The number of weather-related catastrophes in east Asia has more than quadrupled since 1980, with floods and typhoons posing the greatest threats, according to Munich Re.

Losses in the past three decades total $US700 billion ($751.44 billion), with only 10% insured, it says in a new book, Severe Weather in Eastern Asia. About 62% of insured losses were in Japan.

The book, analysing data from Munich Re’s NatCatSERVICE, identifies a significant rise in weather-related losses in the region.

Floods have accounted for 56% of total losses at $US393 billion ($422.01 billion), followed by storms on 34% at $US233 billion ($250.21 billion).

“The number of floods has increased strongly and is expected to increase further in the coming decades,” Munich Re says.

The 2011 Thai floods caused the region’s biggest ever weather-related insured loss, at $US16 billion ($17.17 billion).

“The reasons for the strong increase in losses from weather catastrophes such as floods are primarily socio-economic, such as continued strong economic growth and the resultant increase in values in exposed regions,” Munich Re Geo Risks Research Head Peter Hoeppe said.

Nearly half (45%) of all weather-related events since 1980 were floods, followed by storms (39%) and forest fires, heatwaves and droughts (16%). About 120,000 people have died – 57% from flooding and 39% from storm events.

Increased typhoon activity is predicted for the region. Typhoon Haiyan, which swept across the Philippines on November 8, shows governments and insurers must develop risk-minimisation strategies to reduce the number of victims and losses, Munich Re says.

The study focuses on Japan, South Korea, China, Taiwan, Vietnam, Thailand, Indonesia and the Philippines.

Apart from Japan, these nations will continue to be inadequately insured in years to come, Munich Re says. “At the same time… loss potentials are set to increase drastically as values rise.”

Insurers can help by forging private-public partnerships that increase insurance penetration or cover state assets such as infrastructure, the book says.