Summary: | 碩士 === 華梵大學 === 環境與防災設計學系碩士班 === 96 === Huafan campus locates in Ta-Lun Mountain, where it is the hillside terrain with the altitude between 350 to 570 m, of Northern Taiwan. Characteristics of wind field are an important meteorological factor to describe the hillside climate. Thus the purpose of this paper is to analyze the observed data of wind speed, wind direction and temperature of summer, June to August, from 2004 to 2006 in order to understand the variation features of the wind field over there.
The results show that the diurnal variation of wind speed is gradually increasing around 6 to 8 o’clock in the morning. The maximum wind speed is appeared in noon, then it begins weaken. The start time of wind speed begin gradually increase early as month go. It is clearly shown the cycle of 24 hour of wind speed from spectrum analysis, which the strength is strongest in 2005, secondly in 2006, finally in 2004.
The local wind of the wind field system is dominant by the regional topographically more than the upper level wind and environmental wind. One of the phenomena in the mountain-valley winds is shown the change wind direction in the east-west from the daily variation of wind field. Secondly, the relation between the temperature and wind speed shows that the wind speed will be increased following due to the temperature arises, and vice versa. The temperature difference is formed the mountain-valley wind in general. But it is difficult to find the mountain-valley wind phenomenon under unstable weather conditions.
Furthermore, the diurnal variation of resultant wind shows that the valley wind with the northwesterly and northerly is dominant from 8 to 18 o’clock in days. The mountains winds with the southeasterly and eastwardly are observed before 7 o’clock in the morning and after 19 o’clock in the evening. The transit period of the mountain-valley wind are observed at 6~7 o’clock in the morning and 18 o’clock in the evening. The blow duration of valley wind reached 11 hours at most in July. In general the blow time in mountain wind is obvious longer than that of valley wind.
Keyword: wind field of summer, mountain-valley wind
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