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.