雲仙普賢岳噴火に伴う溶岩流出及び火砕流による土砂量と地形変化

• 石川 芳治

  建設省土木研究所

• 山田 孝

  建設省土木研究所

• 千葉 達朗

  (株) アジア航測

書誌事項

タイトル別名

• Topographic Changes on the Unzen Volcano due to Volcanic Activities from 1991 to 1995

抄録

The Unzen Volcano resumed volcanic activities on November 17, 1990 after a dormancy of 198 years. A series of repeated volcanic activities including magmatic eruptions, lava dome building, and pyroclastic flows occured due to collapses of lava domes and caused substantial changes in the topography of both on the mountain and the land around the foot of the mountain. Collapsing lava domes occasionally produced largescale pyroclastic flows, and their deposited debris was washed down by rainfall, resulting in large- scale debris flows. These events caused severe disasters in the region, as human lives were lost and houses were either destroyed, buried, or burned down, mainly in the Mizunashi River basin and the Nakao River basin.<br>To obtain basic information on the pyroclastic flow and debris flow, we used aerial photographs and topographic maps to analyze the growth of lava domes and the topographic changes on the mountain over a period of four years beginning in late May 1991 (the lava domes began to collapse) until May 1995 (it was announced that this volcanic activity had ceased) and estimated the time sequential changes in the total amount of lava (sum of volume of lava dome and amount of deposited debris), the volume of the lava dome and the deposited debris in a watershed area.<br>The results of the aerial photographs analysis showed that on May 12, 1995, the volume of lava dome, the amount of deposited debris, and the total amount of lava in the entire Unzen Volcano watershed area were about 94 million cubic meters, 119 million cubic meters, and 213 million cubic meters respectively. The maximum amount of lava produced per day was about 310, 000 cubic meters for a period of between May 18 and October 3, 1991, but its daily average had fallen into 3, 000 cubic meters, or about 1/100 of the maximum volume by March 1995.

収録刊行物

• 砂防学会誌

  砂防学会誌 49 (1), 38-44, 1996

  Japan Society of Erosion Control Engineering

キーワード

• Unzen volcano
• Volcanic activities
• Topographic changes
• Aerial photographs analysis

詳細情報

• CRID: 1390001204067457792
• NII論文ID: 130004295718
• DOI: 10.11475/sabo1973.49.38
• ISSN: 02868385
• データソース種別:
  • JaLC
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可