Massive Bangkok style flooding could happen in Vietnam

A fruit vendor waits for customers at a flooded market in Ho Chi Minh City’s District 2

The serious flooding that has hit Thailand over the past three months, inundating large areas of its capital Bangkok, has raised concerns about similar risks faced by Vietnam.

The current images of Bangkok under water could be replicated in Ho Chi Minh City in the future, Dr. Nguyen Huu Ninh, chairman of the Scientific Council of the Center of Environmental Research, Education and Development, told Thanh Nien Weekly in an interview.

Thanh Nien Weekly: HCMC’s geographic characteristics are similar to those of Bangkok. Can such serious flooding happen here?

Nguyen Huu Ninh: Bangkok, Phnom Penh and HCMC are cities with similar geographic characteristics. They are river cities, located on lower sections of rivers, standing just one to three meters above the sea level, so they are frequently hit by natural disasters, especially flooding.

With the biggest rainfall in half a century, and many storms over the past three months, Bangkok, which is located in a low area just 20 kilometers away from the sea, has become a center of the flooding.

During its rapid urbanization process, Bangkok has generated ecological imbalances, filling up reservoirs to build residential buildings and industrial parks.

The exploitation of underground water has also made the city sag by about five centimeters on average each year. Meanwhile, sea levels are rising. Thus, flooding in Bangkok was inevitable, and could happen again in the future.

Here, HCMC could see similar risks. The city’s infrastructure development continues to be concentrated in river areas. Scientists can only sketch out scenarios and give warnings on various issues, but other authorized agencies retain the right to take the advice or not.

Is the risk to HCMC high or low?

High, because tides in the city are rising each year, and it has been frequently hit by flooding. Meanwhile, reservoirs in the southern districts of the city, like Can Gio and Nha Be, have been filled up to serve the construction of residential buildings and industrial parks. Projects to improve the drainage systems in the city have not been effectively carried out.

Meanwhile, climate change has made sea levels rise. The sea level has risen by three to five centimeters in just 10 years, but flood tides hitting the city have risen in the double digits. Every year, the rise in flood-tides has been higher than the previous year.

However, the most important factor is drainage. The city’s drainage system is not good, so the risk of being flooded is very big. In the next 10-20 years, when the sea level gets higher, and the impact of climate change is greater, flooding will be inevitable. It is an urgent issue that needs action right now. We should not let the risk of flooding in HCMC become as serious as in Bangkok.

The images of Bangkok damaged by flooding today could well be seen in HCMC in the future. The high tide in HCMC has risen to 1.57 meters compared to 1.3 meters just 10 years ago. High tides cannot go down in the future, only up.

The likelihood of flooding similar to that of Bangkok happening in HCMC in the next 10-15 years is very high, and the problem will get even more serious unless the city comes up with an overall urban development plan that reconsiders the use of reservoirs and the drainage system.

How do you assess Vietnam’s current ability to cope with climate change impacts?

The most important thing is the ability to adapt. Other things, like greenhouse gases and carbon dioxide emissions, and development of new technology are global issues. The use of wind and solar power and afforestation are ways to reduce climate change impacts. However, the most important task for Vietnam, one of the countries most seriously affected by climate change, is to improve its ability to adapt.

The government has mapped out a national program on coping with climate change since 2009. The program information has been disseminated in provinces and sectors. All localities are working out plans for implementing it, but concrete action is at the preparatory stage.

For example, the issues of dam construction and rice crop cultivation in the Mekong Delta, a region frequently hit by flooding, are still being discussed and no decision has been made.

These are long-term measures. What about the short-term ones?

We still do it in a passive manner. After flooding hits a locality, we upgrade dykes and drainage systems there. We have not yet taken overall and stable measures to deal with the issue. We should take long-term measures like dyke upgrading and ecological forestation.

What are the lessons we can draw from the flooding in Bangkok?

Scientists, 10-15 years ago, warned that Bangkok could face serious flooding because of higher sea levels. Floods have frequently occurred in some areas of Bangkok for around the same period of time. Now, the warnings have come true.

The situation is similar to that in HCMC. Like Bangkok, HCMC is seeing more and more reservoirs and channels being filled up to serve construction projects.

Flooding frequently occurs in southern localities including Vinh Long, Can Tho, HCMC and Ca Mau. We should have plans to cope with the issue in a methodical manner, and apply new technologies such as building floating houses in flooded areas and growing salt-resistant food trees.

We should also shift urbanization to high areas, to western districts like Cu Chi. Why do we develop urban areas in river districts when we know they may be flooded in the future?