Sinking Into Floods

HCM City’s land sinking, while confined to its boundaries, will prove intractable if remedies are not taken immediately The tidal peak of 1.58m, while not significantly greater than the earlier crest, caused many places in HCM City to be more than 1m below water, mainly because land sinking is accelerating here. Statistics show that 79 out of 116 flooded sites in HCM City are plagued by land sinking. Land sinking in HCM City, which aggravates the city’s flooding, is caused by excessive underwater exploitation and rapid urbanization This problem may stem firstly from the alarming rate at which underground water is tapped into. The HCM City Department of Natural Resources and Environment estimates this rate at 750,000 cubic meters per day while experts contend it equals 1.3 million cubic meters, far higher than the rate at which underground water is replenished (200,000 cubic meters per day). Dr. Bui Tran Vuong, from an organization in charge of water resource zoning and surveying in the south, says that the amount of underground water at present trails behind that of 10 years ago. “With the exception of the top layer, five of the six aquifers hold significantly less water. The layers have relatively deep hollows, too.” Evidence of land sinking abounds around drilled wells. Many of these wells in Binh Chanh, Binh Tan and Nha Be districts have seen the surrounding land sink by 30-40cm. In late September, the Geomatics Center from the Vietnam National University of HCM City said that many districts…