In Depth

When Climate Disaster Strikes, Slums Are Vulnerable. Better Maps Help

A group of nonprofits are mapping informal settlements to make aid distribution, reconstruction and resilience planning easier.

A drone image of Blamo Town outside Monrovia, Liberia.

Photographer: Carielle Doe for Bloomberg Businessweek

On a cloudy morning in early May, Charles Gamys sends his drone skyward. Once it’s about 120 meters (390 feet) in the air, he starts to take photos of the landscape below: rows upon rows of shacks, connected by unpaved alleys and dotted with oil palm trees.

These are no casual snapshots. Gamys, 30, is helping create the first map of Blamo Town, an informal settlement outside Monrovia, Liberia’s capital. Blamo Town has been around for almost 70 years and is home to about 20,000 people. On official maps, though, it’s depicted with scant detail. On Google Maps, you can’t see it at all.