Hydrological conditions and the travel time that impact from upstream may reach to the Mekong Delta area

Abstract

    The Mekong river basin has a total area of about 795.000 km2, it runs throught 6 countries: China, Myanma, Lao PDR., Thailand, Cambodiaand Viet Nam with a total length of the mainstream river is 4.800 km, an annual flow of about 475 billion m3. The Mekong river is the world ranking 21st about the total area, the 12th for its length and on the 8th for total annual flow. The Mekong river has a high biodiversity with about 1.300 aqua species, the 2nd place of annual fish production in the world, and supplies food for about 300 million people. Mekong river has a high potential hydropower development, with a total capacity of about 53.000 MW, in which 23.000 MW at the upper Mekong (in Lan Cang river) in China, 13.000 MW on the lower mainstream Mekong river, and more than 17.000 MW are hydropower potential in Mekong tributaries at 4 lower Mekong countries. The proposed plan to build 12 mainstream hydropower dams which may cause some negative impacts to hydrological condition, water quality, biodiversity and may affect to the life activities of tens million of people at downstream countries. This paper presents the possible impact of the mainstream hydropower dams to hydrological condition and the time that impact from upstream may reach to the Mekong delta area.An early warning and prediction the positive and negative impacts to the Mekong delta of Vietnam to assist preparing some mainstream adaptive measures.