Building up or spreading out? Urban growth across 478 cities

New paper by the Seto Lab in collaboration with Anjali Mahendra (who is also onTwitter).

Mahtta, R., Mahendra, A., & Seto, K. C. (2019). Building up or spreading out? Typologies of urban growth across 478 cities of 1 million+. Environmental Research Letters, 14(12), 124077.

Abstract

Urban form in both two- (2D) and three-dimensions (3D) has significant impacts on local and global environments. Here we developed the largest global dataset characterizing 2D and 3D urban growth for 478 cities with populations of one million or larger. Using remote sensing data from the SeaWinds scatterometer for 2001 and 2009, and the Global Human Settlement Layer for 2000 and 2014, we applied a cluster analysis and found five urban growth typologies: stabilized, outward, mature upward, budding outward, upward and outward. Budding outward is the dominant typology worldwide, per the largest total area. Cities characterized by upward and outward growth are few in number and concentrated primarily in China and South Korea, where there has been a large increase in high-rises during the study period. With the exception of East Asia, cities within a geographic region exhibit remarkably similar patterns of urban growth. Our results show that every city exhibits multiple urban growth typologies concurrently. Thus, while it is possible to describe a city by its dominant urban growth typology, a more accurate and comprehensive characterization would include some combination of the five typologies. The implications of the results for urban sustainability are multi-fold. First, the results suggest that there is considerable opportunity to shape future patterns of urbanization, given that most of the new urban growth is nascent and low magnitude outward expansion. Second, the clear geographic patterns and wide variations in the physical form of urban growth, within country and city, suggest that markets, national and subnational policies, including the absence of, can shape how cities grow. Third, the presence of different typologies within each city suggests the need for differentiated strategies for different parts of a single city. Finally, the new urban forms revealed in this analysis provide a first glimpse into the carbon lock-in of recently constructed energy-demanding infrastructure of urban settlements.

ps. The image below was taken from the WRI report that originated the paper.

An Agent-Based Simulation of the Urban Growth in Latin American cities

Barros, Joana (2012). Exploring urban dynamics in Latin American cities using an agent-based simulation approach. In Agent-based models of geographical systems (pp. 571-589). Springer Netherlands. [Ungated version here, and PhD Thesis here]

Abstract:

This paper focuses on a specific kind of urban growth that happens in Latin American cities, called 'Peripherisation'. This is characterised by the formation of low-income residential areas in the peripheral ring of the city and a perpetuation of a dynamic core-periphery spatial pattern. The dynamics of growth and change in Latin American cities are explored using agent-based simulation. The objective is to increase the understanding of urban spatial phenomena in Latin American cities, which is essential to providing a basis for future planning actions and policies. Simulation exercises were used to revisit assumptions about urbanisation issues in Latin American cities and investigate important aspects of growth and change in these cities. These exercises allowed the problem of urban growth in Latin American cities to be unfolded through their dynamics, relating these dynamics to urban morphology, and thus presenting a new and important perspective on the phenomenon.

Population distribution in European capitals

[image credit: Batista e Silva et al, 2013]

The map shows a fine-scale spatial population distribution in selected European capitals. The high resolution map is here, and it comes from this paper:



Batista e Silva, F., Gallego, J., Lavalle C. (2013). A high-resolution population grid map for Europe. Journal of Maps 9(1):16-28.

Abstract:

Population figures are usually collected by national statistical institutes at small enumeration units (e.g. census tracts or building units). However, still for many countries in Europe, data are distributed at coarser geographical units like municipalities. This level of resolution is insufficient for analysis in many fields. In addition, the heterogeneity of the size of the geographical units causes great distortions in analysis, i.e. the Modifiable Areal Unit Problem (MAUP). Dasymetric mapping techniques have long been applied world-wide to derive finer (and MAUP-free) depictions of the population distribution. These techniques disaggregate population figures reported at coarse source zones into a finer set of zones using ancillary geographical data. ... In this article, we test new geographical datasets to produce an updated and improved European population grid map. ... As final outcome of this cartographic exercise, a European population grid map for the reference year of 2006, with a spatial resolution of 100 × 100 meters, is presented and validated against reference data. Resident population reported at commune level, a refined version of CLC and information on the soil sealing degree are used as the main inputs to produce the final map.

Related Paper and data:

• Causes of Sprawl: A Portrait from Space , and the data!

Assorted links

1. Oscar Niemeyer and his buildings- Some of them are incredibly beautiful. Most of them are incredibly nonfunctional
   
   
2. After-tax income in different counties
   
   
3. Classic album covers in Google Street View – in pictures
   
   
4. Cesar A. Hidalgo explaning why we don't really have meritocracy (paper)
   
   
5. Foucault with a Full Head of Hair
   
   
6. Porn trends in the UK
   
   
7. What Does the World Eat for Breakfast?
   
   
8. Fat city: Questioning the relationship between urban sprawl and obesity
   
   
9. Mapping flows in ArcGIS, by Alasdair Rae

[image credit: Alasdair Rae]

Soundtrack: Jorge Ben

200 years of Urban Expansion

We have mentioned the Atlas of Urban Expansion here at Urban Demographics a while ago. It is an amazing project supported by the Lincoln Institute of Land Policy that gathers loads of data for a number of cities across the globe.

Using part of these data, Shlomo Angel and the team at NYU Stern Urbanization Project have recently started working on a new series of great animations showing the expansion of 30 global cities over the last 200 years. Here are the first five cases: São Paulo, Chicago, Paris, London and Los Angeles:

obs. It's a great work and I'm looking forward for the next videos. The only reservation I would make is that these animations can be a bit deceiving as they give the impression of concentric urban expansion. 

Related Links:

• Las Vegas Urbanization (1984-2009)
• Global forecasts of urban expansion
• Buenos Aires Urban Expansion
• Visualizing surface changes over time in every corner on Earth
• The Dynamics of Global Urban Expansion

The earliest sprawl?

Michael E. Smith writes a very interesting piece on How ancient cities can help us understand modern cities. And this paper caught my attention:

Ur, Jason A., P. Karsgaard and J. Oates (2007) Early Urban Development in the Near East. Science 317:1188 [ungated version]

Abstract: It has been thought that the first cities in the Near East were spatially extensive and grew outward from a core nucleated village while maintaining a more or less constant density in terms of persons or households per unit of area. The general applicability outside of the Near East of this southern Mesopotamian.derived model has been questioned recently, and variations from it are increasingly recognized. We can now demonstrate that such variation was present at the beginnings of urbanism in the Near East as well.

[image credit: Ur et al 2007 via Michael E. Smith]

Related Link [updated]: 

• New estudy by SFI - Cities – ancient and modern, big and small – follow same rules of development (ht João Vitor Meirelles)

Comparing Urban Footprints Around the World

Nice post by Matt Hartzell comparing the physical footprints of 54 cities around the world. It reminded me of this interesting study by A. Bertaud and S. Malpezzi on the same topic, and this note by Peter Gordon on Wealth and spatial order of cities.

[click on the image to enlarge it]

[Image Credit: Matt Hartzell's China Blog]

Urban Picture

Would you call this urban sprawl? (via Human Scale Cities, a great blog by the way).

Los Angeles

[Image Credit: ?]

Soundtrack:

Growth and change in metropolitan form

The City Form Lab (SUTD/MIT) has a research project on measuring urban expansion, particularly focused in East Asia. They have recently published the 'Progress report on urban form and land use measures'. After scanning the report, I'm definitely adding it to my reading list.

[Image Credit: SUTD City Form Lab]

Global forecasts of urban expansion

A cutting edge study by Karen C. Seto (Yale) and others on urban growth projections around the world and some of its environmental impacts (via  Urbanization Project). Read a briefing of the study here or here.

Abstract:

"[...] despite projections that world urban populations will increase to nearly 5 billion by 2030, little is known about future locations, magnitudes, and rates of urban expansion. Here we develop spatially explicit probabilistic forecasts of global urban land-cover change and explore the direct impacts on biodiversity hotspots and tropical carbon biomass. If current trends in population density continue and all areas with high probabilities of urban expansion undergo change, then by 2030, urban land cover will increase by 1.2 million km2, nearly tripling the global urban land area circa 2000."

[Image Credit: Yale]

Related Links:

• Las Vegas Urbanization (1976-2010) - more here
• Seto Urbanization and Global Change Group
• Atlas of Urban Expansion

The footprint of the world’s largest metros

A comparison of the built-up area of 129 'extended metros' that represent 35% of the world's urban population: Measuring the Human Urban Footprint (by LSE)

Take a look at the striking difference between Hong Kong and Atlanta. Pop density in Hong Kong is almost 24 times bigger than in Atlanta! Say it '24'.

Hong Kong (Pop.  7,069,378 - Density  25,933 pp/km²)

[Image Credit: LSE]

Atlanta (Pop. 7,506,267 - Density 1,090 pp/km²)

[Image Credit: LSE]

Assorted Links

1. National Geographic Traveler Photo Contest 2012
2. Luis Bettencourt on the Science of Cities
3. Suburban Sprawl and its Causal Effect on Basketball Skills
4. Declining Migration within the US (HT Leo) more here
5. Aerial Photos of U.S. Correctional Facilities
6. Beyond 7 Billion
7. The Price of faith
8. Which nations consume the most water?
9. A World Map of Heavy Metal Density

Metal Bands per 100,00 people

Las Vegas Urbanization (1976-2010)

Some of you might remember this post showing the urban expansion of Las Vegas (1984-2009).

Now, NASA decided to celebrate Landsat 5's 28th birthday publishing a time-lapse video showing the city's outward expansion. (via Mark Byrnes)

It makes me want to have my own satellite..... Don't you feel the same?

Quote of the day

"How do we know 'waste' when we see it? [...] When it comes to land use patterns, the acid test is is simply whether the urbanized area grows or not. Does it attract labor and capital in ways that they can make a go of it?" (Peter Gordon)

It seems to be the case of urban growth in Pittsburgh (increase in urban footprint with no increase in population. and Pittsburgh's economy is not that bad considering the USA context). But could it be more efficient and still make people’s lives better ? The sprawl debate still have a long way to go since it is not a straightforward issue.

In any case, we agree that "You want government policies that make people pay for the social cost of their action, including the environmental cost, but you also want people to make those choices themselves. ... People should be free to choose [where to live] as long as they pay the social cost of their action." (E. Glaeser)

(image credit Don Carter)

Soundtrack: ...looking for flying saucers in the sky

Assorted links on Urban Sprawl

• A Meta-Analysis of Global Urban Land Expansion (more on this paper here)
  
  
• "Wrestling Sprawl to the Ground" a great paper title. The paper is also pretty good!
  
  
• The Costs of Smart Growth Revisited: A 40 Year Perspective (great piece)
  
  
• Growth Rings - The flight of Americans to the suburbs

(image credit: Stephen von Worley)

• Do Freeway Traffic Management Strategies Exacerbate Urban Sprawl?
  
  
• Multidimensional Urban Sprawl in Europe: A Self-organizing Map Approach
  
  
• Is sprawl over? Nops!

soundtrack: subirodoistiozin

Atlas of Urban Expansion

If you are looking for data on urban sprawl around the world, you should check out the Atlas of Urban Expansion by the Lincoln Institute of Land Policy.

This is a sample of what you can do with their data (by Urban Change).

[image credit: Urban Change]

The death of distance and the rise of cities

Glaeser gave this lecture on November 13, 2008, at LSE. This event marked the launch of the Spatial Economics Research Centre.

He starts talking about this apparent paradox "The death of distance and the rise of cities" (audio only). In this lecture he tackles regional policy and declining cities, urban sprawl, urban environment and gas emissions, density, affordable housing and all other trending topics in urban studies you should be aware of.

Phoenix (suburbs) urbanzation 1989 - 2009

These images (taken by NASA) show the urbanzation of Chandler (the fastest-growing satellite city on the outskirts of Phoenix).

ps. 1-  According to NASA: ""Chandler grew from just 3,799 residents in 1950 to 176,581 residents in 2000, based on 10-year census figures." That's an average population growth rate of 8% per year (over a fifty-year period!!!)

ps. 2 - Would you call it 'urban sprawl' ?

[Image credit: NASA Earth Observatory image created by Jesse Allen, using Landsat data provided by the United States Geological Survey. Caption by Michon Scott]

MORE posts on the Urban Evolution of Vegas, São Paulo and  Dubai.

Assorted links

• Glaeser on how housing policies (local land use regulation) might be driving US internal migration. Here and Here.
  
  
• Christoph Gielen and his aerial perspective of the US Urban Sprawl (here and here) via Infrastructurist.
  
  
• US Census Data Show Immigrants Making Path to Suburbs (NYTimes)
  
  
• Worst and best commutes in the US here and here.
  
  
• and the enthusiastic Hans Rosling on global population growth (the message is 'Wolrd Balance' again).

[photo by Christoph Gielen]

[photo by Christoph Gielen]

[photo by Christoph Gielen]

The rise and fall of Urban Sociology (?)

Google has scanned 15 million books originally published from 1800 on. And they have also developed the Google Books Ngram Viewer. It's a tool that charts the usage of any word over time in literature and other books (Google books database). One could irresponsibly use it as a proxy for the popularity of words in literature. And I did!

This chart above shows how often "Urban Sociology" has appeared in the literature (Google database - english literature only) since 1800. It looks to me that the Chicago School have had played an important role in the rising 'popularity' of Urban Sociology*. And it looks that Urban Sociology is not as 'popular' as it used to be....

*obviously, it would be necessary to scrutinize other keywords to conclude this (such as the major researchers in the first Chicago School)

And here are some queries of other keywords of interest:

• Aging Population; Demographic Transition; Demography related words; urban mobility, housing bubble, 'Great Cities' as urban hierarchy (?), Space Syntax, GIS, urban, regional and environmental studies, urban and rural, etc.

And my favorites:

Traffic Jam:

Urban sprawl, compact city, smart city, smart growth, compact growth, New Urbanism.

Thanks Vinicius Netto for the tip!