Exposure to large landslides in cities outpaces urban growth

As the global population grows, more people are moving to steep slopes around cities, increasing their exposure to large landslides. The authors investigated the growth of permanent structures of human settlements from 1985 to 2015 on 1,085 large (>0.1 km²) landslides across 129 cities.

They find that the built-up areas on these landslides has doubled over 30 years, growing faster than the cities themselves. The authors estimate that at least half a million people live on these 1,085 large landslides. The study finds growth of permanent structures on large landslides is driven more by people moving from mountain areas to cities than by urban expansion. The authors observe that informal settlements on steep slopes with landslides are likely putting vulnerable populations at risk. The model approach and findings can be used to inform urban zoning policies and reduce the exposure of marginalized urban communities to landslides.