Every year, over 100 million people are affected by disasters, and many of them move from their homes, leaving them in dire need of help. Despite the huge sums of money spent on delivering humanitarian aid to disaster-struck areas, there is often a severe lack of basic information on the locations of the people in need of help as well as of the number of people who have left the disaster area. This seriously hampers aid coordinators in their efforts to deliver the right amount of supplies to the right places, even when sufficient resources are available.

“This is a huge problem, but by using data supplied by mobile phone operators, we now have a good chance of charting the movements of populations in disaster situations,” says Dr Linus Bengtsson, doctoral student at Karolinska Institutet, who has led the development of the method.

After the Haiti earthquake of January 2010, there were reports of large migrations of people out of the capital Port-au-Prince. Researchers at Karolinska Institutet and Columbia University in New York sought the cooperation of Digicel, the largest mobile phone operator in Haiti, and started to monitor the daily movements of two million mobile phones by analysing anonymised data on which mobile phone towers were used to make calls. They then reported their analyses directly to the UN and other aid organisations working in Haiti.

Later that year, Haiti was struck by a serious outbreak of cholera.

“We rapidly received mobile phone data and within 12 hours we were able to send out analyses describing which areas had received people from the cholera outbreak zone in order to provide information on areas at potentially increased risk of new outbreaks,” says Dr Bengtsson.

The results of their analyses are now published in PLoS Medicine. In their paper, the researchers estimate that over 600,000 people had left Port-au-Prince 19 days after the earthquake, and trace the migration patterns over the country on maps. They also show how the movements of the mobile phones matched those of a large UN-led study conducted in a stable phase six months later. At the same time, their analyses differed widely from the estimated migration patterns that were used during the initial phase of the relief response.

“Our work was very much appreciated by the aid organisations on the ground, and we believe that the method can bring about important improvements in humanitarian relief and development cooperation,” says Dr Bengtsson. “We’re now setting up a non-profit organisation to carry out this type of analyses on a routine basis during future disasters.”

Publication: ‘Improved Response to Disasters and Outbreaks by Tracking Population Movements with Mobile Phone Network Data: A Post-Earthquake Geospatial Study in Haiti’, Bengtsson L, Lu X, Thorson A, Garfield R, von Schreeb J, PLoS Medicine, online 30 August 2011, doi:10.1371/journal.pmed.1001083.

Photo: Linus Bengtsson, photo by Nathalie Roos

For further information, please contact:

Dr Linus Bengtsson, doctoral student
Department of Public Health Sciences, Division of Global Health/IHCAR
Tel: +46 (0)70-750 75 78
Email: linus.bengtsson@ki.se

Dr Johan von Schreeb, surgeon and disaster medicine needs assessor
Department of Public Health Sciences, Division of Global Health/IHCAR
Tel: +46 (0)8-524 833 80
Email: Johan.Von.Schreeb@ki.se