VietNamNet Bridge - Part of the Mekong Delta – home to 20% of Vietnam’s population and 50% of its rice production - is at risk of disappearing as sea levels rise.

A field with saltwater in Ca Mau.

Passing from one field to another in the region, we saw the same things: The water showed a dingy yellowish color and rice grew in wispy rows. 

Bui Van Sim, a farmer in Le Giao village, Thoi Binh district of Ca Mau Province, explained: "This year's crop is totally lost. Saltwater has appeared everywhere. There is no rain; almost 100% of the rice has died."

Ca Mau is a lowland, of which some parts are about to be under sea level, so flooding and seawater encroachment happen frequently. In recent years, under the impact of global warming and sea level rise, 40% of Ca Mau area faces the threat of being submerged by seawater.

Locals like Sim once were accustomed to two seasons of fresh and saltwater. The rainy season was from June to November when water from upstream overflows. This is the time that people desalt the fields to grow rice. After harvest, they let the fields dry and pump saltwater into them to breed shrimp. However, this script is changing.  

Tran Thi Diep, also living in Le Giao, said that usually the period between July and August is the time of abundant fresh water, but this year, there has been nothing even though it is early November. This means that the “golden rice bowl” of Vietnam is experiencing many changes.

Of the 13 provinces in the Mekong Delta, Ca Mau and Kien Giang are most seriously affected. 

80% of Ca Mau is at risk of submersion. The province has nearly 10,000 hectares of agricultural land affected by salinity. Moreover, sea dikes are seriously degraded. 

Kien Giang is heavily influenced by climate change, especially flooding and sea level rise every year. If the sea level rises about 85-105 cm, most of Kien Giang province will be submerged.

Furthermore, according to the calculations of scientists, along with the issue of rising sea levels, the ground of the Mekong Delta is also in danger of serious sinking, pushing the risk of “disappearance” of the most fertile fields. 

The average level of sinking measured in Can Gio District, Ho Chi Minh City is 26.3mm/year; at the estuary of the Hau River (a branch of the Mekong River) in Can Tho, it is 14.2mm/year, while in Ca Mau it is 23.4mm/year.

Additionally, erosion at riverbanks, islets and coastal areas is causing great difficulties for people and local governments. 

A few months ago, Long Khanh islet, Hong Ngu District, Dong Thap Province eroded almost completely. Water invaded residential areas, endangering people’s lives. Hundreds of households need to be relocated, pushing the government into the uneasy situation of finding funds for new land.

In the lowlands like the two provinces of Ca Mau and Kien Giang, the high sea level rise and the sinking have put the interlocking canal system in disorder. 

A house that is about to fall into the river in Ca Mau.

Many rivers see the “backflow” phenomena which brings water from the sea causing soil erosion to the isles. 

Early in September, Ta Thiet Phuong’s family at Cha La village was dismayed because her daughter's house completely disappeared in one night. That night, the tide suddenly rose and pulled the house down the river. Luckily, the family was away that night, so no one was hurt.

Boating along the Nam Can River and Ganh Hao River of Ca Mau, it is easy to see that the houses, including concrete houses, had collapsed or nearly collapsed down the river.

The foundation lands were heavily encroached by water. Most households in Ngoc Hien and Nam Can, the two southernmost districts of Ca Mau, are living in areas below sea level. The dikes built by the locals are just a temporary solution to prevent the homes from seawater on dry days. When the “floating season” comes, people’s lives also float right down the river.

Although they live in the centre of an immense amount of water, people are thirsty in a literal sense. 

Seawater intrudes into the interior; all the rivers, canals, and ponds are full of saltwater. 

The groundwater system is undrinkable because of alum. Some areas like Bien Bach, Thoi Binh (Ca Mau) or several districts like An Bien, An Minh (Kien Giang) often suffer from water shortages. 

Mr. Nguyen Van Cuong at Le Giao village, Thoi Binh, fortunately, has a rare freshwater well. Many regional people have to abandon wells after drilling them because of salination.

In the rainy season, people can catch water from the rains or share a groundwater well. In the dry season, however, water is really an issue. Freshwater is transported from other places for sale at very expensive prices: VND100,000/cubic meter.

However, this resource of groundwater is going to be exhausted. 

Mr. Cuong said: "Nowadays, it is harder for us to pump water by hand than by water pumps. In the last two years, we couldn’t pump water by hand as the water was depleted! The depth of the well is also increasing.”

“Previously, we could find freshwater after a few tens of meters of drilling. At present, finding water at more than 100m of drilling is still hard; if they drill at a shallower level, there is only salty water and alum.”

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According to the climate change scenario for Vietnam, at the end of this century, the average temperature in the Mekong Delta may increase by 1.3 to 2.8 degrees Celsius, the average rainfall may rise by 4-8%, and the sea level will rise by 66cm in low and 99cm in high. 

Each 1m rise in the sea level can cause 39% of the Delta area to be flooded, and affect 35% of the population. This is one of the areas most damaged by climate change in Vietnam.  

A report of the United Nations Development Program (UNDP) showed that the sea level rise will cause 22 million Vietnamese people to be homeless as well as a loss of up to 10% of GDP.

Many research works, seminars and projects about weather issues in the Mekong Delta have been launched. In particular, the Intergovernmental Panel on Global Climate Change (IPCC) recommends major measures for countries: upgrading dyke systems and coastal constructions, and changing the general living habits of the people to adapt and move.

In 2014, Kien Giang approved a VND390 billion (nearly $20 million) project to build a sea dyke system across Rach Gia. This is a part of a project to upgrade the dyke system from Quang Ngai to Kien Giang under the orders of the Prime Minister. The project is expected to be completed in 2016.

In addition, the interference in the flows on the Mekong River cause risks to the Mekong Delta. 

In early September, the Lao National Assembly officially adopted a hydropower project called Don Sahong in the Mekong River, which is set to start construction by the end of 2015. This means the Mekong Delta will have to face a different peril when the flow of the major river is impacted.

When a large area with many residents is affected, many people are forced to migrate and seek assistance. This is a grave problem for land management and social security – a problem that worsens in the Mekong Delta with each passing year.

Hoang Huong

(Funding for this story was provided by the Earth Journalism Network)