Studies on the Relationships Between the Local Topography and the Damage to Buildings Hit by Typhoons ------Observation of Wind Using Balloons------

多年来，我们一直在分析风力对地形的影响。利用统计方法，分析了台风破坏建筑物分布与风速、风向等气象观测数据的关系。为了确定自然风的特征，我们使用气球观测风。在本研究中，我们得到了以下结论。利用简化航空摄影测量技术开发风观测系统。在风力工程研究中，现场三维确定地表附近的自然风的流向是很重要的。我们开发了一个系统，利用航空照片测量水平和垂直方向的气流数据。该系统采用两个雪茄形状的风筝气球，气球上安装有35mm静态相机，该相机对释放的第三个气球进行立体拍摄作为示踪剂，从而对第三个气球的轨迹进行三维分析。2. 建筑物上空风的观测轨迹。我们将该系统应用于建筑物上空的风轨迹观测，并取得了一些有效的结果。Myogane点地面风的实地观测。我们对Myogane点的风向和风速进行了野外观测，并分析了当地地形与风的关系。

We have analyzed the topographical effects of wind forces for many years. Using statistical methods, we have analyzed the relationship between the distribution of damaged buildings resulting from typhoons and meteorological observation data such as wind velocity and direction.To determine the characteristics of natural wind, we observed wind using balloons. In this study, we obtained the following conclusions.1. Development of a wind observation system utilizing simplified aerial photogrammetry.It is important, in the study of windengineering, to three-dimensionally determine on site the flow of natural winds near the ground surface.We developed a system to measure the data of wind flow in both the horizontal and vertical directions utilizing aerial photographs. This system uses two cigar-shaped kite balloons on which are mounted 35mm still cameras, which stereophotograph third balloons released as a tracer, thereby three-dimenionally analyzing trajectory of the third balloon. 2. Observation trajectory of wind over buildings.We utilized the system in observing the trajectory of wind over a building, and obtained some effectual results.3. Field observation of winds on the ground surface at Myogane Point.We carried out field observations to survey the wind direction and the wind velocity at Myogane Point, and analyzed the relationships between the local topography and the wind.