ARCHEOLOGIA NUOVA

DA: "theguardian.com"

(DAL SITO: CIVILTA' MEGALITICHE)

QUESTO E' IL LINK PER VEDERE LE IMMAGINI:

The rise and fall of great world cities: 5,700 years of urbanisation – mapped | Cities | The Guardian

Cities

The riseand fall of great world cities: 5,700 years of urbanisation – mapped

Recentresearch provides a better understanding of urban populations throughouthistory, digitising almost 6,000 years of data for the first time

Watch as the world’s cities appearover 6,000 years

Cities is supported by

Rockefeller Foundation

Kanishk Tharoor

Urbanisation is one of the definingprocesses of modern times, with more than half of the world’s population nowliving in cities, and new mega-metropolises mushrooming in Asia, Latin Americaand Africa. But a comprehensive, digitiseddatabase of city populations through world history has been lacking, with theUnited Nations’ dataset only extending as far back as 1950.

That wasuntil recent research, published in the journal Scientific Data, transcribed and geocoded nearly6,000 years of data (from 3700BC to AD2000). The report produced a gargantuanresource for scholars hoping to better understand how and why cities rise andfall – and allowed blogger Max Galka to produce a striking visualisation on hissite Metrocosm.

“Ingeneral, it helps us see human interaction with the environment,” says leadauthor Meredith Reba of the Yale School of Forestry and Environmental Sciences.“It helps us to understand why settlements grew at the times they did.”

Miningtabular data from two tomes only available in print (the works of historianTertius Chandler and political scientist George Modelski), Reba and her teammapped how city populations developed around the world over the millennia.The resulting dataset – available for free online –bills itself as “a first step towards understanding the geographic distributionof urban populations throughout history and around the world”.

TheSumerian city of Eridu marks the dawn of urbanisation in 3700BC, which tricklesaround Mesopotamia, Iran, India and China before eventually coming west to theMediterranean. Mapping the data makes certain trends and patterns quite clear.For instance, it’s notable that the earliest cities from China to Mesoamericacan all be found in a similar latitudinal belt, suggesting a possible linkbetween early phases of urbanisation and climate.

As late as1800, only 3% of the world’s population lived in cities

Many moreurban centres sprang up around the world thereafter but, as late as 1800, only3% of the world’s population lived in cities. Global urbanisation acceleratedfrom the middle of the 19th century onwards. This precipitous rise is palpablein Galka’s visualisation of the data (and in this one by Quartz), with a burst of cities clottingthe map around 1875 and then again during the 20th century.

The lastentries in the database date to 2000AD; if updated to the present day, thedatabase would include the stratospheric 21st-century growth in urban populationsin Asia. Reba admits that the data “is not final in any sense. Our aim was topull together a richer, global urban population database, and to get this datainto a usable format so it can be tested and improved.”

Though thereport offers no theories of its own, Reba and her team hope that the resultsof their work will help researchers better explore a range of subjects thathave long troubled scholars of urbanisation. Reba’s initial motivation for thestudy was her frustration at the lack of data relating to her own field ofinterest – the relationship between the growth of cities and their proximity toagricultural land. But combined with other data and lines of inquiry, thedatabase can be used to trace deeper ecological and climatic trends, as well asto study the effect of transport, trade routes, and shifting politicalboundaries on urban growth.