Floods, storms, earthquakes and a tsunami displaced 14.9 million people last year, 89 percent of them in Asia, according to an estimate by two Norwegian-backed agencies issued here Tuesday.

"The 10 largest disasters in terms of the amount of people displaced all took place in Asia, including multiple events in China, the Philippines, Sri Lanka and Japan," said Elisabeth Rasmusson of the Norwegian Refugee Council (NRC).

"The worst were the prolonged flood disasters in China and Thailand, which together displaced over five million people."

The estimate, issued on the sidelines of the UN Conference on Sustainable Development in Rio, applies to people who are internally displaced within a country.

But an accurate total of how many of the 14.9 million remain displaced is unclear because data is so sketchy, its authors said.

In northeastern Japan, 492,000 people fled their homes after the March 10, 2011 mega-quake and tsunami, according to the report, compiled with the Swiss-based Internal Displacement Monitoring Centre (IDMC).

One year on, 344,000 of them still live in temporary accommodation, it said.

In terms of the proportion of national population, Sri Lanka was worst hit, for 685,000 people, or three percent of its populace, were uprooted from their homes by heavy seasonal rains and back-to-back floods.