The Ghost Cities of China

China has built dozens of "Ghost Cities" - not necessarily entire cities but new housing areas that far exceed demand and are therefore mostly empty. The poorly regulated climate of the country has contributed to fast growth in construction projects and made it difficult to get a good accounting of where all of these projects are located. Baidu, China's most popular search engine, used an algorithm to locate these places by comparing location data from mobile devices to housing units. Places with a high density of housing, but low mobile use are assumed to be areas of vacant housing. The map below shows 20 of the top 50 cities for vacancy rates. They do not show all cities or rank them for fear of having a negative impact on real estate sales.

The Baidu study used Baidu Maps, their mapping platform to determine density by using points of interest. The study is imperfect for many reasons, for example mobile use as a proxy for activity excludes people that do not use these devices. The study also factors in tourist areas as places that are empty during certain times of the year.

The study found that most of these "ghost" cities are "second or third tier" cities-tiers are determined by income, education, technology and other factors. They are also mostly clustered in the east and especially the northeast. Inner Mongolia is also well represented. These findings agree with a map compiled the South China Morning Post.

This map shows a "demolition index" based on future supply versus future demand for housing. The redder end of the spectrum are cities that are most likely to become ghost cities.  The results can be viewed interactively here. From the article:

"From the map, the 'ghost towns' are clustered in northeast China, where local economies rely heavily on natural resources, heavy industries and farming, and are not diversified enough to offer a variety of jobs."

Though some of these places and beginning to get inhabited, Business Insider recently used Digital Globe to showcase how empty many of these places still are. Here are a couple of examples.

Erenhot, Inner Mongolia - Large mansions along empty, sand blown streets.

Dongsheng, also in Inner Mongolia

More voyeuristic pictures can be seen at Business Insider

The World's Megacities

The Economist has a bubbly interactive map/video of the world's megacities (those with a population of 10 million or more) from 1950 to 2030. According to these population figures, from the United Nations, nearly 9% of the world's population will be living in 41 megacities by 2030. The video is a bit slow because it cycles through every year for the 80 year time period. Here are some stills from now, then and the future.

Megacities are shown as red proportional circles. In 1950 (above) there were only two megacities, New York and Tokyo. Today (2015) there are numerous megacities, mostly in Asia. 

By 2030 the most noticeable growth of cities will be in Africa.

The UN data are usually for metropolitan areas, including suburbs, but some of the populations are listed for the "city proper." These inconsistent figures provide good ammunition for the complain-y comments at the bottom of the page. 

You can search a city or click on one for a graph showing that city's population curve.The vertical line indicates the chosen year, in this case 2014.

Beware of the constantly changing y-axis when comparing cities.

You can also click the legend at the top to turn on or off size categories of cities. So if you want to only see the megacities of 2015, you get this.

The UN has its own version of these maps. They're not as flashy but they shade the countries by percentage of urban population which is a nice touch.

The smaller circle sizes create less drama but the map still effectively tells the same story.

Musician Inspired by Population Map

Vienna Teng's new album Aims features this map on the cover. It shows population migration within the Detroit metropolitan area.

The map is from Stephen Von Worley's Data Pointed blog. I'm not sure why the colors look so washed out in Teng's cover. The original is much more "pretty"

The inspiration comes from digging beyond the typical narrative of population flight from the inner cities (red is population loss) to see that there hope in the small patch of blue located near downtown. This is not really a new story, people have been moving into downtown areas for several decades now. Still, it's a good reminder that our cities still have much to offer as places to live. There are lots of other striking images of various US metropolitan areas to see on Von Worley's blog post, most of them showing a similar pattern.

Moving Migration Patterns

Since 1993 Atlas Van Lines has been mapping migration patterns in the United States and Canada based on interstate moves. Here is a map of their results for 2012. Blue states and provinces have a 55% or higher net gain (of household goods) while the orange-ish color represents states that are losing goods. The assumption is that people are following their stuff. The reddish brown places are "balanced."

You can click on any state or province to see its ten year history. I like that Yukon Territory has a special inset map even though nobody moved in or out of there (though if you click it there has been some activity there in the past.)

If you scroll down the page you will see some summary text and you can also open up this infographic for more details.

1940s New York

The 1940 U.S. Census records were recently released by the National Archives. With a little work you can find any street (that existed in 1940) and see the census forms. They tell you the names, ages, occupations, salaries and state or country of birth for all residents. I was able to locate my mother and her family in South Philly. My father grew up in the Bronx and though I couldn't find him (his parents briefly lived in New Rochelle, NY), I was able to track down other members of the family at the apartment we used to visit in my youth.
The Center for Urban Research at the City University of New York (CUNY) has placed a 1943 market analysis of New York City online to give context to these census records. The page, Welcome to 1940's New York, has interactive maps and profiles for each neighborhood in the city.

Above is Highbridge, my father's neighborhood in the Bronx. The colors give an indication of wealth (based on rent and other expenditures) with the blues and greens at the low end and the oranges and reds at the high end. My dad's block is green, at the lower end of the spectrum.

The descriptions are also worth a read. "Highbridge is a heavily populated and good residential district." The "new and better buildings" are along the Grand Concourse, and the retail outlets "while small, are of a good class...." It makes me wonder how they would describe the African Movies Mall.

In the case of neighborhoods with a greater diversity of wealth, such as Greenwich Village, they added purple and yellow to the top of the wealth chart.

The description of Greenwich Village as "not a neighborhood of artists and writers" where "remodeling has changed many of the bohemian haunts" and it's popularity among "business couples" makes for an interesting early take on gentrification.

The interactive map overlays the demographic profile for every neighborhood, giving an overall impression of the geographic patterns of wealth and poverty, much of that unchanged today.

American Migration

Forbes has a very nice interactive map showing migration within the USA. Click on any county and you can see where people are coming from (in blue) and where they are leaving for (in red.) Hover over a county to get the specific numbers. Clicking the year under the bar chart will give you the figures from that year.

Data is from the IRS and a more detailed description can be found here. You can see the effects of the housing bubble when comparing 2005 to 2009 in certain cities, especially Las Vegas which went from mostly blue to an almost even split. The per capita income figures are also shown for each county. This shows that many cities and other areas are exporting wealth and importing poverty. Click the map above and explore.

Map of the Week Miscellany for September, 2011

There's a lot going on this week and if I only didn't have to work I could devote more time to these posts and make them more meaningful but be careful what you wish for. Anyway here are a few interesting items I've found this week:

An Army Corps of Engineers map of the flood control structures in Wilkes Barre, Pennsylvania.

 The manual this map appears in describes how the levees in Wilkes Barre and across the river in Kingston can form a bottleneck and make flooding worse for communities downstream. In 1972 these walls were too short to contain the flow from Tropical Storm Agnes and the city was flooded. The water stored from this flooding helped spare downstream places like Sunbury. Since then the levees have been raised, partially sparing Wilkes Barre from this weekend's floods (though water did get in by seeping under the levees.)

This sent more water to downstream places like Bloomsburg, where record setting flooding occurred.


Below is a map from the AP showing the some of the worst hit places.

Daniel Huffman's wonderful river schematic map shows how these places interconnect.

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Other Miscellaneous Notes:
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Tomorrow night (September 15th) David Byrne will squish an inflatable globe under the High Line in New York City. It will be there until October 1st. To sort of quote one of his songs "this was a parking lot, now it's all covered in globe." More information is available from New York Magazine.

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From LA Taco ("Celebrating the taco lifestyle in Los Angeles") comes this chart showing the population growth of the largest cities in the USA. 

We're Number 5!

As children, we knew our city was the fourth largest and that it would always be that way. Then in 1990 something awful happened-Houston moved ahead of us. Still, we could take solace in the fact that our metropolitan area was number 4 and Houston only got ahead by swallowing up a bunch of suburbs. Now that the Census 2010 verdict is in we are number 5 on all counts and just barely hanging on. These maps from the Philadelphia Inquirer illustrate our angst.

 Dallas? Are they counting by number of parking spaces?

Using county based metropolitan areas creates some size anomalies and makes the maps look a bit goofy. Riverside? Why do they even get their own metropolitan area? It looks like they're including San Bernardino county also, making for one huge skyscraper that is mostly desert.

The north facing perspective also means losing San Francisco and Baltimore behind their larger "neighbors" but if you flipped it around you'd lose San Diego so something had to give. Of course all of this seems pretty insignificant when compared with the largest cities in the world. A little perspective goes a long way.

Map of the Week-US Population Change

It's that time again when redistricting claims much of my time at work. I don't work directly with the overall US population figures, but I've been exposed to lots of ugly, poorly designed maps showing population change across the country. This map from Brookings Institute Demographer William H. Frey is one of the better ones though it's not clear if he's using the final 2010 Census figures or one of the estimates.

The resulting patterns are fairly predictable and consistent with previous decades. The ring around Minneapolis nicely exemplifies the exurban migration that may finally be starting to ebb a bit. The continuing growth of areas with the poorest access to fresh water is not really news but shows up clearly.

What is interesting is how many counties are losing population. The population loss in the Great Plains is old news but the huge number of counties in the less than 10% loss category is surprising. Unfortunately the pattern is lost a bit by the dull color choice for that category.

Map of the Week-Election Cartograms

You may have heard that the US Presidential Election just is around the corner. The best way to see the true distribution of electoral votes is to use a cartogram. A cartogram is a map showing areas sized by some factor other than area (in most cases population). Cartograms are usually pretty ugly things.


They can be one-legged spiny monsters;








or they can be acid trippy lava lamps.








That's why when I'm shopping for a cartogram, I usually go with the more subdued kind that you get from a serious sedate publication like the New York Times. By the way - if these colors don't look right to you, change them! Many of these sites let you change the states to whatever color and pattern makes you happy.

Map of the Week-What is and How is Cascadia?

Attention residents of Cascadia (outlined in green on the map on the right): Sightline, a Seattle based think tank has a slew of maps showing health, environmental and economic data for your region. There are some nice animations but they don't come over well on this page so here are some static maps. On the left is the Seattle area classified by walkability and on the right is a map with pie charts showing the decline of Salmon stock in the region. For lots of other interesting maps of the region, visit their maps page.

MOTW #48

There's been lots of ballyhoo about the US Population
having reached 300 million this past week. Here is a pretty cool
interactive map from MSNBC's web site. There's a timeline on the
bottom so you can see population change through history and lots of info
when you scroll around the states. I had trouble with this in Internet
Exploder but it worked great in the Netscape/Firefox world. Happy
mapping!