For generations farmers and their families harvesting their rice paddies in the fertile Mekong Delta have relied on the river’s bountiful fish resources and rice production for their subsistence.
For millions, the pulse of life is the constant flow of the river. Those living along the Mekong and its Delta tributaries have recognized their “water civilization” as natural wealth to be conserved and sustained for future generations.
But experts and farmers know that the intricate network of rivers and canals is seriously threatened from climate change, rising sea levels, industrial pollution and the adverse impacts of upstream hydropower dams.
Across the entire lower Mekong Delta, rising temperatures and changes in the intensity of rainfall, river flow, floods and droughts are destroying crops, fisheries and homes. Once hailed as biodiversity treasure and a rice bowl for Vietnam, an increasing number of provinces are experiencing historic devastating droughts and facing real food-security challenges.
The Mekong River rises on the Tibetan Plateau and flows nearly 4,200 kilometers before dividing into the Cuu Long (“Nine-Tailed Dragon”) and spilling into the South China Sea. In the Mekong Delta, almost 2 million people in six coastal provinces are suffering extreme freshwater scarcity.
Record low water levels in most of the waterways and rivers are causing saltwater intrusion that is reaching far inland, up to 90km from the estuaries, wiping out crops and contaminating water supplies. For too many rice farmers, their shouts of “too much water” have gone unheard; and now more often, the cry is “too little water.”
Agricultural researchers warn that unless urgent measures are undertaken, the entire Mekong Delta, home to more than 20 million people, could be mostly underwater within a generation.
“Without rapid action, the delta and its livelihoods could become victims of global and regional environmental change,” said Rafael Schmitt, a senior scientist at Stanford University’s Natural Capital Project.
The Mekong Delta is extremely vulnerable to climate hazards. As climate change poses existential threats to fragile ecosystems in the delta, studies predict rising air and sea temperatures.
According to Vietnam’s Agriculture Ministry, the delta is losing about 500 hectares of land per year to erosion. As well, unsustainable land and water management practices are polluting rivers and canals. Saltwater intrusion has risen to 4 grams per liter in many places, four times the level allowed for most crop tolerances.
Rice bowl revisited
At the start of its Doi Moi (“Renovation”) reform program in 1986, Vietnam’s political leadership invoked national plans to raise the country out of poverty and the hardships resulting from the protracted Vietnam War. A central part of that new strategy was opening up rice farming not only to feed the nation but to be a major rice exporter. Rice matters because it is the staple diet for half the world’s population.
Now scientists have provided evidence that the Vietnamese are facing perhaps their biggest challenge: climate change, with its intense storms, droughts, and food insecurity.
In the Mekong Delta, where more than a third of households have less than half a hectare of rice land, the government has been encouraging a “small field, large farm” model to be coordinated by large agribusinesses or conglomerates like the Loc Troi Agricultural (LTA) Products Group. Now farmers are engaged in contract farming practices that encompass nearly 10% of the rice-paddy area in some provinces.
For many farmers, this new model provides a sustainable safety net. Loc Troi’s system includes more than 40,000 small farmers, and it enables the company to oversee from seed to harvest and transportation a network of 24 factories located throughout the delta for drying, milling, storage, and delivery of rice.
With a reputed daily capacity of nearly 26,000 metric tons of rice drying, more than 22,000 tons of rice milling and 1 million tons of rice storage, LTA can meet the large volume of international orders in Europe, North America, Japan and Australia, and along the way it is educating farmers to adopt new rice production practices that do not include the overuse of fertilizers and pesticides.
A recent government-released report on transformation of development models and integrated planning focuses on the change in an agricultural model and assesses the impact of the Mekong Delta Integrated Plan for 2021-2030.
Hanoi’s policy planners understand all too well the grave challenges attributed to climate change, economic decline, labor shortages and raw-material sources that fail to meet export quality standards.
The report also details the urgency for investment in the delta and for international cooperation and partnerships to mitigate climate change.
Professor Vu Thanh Anh, the former dean at Fulbright University Vietnam and now a senior lecturer and head of the research report team, says the Covid-19 pandemic had a huge impact on local economic growth but the Mekong Delta was one bright spot, with the agricultural sector growing by 3.4%.
The central government was moved to take decisive actions after the Mekong Delta suffered huge losses when severe drought combined with rising sea levels at the end of 2015 and 2016. By 2017, the introduction of Resolution 120 placed an emphasis on sustainable and climate-resilient development in the region.
The national policy has given rise to agricultural cooperatives to develop sustainably and enable farmers to also focus on planting fruit trees, since inefficient rice-growing areas are easily converted to the cultivation of fruits and vegetables tolerant to drought and salt.
Also, over the past decade, the region has witnessed a steady migration of residents leaving their farms to find work in the urban areas, especially in Ho Chi Minh City. The delta provinces with the largest population decline in 2020 were Hau Giang, Tra Vinh, Soc Trang, An Giang and Ca Mau.
According to an article published by the Earth Journalism Network, many areas where rice growing was inefficient have been converted to grow more salt- and drought-tolerant crops such as dragon fruit, coconut, lotus, areca and watermelon.
Mekong Delta ecologist Nguyen Huu Thien said: “Climate change will be the most significant environmental impact in the future. Flood and inundation are increasing frequency; and magnitude, following sea-level rise, seasonal tropical storms increase as a result.”
Hydropower threats to delta
The Mekong River flows through five countries, China, Myanmar, Laos, Thailand and Cambodia, before entering Vietnam. All of these countries see hydroelectric power as crucial to their economic growth.
By 2021, the upper Mekong River had 141 dams in operation. In addition, there are 36 more under construction. By 2032, there will be a total of 468 hydroelectric plants on the Mekong and its tributaries. While most of these plants are not located in Vietnam, they are adversely affecting the living conditions of more than 20 million citizens in the lower delta.
The data present a grim picture on the impact of the dams and the downstream ecosystems with a systematic decline seen in fishes caught and rice production crops. The overall drop in rice cultivation is directly correlated with the absence of floodwaters that have historically spurred the growth of floating rice, the signature crop of the Mekong Delta.
The balance of river and sea is shifting dramatically. Past and present droughts in the delta have devastated food supplies and added to the rancorous debate on China’s upstream “run-of-the-river” geopolitical paradigm. The dams are preventing not only the floodwaters from reaching Vietnam’s lower Mekong Delta but also the flow of sediment that nourishes the soil and provides food for fish.
In a full disclosure, I am a co-founder of the Mekong Environment Forum (MEF), a non-governmental organization located in Can Tho, Vietnam. Our outreach programs and citizen science-oriented workshops address myriad environmental issues.
In a past MEF-coordinated symposium, Philip Minderhoud and Sepehr Eslami Arab of Utrecht University, research members of the Rise and Fall Project, presented their findings from six years of research revealing that saltwater intrusion in the Mekong Delta is less than 5% due to climate change, but mainly attributed to hydropower development.
According to the two researchers, the fluvial sediment supply has dropped nearly 90% because of the upstream dams. Their studies and others highlight that upstream hydro-infrastructure developments impact flow regime, sediment and nutrient transport, bed and bank stability, fish productivity, biodiversity and biology of the basin.
The depletion of sediment flow to riverbeds and banks is quickly increasing far beyond climatic trends. When the dams regulate the flow of the Mekong and kill the flood pulse, Tonlé Sap lake can no longer function as a historical flood-retention reservoir and thus fails to supply needed water to the Mekong Delta.
Simultaneously, the delta’s deeper channels invite increasing saltwater intrusion from sea-level rise and tidal amplification. The ocean tides travel up the Hau River, spilling over dikes and eventually flooding downtown Can Tho. The natural system that buffers the floods reaching the delta is rapidly being altered.
The floodplains play an important role for the agro-ecosystem and the socio-economy of the Mekong Delta, since they provide natural flood retention and reduce the discharge peaks in the flood season.
Hydrologists agree that dam operations affect rivers by redistributing flows and in interannual variability. While the distinctions between dam-driven versus climate-driven alterations prove inconvenient at times, Tonlé Sap is now in a serious state of collapse because of China’s upstream dams.
The years of dam-building and droughts intensified by climate change have changed not only one of the world’s richest freshwater fisheries but have impacted on those living downstream in the Delta.
Brian Eyler, director of the Stimson Center’s Southeast Asia Program and author of Last Days of the Mighty Mekong, through satellite data showed that China’s record of impounding water has led to far more serious drought for downstream countries.
Eyler’s focus on a US government-funded study published by Eyes on Earth highlights that evidence from the physical river gauge of the Mekong River Commission and remote sensing confirms that the ongoing droughts are the result of the Chinese water-management policy.
The data reveal that from 1992 to 2019, satellite measurements of “surface wetness” in China’s Yunnan province suggest the region actually had slightly above-average combined rainfall and snowmelt from May to October 2019.
“When drought sets in, China effectively controls the flow of the river,” Eyler said.
All recent data paint a damning picture of China’s upstream restriction of water flow from the Mekong’s upper basin. The scientific study confirms that China could have done much to alleviate drought and maintain an above-average river level.
Stimson’s research reveals a systematic pattern of Beijing’s “run-of-the river policy” that translates simply: Water should never be shared without China using it first or unless someone downstream pays for it. This action is punctuated in the failure of China to sign any international treaties for its transboundary rivers.
In a geopolitical showdown, the Chinese government believes that Mekong water is a sovereign resource rather than a shared resource, placing the downstream governments’ need to secure free access to international water resources, biodiversity conservation and food security at risk. Beijing’s water diplomacy program is flawed, since its dams weaken the river’s flow and allow seawater to intrude further upstream.
For three decades, China has been building dams on the upper Mekong reaches, worrying countries downstream that China could one day turn off the tap. In 2020, a record drought wiped out crops and resulted in a humanitarian crisis in downstream regions.
Chinese leaders have reaffirmed that China has overcome its own difficulties and increased water outflow from the Lancang River to help Mekong countries mitigate the drought, and said that China and its neighbors must trust and help one another to move forward together.
Yet for too many neighbors in downstream deltas, China’s behavior continues to exacerbate drought, causing a decline in fish catches and a drop in rice production, revealing a vast gap between Beijing’s actions and words.