The proportion of the global population exposed to floods has grown by a quarter since 2000, a 10-fold difference from what scientists previously thought, analysis has uncovered.
After observing daily satellite imagery to estimate both the extent of flooding and the number of people exposed to over 900 large flood events between 2000 and 2018, the researchers found that between 255 and 290 million people were directly affected.
However, between 2000 and 2015, the number of people living in these flooded locations increased by 58-86 million, according to the findings by Cloud to Street, a flood mapping platform and member of Willis Towers Watson's (WTW) Willis Research Network.
When combined with a growing number of flood events, the researchers concluded that there has been a 24% increase in the proportion of the global population exposed to floods since the turn of the millennium.
The analysis involved the refining of geospatial data with artificial intelligence and other methods, instead of relying on modelled estimates widely used by the insurance industry, and is available on Cloud to Street's Global Flood Database.
The platform's CEO, Bessie Schwarz, said: “More people and more assets are impacted by flooding than any other climate-fuelled disaster. The Global Flood Database will help insurers understand the changing nature of flood risk and offer more competitive insurance coverage.
“We are proud to enable governments and insurers to protect millions of people and billions in assets they have never been able to before.”
Today, most flood maps rely on modelling that simulates floods based on available ground data, such as elevation, rainfall and ground sensors, which are time intensive and can have substantial limitations, entirely missing flooding incidents in regions not historically prone to flooding.
This makes it harder to address the insurance gap in the developing world, where some 90% of economic losses from disasters remain uninsured, putting economically vulnerable households at greater risk, and slowing recovery efforts following disasters.
Further findings from the latest research show that nearly 90% of flood events occur in South and Southeast Asia, with large basins such as the Ganges-Brahmaputra having the largest absolute numbers of people exposed.
By 2030, climate and demographic change are forecast to add 25 new countries to the 32 already experiencing increasing floods.
The new satellite data also uncovered previously unidentified increases in flood exposure in Southern Asia, Southern Latin America, and the Middle East.
Simon Young, a senior director at WTW's Climate and Resilience Hub, said: “The collaboration between Cloud to Street and the Willis Research Network is already delivering beyond our expectations, particularly in the research and development of tools to better understand flood risk and mitigate the economic impact of flooding for communities throughout the world.
“Alongside our Willis Re and alternative risk transfer units, the Climate and Resilience Hub is also creating innovative parametric solutions building on this rapidly evolving flood mapping technology.”
Image credit: iStock
Author: Chris Seekings