The practicability of a surface wind sensor (SWS) is examined by comparing the mean and fluctuating wind velocities obtained from this instrument with those measured by an omni-directional multi-channel anemometer (OMA) with a globe probe and a hot-wire anemometer (HWA) at pedestrian level on flat ground, around a high-rise building with a square plan and areas in an urban city. The surface wind sensor (SWS) used in this study is similar to one developed by Irwin.
It is found that this surface wind sensor (SWS) is applicable to measurement of wind velocity around high-rise buildings and areas in an urban city because the mean wind velocity and the gust factor obtained from the surface wind sensor (SWS) shows good agreement with those from the multi-channel anemometer (OMA) and the hot-wire anemometer (HWA).
Recently, tornado disasters have often occurred in Japan; e.g. Saga City (F2) in 2004, Nobeoka City (F2) in Miyazaki and Saroma Town (F3) in Hokkaido, 2006. However, the countermeasures against tornado disasters have not established yet. Therefore, the authors conducted questionnaire surveys twice, which were answered by the residents in Saroma Town, in order to collect information useful for constructing the preparedness manuals against tornado disasters for governments and residents from the viewpoints of prevention, preparation, emergency management and restoration. The results of the first survey show the characteristics of the disaster, i.e. damage to buildings and harm to humans, as well as the actions of the governments and residents during and after the tornado. The second survey focuses on the restoration of the stricken area, both physically and psychologically.
A tornado struck Wakasa Region of Saroma Town in Hokkaido on November 7, 2006. The tornado killed nine people and injured more than 30 people. Many buildings were collapsed or damaged by this tornado. The authors made a damage investigation just after the disaster. This paper presents the characteristics of the damage. It was found that completely and partially destroyed houses were all located along the track of the tornado. The roofs were flown off and walls and windows were broken by flying debris. The aspects of the building damage are closely related to the materials and method of construction typical of snowy cold regions.