学会誌「自然災害科学」

自然災害科学41 Vol.16,No.1, 1997, p27f

【論文】[Regular Paper]

雲仙岳に大規模な土石流を発生させた豪雨の特徴

Characteristic Features of the Heavy Rainfalls Which Caused Violent Debris Flows at Mt. Unzen

荒生 公雄*・中根 重勝**・岩崎 博之***・藤吉 康志****・武田 喬男*****

Kimio ARAO*, Shigekatsu NAKANE**, Hiroyuki IWASAKI***, Yasushi FUJIYOSHI**** and Takao TAKEDA*****

Abstract

Heavy rainfalls over the Shimabara district in Nagasaki Prefecture have frequently caused violent debris flows associated with the eruption of Mt. Fugen at Unzen for recent several years. The most serious debris flows took place on 28 April and 18 June in 1993. The purpose of this study is to reveal the structure and formation of these heavy rainfalls using an RHI radar. The main results can be summarized as follows.

(1) The individual rain-cells which attacked Mt. Unzen appeared near the Nagasaki Peninsula and developed over the Tachibana Bay and the Shimabara Peninsula.

(2) These strong rain-cells moved to the direction of ENE with velocity of 60～70 km/h.

(3) The careful look-out for the western sea region is most essential for preventing the disaster of violent debris flow in the Shimabara district.

キーワード:

土石流，雲仙・普賢岳，豪雨，気象レーダー，土石流防災

Key words:

debris flow, Mt. Fugen at Unzen, heavy rainfall, meteorological radar, prevention of debris flow disaster
*
長崎大学教育学部
Faculty of Education, Nagasaki University
**
長崎大学水産学部
Faculty of Fisheries, Nagasaki University
***
群馬大学教育学部
Faculty of Education, Gunma University
****
名古屋大学大気水圏科学研究所（現在，北海道大学低温科学研究所）
nstitute for Hydrospheric-Atmospheric Sciences, Nagoya University (at present: Institute of Low Temperature Sciences, Hokkaido University)
*****
名古屋大学大気水圏科学研究所
nstitute for Hydrospheric-Atmospheric Sciences, Nagoya University