This map depicts net migration for dryland areas of the world during the decade of the 1990s, expressed as the net number of migrants per square kilometer. Net migration is the difference between the number of people entering and the number leaving a region in a specified time period. This map is the first global map of net migration that shows migration patterns within countries, not just national totals. The data behind this map can help us understand if people have been moving into, or away from, areas experiencing environmental degradation or stress, or areas highly vulnerable to climatic variability and change. Information of this kind is critical to climate change adaptation planning, among other uses. Net migration is one of two fundamental components of population growth (the other is natural increase, the difference between births and deaths).
Fonte:
Center for International Earth Science Information Network, 04/02/2013
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