1. 1 Hydrological Regime of the Mekong River Hydrological Regime of the Mekong basin depends on climatic conditions of the wet and dry seasons. High water period from Jul. to Nov.; Low flow period from Feb. – April (see following graph KRATIE). High water period depends on the position within the basin. Upper basin earlier – lower basin later. Flood season in mainstream and tributaries, from June- July to Nov-Dec accounts for 85-90% of total annual water volume. Peak month of Sept accounts for 20-30% of annual flow.

2. 2 Monsoonal climate dry season November to May wet season June to October Different climatic condition (rainfall) cause area specific contributions of water to the Mekong flow 35% 20% Contribution to Mekong flows 16%Climate

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4. 4 The % contribution of flow from China to average monthly flow at … % Flow from China dominates the dry season hydrology of the Lower Mekong Flood season flows mostly originate within Laos and the lower basin The % contribution of flow from China to average monthly flow at … References and Sources for Further Reading: MRC, 2006: BDP Training Material.