Upstream flow contributes only a small portion of the total annual flow of the Mekong River. Most of the total flow volume is delivered to the Mekong from tributaries in the Lower Mekong Basin (see Table 1); however, the importance of upstream flow should not be underestimated as dry-season snow melt from China contributes to over 24% of the total flow.
Table 1. Proportional contributions to total Mekong River mean annual flow by river reach, distinguishing those made by the left and right bank tributary systems.
|River Reach||Left Bank (%)||Right Bank (%)||Total (%)|
|China – Chiang Saen||1||3||4|
|Chiang Saen – Luang Prabang||6||2||8|
|Luang Prabang – Vientiane||1||2||3|
|Vientiane – Nakhon Phanom||18||4||22|
|Nakhon Phanom – Mukdahan||3||1||4|
|Mukdahan – Pakse||4||6||10|
|Pakse – Kratie||22||2||24|
The flood season in the Mekong River Basin lasts from June to November and accounts for 80 to 90% of the total annual flow (MRC 2010). The annual flood season is especially important in the Lower Mekong Basin where it has shaped the environment and its inhabitants.
Many of the Mekong’s key ecosystems have developed as a result of seasonal flow fluctuations. The area’s extensive wetland habitats would not exist without the annual flood. Likewise, the life-cycles of many Mekong fish species depend on it. Fish migrate to deep pools in the mainstream to seek refuge during the dry season; later, during the flood season, they migrate back to spawning and nutrient-rich feeding grounds on floodplains.
See the Fisheries section for more information.
Government officials and community representatives from Laos’ Xe Bang Hieng and Thailand’s Nam Kam river basins cerebrated today the conclusion of a five-year bilateral wetland management project, which has improved community-based management practices in
The Mekong River Commission Secretariat has received an official notification from the Lao Government that it will undertake the formal process of prior consultation on its Pak Lay hydropower project in the Pak Lay area in the Lao PDR’s northern province
To celebrate today’s Lao National Tree Planting Day and 5th June World Environment Day, Head of the Mekong River Commission Secretariat and staffers...