Southeast Asian countries would have likely experienced a much less severe drought last year if it were not for
China's dams, a new study says, prompting a pushback from the intergovernmental Mekong River Commission (MRC).
The 4,000-km (2,485-mile) Mekong is one of the world's longest rivers - winding through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam - and millions of people rely on it daily for food and income.
Based on satellite data, water resources monitor Eyes on Earth calculated the Mekong's water flow stemming from snow-melt, soil moisture, and precipitation.
Using information from 1997 to 2001 to compute representative flows under normal conditions, authors Alan Basist and Claude Williams found that although China saw slightly above-average water flow from the Mekong last year, the data from Thailand's Chiang Saen gauge, the facility that monitors water level, showed that much less water had made it downstream.
Their findings show a variation between the height of the river under natural conditions, and the time that the dams started operating.
For example, in 2019, when the water level was expected to be at approximately 7.5 metres, the indicator showed that the water level only reached 2.5 metres.