The eastern part of Ho Chi Minh City. Photo: VOV

A team of researchers at Nanyang Technological University, working with a group at NASA's Jet Propulsion Laboratory and another colleague at ETH Zürich describes using satellite-based radar to measure the degree of land subsidence of 48 of the world's most populous coastal cities between 2014 and 2020.

The team found a rate of subsidence of 16.2 millimeters per year, while some of them have land sinks by 43 mm per year. The current global sea level rise is 3.7 mm per year. The median rate for Ho Chi Minh City, 16.2 mm/year.  In a case study with Ho Chi Minh City, the team found that an additional 20 square kilometers could be submerged below sea level and flooded if the current rate of subsidence continues through 2030.

Survey results published in August by the Japan International Cooperation Agency (JICA) in Ho Chi Minh City showed that the city land sinks on average by about 2 cm per year, in some places up to 6 cm per year.