Key messages for this weekly report are presented below.
Rainfall and its forecast
- During 11-17 January 2022, rainfall was observed from Chiang Sean to Luang Prabang in the upper part, varied from 43.50 millimetres (mm) to 46.20 mm.
- There will be some rain for the next 7 days over the Mekong region from 18 to 24 January 2022 due to low-pressure line dominating the LMB.
Water level and its forecast
- The MRC’s observed water level at Jinghong shows an increase of about 0.69 m from 535.25 m on 11 Jan to 535.92 on 17 Jan 2022 (recorded on 7:00 am), and stayed about 0.01 m higher than its two-year average (2020-2021) value. The outflow at Jinghong station was up from 820.21 m3/s on 11 Jan to 1,276.90 m³/s on 17 Jan 2022.
- Along with a sudden increased outflow from Jinghong upstream, water level of monitoring station at Chiang Saen in Thailand also increased about 0.21 m from 11 to 17 Jan 2022 and stayed about 0.04 m higher than its long-term average (LTA), considered normal. However, water level at Lao PDR’s Luang Prabang was stable, compared with last week and stayed close to its historical maximum value. WLs at the monitoring stations from Chiang Khan in Thailand to Vientiane of Lao PDR slightly increased about 0.01 m and stayed about 0.21 m higher than its LTA value at Vientiane. The current WLs from Nong Khai in Thailand to Paksane in Lao PDR are close to their historical minimum level, which considered very critical. WLs from Thailand’s Nakhon Phanom to Savannakhet in Lao PDR decreased about 0.10 m and continued staying below their LTA level. WL at Savannakhet in Lao PDR dropped and stayed close to its historical minimum level, which considered very critical. Water levels from the stretches of the river from Kratie to Kompong Cham in Cambodia, moreover, were decreasing due to less contributed rainfall from the upstream part (at Pakse and 3S area in Viet Nam).
- The water volume of the Tonle Sap Lake up to 17 Jan 2022 was lower than its LTA but higher than the levels in 2019, 2020 and 2021 during the same period from 4 to 10 January 2022, and still considered critical.
- Water levels at Tan Chau and Chau Doc remain fluctuating in between their Minimum and Maximum values due to the tidal process.
- Over the next seven days, the water levels across the monitoring stations are expected to go up at the upper and middle parts and go down at the lower part in Cambodia. Water levels at most stations are remaining lower than their long-term average value.
Drought condition and its forecast
Drought condition of the LMB from 09 to 15 January 2022 was normal all over the LMB except some moderate drought in north-eastern part due to severely dry soil moistures during the beginning of dry season. The region showed no significant threat except some moderate and severe dry soil moistures which is a normal situation during dry season.
For the upcoming three-month forecast, the LMB is likely to receive average rainfall and under normal conditions in January. In February the region is forecasted to get some rain in the lower part of the LMB covering mainly Viet Nam. While, in March it is forecasted that the entire LMB will be much wetter than its long-term mean of March mainly over the central and lower parts of the region.