Maps show how cities spread across the world in 6,000 years

Maps show how cities spread across the world in 6,000 years


Mapping the history of urbanizationHalf of humanity lives in cities today. By 2030, this figure will go up to 60%, as per UN estimates. In 1960, only 34% of the world lived in cities.

Have you ever wondered how our cities spread and why? What were the world’s first cities? How many people lived in these cities? Which are the cities that disappeared with time and which ones survived? How did cities influence their local and regional environments?

Mapping the history of urbanization

Tracking history of cities and their population was a challenging task till recently since the most comprehensive collection of urban population data available — U.N. World Urbanization Prospects – goes back till 1950.  Now in an outstanding visualization created for his website Metrocosm, blogger Max Galka traces the origin and history of cities from 3700 BC onwards using the data from a new study called Spatializing 6,000 years of global urbanization from 3700 BC to AD 2000 by a team of Yale researchers.

Galka took the population data from Yale research and puts it on top on of a NASA Blue Marble basemap and built it using D3, using the Canvas implementation described here on Bocoup.

The Yale research

The research team from Yale developed the first spatially explicit dataset of urban settlements from 3700 BC to AD 2000, by digitizing, transcribing, and geocoding historical, archaeological, and census-based urban population data previously published in tabular form by Chandler and Modelski. A reliability ranking for each geocoded location was created so as the geographic uncertainty of each data point could be assessed. The dataset can contribute to an improved understanding of contemporary and historical urbanization trends.

The research team used two principal sources: Tertius Chandler’s Four Thousand Years of Urban Growth: A Historical Census, and George Modelski’s World Cities: -3,000 to 2,000. The dataset that they presented is a spatial rendering of Chandler’s and Modelski’s original datasets.

Thus the study creates opportunities to view the global urban history over a much longer time frame, beginning with the first urban civilization — the Sumer — in the southern-most part of ancient Mesopotamia (now Iraq).

Mapping the history of urbanization
Beginning of the Sumer civilization

For the first few thousand years after the establishment of sprawling agricultural populations around the Nile, cities remained roughly in the same latitudinal area as Mesopotamia. Slowly, urban settlements begun to spread further east towards India and China.

Mapping the history of urbanization
In the early years, cities remained roughly in the same latitudinal area as Mesopotamia

But it was only in the 19th century that urbanization became a truly global phenomenon.

Mapping the history of urbanization
Urbanization a global phenomenon

Another interesting visualization that gives a peep into how urbanization spread is the World Population History Map by the Population Connection.