Characteristics of the 2011 Chao Phraya River flood in Central Thailand

A massive flood, the maximum ever recorded in Thailand, struck the Chao Phraya River in 2011. The total rainfall during the 2011 rainy season was 1,439 mm, which was 143% of the average rainy season rainfall during the period 1982-2002. Although the gigantic Bhumipol and Sirikit dams stored approximately 10 billion m 3 by early October, the total flood volume was estimated to be 15 billion m 3. This flood caused tremendous damage, including 813 dead nationwide, seven industrial estates, and 804 companies with inundation damage, and total losses estimated at 1.36 trillion baht (approximately 3.5 trillion yen). The Chao Phraya River watershed has experienced many floods in the past, and floods on the same scale as the 2011 flood are expected to occur in the future. Therefore, to prepare of the next flood disaster, it is essential to understand the characteristics of the 2011 Chao Phraya River Flood. This paper proposes countermeasures for preventing major flood damage in the future.