Publication: Rapid Urban Growth in Flood Zones: Global Evidence since 1985
Date
2022-04
ISSN
Published
2022-04
Author(s)
Avner, Paolo
Marconcini, Mattia
Su, Rui
Strano, Emanuele
Bernard, Louise
Riom, Capucine
Abstract
As countries rapidly urbanize,
settlements are expanding into hazardous flood zones. This
study provides a global analysis of spatial urbanization
patterns and the evolution of flood exposure between 1985
and 2015. Using high-resolution annual data, it shows that
settlements across the world grew by 85 percent to over 1.28
million square kilometers. In the same period, settlements
exposed to the highest flood hazard level increased by 122
percent. In many regions, risky growth is outpacing safe
growth, particularly in East Asia, where high-risk
settlements have expanded 60 percent faster than safe ones.
Developing countries are driving the recent growth of flood
exposure: 36,500 square kilometers of settlements were built
in the world’s highest-risk zones since 1985–82 percent of
which are in low- and middle-income countries. In
comparison, recent growth in high-income countries has been
relatively slow and safe. These results document a
divergence in countries’ exposure to flood hazards. Rather
than adapting their exposure to climatic hazards, many
countries are actively increasing their exposure.
Citation
“Rentschler, Jun; Avner, Paolo; Marconcini, Mattia; Su, Rui; Strano, Emanuele; Hallegatte, Stephane; Bernard, Louise; Riom, Capucine. 2022. Rapid Urban Growth in Flood Zones: Global Evidence since 1985. Policy Research Working Paper;10014. © World Bank, Washington, DC. http://hdl.handle.net/10986/37348 License: CC BY 3.0 IGO.”