Putting the World’s Slums on the Map
Researchers and residents are turning to open-source data tools to fill information gaps about informal settlements that often get left off official maps.
Shanties climb a hillside in the Pamplona Alta sector of southeastern Lima, Peru, where a digital mapping project is seeking to better connect slum residents with city services.
Photographer: Cris Bouroncle/AFP via Getty Images
When Alejandro Velásquez recently used a job-search website to look for work, he was asked to locate his house on a digital map. He couldn’t do it, because his house didn’t appear on it — he lives in La Vega, a slum district of Caracas, Venezuela’s largest city. He added a relative’s address, but all the job options were far from home. His neighborhood, like thousands of slum communities in the global south, is barely represented in maps.
Often, these areas are depicted in the official information systems of city governments as empty polygons named “informal zones” or “areas of development.” More than 1 billion people live in these areas of the world’s cities, according to the United Nations, and their numbers have been growing as urbanization trends continue. But severe information gaps keep much of this landscape hidden: Unlike formal areas, slums might not have their streets, services and buildings mapped on platforms such as Google Maps.