台风灾害之水文因子之探讨-以台北市为例

Study on the Hydrological Factor in the Typhoon Hazard of Taibei City

台湾位于西太平洋台风行径之要冲,根据中央气象局统计,每年平均有3.5个台风侵台。台北市处于台北盆地内,地势低洼,每逢台风来袭或暴雨来临时便造成淹水或坡地灾害。本研究搜集台北地区之台北、竹子湖、鞍部等主要气象站,自1960至2008年间共计75起台风灾害降雨资料,针对台风特性与降雨重现期距频率分析进行探讨,结果显示,台风特性与测站地形因素对于总降雨量有一定程度影响;经分析重现期距与重大水文事件得知:受降雨延时长及瞬时暴雨而导致排水负荷不足为灾害发生之主因。

Located in the gateway of Typhoon from West Pacific Ocean, there are in average 3.5 times of typhoons invasion at Taiwan Region per year in accordance with the statistic by the central meteorological observatory. Since the Taibei City is at the Taibei basin with low terrain, it always caused the flood or slope hazards when the Typhoon or rainstorm coming each time. The essay collected the 75 times of typhoon hazards rainfall materials from 1960 to 2008 at the main weather stations in Taibei region such as Taibei, Zhuzihu, Anbu, etc. It was conducted the study on the analysis of typhoon characteristics and rainfall repetition period distance frequency. The results show that the typhoon characteristics and the landform of the weather stations have the certain impacts on the general rainfall. After the analysis of repetition period distance and the important hydrological events, the results show that the main reason of hazards is the shortage of drainage load which resulted from the long rainfall delay and instant rainstorm.