A new white paper from Moody’s reveals that 2.7 billion people — more than one-third of the global population — live in areas vulnerable to inland or coastal flooding.

Moody’s estimates that approximately 2.4 billion individuals live in locations that are exposed to inland flood risk at the 100-year return period, representing just over 31 percent of the global population. (Return period is defined as the inverse of the probability of occurrence, for instance a 100-year return period represents a 1 percent chance in any given year.)

Approximately 260 million people are at risk from coastal flooding at the same return period, with over 70 percent of those individuals living in just 5 countries: Bangladesh, China, India, Vietnam and the Philippines.

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South Asia is the most flood-prone region, with almost 40 percent of its population susceptible to inland flooding and just over 5 percent at risk from coastal flooding at the 100-year return period level.

Oceania is the least-exposed region to inland flooding, with just under 17 percent of its population at risk, while the Europe and North Asia region is least exposed to coastal flooding, with just 0.27 percent facing potential coastal flood threats.

Moody’s finds that the country most exposed to flood risk is Suriname, in Latin America. Based on the 2012 census, almost half of Suriname’s population is living in Paramaribo, the country’s capital. When looking at the 100-year map, the entire city is exposed to inland floods, leaving 92 percent of the population exposed to inland flooding.

“Flooding is a pervasive and recurrent natural hazard that has far-reaching consequences for both human communities and the environment,” Moody’s says in the report. “As flooding continues to pose a growing threat, understanding the populations most vulnerable to its effects is paramount for effective disaster management and mitigation efforts.”