Mekong Delta extinction an extreme prediction: Vietnam expert

By Gia Chinh   November 2, 2019 | 02:02 pm GMT+7
Mekong Delta extinction an extreme prediction: Vietnam expert
A man catches fish on a flooded field in Long An Province in the Mekong Delta, October 2019. Photo by VnExpress/Hoang Nam.

A Vietnamese expert says a scientific paper warning the Mekong Delta could be submerged underwater by 2050 uses incorrect data and ‘extremist scenarios.’

While the paper’s message is worthy of recognition, it has insufficient scientific backing and is "based on multiple extremist scenarios at the same time," Huynh Thi Lan Huong, deputy director of the Vietnam Institute of Meteorology, Hydrology and Climate Change, said Friday.

The institute functions under the Ministry of Natural Resources and Environment.

Huong was referring to a paper released Tuesday by Climate Central, a U.S.-based a nonprofit news organization that analyzes and reports on climate science. The paper said the entire southern part of Vietnam, including the Mekong Delta and the nation's economic hub, HCMC, could be underwater by 2050.

The study, published in Nature Communications, said sea levels projected by that year are high enough to consign an area currently home to a total of some 150 million people permanently below the high tide line, which means rising seas could affect three times more people by 2050 than previously thought.

Huong said that coastal geographical statistics used in the paper was constructed by calibrating geographical statistics of the U.S., before applying them to other regions of the world. This method thus yields low accuracy, she added.

"The study did not calibrate statistics for the Mekong Delta, so it did not accurately reflect the region's actual elevation data," she said.

Moreover, the authors of the study have presumed a sea level increase of two meters combined with a high tide scenario to simulate a map for flooding risk. This method actually combined both negative scenarios, which would naturally lead to a severely negative vision.

"[The simulation] does not differentiate between flooding caused by sea level rise due to climate change which is permanent and flooding caused by tidal effects which only lasts for a few hours," Huong said.

The environment ministry had in 2016 sketched out scenarios on climate crisis impacts and rising sea levels, she noted.

Sea level would increase by one meter by 2100, and would potentially flood about 18 percent of HCMC and 39 percent of the Mekong Delta, Huong said, adding that Climate Central’s data "could not be better than data provided by the Ministry of Natural Resources and Environment" as Vietnamese authorities have simulated such scenarios based on national standards.

A map of flooding scenario in the Mekong Delta by the Ministry of Natural Resources and Environment in 2016 forecast that less than half of the deltas area will be under flood level by 2050.

A map of flooding scenario in the Mekong Delta by the Ministry of Natural Resources and Environment in 2016 forecast that less than half of the delta's area (red) will be under flood level by 2050.

Several studies over the last decade have predicted that the Mekong Delta, which spreads over 40,577 square kilometers (over 10 million acres) and is currently home to 21.49 million people, would soon sink as sea level rises in the future, partly due to the climate crisis.

In September a group of Dutch scientists said the Vietnam's Mekong Delta has an "extremely low mean elevation" of just around 0.8 meters above sea level, which is dramatically lower than the 2.6 meters assumed earlier from NASA's Shuttle Radar Topography Missions data.

The team's findings estimated that at its current rate of subsidence the delta could be under 0.8 meters of sea within 57 years, requiring over 12 million people to relocate.

 
 
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