Abstract
The wind is observed at the lower part in a built-up area. It is intended to clarify the influences of the high-rise building on the air flow in the streets. The measuring site is located at Minato-ku Tokyo, Japan. Eight anemometers are arranged at several hights, from 6m to 130m. The observation began in Aug., 1972, and has finished May., 1977. In the previous report, the air flow before the construction of the high-rise building was reported. In this report, the change of air flow pattern due to the construction is reported. The effect of the windbreaks composed of massed of trees which are planted to shelter the pedestrians or shops from the strog wind are also reported. The main results are as follows. 1) The wind rose; After the construction, the shape of the wind rose has become to have sharp peaks becouse the air flow pattern around the high-rise building has become to be very clear and steady. 2) The gust factor; The value of the gust factor near the ground decreases at the place where the wind speed increased after the construction of the high-rise building. The value of it raises up at the place where the wind speed goes down after the construction of the high-rise building. 3) The windbreaks composed of massed of trees are effective to shelter the strong wind.
