(Paris, AFP) - Satellite image concludes that according to a study reported that two-thirds of the world facing the threat of a major delta area and the twin threats of rising sea levels. In the past 10 years, the world's 33 largest delta, there are 85% of the encountered severe floods affected an area of up to 26 million square kilometers. If the sea level continues to predict the speed of the current rise in this century the Delta affected area is expected to increase by 50%.
The report notes that, in addition to Australia and Antarctica, all the world's densely populated delta areas are subject to a serious threat, while Asian delta face of such threats is the most serious.
Threatened delta, China accounted for three of the most serious
From the University of Colorado researchers to the delta region is divided into five levels of threat levels, there are 11 areas in Asia have been included in the most serious level of threat, the population giants China alone accounts for three of them, they include north of the Yellow River Delta, near Shanghai, the Yangtze River Delta and the Pearl River Delta near Guangzhou.
In addition, in the Nile delta in Egypt, Thailand's Chao Phraya River Delta, as well as France's Rhone delta, also belong to groups at highest risk.
Level of threat for more than a few slightly smaller than a total of 7 Delta region, including Bangladesh, the Ganges delta, Myanmar's Irrawaddy River Delta, Vietnam's Mekong Delta and the United States, Mississippi Delta.
In the "natural earth sciences," the report published in the journal noted that in the absence of human activities on the circumstances, the river will naturally bring the upper reaches of the earth and sand delta sedimentation. As human demand for energy and resources, increasing the upper reaches of major rivers in the area have buildings such as dams and water diversion project, delta growth and survival depends less and less sediment. At the same time, some areas but also because of oil and gas exploration, as well as activities such as drawing groundwater, leading to aggravate the problem of ground subsidence.
On the other hand, climate warming caused by sea level rise, also pose a great threat to delta areas. The United Nations Intergovernmental Panel on Climate Change has predicted that by 2070, global sea level will rise by 21 cm to 71 cm.
The researchers concluded: "These phenomena mean that there is an increasing number of Delta area will be submerged."
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