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2-7. Livelihoods and Environmental Issues inVietnam’s Mekong River Delta
1Vietnam’s Mekong River DeltaThe Mekong River Delta is a huge tropical wetland that plays an important role in conserving thebiodiversity of the Mekong River, an international waterway. The Mekong Delta is spread out over an
area of 36,000 km2. Of this, two million hectares (20,000 km2) are farmland, the main crop being rice,
the staple food of Southeast Asia.
The people of the Mekong Delta live on land lying less than 10 m above sea level, making this an area
extremely vulnerable to climate change. If the sea level should rise one meter, 25% of the current landarea of the Mekong Delta, home to 3.5 to 5 million people, would be lost.
The delta plays a crucial role in Vietnam’s domestic food supply and exports, supplying 53% of riceand other grain production, 80% of the fish harvest, and 75% of fruit production.
The delta area consists of 12 districts, with Can Tho as the central city. The present population of thedelta is 18.6 million, 26% of the total population of Vietnam. Historically, the people of the delta havemade their livelihoods by settling densely along the banks of the river and the canals that branch off
on either side. Separating the socioeconomic development of the delta from the water resource regime
is totally inconceivable.

Water Resource Issues in the Mekong Delta
There are five limiting factors constraining agricultural production in the delta. Two of these, floods
and the shortage of fresh water, concern water quantity. The remaining three factors of seawater
intrusion, soil acidity and water pollution, concern water quality. In addition, water issues thattranscend international borders, sea level rise due to climate change, and dam construction on theMekong River mainstream are looming on the horizon as disturbing issues for the future. Each issue isdiscussed below.
Flooding: Floods occur in the Mekong Delta from August to October each year. The average dischargeof the Mekong River in the wet season is about 39,000 m3/sec. Roughly 1.2 to 1.9 million hectares of<2-7>1<Nature and Our Future: The Mekong Basin and Japan>

the delta are inundated during this season, making agriculture impossible in the flooded areas. In thedry season, however, the average discharge of the Mekong River falls to between 1,700 and 2,500 m3/sec. Moreover, not only does the water table drop two to three meters in the dry season, there is hardly
any rainfall in the area during this period.
Seawater intrusion: Seawater (salinity) intrusion is caused by seawater flowing inland wheninsufficient freshwater is flowing through the estuaries. Sea tides also affect the delta’s water regime.
The mechanism of salinity intrusion in the Mekong Delta is very complex. At present, 1.7 to 2.1
million hectares (roughly 40 to 50% of the Mekong Delta) are affected by seawater intrusion.
Soil acidity: Extensive areas of the Long Xuyen Quadrangle, the Plain of Reeds, and other areas
have surface soil acidity. The total area of this land amounts to about 1.6 million hectares, 40% of thetotal area of the Mekong Delta. It is known that artificial drainage of acid surface soil resulted in theacidification and accumulation of Fe2+ (iron ion) and Al3+ (sulfide ion) in canal water. Highly acidicwater may be harmful to the health of humans, animals and plants.
Water pollution: Rapid population growth and the expansion of residential areas along the river banks
are having adverse impacts on the water environment. Water quality parameters along the river andcanals in the Mekong Delta are generally related to the use of fertilizers and pesticides in agriculture,nutrient-rich effluents from aquaculture and animal husbandry, and wastewater from industrial plants.
Climate change and sea level rise: According to the Intergovernmental Panel on Climate Change (IPCC)
4th Assessment Report, in the last ten years climate change has become one of the world’s mostserious socioeconomic and environmental problems, and the Mekong basin is considered to be one of
the areas of the world most acutely affected by climate change and sea level rise (IPCC 2007). A study
on the future impacts of climate change on the Mekong delta by Can Tho University and Thailand’s
Chulalongkorn University have shown that the Mekong basin will experience severe impacts related
to floods from the upper reaches and seawater intrusion in the lower reaches.
Transboundary environmental problems caused by the Mekong River mainstream dams: The Mekong
region is now facing a new issue. China already has six operational dams2 and another two dams3
planned on the Mekong River. Further downstream in the Mekong, 12 dams are also now in theplanning and construction stages4; eight in Laos5, two on the Thai-Lao border6 and two in Cambodia7.
If these Mekong River mainstream hydropower dams are completed, thousands of people will lose
their homes and will be relocated, the flow of the river will be altered, sediment loss and erosion will
increase, river navigation will be disrupted, biodiversity will be reduced, fish resources will be lost,and further potential negative impacts, as yet unknown, are likely to occur.
Of all the dam plans for the Mekong mainstream, the Xayaburi Dam is the farthest advanced. Ifconstructed, this will be the first hydropower dam on the lower reaches of the mainstream of theMekong River. The governments of Cambodia and Vietnam, located downstream from the dam, havebeen requesting that the government of Laos, which is constructing the dam, carry out cross-borderenvironmental impact assessments. The government of Laos, however, has not answered this request.
If the mainstream of the Mekong is blocked, the flow of the river will be altered and the approximately<2-7>2

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30 million people living in the lower Mekong River basin may be seriously affected by adverse
transboundary impacts.

Concluding Remarks
The impacts of climate change and transboundary dam development will bring about both quantitativeand qualitative changes in the flow of the Mekong River, threaten the livelihoods of the people andfood production, and further exacerbate the environmental issues we are now facing.
The Mekong delta’s economy depends upon natural resources. People’s food security is supported byan economy that has rice production at its center, and is made possible by aquaculture, agriculture, andservices that are tied to the Mekong River. These are all crucially affected by water, land and climate.
Sustainable development in the Mekong Delta is founded upon a stable social system built upon thepremise of secure access to water, which is the basis of food security. Collapse of this system willundoubtedly result in severe impacts on social stability and Vietnam’s economic growth. Cooperation
among scientists, policymakers, government agencies, NGOs and local people will be necessary tobuild a strategy and action plan to resolve these enormously complex problems.
References
Intergovernmental Panel on Climate Change (IPCC). 2007. IPCC Fourth Assessment Report: Climate Change 2007 (AR4).
http://www.ipcc.ch/publications_and_data/publications_and_data_reports.shtml#1

Rported by Le Anh Tuan (Can Tho University) and Summarized by Mekong Watch

1. This article is a summary of a report given by Dr. Le Anh Tuan from the Research Institute for Climate Change (DRAGON InstituteMekong), College of Environment and Natural Resources, Can Tho University (Vietnam) at the international workshop, Establishingan East-Asian Civil Society Network to Discuss Sustainable Natural Resources Management in the Mekong River Basin sponsored byMekong Watch on December 12, 2012 in Tokyo, Japan.
2. Gongguoqiao, Xiaowan, Manwan, Dachaoshan, Nuozhadu, and Jinghong Dams
3. Ganlanba and Mengsong Dams
4. The number and status of the dams have been updated by Mekong Watch.
5. Pak Beng, Luang Prabang, Xayaburi (under construction), Pak Lay, Sanakham, Lat Sua, Thakho, and Don Sahong Dams
6. Pak Chom and Ban Koum Dams
7. Stung Treng and Sambor Dams

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