Flood and Typhoon Disasters in Viet Nam in the Half Century Since 1950

Disasters in Viet Nam are discussed by compiling recent data on the geophysical and social environments, the frequency of disasters, and the values of human and financial losses in 1953–1991. Examinations of yearly frequency and damages caused by typhoons indicate a relatively increasing value of losses in spite of a constant or decreasing frequency in the decade of the 1980s, meaning inadequate prevention programs. The two successive typhoons in 1985 are described as the most catastrophic disaster for 100 years, in which high waves combined with high tides destroyed the dike system and flooded a large area in the central part of Viet Nam, which suggests some serious deficiencies in prevention efforts, especially in coastal areas. Disasters on the coast have been significant because of the rapid growth of the population in the low lands and the destruction of coastal environments, such as coastal erosion caused by a deforestation of mangroves and a short supply of sand. As an example, coastal erosion at Ha Nam Nimh province in the northern part of Viet Nam at an average receding speed of around 15 m/year is described.