Low-cost population maps help poorer countries

12 December 2007

Inexpensive, high-resolution population maps developed by Oxford University scientists could benefit low-income countries where populations are set to boom.

The maps, created by combining satellite imagery, land cover information and census data, would help countries map population growth and anticipate its social, economic and environmental impacts. The new approach was tested by creating high-resolution settlement maps of Kenya, Uganda, Burundi, Rwanda and Tanzania, which are freely available as part of the Malaria Atlas Project (www.map.ox.ac.uk).

The research was funded by the Wellcome Trust and led by Dr Andy Tatem from Oxford University’s Department of Zoology, he said: ‘These East African nations are the sort of countries that desperately need accurate population maps but, currently, are unable to afford them. Working with researchers based in the region, we have been able to test our new mapping technique and have found that it is more accurate than existing products and could cost as little as one cent – a hundredth of a US dollar – per square kilometre.’ A report of the research will be published in PLoS ONE on 12 December 2007.

Inexpensive population maps are likely to prove vital as the population of the world is forecast to grow by 2.7 billion between 2005 and 2050 with the vast majority of this growth occurring in low-income countries. Many of these countries still rely on maps from the 1970s and cannot afford to undertake detailed national-scale mapping.

The team created settlement maps from satellite imagery (from Radarsat-1 and Landsat) and then combined this with data on land cover (from www.africover.org) and census data for the East African region to produce their estimated population maps. They then tested the accuracy of these maps against detailed census data for 50 Kenyan districts.

‘What we have shown is that, in just a matter of weeks, a small team can accurately map settlements and populations down to 100m resolution across an area of almost two million square kilometres,’ said Dr Andy Tatem. ‘Even more importantly we can do this at a fraction of the cost of existing mapping products, raising the possibility that these automated methods could be used to create easily-updateable maps for the whole of Africa or, indeed, many other parts of the world.’

For more information contact Dr Andy Tatem on +44 (0)1865 271262 or email andy.tatem@zoo.ox.ac.uk alternatively contact the University of Oxford Press Office on +44 (0)1865 283877 or email press.office@admin.ox.ac.uk