On the morning of August 24, 2020, the third Lancang-Mekong Cooperation (LMC) Leaders’ Video Conference was held. Premier Li Keqiang and Laos Prime Minister Thongloun Sisoulith co-chaired the meeting. Cambodian Prime Minister Hun Sen, Myanmar President U Win Myint, Thai Prime Minister Prayuth Chan-ocha and Vietnamese Prime Minister Nguyen Xuan Phuc attended the meeting. Cooperation between the Mekong River countries has long been established, but due to the recent deterioration of Sino-US relations, the Mekong River basin has become a new focus of the dispute between the two countries, and some media outlets even call it the “next South China Sea.” Since the beginning of 2020, former US Secretary of State Mike Pompeo has held several meetings with five countries in the Mekong basin, including Myanmar, Cambodia, Thailand, Laos, and Vietnam.

    In addition to the US government, some think tanks and NGOs have also frequently spoken out in the media and released relevant reports and projects regarding this issue. The most influential one is a report issued by Eyes on Earth (EoE), a research institute in the US. This report, which was supported by the Sustainable Infrastructure Partnership, implemented by Pact as part of the US Department of State's Lower Mekong Initiative, criticized China’s “hoarding of water sources in the upper Mekong River and affecting the livelihoods of people in downstream countries”, sparking heated debates about the causes of the growing seasonal water shortage in the Mekong basin. Moreover, the Mekong Dam Monitor, sponsored by the US Department of State, officially launched on November 15, 2020. The Mekong Dam Monitor is an open-source online platform that promises to provide weekly updates using remote sensing and satellite imagery on the levels of reservoirs at 13 dams along the Mekong’s main stretch, as well as at 15 tributary dams with power generation capacities greater than 200MW. It further seeks to circulate weekly visualizations and analysis of "China’s 11 dam cascade on the upper Mekong".

Crisis on the Mekong River

Among about 260 international river basins, the Mekong River, which originates in China, is the 12th longest in the world. The Mekong River plays a significant role in the development of riparian countries. For centuries, the river has been a vital lifeline nourishing tens of millions of people in the region, and it is also a source of production activities such as fishery, agriculture, hydroelectric power and transportation. In June 2020, the “Annual Report on the State of World Fisheries and Aquaculture” issued by Food and Agriculture Organization (FAO) listed the Mekong River basin as the world’s most productive freshwater fishery. At the same time, the research of World Wide Fund for Nature (WWF) estimated that the Mekong basin accounts for a quarter of the world’s annual freshwater fish catches.

In recent years, droughts, floods and other disasters occur frequently in the Mekong River basin. In 2019, the lower Mekong basin suffered a severe drought, with water levels dropping an average of 70-75% compared to the same period in 2018. In addition, the flood cycle has become irregular, seriously affecting fisheries, agricultural production and residents’ lives. Tonle Sap in Cambodia is one of the examples. This inland lake is one of the most biologically diverse areas and the largest freshwater fishery in the world. The lake has dried up rapidly in recent years, leading to the death of a large number of fish schools, and depriving tens of millions of families in the Mekong basin of their main food source.

Controversy over the Causes of Drought in the Mekong River

In April 2020, EoE released a report named “Monitoring the Quantity of Water Flowing Through the Upper Mekong Basin Under Natural (Unimpeded) Conditions”, which compared actual measurements of the Mekong River Commission river gauge in Chiang Saen, Thailand to a natural river flow model derived from remotely sensed wetness index to measure all forms of wetness. The calibration (1997 to 2001) was used to form the foundation of a regression equation to quantify the relationship between the wetness and gauge measurements. The report concluded that China’s operations of 11 upstream dams exacerbated drought conditions in the lower basin by restricting the natural flow from China during the wet season. With the widespread dissemination of research results, the report triggered discussions from all walks of life on the reasons for the increasing seasonal water shortage in the Mekong River basin. The Stimson Center cited the research as evidence, claiming that China’s water management policies are the direct cause of the drought in the lower Mekong River.

However, many institutions and individuals, including the Mekong River Commission (MRC), the Australian-Mekong Partnership on Environment, Resources and Energy Systems (AMPERES), scholars at Aalto University and others questioned the research conclusions of the EoE and the Stimson Center. Their views were mainly classified into the following five points.     

First of all, a simple regression model is not able to adequately describe the complex hydrological process of Lancang River. The model took dams in the upper Mekong River as the only factor affecting the downstream water flow, and did not take into account the impact of rainfall in the downstream basin and downstream tributary flow on the 2019 drought, so it cannot scientifically reflect the true cause of the 2019 downstream drought.

Second, a key limitation of the report is that the authors’ analysis was based on water level, rather than water volume. And water level data alone cannot fully reflect the flow of the Lancang River, or the amount of water stored and released by the reservoirs. Specifically, scholars at Aalto University estimate runoff produced upstream of the Jinghong Dam (the last in the Lancang cascade) using a total of 26 freely and openly available runoff datasets. From their analysis, only 2 of the 26 datasets predict (on average) smaller runoff volume produced during the wet season than the Lancang cascade active storage capacity. By changing the research question and designing a methodology to address this question under data scarcity, scholars at Aalto University reach an opposite conclusion from the EoE report - it seems likely that the upper Mekong Basin experienced drought-like conditions.

Figure 1: 26 independent estimates and the ensemble mean of a) the range of runoff produced upstream of jinghong dam during rainy season, and b) the cumulative runoff produced during wet season. The active storage capacity of the lancang cascade is shown. The ensemble mean is highlighted.

(CREDIT: Aalto University)

Third, the monthly water level data is too rough to accurately reflect hydropower operations with relatively short time spans. It would be more convincing if daily water level data is used. The time span of data selected for regression model is only 5 years (1997 to 2001), which is insufficient to represent the real hydrological situation of the Mekong River. The report uses the years 1994 through 1996 as the validation period to test the stability of the model, however, the Manwan hydropower dam on the upper Mekong River was built in 1993, so the water level after that could not be regarded as the water level data under “natural flow conditions”, meaning that there is a problem in the selection of time span in the model.

Fourth, the flow of the Mekong River varies greatly, but the baseline used in this research is too short to reliably identify the correlation between the water level and the humidity of the upstream basin. According to Cambodia Daily, there is no scientific basis for the concept of “tap”. For any river, its runoff is formed by a combination of many factors. Climate factors are the most basic and important factors affecting runoff. Precipitation and evaporation in climate factors directly affect the formation and change of runoff. Temperature, wind and humidity in climate often also affect runoff by affecting precipitation and evaporation. In addition, the underlying surface runoff factor is also one of the main factors affecting the flow, mainly including geomorphology, soil properties, lake and marsh rate, vegetation coverage rate, etc. It is true that human activities can also exert influence on the temporal and spatial distribution of runoff, such as building dams, transferring water across basins, and artificial rainfall. The EoE report and the Stimson Center article, which simply attributes the flow of water in a basin to the construction of dams upstream, is unconvincing. Finally, the research hardly cited peer-reviewed literature on the Mekong River system, and there is also no evidence that it has been peer-reviewed, which are two key safeguards in the scientific research process.

Besides, some organizations from China have also disputed the conclusions of the EoE and Stimson Center. The Global Environment Institute (GEI) published an article on May 22, 2020, arguing that the EoE report arouses many questions partly because the authors’ models are scientifically flawed and their conclusions are not convincing. On the other hand, it is also because some institutions have made groundless and politicized remarks on the report through many media outlets, which has contributed to the tense international relations.

In July 2020, Tsinghua University and China Institute of Water Resources and Hydropower Research jointly released a research report on “Drought Characteristics of Lancang-Mekong River Basin and the Impacts of Reservoir Regulation on Streamflow”. Overall, the study pointed out that China’s dams could store water in the rainy season and release water in the dry season, which would help to solve the drought problem. Specifically, based on the figure 2 from the study, the nature and observed regime curves during 2010-2019 clearly showed that reservoir operation reduced the runoff during the rainy season and supplement the runoff during the dry season.

Figure 2: Natural and observed regime curves at Chiang Saen Hydrological Station

(Credit: Tsinghua University)

Also, the study indicated that compared with the past 60 years, the frequency of major droughts in most parts of the Lancang-Mekong River region increased in the past 59 years, and countries in both the upper and lower reaches of the basin had been severely affected. Annual scale (12 months) of SPEI and SPI results both indicated that 2019 and 2015 were the most severe drought years in history, as shown in Figure 3. Drought in 2019 was characterized by a long duration and heavy and low rainfall during the rainy season. The region with the highest frequency of drought was located in the middle and upper reaches of Lancang River in China and the highest frequency of drought occurs during the Mekong River’s dry season, which was also the peak season for agricultural irrigation.

Figure 3: Dynamics of SPI12 (1981-2019) and SPEI12 (1901-2019) of the LMRB

(Credit: Tsinghua University)

Chinese and the US studies have drawn different conclusions about whether Chinese dams have contributed to the Mekong’s drought. It is not only due to the technical differences, but also reflects the geopolitical disputes between China and the US. In 2009, the US established the LMI. So far, the US has invested $120 million on this initiative. And China has also been strengthening the activities of its LMC group. In 2016, the organization set up a $300 million research fund to subsidize small and medium enterprise cooperation projects in five downstream countries.

In response to the different conclusions of Chinese and the US reports, Sebastian Biba, a researcher at Goethe University in Frankfurt, Germany, pointed out that environmental factors such as climate change are indeed related to drought, but China’s dams have exacerbated the situation. Biba further stated that the different findings between China and the US were a signal that the Mekong River has become a region of geopolitical disputes. Witoon Permpongsacharoen of the Mekong Energy and Ecology Network also agreed that it was becoming a geopolitical issue between the US and China, just like the South China Sea.

Zhai Kun, a professor at the School of International Studies at Peking University, pointed out that the increasing number of extreme weather in the Mekong River region made it difficult for the MRC to predict and manage hydrological information at the technical level. In addition, some countries outside the region tried to bypass the MRC by establishing the Mekong Dam Monitor, which put great pressure on the MRC. This pressure sometimes led the MRC to draw exaggerated “concerns” and conclusions about the true state of the Mekong river’s water resources, perhaps without investigation and research based on objective facts. He added that as Mekong river was so vital to the lives of the people living along its shores, a certain degree of exaggerations from some technical officials was justifiable to some extent.

Cooperation through Data Sharing

For a problem as large as the ecology of a river, there are likely to be deficiencies in any study, and researchers may even be biased. Therefore, it is essential to promote data sharing and dialogue in an open and transparent manner. As two researchers from Aalto University commented on the controversy: “Research should be used as a catalyst for science-based policy discussions in the public domain, rather than a definitive answer that ends the conversation. Despite its shortcomings, the study does encourage open and diverse discussion. In general, the dialogue we want to see is not a one-way dialogue from ‘experts’ to the public, but an iterative process that encourages public debate. This requires scientists and decision makers to maintain a certain degree of humility.”

An Pich Hatda, chief executive of the Secretariat of the MRC, addressed : “We call on the six countries of the Mekong River to enhance the sharing of data and information with the MRC on the operation of their dams and water infrastructure in a transparent and expeditious manner.” Moreover, the AMPERES also emphasized the importance of data sharing. They believed the five principles of data production and management, including transparency, openness, peer review, fairness, and separating data production from political considerations, are crucial to maintaining evidence-based Mekong discussions. And the partnership recommended all stakeholders to learn from the experience of the Intergovernmental Panel on Climate Change (IPCC). As an international organization in the field of climate change, the IPCC is committed to the study of scientific issues in climate change, and is the scientific basis for decision-making of the UNFCCC. In the case of the Mekong River, an IPCC-style investigation requires authorization and supervision from the governments of the basin countries, a platform for the substantial participation of civil society, and an independent scientific evaluation process.

As the most downstream country, Vietnam is particularly vulnerable to poor management of upstream water resources. As ASEAN’s rotating presidency in 2020, it was expected to advance the Mekong issue on the ASEAN agenda. At the 55th Council Meeting of the Asian Organization of Supreme Audit Institutions (ASOSAI) on July 27, 2020, the Vietnamese side expressed the importance of water resources auditing on the Mekong River. And the State Audit of Vietnam (SAV) will be the main implementer of ASOSAI’s cooperative environmental Audit in Southeast Asia during 2020-2021, aiming to promote the sustainable use of the water resources of the Mekong River, not only ensuring the harmony of the interests of the countries along the Mekong River, but also not having a negative impact on the lives of local residents.

As a country on the upper reaches of the Mekong River, China attaches great importance to its relations with countries in the Mekong River basin, and has also expressed its willingness to share hydrological information and promote cooperation in water resources. During the third LMC Leaders’ Video Conference on 24 August 2020, Premier Li Keqiang put forward six proposals on strengthening LMC, one of which is “taking water cooperation to a new height,” which means that China is willing to do more to help countries better utilize water resources within its capacity. Premier Li pointed out that China would share annual hydrological information of the Lancang River with Mekong countries, and jointly build an information sharing platform for Lancang-Mekong water resources cooperation to better cope with floods and droughts. In addition, China would hold regular ministerial meetings and forums on water resources cooperation, implement cooperation projects on dam safety and flood warning, and enhance the capacity of comprehensive river basin management and water resources management. To address Premier Li’s proposal, the Ministry of Water Resources officially provided five Mekong countries and the MRC with the annual hydrological information of the two international hydrological stations(Yunjinghong and Manan) on the Lancang River on November 11, 2020.

On April 13, Chinese State Councilor and Foreign Minister Wang Yi attended and delivered a speech at the reception marking the fifth anniversary of the Lancang-Mekong Cooperation (LMC). In March 2016, the first LMC Leaders’ Meeting was held in Sanya, Hainan province, launching the LMC process in all respects. Over the past five years, the LMC has yielded fruitful results and important progress has been made in building a community of shared future among Lancang-Mekong countries. By March 2021, China has held three Leaders’ Meetings, five Foreign Ministers’ meetings, seven Senior Officials’ meetings and ten Diplomatic joint Working Group meetings. All the six countries have set up LMC national secretariats or coordinating bodies in their respective foreign ministries and establish joint working groups on priority areas. The Lancang-Mekong Water Resources Cooperation Center, the Lancang-Mekong Environmental Cooperation Center, the Lancang-Mekong Agricultural Cooperation Center and the Global Mekong Studies Center have all been established and put into operation.

As the largest clean power operator in the Lancang-Mekong Sub-region, China Huaneng Group Co., Ltd. actively promotes cooperation with Mekong countries to meet the water demand for navigation, ecology and people’s livelihood. From April 26 to 29, China Huaneng Group Co., Ltd. and the Lancang-Mekong Water Resources Cooperation Center jointly held the “Lancang-Mekong Water Resources Week 2021” event in Yunnan province. Diplomats from Mekong countries and representatives from the Chinese Ministry of Foreign Affairs, Ministry of Water Resources, Lancang-Mekong Center and other institutions attended the event. Through field visits and discussions, the delegates had a detailed understanding of the hydrological characteristics of the Lancang River and the role of the cascade reservoirs in the Lancang River basin, and reached consensus on in-depth cooperation in the areas of sharing data, strengthening technical cooperation, and jointly dealing with floods and droughts in the Mekong region.

From August 19 to 20, the inaugural ASEAN-MRC Water Security Dialogue was held. Officials and experts empathized the role of technology to manage water-related risks while while improving the quality and quantity of reservoir water. Delegates also suggested pursuing engagement with a broad range of institutions and the greater use of public-private partnerships. Kung Phoak, Deputy Secretary-General of ASEAN for ASEAN Socio-Cultural Community, highlighted the value of promoting regional cooperation and strengthening linkages among ASEAN countries to tackle emerging water issues that include equitable access to safe and affordable water supply, sufficient water to ensure food security to support the region’s economies, and sustained solutions that mitigate water-related hazards.

    Indeed, in the current relatively turbulent international situation, it is particularly vital to strengthen cooperation between China and the Mekong countries. Data sharing will help countries and all walks of life participate in discussions, have equal dialogues, and reduce differences caused by information asymmetry, ultimately achieving “mutual benefit” in the upper and lower reaches of the Mekong River. Looking ahead, China is ready to work with Mekong countries and other relevant stakeholders, respect the legitimate concerns of relevant countries, properly address issues related to the Mekong River, promoting the prosperity and development of the Mekong River.