Key Messages

Key messages for this weekly report are presented below.

Rainfall and its forecast

During December 06-12, less rainfall was observed over the Mekong region, varied between 1.00 mm and 10.50 mm.

There will be below-average rain for the next 7 days over the Mekong region from 13 to 24 December 2022 due to low-pressure line dominating the Mekong region.

Water level and its forecast

The MRC’s observed water level (WL) at Jinghong showed an increased value about 0.60 m from 535.24 m to 535.84 between 06 and 12 Dec 2022. The outflow increased from 827.00 m3/s to 1210.00 m3/s between 06 and 12 Dec 2022.

Along with the increased outflow at Jinghong upstream, water level of monitoring station at Chiang Saen in Thailand was up about 0.16 m during the report period and stayed 0.26 m below its LTA, considered low water level. WLs at the monitoring stations at Chiang Khan in Thailand increased about 0.12 m, while at Vientiane in Lao PDR decreased about 0.36 m, staying about 0.76 m and 0.18 m below their LTA value respectively. The current WL from Nong Khai in Thailand was about 1.22 m lower than its LTA value, while at Paksane in Lao PDR it was about 1.17 m lower than its LTA level, which considered low water levels. WL from Thailand’s Nakhon Phanom to Pakse decreased between 0.01 m and 0.46 m. The current WLs at Khong Chiam and Pakse were staying very close to their LTA level, which considered normal. Water levels from the stretches of the river from Stung Treng to Kratie and at 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 12 December 2022 was still slightly higher than its LTA during the same period from 06 to 12 Dec 2022, considered normal.

The current water levels for most of the stations are below their LTA value. WLs at the 2 tidal stations at Tan Chau and Chau Doc fluctuated between minimum, maximum levels and their LTA value, during this monitoring period.

Over the next seven days, the water levels across most monitoring stations are expected to go down and remain lower than their long-term average value in most stations.

Drought condition and its forecast

During December 4-10, the LMB was normal. With a much better soil moisture condition, the combined drought indicator show no drought threat, in overall, over the LMB.

For the coming two months, December is receiving below-average rainfall in the northern and southern parts covering Chiang Rai, Payao, Bokeo, Phongsaly, Luangnamtha, Vientiane, Otdar Meanchey, Siem Reap, and Preah Vihea with moderate and severe droughts. The forecast predicts that the eastern area is also extremely wet in December. While January 2023 is forecasted to be wet in the eastern part and normal in other places.

Source: Mekong River Commission