15 Minute Maps
This podcast is dedicated to those people making positive change in the world using GIS, mapping and cartography. Each guest is given 15 minutes to describe their dream map, and how it could impact the work they do.
Hello and welcome to 15 Minute maps, where I ask my guests to let their minds roam free and come up with a new idea for their dream map. The first known map of the world was created three thousand years ago, (of a flat disc-like world surrounded by water,) and today we are making maps of the furthest reaches of the known universe. In between lie a myriad of mapping possibilities. What if we could do away with resource limitations… think beyond the conventions of time, space and political boundaries? What new kinds of map could we dream up?
15 Minute Maps
Episode 19 - Yann Rebois: Mapping the Invisible in Cities
Urban crises are some of the hardest environments to map — and yet that’s where millions of the world’s most vulnerable people live.
In this episode of 15-Minute Maps, Hugo Powell is joined by Yann Rebois, Earth Observation Strategist at Médecins Sans Frontières (MSF) and former Head of Geodata & Analytics at the ICRC. Drawing on decades of field experience and satellite analysis, Yann shares his vision for a map that can finally make urban vulnerability visible.
Yann’s dream map focuses on one of humanitarian response’s biggest blind spots: understanding who lives where in dense, damaged, and rapidly changing cities — and what “habitability” really means after conflict or disaster.
Together, they discuss:
- Why population estimates break down in urban crises
- The limits of building footprints and satellite imagery in cities
- How proxies like water tanks and solar panels can reveal where people have returned
- Why “destroyed” doesn’t always mean “uninhabited”
- How GIS and Earth observation directly shape medical, water, and vaccination responses
- The challenge of detecting flooding and damage in dense urban environments
This episode offers a rare inside look at how satellite data, field knowledge, and humanitarian logistics come together — and why better urban maps are essential for effective aid.