昭和57年7月長崎豪雨による都市地質災害

概要

論文の詳細を見る
The heavy rain brought (produced) by the developmment of the baiu front was poured on the Nagasaki area on July 23, 1982. The 1-hour precipitation registered 187 millimeters at the town office of Nagayo-machi, just north of Nagasaki City, and the value marked a new No. 1 record of the meterological observation in Japan. More than 3,700 landslides occurred by this heavy rain in the Nagasaki district with 262 peoples were buried to death by the landslides and 37 people were drowned to death by the f1oods. Most landslides caused by the 1982 Nagasaki disaster belong to the debris slide. The debris slides occurred in the Nagasaki Volcanics mainly composed of pyroxene andesite lavas and pyroclastics. Mudflows occurred in places of the lava domes of the hornblende andesite were in the eastem part of Nagasaki City. The front of the mudflows splayed out at the valley mouth destroyed many houses which were built on the old mudflow deposits. The downtown of the Nagasaki City was underwater during several hours in the midnight of July 23. The maximum depth of the f1ood water were reached over two meters locally. This catastrophic flood was caused by the combination of the overflows of the river water and the high tide of spring.
日本地質学会の論文
1983-12-25