Monday, October 31, 2011

The Laws of Migration illustrated

Waldo Tobler presents a three-minute short talk about Ravenstein (the author behind (the Laws of Migration, 1885).

Friday, October 28, 2011

Multiple Choice Statistics Homework

Try this:

(via Nathan Yau via @gnat)

Soundtrack for this post: Tim M.

Thursday, October 27, 2011

Countdown to a World of 7 Billion

UNFPA has just published this year's State of World Population report. Yes! According to official estimateswe, we are about to reach 7 Billion People on earth. So I decided to replay this post:

And talking about the world population, every now and then someone comes up with the overpopulation issue. Usually it is referred to as the "overpopulation problem" or the "demographic bomb".

This is the promo motion graphic for the World Population Special Series brought by National Geographic (the article here and some pictures here). I couldn't agree more with these two conclusive excerpts:

"But one can also draw a different conclusion—that fixating on population numbers is not the best way to confront the future. People packed into slums need help, but the problem that needs solving is poverty and lack of infrastructure, not overpopulation. Giving every woman access to family planning services is a good idea—“the one strategy that can make the biggest difference to women’s lives,” Chandra calls it. But the most aggressive population control program imaginable will not save Bangladesh from sea level rise, Rwanda from another genocide, or all of us from our enormous environmental problems."

"The number of people does matter, of course. But how people consume resources matters a lot more. Some of us leave much bigger footprints than others. The central challenge for the future of people and the planet is how to raise more of us out of poverty—the slum dwellers in Delhi, the subsistence farmers in Rwanda—while reducing the impact each of us has on the planet."

Thursday, October 20, 2011

It's all about cities connections

Roads, railways, Airline routes, tranmission lines and submarine cables: In the end, it's all about cities connections!

Great work on mapping the Anthropocene by Felix Pharand-Deschenes and Globaïa Team. Thanks Romulo Krafta for the tip!

! Now this is comparable to the BBC series Britain From Above !

You may click here for more awesome images.

funny obs.: The number of Mcdonald's restaurants is considered as one "Anthropocene Indicator" !

obs. 2: You must be asking as I am : "Where did he get this data?!!"

obs. 3: Sorry Professors Erle Ellis and Navin Ramankutty...

Wednesday, October 19, 2011

Urban Picture

Just a short post today as I've been busy in the last few days...
Urban Picture of the Day'NY state of mind vs LA state of mind' [beautiful photo by jimmay bones]

Soundtrack for this post: Manamanah (1976) - petit gateau version here!

Tuesday, October 18, 2011

Community connections via mobile phone

What criteria one should use to define a region? How about 'community' connections via mobile phone ?

Check this out (via Nathan Yau).

Saturday, October 15, 2011

Thursday, October 13, 2011

Assorted Links on S. Syntax and Accessibility

    • Quote: "[Congested] road segments are only the appearance—they're not the problem" Yu Zheng 
    • Quote: "They found that when city planners added new connections between regions that algorithms had identified as flawed, conditions did indeed improve."

off-topic: Brasília From Above

This is not much compared to the BBC series Britain From Above.... but it's still Brasília !

(thanks Paulo Afonso Rheingantz for the tip)

Tuesday, October 11, 2011

Urban Primacy

Another post inspired by Phil McDermott, now with some charts on Urban Primacy.

Urban Primacy indicates to what extent economic development is concentrated in a few cities (population, economic activities, services, etc.). It's all about Christaller's Central Place Theory and Agglomeration Economies!

Phil McDermott saysExcessive primacy may increase economic volatility because the contrast between a rich centre and poor periphery is politically destabilising. One centre dominating financial, human, and intellectual resources may also increase national vulnerability to structural decline.“ One should also note that excessive primacy can also mean excessive concentration of opportunities and public services. And that's a classic starting point for the debate over balanced urban networks and polycentrism.

Number of Cities by Size Category (2010)
[image credit: via Cities Matter]

Population Share of Largest City, Ten Nations, 1990 and 2010
[image credit: via Cities Matter]

Share of national GDP and Population of selected cities
Source: World Bank, 2007

*** And here you have peculiar way to visualize urban hierarchy in Brazil.

Soundtrack for this post: Clapton

Monday, October 10, 2011

Demographic Dependency Ratio

New Geography have just published a piece by Emma Chen and Wendell Cox on the challenges posed by aging and declining fertility. Worth 5 minutes of your time.

UNDP global old age and child dependency ratios
[image credit: New Geography]

Sunday, October 9, 2011

Urban Growth Trajectories

Phil McDermott highlights some points from the report ‘State of the World's Cities 2010/2011‘ (UN-Habitat).

I have chosen to reproduce here two charts that I find most interesting.

Urbanization Pace (1950-2010)
[image credit: via Cities Matter]

Urbanization and poverty headcount, 1981-2005

Source: World Bank, 2007

  • I got surprised with Iran! and with  East Asia & Pacific!

  • Phil McDermott saysit is clear that the west is no longer the focus of urbanisation and is unlikely to hold many of the answers to today’s urban growth challenges”. I wouldn't be so sure about the `unlikely to hold many of the answers` part. Anyway, thank you Phil for the post.

Give us a “Like” on Facebook !

We have reached  so far !

Soundtrack for this post: Queen Bitch by Seu Jorge

Up Coming Events

Thanks M. Batty and R. Ojima for the tips.

soundtrack for this post: Gil.

Thursday, October 6, 2011

Replay: How expensive is your city (iPod) ?

A 'replay post' in honor to Steve Jobs (1955-2011):
[image credit: Uhull S.A.]

How expensive is your city (iPod) ?  

The most expensive and richest cities in the world measured by the iPod index ! "And what the Hell is that?" you might ask. It's something similar to the "Big Mac Index" (but stupid).

"The newly introduced iPod index measure how long an employee would have to work to be able to afford the Apple MP3 player." Here.

Tuesday, October 4, 2011

Global Rural-Urban Mapping Project

My demographer friend Joice Melo Vieira came up with another great tip !

Developed by the NASA Socioeconomic Data and Applications Center (SEDAC) operated by CIESINGRUMPv1 is actually a collection of three global data sets (All data sets are available for download):
  1. Population density and population count grids build on SEDAC’s Gridded Population of the World, Version 3 data set (GPWv3), which does not distinguish between urban and rural areas. GRUMPv1 identifies urban areas based in part on observations of lights at night collected by a series of Department of Defense meteorological satellites over several decades.

  2. A geo-referenced database of urban settlements with populations greater than 5,000 persons, which may be downloaded in both tabular and shapefile formats.

  3.  An urban-rural “mask” (urban extents grid,) which identifies those areas of the Earth’s land surface that appear to be urbanized based on a combination of night-time lights, and, where there are no lights, settlement points that are buffered according to population size.
     also includes four ancillary data sets: land/geographic unit area grids, national boundaries, national identifier grids, and coastlines. All grids are provided at a resolution of 30 arc-seconds (~1km), with population estimates normalized to the years 1990, 1995, and 2000. 

soundtrack for this post: Dog Days Are.

Monday, October 3, 2011

off-topic: Halo

A scene from last friday (09/30/2011). A solar halo at lunch time in Brasília. it is not 2012... dammit!
[Photo credit: Rafael Pereira]

New blog on Brazilian demographics

My friend Ricardo Ojima and some other researchers have just started a new demography blog focused on the Northeast Region of Brazil.

The Blog is called "Demografia do Nordeste". Long live to the blog!