1953 Northern Kyushu flood

The 1953 North Kyushu flood was a flood which hit Northern Kyushu, Japan (Fukuoka Prefecture, Saga Prefecture, Kumamoto Prefecture and Ōita Prefecture) in June 1953. The flood was caused by cloudbursts and prolonged rain from the Meiyu rain front which dropped 1,000 mm (3.3 ft.) of rain over Mount Aso and Mount Hiko. This downpour resulted in the overflow of many of the surrounding rivers, such as the Chikugo River.

The flood was a major disaster with 771 people dead or missing, 450,000 houses flooded, and about 1 million people affected. Due to the severity of the disaster, flood control measures along rivers in Northern Kyushu were fundamentally revised, with many of the changes still in place.

The flood was not given an official name by the Japan Meteorological Agency which has resulted in it being referred to differently in a variety of sources. In Kumamoto Prefecture, Shirakawa Great Flood (白川大水害) or 6.26 Flood (6.26水害) are usually used. In Kitakyushu city, they tend to use North Kyushu Great Flood (北九州大水害).

Causes

The flood was the result of a combination of meteorological and geological factors that contributed to large amounts of precipitation as well as topographical features which exacerbated the effects of the precipitation.

Meteorological

Early June the Meiyu rain front had briefly come to a standstill over north-central Kyushu, raining over the city of Fukuoka and Nagasaki at the start before latter bringing rains over Kumamoto.