Investigation of serious tornado damage in Saroma-cho, Hokkaido

北海道佐吕间町严重龙卷风灾害调查

• 批准号: 18900003
• 负责人: TAMURA Yukio
• 金额: --
• 依托单位: Tokyo Polytechnic University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Special Purpose
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18900003/
• 关键词: tornado; supercell; Doppler radar; numerical cloud resolving storm simulator; mesocvclone; gust damage; windborne debris; questionnaire survy

An investigation was carried out of a tornado and damage caused on November 7, 2006 in Hokkaido, Saroma-cho from both meteorological and a engineering viewpoints. The following points were clarified. The cumulonimbus that brought the tornado was about 10 km high and 20 to 30 km in diameter. It had typical supercell characteristics, i.e., a pair of a strong up and down draft regions and the vault and embryo curtain. The foehn phenomenon had been caused by wind from the south flowing over mountains. This phenomenon greatly affected the generation of the tornado. A complex geometrical feature around the site was another factor in the tornado's generation. A technique using Doppler radar data and numerical cloud resolving storm simulator was applied to a short-period tornado forecast. Applying horizontal wind speeds and the mixing ratio of rain obtained by dual Doppler radar analysis improved the estimation.A detailed investigation of damage to buildings showed that the damaged area was about 1 km long and about 100 to 250 m wide. Most of the debris was scattered in the northern area of Iwasa district, while some flew more than 20 km, reaching the Okhotsk-sea. A questionnaire survey was circulated to 151 families throughout the damaged area. From the primary result of the questionnaire, relations between dam age and structure of houses, meteorological phenomena under the tornado, people's behaviors and government actions were studied. There was considerable damage to houses due to the impact of flying debris, and some roofs were blown off. The standard spec and method for inspecting the exterior cladding materials damaged by flying debris were surveyed. The results should be valuable for further evaluation of countermeasures to tornados.

一场龙卷风进行了调查，并于2006年11月7日在北海道造成了损害，来自气象和工程学的观点。阐明了以下几点。带来龙卷风的累积小熊高约10公里，直径为20至30公里。它具有典型的超级电池特征，即一对强大的上下草稿区域以及拱顶和胚胎窗帘。敌人现象是由南部流过山脉的风引起的。这种现象极大地影响了龙卷风的一代。该站点周围的复杂几何特征是龙卷风一代的另一个因素。使用多普勒雷达数据和数值云解决风暴模拟器的技术应用于短期龙卷风预测。应用水平风速和通过双多普勒雷达分析获得的降雨的混合比改进了估计。对建筑物损坏的详细研究表明，损坏的面积约为1 km，宽约100至250 m。大多数碎屑散布在伊瓦萨地区的北部地区，而有些碎屑飞到了20公里以上，到达了Okhotsk-sea。在整个受损区域中，调查问卷调查分发给了151个家庭。从问卷调查的主要结果，研究了大坝年龄与房屋结构，龙卷风下的气象现象，人们的行为和政府行动之间的关系。由于飞行碎屑的影响，房屋受到了相当大的损害，有些屋顶被吹走了。调查了检查被飞行碎屑损坏的外部覆层材料的标准规格和方法。结果对于进一步评估龙卷风的对策应该是有价值的。