In these charts, the x-axis is time, and the y-axis is height. The more movement there is on the x-axis, the more the city grew horizontally-- i.e. sprawl--while the y-axis shows vertical growth--i.e. tower construction.

Most Indian cities sprawled but stayed squat.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

While Chinese cities grew both outward and upward at incredible rates.

2013-06-03

The Insane Growth Of China's And India's Megacities Mapped Through Satellite Imagery

These charts—made with information from weather satellites scanning the ground—show how wide and how tall cities around the world have grown. What’s happening to the size of cities in Asia will blow your mind.

Faced with the incomprehensible scale of worldwide mega-urbanization, observers have alternately fallen back on sheer numbers or city comparisons to drive home the speed at which cities in the developing world are growing. For example, New York University’s Shlomo "Solly" Angel projects the world’s urban population will double in 40 years, while urban land cover—including everything from skyscrapers to slums—will triple in size during that span. Grasping to put such numbers into context, the McKinsey Global Institute estimates China will build the equivalent of New York every other year for 20 years, while India needs to add the equivalent of a Chicago to its building stock annually.

The mind reels, but such comparisons tell us little about the truth on the ground—is the urban future of India more likely to look like Chicago or Dharavi (Mumbai’s famous slum) or something else completely? A satellite designed to measure ocean winds offers us a clue.

University of New Hampshire Earth system scientist Steve Frolking, together with researchers at Yale and Boston University, recently published a paper plotting the growth trajectories of a hundred cities over a decade, combining satellite data on the spread of city lights with recordings from the SeaWinds scatterometer mounted on NASA’s QuikSCAT planet observation satellite, which operated from 1999 until 2009. Typically used to measure the effects of wind on the oceans’ surface, the sensor’s microwave transmitter also bounced signals off the cities in its 1,800 kilometer-wide orbital path.

Frolking broke each city down into a grid, plotting each cell as an arrow with its trajectory rendered over time: the head corresponds to 2009, the tail to 1999. In doing so, we can see how each section of the city, from the exurbs to the CBD, changed over the decade in question. The longer the arrows extend horizontally means that the part of the city has expanded outward. The longer they extend vertically shows that the city is expanding upward, building more towers. The results tell three distinct stories about humanity’s recent urban evolution.

The first is that Indian cities—joined by many in Africa and Latin America—have sprawled out rather than up. Whether Bangalore, Hyderabad, Delhi, Kolkata, or Pune, the fastest growth occurred at the cities’ edges, while the core remains low-slung.

At the opposite end of the spectrum, Frolking and company found that developed world capitals such as London, New York, and Tokyo added considerable mass and height to their skylines while growing slowly, if at all on the periphery.

And to no one’s surprise, China’s megacities did both. Not just Beijing and Shanghai, but also second-tier cities such as Shenzhen, Dongguan, Foshan, and Tianjin experienced patterns of growth that resemble no other nation on the planet—a point that paper co-author Karen Seto, who has studied Chinese urbanization for decades, drove home in her presentation at a "science of cities" confab at Arizona State University last month.

"I had never studied cities before, and what struck me was the fundamental difference in backscatter between China and India, where the population sizes are similar, but the pattern is totally different," says Frolking. Because the SeaWind went offline in 2009 when its antenna failed, more recent data isn’t available, but Frolking is hopeful that a new Indian satellite may yield higher-resolution results. "This is still a really blurry view of the planet."

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10 Comments

  • michelle

    Curious to see the data on Toronto as it is now the 4th largest city in the world surpassing Chicago.

  • Mahesh R

    Strange but the list of India's big cities include the much hyped Bangalore along with Hyderabad and Pune. No mention of Chennai which bigger than these, a manufacturing powerhouse, has a whopping real estate growth but still ignored.

  • marian barnes

    i hope the people in these cities will be civilized,educated and family values in these
    megacities stress the humanities,the arts instead of simply
    sprawling "urbania"

  • BobbyWong

    No surprise here, since the data echo China’s rapid
    development and the different phases of development over the decades. Average
    commercial lease hold was 20 year and residential lease hold was 40 decades ago.
    Now they are up to 70 years.

     

    The factories and apartments built next to each other in the
    80’s were meant to be obsolete and redeveloped when the time comes. Take
    Shenzhen, 10 years ago it was an intermix of factories and homes with the goal
    of quickly create manufacturing capacity. Today, Shenzhen is busy tearing down
    the 5 story walk up apartments and rezoning the city to new zoning standards,
    building factories in industrial parks with proper facilities and residential,
    business districts with world class high rise towers.