(Bloomberg) -- Gross domestic product at risk of flooding inIndia, the world’s second-most populous nation, may surge 10-foldby 2030 as cities expand and climate challenges worsen, accordingto the World Resources Institute.

Anew online global flood-analyzing tool developed by WRI andfour Dutch research agencies showed India topped the list amongcountries with population affected by river flooding on averageeach year.

WRI ranked 163 countries by number of people impacted by riverflooding. Led by India, the 15 worst-hit accounted for almost 80%of the total population affected. Bangladesh was a distant second,then China, followed by Vietnam, Pakistan and Indonesia, the toolshowed. (Click chart below to enlarge.)

India faces more potential change in exposed GDP than anycountry at $140 billion. China is next at $98 billion. Using whatWRI called “a middle-of-the road scenario,” the analyzer estimatesIndia’s current GDP exposed annually could increase 10-fold from$14 billion to $154 billion by 2030. (Click chart below toenlarge.)

River flooding currently impacts 21 million people worldwide onaverage and costs $96 billion in GDP each year, according to theanalysis. In 15 years, those numbers may grow to 54 million peopleand $521 billion in GDP affected annually.

The cost and loss from floods played out last September whenIndia deployed 300,000 military personnel in the Himalayan state ofJammu and Kashmir to rescue 130,000 people after a week of raincaused riverbanks to burst, killing about 500 in India andPakistan. In 2013, the worst flash floods in 90 years killed 580and left 5,000 more missing in the northern states of HimachalPradesh and Uttarakhand.

Mitigating Risks

Annual economic losses from natural disasters have almostquadrupled in the past three decades, the World Bank said in2013.

In particular, southeast Asia faces a notable increase in risk,according to Hessel Winsemius, a researcher at Netherlands-basedDeltares, one of the project partners.

The Aqueduct Global Flood Analyzer estimates current and futurepotential exposed GDP, affected population and urban damage fromriver floods for every state, country and major river basin in theworld.

Attention to flood-risk reduction will be needed in fast-growing cities in areas such as Ho Chi Minh in the Mekong delta,Dhaka in Bangladesh and Shanghai in the Yangtze basin, he said.

“In changing climate in particular, memory of historical floodsfrom the last few years is not a good estimation of what floodrisks could be in the coming years,” said Erin Coughlan, seniorclimate specialist for the Red Cross Red Crescent Climate Centre.“People need to evaluate those risks and take action now instead ofbeing surprised in the future.”

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