Thailand’s space development agency has released the satellite photographs showing the water color of the Mekong River has turned to blue-green, while the river has been experiencing unusually dry again since early this year
The Geo-Informatics and Space Technology Development Agency or GISTDA has released the photographs on its FB Page showing in comparison the Mekong River’s color, which has changed from light green in early January to blue this month.
The agency said this was a stark contrast of the water color of the river, not to mention that it is supposed to be brownish following normal sediment loads.
The agency noted that the aquamarine hue of the river has reflected how low the water levels in the river have dropped over the past month. Some bedrock river bottoms or sand bars in the middle of the river and by the riverbanks have become clearly visible, the agency said.
“The blue color of the river has reflected how critical the situation is,” said GISTDA.
This is the second time that the river’s color has evidently changed. The phenomenon was first reported by NASA Earth Observatory in November 2019, when the satellite Landsat 8 had captured the blue-green color of the Mekong River in northern Thailand before further along the Lower Mekong.
This was different from it used to be when compared with the photo of the river section captured by the same satellite in 2015, which showed the river still looked brownish with its normal sediment loads.
The Mekong River in 2015 and 2019. Credit: NASA Earth Observatory
Since mid-2019, an unusual drop below the historical long-term minimum levels of the Mekong River had been reported.
The Mekong River Commission (MRC) said some key factors had contributed to the state of what was described as the “regional low flow” of the Mekong river basin, including the very deficient rainfall over the Mekong basin since the beginning of this year.
The organisation also cited the deficient groundwater in the region, and more critically, it said the amount of water flowing from the upper part of the basin as “possibly being a potential contribution of the low flow”.
During that time, China had notified downstream countries that Jinghong Dam upstream was undergoing grid maintenance, prompting the water discharge from the dam to be cut down from around from 1,050-1,250 cubic meters per second (m3/s) to 504-600 m3/s.
This was not to mention that the first Lower Mekong dam, Xayaburi, then started to be operational.
Following the unusual drop of the water levels in the river, the river’s color eventually turned to blue-green. (Read: ‘Extremely low flow’ and plus prompt the Mekong aquamarine hue)
The MRC itself quickly analysed the situation and said “many factors” may have contributed to the occurrence, including the “extremely low flows” in the river. However, it stopped short to point whether the dam operations upstream played a role in all these unusual phenomena.
This year’s early low flows
This year, China had sent the notification to downstream countries in early January again, informing that the dam would reduce the water discharge, from 1,904 cu m per second to 1,000 cu m per second during January 5 to 24 for power grid maintenance.
The Office of National Water Resources projected the impacts on water levels in Thailand’s section, saying the river level in Chiang Saen would drop around 30 cm during the period, in addition to the drop by 60 cm during January 2 to 4 already.
Further downstream of the Xayaburi dam, provinces like Loei, Nong Khai, down to Ubon Ratchathani, the water levels would also drop by 30 cm, but these would also depend on “the operation of the Xayaburi dam”, the office noted.
The MRC also projected and reported the drop of water levels in the river, and for a week or so in February, it reported that water levels along the lower Mekong River in Chiang Saen had still experienced a slight decrease.
Down to Lao’s Luang Prabang, the water levels also slightly decreased, but it stayed about 2.80 metre above its long-term minimum average “due to the influence of dam operations upstream and Xayaburi”, the organisation noted.
Worse was the river section further downstream from Chiang Khan to Nong Khai province and Lao ’s Paksane as they saw the decrease of water levels even below the minimum levels. At Paksane, the situation was considered as “very critical” for its 5-weeks long low flows.
This low water level was probably due to the influence of upstream dam operation, the MRC said.
The US supported Mekong Dam Monitor said during the week of January 25 to 31, daily restrictions and releases of Jinghong dam continued leading to more extreme ups and downs in river levels in the Golden Triangle (around Chiang Saen).
Chiang Saen, Pak Chom, Don Sahong, along the Mekong mainstream remained at rock-bottom minimum levels, extremely abnormal for this time of the year, the satellite and GIS analysis platform noted.
Sustainable development advocates, meanwhile, have called on Thai Banks to improve its loan programs for dam development projects on the Mekong River, especially the Luang Prabang dam, the fifth project planned next to Xayaburi.
Phairin Sohsai, Thai-Mekong Campaign coordinator at International Rivers, and a member of the Fair Finance Thailand Coalition, said the group has just sent a letter to seven Thai commercial banks, calling them to show their stances on the Luang Prabang dam, and more critically, to consider adding Mekong mainstream hydropower projects on their exclusion lists.
Late last year, the coalition already raised concerns over risks on lending programs by Thai banks to the dam although its power purchase agreement has not yet been signed.
What they fear is additional transboundary impacts the dam could further cause whereas recommendations and concerns made by the Mekong countries in the so-called consultation process of the dam have not yet been addressed, including transboundary impacts.
Sarinee Achavanantakul, a coordinator of the coalition said the Thai Bankers’ Association has announced sustainable banking practices, with the Sustainable Banking Guidelines and Responsible Lending issued for its members.
Thus, Thai commercial banks should announce inclusion of “mainstream Mekong hydropower projects” into their Exclusion Lists by this year. They should also declare their stances not to give loans to the Luang Prabang dam project unless it has addressed appropriately concerns and recommendations raised by the Mekong countries through their joint statement.
The point of concern, she added, was on a financial risk. According to Moody’s Institute, she cited, Laos has been downgraded for credit rating from B3 to Caa2, or equivalent to a “junk bond” level.
Niwat Roykaew, a representative of the Network of Thai People in Eight Mekong Provinces, said there are some reasons why Thai banks should not give loans to the project. First, Thailand’s power reserve is now over 50%, thus there is no need for electricity fed by the dam.
Second, the project has no transboundary impacts assessed yet despite the fact that it could carry more risks than the Xayaburi as it sits on an unstable seismic area.
Third, other MRC country members have called on the transboundary impact assessment of the project, which still remains unheard. Last but not least is the financial risk that could increase over time due to uncertainty in factors mentioned, Mr. Niwat warned.