In January 2015, heavy rains triggered unprecedented floods in Malawi. Over the next five weeks, the floods displaced more than 230,000 people and damaged over 64,000 hectares of land.
Almost half the country was labeled a "disaster zone" by Malawi's government. And as the humanitarian crisis unfolded, relief agencies, such as the Red Cross were faced with the daunting task of allocating aid and resources to places that were virtually unrecorded by the country's mapping data, and thus rendered almost invisible.
Humanitarian workers struggled to navigate in many of the most affected areas, and one result was that aid did not necessarily reach those most in need.
To prevent similar knowledge gaps in the future, researchers, volunteers and humanitarian workers in Malawi and elsewhere, have turned to an unlikely partner: Facebook.
In 2016, as part of its "Missing Maps" project, the Red Cross accessed Facebook's rich population density data to find and map people who were critically vulnerable to natural disasters and health emergencies, but remained unrecorded in existing maps.