Mekong River is the most important waterway in Southeast Asia. –Photo MRC

New report: Climate, human activities are key causes of Mekong flow changes

The Mekong River has experienced increased dry season flow and reduced flood season flow triggered by climate change and water infrastructure development, a new study has found.
The Joint Study partners – the Mekong River Commission (MRC) and its upstream counterpart, the Lancang-Mekong Water Resources Cooperation Centre (LMC Water Centre) – presented their Phase 1 findings on Southeast Asia’s most important waterway at the recent 13th MRC Regional Stakeholders Forum.
“More specifically, in the last decade (2010–2020), more frequent droughts in mild/moderate than severe/exceptional droughts occurred… While severe droughts increased in the middle and lower parts of the Mekong River Basin, the exceptional drought did not change much in the recent decade,” the report stated.
“The construction of reservoirs in Thailand is mainly for irrigation. In Laos, central Vietnam and China, storage has been developed mainly to support reliable power generation. Reservoir development in Myanmar is mostly at the planning stage, while fewer large reservoirs have been developed in Cambodia due to the flat topography.”
The CEO of the MRC Secretariat, Dr Anoulak Kittikhoun, said the Joint Study symbolises a deepening relationship and trust between the two sides. “It’s the result of an unprecedented level of effort that the MRC and LMC have invested in our existing cooperation,” he said.
“Indeed, while we’ve conducted some joint research and studies before, this current effort sets a high bar. It truly shows a great commitment towards future cooperation between our two organisations.”
The report urged the riverine neighbours to further jointly study the different impacts of development and climate change along key parts of their common river, as well as to share critical data – including “real-time sharing of storage levels and hydropower operations”.
The MRC and LMC Water Centre agreed to this Joint Study in late 2019, as they expanded upon previous collaboration.
As this Phase 1 report notes, “In both 2016 and 2019, joint studies conveyed objective information about the severe droughts to the public and made scientific evaluations of the effects of water supplement from the Lancang reach to alleviate the drought conditions on the Mekong reach.”
Among the most significant features of the report, it recommends that the Mekong partners enhance notifications of any sudden change in the ways water storage operates: “As global climate change and the associated droughts and floods will play an increasingly important role in driving the basin’s hydrological conditions, it is critical for basin countries to share more information on meteorological flow conditions, extending to tributaries.”
The report continues: “Real-time data on storage levels and hydropower operations is crucial for operational models and adaptive management. Long-term data on tidal changes, water and land use, and Mekong delta groundwater levels support basin-wide research. The information-sharing platform proposed under the LMC cooperation framework provides an unprecedented opportunity.”

By Times Reporters
 (Latest Update October 11, 2023)