shenzhen, and Guangzhou dominate the region, which, incorporating five other emerging cities, has experienced explosive growth over the past 30 years. By studying the Pearl River Delta, we can better understand the challenges ahead as the world’s population becomes increasingly dense and urbanized.

Eight major urbanized zones in the Pearl River Delta comprise the world’s largest megacity. Image © SOM

The region has risen on the back of China’s meteoric manufacturing sector, which produces many of the household and retail commodities sold throughout the world. The reasons for this manufacturing surge are manifest: the availability of funding through Hong Kong’s extensive financial sector; one of the cheapest and largest labor pools globally; and one of the best seaports in the world. On top of this is the positioning of Shenzhen as a special economic zone, established by Deng Xiaoping in the early 1980s, where companies face few, if any, regulatory hurdles to growth.

In the Pearl River Delta, we can see, writ large, the issues that many urban areas across the globe are currently — or will soon be — facing.

For most people, issues related to Chinese manufacturing and urbanization barely percolate into the subconscious. But, for the 200 million people in southern China and northern Southeast Asia, the Pearl River Delta’s urban conditions dominate many aspects of daily life. Moreover, the issues that the Delta is grappling with today are the same issues many cities are tackling: mobility, densification, land use, and quality of life. Complementary to these are significant environmental issues, such as poor water quality, land subsidence, habitat loss, diminishing food sources, and resiliency against sea level rise. In the Pearl River Delta, we can see, writ large, the issues that many urban areas across the globe are currently — or will soon be — facing.

Several distinct ecosystems make up the Pearl River Delta’s complex watershed. Image © SOM

Earlier this month, architects, urban planners, and developers convened in the Pearl River Delta for the global meeting of the Council on Tall Buildings and Urban Habitat. While this group is most well known as the official arbiter of building heights, the conference attracts designers and professionals concerned with urbanization generally. The Delta is an appropriate venue for the event — by 2020, the PRD will have three of the world’s 20 tallest buildings, more than any other metropolitan area. So, while skyscrapers were a main topic of the conference, a parallel line of inquiry considered the urbanization of global cities — an apt subject for this rapidly urbanizing region.

A team of urban designers and architects from SOM’s City Design Practice recently undertook a comprehensive analysis of the Delta’s urban patterns and the environmental challenges it faces. We concluded that Pearl River Delta governments must coordinate and pursue two regional initiatives. The first of these is a commitment to creating greater density in existing cities, which is crucial for reducing the continued loss of sensitive estuary wetlands. The second initiative is a parallel commitment to environmental restoration. Each effort requires a different focus and set of tools, but they are complementary and should be advanced together.

SOM’s master plan to transform a formerly industrial district in Guangzhou combines land use, transportation, and environmental strategies. Image © SOM

Creating greater density in existing urbanized areas involves a series of strategies, including the continued expansion of regional rail and subway lines to form a comprehensive transit network. This, in turn, will allow for greater density around transit stations without adding road infrastructure, creating vibrant, walkable, and mixed-use neighborhoods, rather than car-dependent ghost towns. The knock-on effects of transit investment are considerable: they create more variety in housing types and allow multi-generational families to stay connected. The Pearl River Delta must continue to pursue this strategy while limiting sprawl in sensitive ecological areas.

In tandem with urbanization strategies, the Delta region must forcefully and comprehensively confront environmental issues. It is currently estimated that 35 percent of the Delta’s waterways have China’s lowest possible rating for water quality; essentially, one in three streams is unfit for human contact. This pollution is not only a serious threat to human health, but also affects both fish populations and aquatic plants, which are critical to feeding the region’s population. SOM recommends that the Pearl River Delta adopt a comprehensive regional watershed management plan, similar to those created in the Netherlands, in Louisiana’s Gulf Coast, and in the San Francisco Bay.

The threat of sea level rise has dramatic potential consequences for the highly urbanized region. Image © SOM

At this pivotal moment in the Pearl River Delta’s transformation, the decisions that are made today will have a crucial impact for future generations. The regional government should undertake a comprehensive environmental plan in the next two years to develop a long-term framework for sustainable development. It is only through such an effort that these issues can be addressed. If the world’s largest megalopolis can move in a visionary and coordinated manner, the Pearl River Delta can demonstrate that economic prosperity, livable cities, and environmental leadership can successfully coexist.

View of Shenzhen, China. Photo © Sean Pavone