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Though not inherently a risk driver itself, rapid, uncontrolled or poorly planned urbanization can increase the likelihood of disasters. Cities often develop at the expense of altering natural landscapes and changing ecosystem dynamics, resulting in higher exposure of people and livelihoods to natural hazards, as well as creating new risks. For example, an increase in impervious surfaces can increase the risk that a normal rain event ends up in a catastrophic flood. Additionally, increasing population densities often mean an unequal distribution of services, where the most marginalized citizens are pushed to the most marginal areas, such as steep slopes or floodplains, where they are disproportionately at risk.

Related Cases


On 1 September 2021, remnants of Hurricane Ida, the costliest disaster of 2021, brought historic rainfall to New York City, triggering the city’s first-ever flash flood alerts as water flooded streets, subway stations and apartments.

Lagos faces increasingly severe annual flooding, exacerbated by sea level rise and subsidence. In 2021, floods again submerged vehicles and houses, displacing thousands from their homes.

In summer 2021, drought and low humidity combined with record-breaking heat of up to 48.8°C (119.8°F) led to fire outbreaks across the Mediterranean countries, killing more than 100 people and burning more than 620,000 ha of land in July and August

From March 2020 to September 2021, a herd of approximately 15 Asian elephants left their home in Xishuangbanna National Nature Reserve. Along their journey, the herd broke into homes, damaged buildings and infrastructure, and destroyed crops, totaling estimated damage of over $1 million.

From October to November 2020, 9 storms in 7 weeks caused widespread flooding in central Viet Nam. As a result, a total of 7.7 million people were affected by the disruption to basic services and 291 people lost their lives.

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