Summary of Flood and Drought in Mekong River Basin

Abstract

Flood and drought disasters occur frequently in Mekong River basin owing to ocean climate and climate change. Based on the collected floods and droughts in Mekong River basin in recent 20 years, the losses, causes and effects of flood and drought disasters are analyzed. The main conclusions are drawn as follows: (1) Flood-caused fatalities in the Mekong River Basin were most serious, 825, in 2000, followed by 2001 (489), 2011 (396), 2013 (247) and 1996 (173). Cambodia and the Cuu Long Delta, Viet Nam take the largest shares while the share is small in northeastern Thailand and Lao PDR. (2) Flood imposes significant impact on agriculture. 2000 saw the biggest agricultural impact of floods, approximately 2.50 million hm², followed by 2011, about 500,000 hm². Seen from the geographic distribution, agricultural impact gathered in the Cuu Long River Delta, Viet Nam in 2000, and Cambodia. (3) Flood incurs serious economic loss in countries in the basin. Cambodia ranks top by 1.4 billion USD, followed by Viet Nam by 980 million USD and Lao PDR by 590 million USD. Thailand ranks bottom by 310 million USD in 1996–2014. (4) Extreme floods take place more frequently and cause a huge loss upon the beginning of the twenty-first century. The flood loss amounted to 1.164 billion USD in 2011, taking up 35% of the gross flood loss in 1996–2014; to 651 million USD in 2013, taking up 20%; and to 462 million USD in 2000, taking up 14%. (5) Drought features extensive influence, long duration and huge economic loss. Seen from spatial distribution, drought loss is heavy in northeastern Thailand, Cambodia and Viet Nam and relatively mild in Lao PDR.

Myanmar’s territorial area in the Mekong River Basin takes up approximately 3% of the drainage area of the Mekong River, and the mainstream Mekong River is the boundary river between Myanmar and Lao PDR. According to the statistical analysis of flood disaster data of Mekong River Basin countries, Myanmar’s flood disasters mainly took place outside the Mekong River Basin. Therefore, emphasis is placed on the Mekong River Basin in Cambodia, Lao PDR, Thailand and Viet Nam when it comes to the analysis of flood disasters in the Mekong River Basin in this paper.