Dr. Duong Van Ni, Adapting to a Saltier Mekong Delta

On a bright blue plastic chair, he sits. A man in his late fifties, with a helmet of shiny black hair and hazelnut eyes, dressed in a smart casual outfit, twirling his foot in a black flip-flop. It’s hot outside, and the coastal area of Mekong Delta hasn’t seen rain for a while.

“I came to [the northern province of Mekong Delta] twenty years ago,” says Dr. Duong Van Ni. For more than thirty years now he has been teaching, twenty of which has been at the Can Tho University, leading an agricultural research center in Vietnam. But his passion to educate doesn’t end in the classroom.

“I learned with my team of researchers at the University that we understand some parameters [around agriculture] that local people don’t”, says Dr. Van Ni. “So we can share this knowledge with them. But the opposite is true too and, actually, we can learn something from them as well.”

Right now, paddy rice field cultivators in the Mekong Delta, usually no further than 50 kilometers away from the sea, are Dr. Van Ni’s most favorite students. He spends his time travelling around the area, teaching them how to use his newest invention – a low cost and handheld gravity meter – which he gives away for free.

A tool that looks like a glass peppermill with a tiny one-sided graded sand clock floating inside, involves simple mechanics: “You take [the floating part] out, and you fill [the cruet] with water,” Dr. Van Ni explains. “And it depends on how much salt there is in the water – more salt, it will [go] up, less salt, it will [go] down.”

While the tool sounds simple, the impact it can have for the sustainable development of the whole Mekong Delta is enormous.

“The Mekong Delta is a young land,” says Dr. Van Ni. “So that’s why the Delta depends very much on the water regime and the hydraulic situation up the Mekong River, [flowing] through six countries until it finally reaches the sea.” Historically, the area had two easily distinguishable rainfall seasons – the rainy and the dry ones.

“But then the climate [changed] – it made the rainfall patterns become more [uncertain],” Dr. Van Ni continues.

Misbalanced rainfalls meant that the sea level has risen, and floods in the upper part of Delta reduced the flow of the river, leaving it unable to push salty seawater away from the shores of the Delta.

Salty water never went inlands by more than 20 kilometers, but now these numbers have tripled: Newest research suggests that salty water intrusion now goes 40 to 60 kilometers upstream. This is exactly where many of the farmers cultivate their salinity-sensitive paddy rice fields.

Knowing that rice can grow only in conditions of up to four grams of salt per liter of water, Dr. Van Ni started to look for a solution. He couldn’t just let the farmers switch to shrimp farming as this would not only expose them to more risks related to shrimp diseases, but also threaten the environment while destroying protective mangrove forests.

“So far, the research can develop [models] and try to predict what may happen,” says Dr. Van Ni. “But the results aren’t always true.” The results that he gathers from the farmers already using salinity meters never lie, and the researcher is slowly building a map, showing the areas that have to deal with the most severe problems.

In the future, Dr. Van Ni’s research would help to fully understand the problem of infiltrating seawater. As efficient water management and the maintenance of river basins’ natural resource bases is one of the most important factors influencing sustainable development of troubled regions around the world, such knowledge could become a game changer.

“In the Mekong Delta, especially in my work in the rural area, I recognized that the climate factors have changed many years ago,” says Dr. Van Ni. “But only around 1965 [did I first] hear people mention climate change – when I attended an international conference in Europe.”

And even though Vietnam is almost 10,000 km from Europe, Dr. Van Ni repeats the credo that many climate activists around the world are guided by today: “We need to think and talk globally, but we need to act locally.”

It is widely known that the IPCC predicts a worldwide temperature rise of 2 degrees Celsius by 2050 using mid-range carbon emissions scenarios. However, this is much more severe for the Lower Mekong Delta region, where Vietnam is located: Climate scientists predict a temperature rise of 3 to 5 degrees Celsius, according to the USAID. In addition to longer periods of salty water in the Mekong Delta due to longer floods, climate change has already caused a rise in sea level of 12 cm in the area, according to the World Bank.