About 2.4 billion people, or one-third of the world’s population, live in areas exposed to inland flood risk, according to a Moody’s white paper.

The paper says the proportion of people exposed to flood risk has steadily increased since 1975, driven by factors such as the rising frequency and severity of inundations due to climate change, urbanisation and land-use practices.

And it will get worse. “Flooding is a pervasive and recurrent natural hazard that has far-reaching consequences for both human communities and the environment. 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.”

South Asia is the most threatened region, with almost 40% of inhabitants susceptible to inland flooding and more than 5% at risk from coastal flooding.

Oceania is the least-exposed region to inland flooding, with less than 17% of its population at risk, while Europe and north Asia are least exposed to coastal flooding.

The paper says while the population has been increasing in most regions in the past 50 years, it is not clear whether the number exposed to flood risk has been growing at the same rate.

Urban development strategies can vary greatly depending on the region or country and often reflect a community’s risk tolerance.

The paper says in areas with risk-averse strategies, urban development is carefully planned and executed to minimise threats such as flooding.

“This typically involves a series of preventative measures. One common measure is the implementation of strict zoning laws. These laws regulate land use to prevent construction in areas prone to flooding.”

Click here for the paper.