- 自然災害科学 (ISSN:02866021)
- vol.23, no.2, pp.293-302, 2004-08-31
Heavy rainfall caused by a baiu-front (stationary front) occurred in Niigata prefecture from July 12 to 13, 2004. The Japan Meteorological Agency called this event the "Niigata and Fukushima heavy rainfall of July 2004". In Tochio city, Niigata prefecture, an hourly precipitation of 58 mm was recorded on July 13, with the precipitation in a 48-hour period amounting to 427 mm. This constitutes the highest amount of rainfall in this period since that recorded in 1936 at Tochio observatory. The highest 1-hour precipitation records in the last 25 years were revised at 3 observatories, and the highest 24-hour precipitation rate was revised at 10 observatories based on the data of the Japan Meteorological Agency. During this heavy rainfall, 16 persons were killed, 476 houses were destroyed, and about 13,500 houses were inundated. Eleven levee breaches occurred in class-A rivers, causing serious inundation damage in Niigata prefecture. Most of the inundation damage occurred in Sanjo city, Mitsuke city, and Nakanoshima town. In particular, 23% of the households in Sanjo sustained over floor inundation. The deaths of 12 persons were due to drowning. This is the largest number of drownings by heavy rainfall since the Nagasaki heavy rainfall disaster on July 1982. Moreover, 14 victims were elderly persons more than 60 years old. Evacuation counsels were issued from 4 hours to 20 minutes before the levee breaches. We could say that as compared with past rainfall disasters, these responses were quick. However, many persons were lost their lives and much property was inundated. The development of a disaster information dissemination system is necessary in local communities.