蓮華池地區降雨－延時－頻率關係及不同降雨延時之設計雨型歷線

Rainfall Depth-Duration-Frequency Relationships and Design Storm Distributions of Different Durations for the Lienhuachih Area of Central Taiwan

盧惠生(Hui-Sheng Lu)

《台灣林業科學》 14卷1期 (1999/03) Pp. 63-76

https://doi.org/10.7075/TJFS.199903.0063

摘要

降雨歷線資料為上游集水區推估洪水流量歷線的重要依據。本研究乃以台灣中部地區蓮華池降雨資料，分析不同降雨延時之降雨型態特性，建立降雨－延時－頻率關係，推導不同降雨延時之設計雨型歷線。獲悉蓮華池不同降雨延時之降雨歷線型態均為中峰型雨型。雨峰時間位置：6小時降雨延時在50%處，12小時降雨延時在41.7%處，24小時降雨延時在62.5%處，72小時降雨延時在54.2%。雨峰降雨比率：6小時降雨延時為37.65%，12小時降雨延時為26.99%，24小時降雨延時為19%，72小時降雨延時為14.14%。採用對數皮爾遜第三型分佈法進行頻率分析，建立降雨－延時－頻率經驗推估式。並以位序法解出不同降雨延時之設計雨型歷線，同時建立不同降雨延時設計雨型歷線的指數型經驗推估式，顯示效果尚佳。

關鍵字

集水區 ； 降雨型態 ； 設計雨型歷線 ； 頻率分析

並列摘要

Hyetographs are important in estimating stormflow hydrographs from upstream watersheds. In this study, analyses of storm pattern characteristics, establishment of rainfall depth-duration-frequency relationships, and development of design storm distribution for different durations were carried out with rainfall records of the Lienhuachih weather station in headwaters of the Shuilichi watershed of central Taiwan. The results showed that hyetographs of different durations at Lienhuachih were mostly middle peak type of storm pattern. The time to rainfall peak as the percentage of different durations for 6-h, 12-h, 24-h and 72-h durations were 50%, 41.7%, 62.5%, and 54.2%, respectively. The rainfall peak ratio of 6-h, 12-h, 24-h and 72-h durations were 37.65%, 26.99%, 19%, and 14.14%, respectively. Rainfall frequencies of different durations were analyzed with the log-Pearson type Ⅲ distribution. An empirical equation of rainfall depth-duration-frequency was also established. Design storm distributions of different durations were solved by using the ranking method. Exponential equations to estimate design storm distributions for different durations were also derived and showed good agreement.

並列關鍵字

watershed ； storm pattern ； design storm distribution ； frequency analysis