Key messages for this weekly report are presented below.
Rainfall and its forecast
- This week, rainfall was observed from Chiang Saen in Thailand to Tan Chau in Viet Nam, varied from 14.00 mm to 230.60 mm over the Mekong region.
- There will be rainfall for the next 7 days over the Mekong region from 24 to 30 May 2022. Water level and its forecast
- According to MRC’s observed water level at Jinghong, it showed a decreasing water level (WL) of about 0.10 m from 536.63 m to 536.53 m during the weekly monitoring period from 17 to 23 May 2022.
- Water level along the lower Mekong River in Thailand’s Chiang Saen was increasing about 0.35 m and staying about 1.54 m higher than its Long-Term Average (LTA) level, which is considered normal. WL at Lao PDR’s Luang Prabang rapidly decreased 0.09 m compared with last week and stayed 0.22 m higher than its historical maximum value. WL at the monitoring stations at Chiang Khan in Thailand increased by about 0.05 m, while at Vientiane in Lao PDR it decreased about and 0.18 m. The current WLs at these stations are about 2.72 and 2.28 m respectively higher than their LTA value, which considered abnormal. WLs at Nong Khai and Paksane increased 0.06 m and 1.05 m, respectively, and stayed about 1.31 m higher at Nong Khai while at Paksane it is about 0.53 m lower than its maximum value.
- Water levels from Thailand’s Nakhon Phanom to Pakse were staying close to their maximum value. The water levels at these stations were considered abnormal, except that at Savannakhet which was higher than its LTA value. Water levels from Cambodia’s Stung Treng to Kompong Cham were staying close to their maximum value. Water levels at Chaktomuk and Koh Khel on the Bassac River and Prekdam on the Tonle Sap River and also at Neak Luong on the Mekong were increasing about 0.20 m and staying higher than their LTA value.
- The water volume of the Tonle Sap Lake up to 23 May 2022 was slightly higher than its LTA and higher than the levels in 2019, 2020 and 2021 during the report period, and considered normal.
- For the tidal stations at Viet Nam’s Tan Chau and Chau Doc, WLs fluctuated between their LTA and Minimum levels due to daily tidal effects from the sea and considered critical.
- Over the next seven days, the water levels across the monitoring stations are expected to go up from Chiang Saen to downstream from Nakhon Phanom to Pakse and from Stung Treng to Kompong Cham in Cambodia.
- The current WLs higher than or close to their maximum value are at Luang Prabang, Chiang Khan, Vientiane, Paksane, from Nakhon Phanom to Pakse, and from Stung Treng to Kompong Cham, while the rest of the key stations have WL higher than their LTA value.
Drought condition and its forecast
- Drought conditions of the LMB from 15 to 21 May 2022 were normal in all areas from the north to the south. There was no drought threat over the region, except some little moderate meteorological drought in the northern part of the region.
- For the upcoming three months’ forecast, the LMB is likely to receive ample amount of rainfall in May and below average rainfall in both June and July 2022 from the middle to the lower part of the region. Based on the weather forecast, May is likely to be much wetter than normal year especially in the north and central parts of the LMB.