VietNamNet Bridge - Ca Mau peninsula is continuing to sink, according to research by the Southern Region Geological Mapping Federation under the General Department of Geology and Minerals of Vietnam.

Dr. Do Van Linh, Deputy Head of the Southern Region Geological Mapping Federation, said the deepest subsidence in Ca Mau was measured 1.71 cm a year, while the average subsidence due to groundwater exploitation was about 0.35 cm a year.

There are three reasons for this situation: subsidence due to young sediment and water exploitation, and by tectonic movements. This trend will continue in the coming years.

Previously, studies of the Norwegian Geotechnical Institute (NGI) showed that Ca Mau is sharply subsiding. The subsidence speed measured was higher than the studies of the Southern Region Geological Mapping Federation.

According to NGI, Ca Mau may suffer from serious subsidence on the surface, as the result of surface water pumping activities of 109,096 wells with the total pumped water volume of 373,000 m3 a day.

If the exploited water volume is divided for the total area of Ca Mau province (approximately 4,350 km2), the speed of subsidence is 1.9 to 2.8 cm a year. If the area of Ca Mau province is 5,300 km2 instead of 4,350 km2, the subsidence rate is 1.56 to 2.30 cm a year.

NGI's research also pointed out, in 15 years (1998-2013), ground subsidence rate would be 30-80 cm and it is predicted that in the next 25 years, the rate of subsidence will increase to 90-150 cm and 210 cm in the next 50 years.

Thu Ly