Ho Chi Minh City, a Vietnamese city where 9.2 million people live today, is considered the capital of Southwest Asia. Its location, close to the mouth of the Mekong River that flows from Tibet to southern Vietnam, made it a vibrant commercial city, culturally open to the world. In 50 years, she may begin to sink. First, it will be covered by salt water at high tide, and later it will be completely flooded.
Ho Chi Minh City is expected to join other cities that exist below the water line, such as New Orleans and Amsterdam, but unlike them, it does not have a drainage system. It takes a long time to build such systems, much more than the time available to the city’s residents. The case of New Orleans also shows that systems of dams do not always withstand pressures, and a city that lives permanently below sea level is at enormous risk.
20 million people will have to leave their homes
The melting glaciers are raising the sea level, but this is only one of the reasons, and not the main one, that the Mekong Delta region is going to be washed by sea water soon. A series of political and economic processes combine to sink the region. The tangle of interests is so tangled that scientists studying the issue are not at all optimistic, but they keep shouting: the Mekong must be saved.
Dr. Raphael Schmitt from Stanford University is one of the researchers who signed an article recently published in the journal Science and explained what is happening to the Mekong Delta and what can be done about it. In an interview with Globes, he says that he is the lead researcher in the Natural Capital Project at Stanford, which tries to understand the relationship between nature and society “The connection between these factors is critical in the face of climate change,” he says.
“My specialization is in water resources engineering. I try to understand how humanity’s need for water will change in the future and where it will meet the water supply we will have in the future. To this end, I try to understand the function of rivers. Today I specialize in the Mekong, but my research is relevant to many rivers throughout The world, like the Amazon or the Nile.”
From Schmitt’s words, it is easy to be convinced that rivers are one of the critical resources for the existence of humanity. “They are sources of water and a source of fish, that is, a source of healthy and rare protein for many populations. One of the important things they do is carry sediment from the interior of the country to the coasts. They reach the sea, and from there they have nowhere to go and the sediment collects at the end of the river, and the sediment layers are formed in the delta.
“The doors we know were created quite recently in geological terms, only 10,000 years ago, since the Ice Age. That is, there were river doors before that, but the Ice Age buried them, and only after it were the doors formed in their locations today.”
The Intergovernmental Panel on Climate Change (IPCC) estimates that by 2050, about a billion people will live on the coasts. Among them, about 300-500 million live in delta areas. Many want to live in these areas, which serve as important junctions between the rivers (significant traffic routes within the countries) and the sea (an international transit route). In the past, such placement was even more dramatic.
“The lands of the Delta are very fertile, and this was also more critical in the past, before the development of innovative agricultural methods,” says Schmitt. “The result is that the delta areas are very populated, and the lives and quality of life of many people are in danger.”
In the Mekong Delta, which is the size of the entire Netherlands, sits Ho Chi Minh City and the city of Can Tu, with 1.2 million inhabitants. Another 10 million people live in other cities in the region. In other words, a total of 20 million people live in the area, and all of them will be forced to leave their homes in the next 50-60 years if the downward trend continues.
The delta which is considered a biological treasure chest
Along with humans, unique animals also live in the area. In the past, the Mekong Delta was called a “biological treasure chest.” Research expeditions to the region discover new species of animals and plants that were previously unknown to science in the more remote areas of the delta. In 2005, a species that was already thought to be extinct was rediscovered there – the Laos rat. This story is often told as a source of encouragement and optimism among activists to prevent the extinction of animal species.
The Mekong Delta is the leading agricultural and fishing region in Vietnam, by a wide margin from other regions, and is also a leading tourist destination. The region’s share of industry and foreign investment is more limited (although Ho Chi Minh City itself is dominant in this area as well), and the Vietnamese government is trying to change that. That’s part of the problem.
Laos rat, rediscovered / Photo: Wikipedia
“The lands in the huge delta area are one to two meters above sea level, and as we all know, the sea is rising. This is a problem in itself, but that’s not all,” says Schmitt. “At the same time, the ground level of the delta is dropping, for reasons that are almost entirely related to resource management. For example, if we have a lot of agriculture in the delta, then the farmers are pumping the groundwater. If they do it at a fast rate, the land will sink into the space where the water used to be.
“Another issue is mining. If gas or oil is discovered in the delta area – and it happened – then when they are extracted, an empty space is created again and the earth sinks into it. The same is true for sand. When you need to build in the area, sand from the delta is used for construction, and sometimes the amount is so large, which is really lacking in terms of the height of the delta.”
Sea level rise is only part of the problem
Vietnam today has a one-party authoritarian rule. Recently, the government decided to build a ring road around Ho Chi Minh City, and the sand is expected to come from the delta area. The project requires 15 million cubic meters of sand, and 7.2 million are currently missing, according to a report published in September 2022. Everyone agrees that the road is needed to address chronic traffic jams around the city, but environmental activists have pleaded with the government to take the building materials from other sources.
At the moment, the plan has not changed. “The project gives the delta region an opportunity to develop, to fulfill its dream of catching up with the socio-economic momentum of the entire country,” state government officials.
Not all decisions regarding the Mekong are in the hands of the Vietnamese government. According to Schmitt, it would be possible to replace the mined sand with new sand from the river, but even upstream there are those who desire it: the Mekong also passes through China, Burma (Myanmar), Laos, Thailand and Cambodia.
Dr. Raphael Schmidt / photo: private photo
Sometimes even projects with environmental intentions cause a decline in the face of the land. “Each country started building dams and reservoirs on the river for different uses and for different reasons, mainly dams to generate energy,” says Schmitt. “It’s basically a good idea, since these dams create energy with relatively ‘green’ methods, but even if not intentionally, the dams stop the soil from going down the river. We estimate that there was a 50% decrease in the amount of soil sediments that reach the river.”
The increase in the risk of flooding increases the legitimate desire to manage it. “Farmers and local government officials create drainage canals to prevent certain areas from flooding. Thus, if in the past a stream rich in soil and sand would arrive, encounter an obstacle, flood the area around the obstacle and spread the soil over a wide area, today the soil flows unhindered through a canal The drainage, straight to the sea.”
These occurrences are relatively new to research, Schmitt says. “In the past, all the focus was on sea level rise. Gradually, the critical role of groundwater pumping and sand mining also became clear. The studies I participated in revealed the significant role of the drainage canals.”
The result of all this together is that unless there is a dramatic change for the better, by the end of the century there will be no delta in the Mekong. There will be a sea there. The rate of drowning of the delta has been accelerating in recent years.
In this scenario, what does the life of the residents in the area look like before and after sunset?
“Depends on what the government will do. The first thing we will see is seawater that will seep into the fertile lands and harm agriculture. It is possible that then the government will build another system of drainage canals, as happened in the Netherlands. But you have to understand that this is a crazy construction of infrastructure. The Dutch have been doing this for hundreds of years. The people of the Mekong do not have hundreds of years to invest in this effort, but only 50 years at most, and their coastal nest is longer.
“The flooding of the delta will lead to damage to economic development, and as a result we are expected to see unemployment, hunger, poverty, disease, further pollution and the extinction of animal species. The flooding will lead to a global shortage of rice, fruit and seafood. The residents of the area are used to floods of about 10 cm, In other words, there is some resilience, but new studies talk about how already in 2050, we will see floods of 70 cm from time to time, and these will increase gradually until the whole area is flooded.”
Will a new delta actually be created that touches the new sea line?
“Basically yes. The existing delta land will be lost, but a new delta will begin to form at the new interface between the river and the sea. However, for many years, it will still be small and not so fertile, and in the meantime these trends continue and the new area can also drown. Such a new delta will also be significantly lower from the delta today, and very sensitive to tropical storms.”
To rearrange the chairs on the Titanic
The main challenge today in collecting the researchers’ information is the fact that the river flows between several countries, says Schmidt. The collection of information is managed by the Mekong Research Commission, which includes all the countries in the southern part of the river. The organization investigates not only the drowning of the Mekong, but also other problems of the delta region such as drought and pollution. Although China is not a member of it, the organization recently signed an agreement to receive information from China on rainfall amounts in the areas relevant to the river. This is one of 30 agreements that the organization signed with different countries and research groups, according to its latest strategic report published at the end of 2020.
Schmitt gets the raw information from these factors and then models their influence. “Since so many variables work together here, we build computer models of the river, and put into them all the information we have from the field, to see how each of them interacts with the other variables.” Thus, for example, it turned out that the height of the delta decreases at a rate 10-20 times higher than the rate at which the sea rises.
Are there any objections to the collection of the information?
“Of course, the issue is very sensitive. When the government of Vietnam, for example, misses out what is happening in the Mekong Delta, it does not always emphasize the same things that we emphasize. There are scientists who do not want to join our efforts because the conclusions we draw contradict the official narratives of their country. For example , the question of how much water is removed from the delta or how much oil is produced, is a very sensitive question.
“In the article we published on the subject, we called the steps that the governments are taking today ‘rearranging the chairs on the Titanic,’ and right now it seems that the likely scenario is that we will not be able to stop the process. But in recent years, there has been more awareness, and that is encouraging.”
Consumers also have the option to help save the Mekong
What other steps would you like to see?
“There is a move to impose quotas on groundwater pumping. This is a very difficult move, especially since along the river there are also areas that sometimes suffer from drought, so how do you tell people not to pump water? It is a challenge that needs to be taken care of with the cooperation of many parties.
“Another thought is to give up the drainage canals and allow flooding to occur in the rainy seasons. For this, the farmers must be convinced to give up a crop of rice in the rainy season. We need to find a way to compensate them, for example maybe they can sell rice with a ‘Delta-friendly’ label and its price will be a little Higher. Already today, businesses that invest in a way that endangers this delta may suffer from a reputational problem.” This, says Schmitt, is our job. Invest and purchase goods from businesses that are run in a way that can prevent the problem from worsening.
“There is also a thought about switching to crops other than rice, which encourage the accumulation of soil. The dams can be built in a way that allows the movement of soil, and the sand used for construction can be replaced with other materials.
“Delta areas are the first line in the fight against climate change, and they are studied significantly less than other aspects of climate change. My colleagues and I would like to give them much more visibility in this discourse.”