Farmers in Hoa Quy Ward in the central city of Da Nang's Ngu Hanh Son District use drinking water to save their crops during a drought. From 2001-10, natural disasters have cost Viet Nam an average of 1.5 per cent of GDP annually — VNA/VNS Photo Vu Cong Dien

The institute said the annual flow in the Red River had decreased in recent years, but strong flood events were occurring more frequently.

The number of serious flash floods also increased from eight in 1981-90 to 103 from 1991-2000 and 87 from 2001-07. The daily maximum rainfall is also rising, especially in Ha Noi and central provinces.

The Minister of Natural Resources and Environment, Nguyen Minh Quang, said natural disasters had cost the country an average of 1.5 per cent of GDP annually between 2001-10 and an estimate of 9,500 people killed or missing.

"All of the disasters resulted from climate change, which will continue to have a devastating effect on socio-economic development," Quang said. "Climatic extremes are now much more complicated."

Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change (IPCC) since 2002 and who was co-awarded the Nobel Peace Prize in 2007, said while societies in Asia had a long record of adapting to the impacts of weather and climate, insufficient information would probably hinder efforts.

Pachauri said the new IPCC report suggested that the frequency of heavy precipitation events had increased over most land areas. This could be seen in the increased occurrence of extreme rains causing flash floods in Viet Nam.

IPCC also indicated that rising sea levels would inundate land occupies by millions of people in South, South-east and East Asia. It also said that the annual number of people flooded in coastal areas would increase from 13 to 94 million in the most conservative scenario, with 20 per cent in Southeast Asia.

The report recommended adaptation strategies that included raising income levels, education and technical skills, increasing access to renewable energy, improving disaster preparedness and management and empowering communities.

UN Resident Co-ordinator Pratibha Mehta said that in recent years, storms in the south of Viet Nam arrived much earlier than in the past, and that there had been an increase in flash floods and landslides in mountainous areas, for example in northern Ha Giang and Yen Bai provinces in 2012.

She added that even in areas where residents had lived with floods for decades, some were not prepared for the increased frequency of tropical storms.

Thuc from the Institute of Meteorology, Hydrology and Environment said climate change must be integrated into efforts to reduce poverty, increase access to basic services, including education. He said the issue could not be tackled separately.

(VNS)