This web may not look much like a map at first glance, but it is. Instead of mapping physical geography, though, this map charts where in the world people are moving to and from, to give us a snapshot look at the worldwide migration patterns over 20 years.
Top image: A working map of migration by country tweeted by the Wittgenstein Centre for Demography and Global Human Capital.
The map was created as part of paper published this week in Science by researchers from the Wittgenstein Centre for Demography and Global Human Capital. Researchers used data published by the UN collected through a mixture of surveys and census. Then, they ran that data through software intended for use in creating genetics visualizations. The result was this map:
Curiously, although the number of migrants changed throughout the years, researchers found that the percentage of migration worldwide has remained relatively constant since 1990 (the period researchers began looking at the data) at around 0.6% of the world's total population.
The low point, between 1995-2000, researchers say, can be accounted for by world conflicts, including those in Rwanda and Afghanistan. Post-1995, however, the percentage stabilized. Besides the stability of the overall percentage of the world's population that was moving from one place to another, researchers were able to identify three other major trends in their data:
1) Migrants from sub-Saharan Africa primarily migrated to other countries in Africa.
2) Migrants from South Asia and Southeast Asia were mostly migrating to Western Asia or Northern America, while migrants from Latin America were moving to Northern America or Southern Europe.
3) You'll notice few of the lines are cutting across the middle of the circle, that's because people primarily move short distances.
Mapping this way is not wholly a new idea — mapmakers have been experimenting with flowmaps for at least the last 150 years, as this 1858 migration map from Charles Minard attests.
But, though the researchers took inspiration from the map, it really only works for showing migration when very few people are moving to very few places. When you're looking at a much more complicated and linked dataset — like the migrations of millions of people to across almost 200 countries — flowmaps like the one above would be almost unusable.
By looking at the data as a web, it's easier to get a sense of the scale and direction of how we move across the world. Researchers are already working on even more detailed maps of migration flows, like this working map of flows between 60 countries over the period between 2005-2010:
Images via Science and the Wittgenstein Centre for Demography and Global Human Capital.