台灣地區年最大一日雨量區域頻率分析之研究：(Ⅱ)實例分析

Study on Regional Frequency Analysis for Annual Maximum Daily Rainfall in Taiwan

陳儒賢(Lu-Hsien Chen) ； 陳清田(Ching-Tien Chen) ； 洪毓婷(Yu-Ting Hong)

《中華水土保持學報》 41卷2期 (2010/06) Pp. 1-13

https://doi.org/10.29417/JCSWC.201006_41(2).0001

摘要

本研究主要目的是針對台灣地區雨量測站之年最大一日降雨量進行區域頻率分析。首先，本研究選用全台灣127個雨量測站，共計20年之年最大一日雨量資料進行主成分分析，總共擷取累積解釋百分比80%以上之9個主要成分，再加上雨量測站之地文因子作爲SOM網路之輸入項。由SOM網路之二維映射圖可知，127個雨量測站可被分成17群，因此可將台灣地區劃分成17個均一性區域。再者，經由以線性動差爲基礎的不一致估量、異質性估量及適合度估量評估同一區域之雨量資料是否一致及均勻，並選取一合適的機率分佈函數。結果顯示，這17個均一性區域均通過測試，屬於GEV分佈共計兩個區域；屬於GPA分佈共計九個區域；屬於PE3分佈共計四個區域；屬於GLO及LN3分佈各只有一個區域。最後，本研究計算出17個均一性區域重現期距分別爲5、10、20、50及100年之頻率降雨量及其90%信賴區間。本研究推估所得之區域頻率分析結果，未來將可作爲台灣地區水利設施規劃設計時之參考。

關鍵字

區域頻率分析 ； 主成分分析 ； 自組織映射圖 ； 線性動差

並列摘要

The purpose of this paper is to carry out the regional frequency analysis for annual maximum daily rainfall in Taiwan. First, the 127 annual maximum daily rainfall data with 20-year record length in Taiwan are available. Principal component analysis (PCA) is applied to obtain the principal components. It is found that the first nine principal components explain over 80% of the information. Based on the transformed data resulting from PCA and the geographic characters of the gauges, the self-organizing map is used to group the rain gauges into specific clusters. A two-dimensional map indicates that the 127 rain gauges can be grouped into 17 clusters. Then the 17 homogeneous regions for regional frequency analysis are delineated. The L-moment based discordancy, heterogeneity, and goodness-of-fit measures are used to test whether regions may be acceptable as being homogeneous and select the regional probability distributions of rainfalls. The results show that the 17 regions are sufficiently homogeneous, and the best regional probability distribution for 2 regions is the GEV distribution, the GPA distribution is the best distribution for 9 regions, the PE3 distribution is the best distribution for 4 regions, and the GLO and LN3 distributions are the best distributions for only one region, respectively. Finally, the rainfall magnitude and 90% confidence intervals of various return periods for each region are estimated. The results will provide a reference for the future design of hydraulic structures in Taiwan.

並列關鍵字

regional frequency analysis ； principal component analysis ； self-organizing map ； L-moment