台灣地區暴雨強度-延時-頻率分析之研究

Abstract

本文主要利用L-動差法及合適度準則，針對全台灣92個自記雨量站，求 其適用之分佈；並發展各單站以重現期距25年，延時1小時之降雨強度為 指標之無因次暴雨強度-延時-頻率(Intensity-Duration-Frequency, IDF)公式。為了提高區域化分析之準確性，以各雨量站之IDF參數數及地 理位置為變量，利用集群分析方法(Cluster analysis)，以東經{EMBED Equation |}、北緯{EMBED Equation |}及東經{EMBED Equation |}、北 緯{EMBED Equation |}之連線為界，將92個雨量站分成南北二群 由於IDF 公式中各參數與年平均降雨量及高程可以建立良好數學關係，且依據集群 分析之結果，可推導得各群IDF公式中參數之區域關係式，以提供在無雨 量紀錄地區雨量推估之用。 The purpose of this study is to identify appropriate probability distributions for the annual maximum precipitation of various duration at ninety-two recording rain gauging stations in Taiwan .The method used in the frequency analysis is the L-moment method along with various goodness-of-fit procedures. Also, this study aims at developing a non- dimensional rainfall intensity-duration-frequency (IDF) equations based on a rainfall intensity with 25-year return period and 1-hour duration.To enhance the accuracy of the regional analysis, the cluster analysis was applied using the parameter in the IDF equation and geographical coordinates of each station. It is found the 92 raingage stations can be clustered separated by into two areas separated by the line connecting ({EMBED Equation |} E , {EMBED Equation |} N) and ({EMBED Equation |} E , {EMBED Equation |}N), as the demarcation.In the regional analysis, empirical relationships for each groupwere developed to relate each parameter in the IDF equation to the mean annual precipitation and elevation. The regional equations for the parameters in the IDF equation can be used to estimate extreme precipitation characteristics at locations where there is no precipitation record.