The Mekong: A Drought-prone Tropical Environment?

The notion of drought as a hydro-meteorological hazard in tropical monsoon regions is not perhaps one that fits naturally with conventional perceptions. The term 'monsoon' is commonly regarded as synonymous with torrential rainfall, moisture surplus, floods and climatic predictability. The paper seeks to dispel such perceptions in a review of recent historical events within the Lower Mekong Basin. A weak monsoon results in deficient flows and water levels that can have severe impacts upon agricultural production across the Cambodian flood plain and the delta in Viet Nam, where natural and controlled inundation is the basis of padi rice production. Lower flows also cause an increase in saline intrusion in the delta, which further reduces agricultural output. The impacts of an early end to monsoon conditions on agriculture in Thailand and Lao PDR are also revealed, which serves to emphasize the potential negative consequences of climate change which not only is expected to result in the increased inter-annual variability of regional rainfall, but also there could be impacts upon its seasonal pattern and timing. In concluding, the paper refers to building drought management capacity in the region through a climate change and adaptation initiative, including forecasting, impact assessment, and the development of management, preparedness and mitigation policies.