Image: JRC GEM
How close do you live to a city of 50,000 or more? How long does it take you to reach the "wilderness"? A fascinating map created for the World Bank World Development Report 2009 explores the question of accessibility of markets, hospitals, schools or water to populations across the world. In attempting to more consistently define "urbanization", the map leads to several amazing conclusions.10% Wilderness
Only 10% of the earth's land is "remote": defined as more than 48 hours travel from a large city. The developers of the accessibility map gathered data on roads, rivers, rails and land cover classes to estimate travel speeds. Land travel speeds used by the team range from 2 minutes per kilometer (0.6 mile) on artificial surfaces to 60 minutes per kilometer in densely forested environments. This shocking statistic demonstrates the challenges facing conservation efforts.
Conversely, over 95% of the world's population lives on only 10% of the land. It is the apparent contradiction between these two statistics which reveals a key underlying factor in this new mapping technique: the speed and efficiency of expanding global travel networks means that no one is far from anywhere anymore.
The Agglomeration Index
The European Joint Research Center used a newly developed measure of urban concentration called the Agglomeration Index to create the global map of accessibility. Hirotsugu Uchida, of the University of Rhode Island, and Andrew Nelson, of the European Joint Research Center's Global Environmental Monitoring unit, developed the Agglomeration Index to provide a consistent method for analyzing urbanization. The current system used by the World Bank, which relies of self-reported data, suffers from different cultural understandings of the concept of "urban".
You can download a poster-sized version of the global map of accessibility from the JRC Global Environmental Monitoring website.
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