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題 名 | 自組織映射圖網路與線性動差法於區域乾旱頻率分析之研究=A Study on Regional Drought Frequency Analysis Using Self-Organizing Map and L-Moments |
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作 者 | 陳儒賢; 洪毓婷; 許臣王; | 書刊名 | 農業工程學報 |
卷 期 | 57:2 2011.06[民100.06] |
頁 次 | 頁57-77 |
分類號 | 328.633 |
關鍵詞 | 區域乾旱頻率分析; 標準化降雨指標; 自組織映射圖網路; 線性動差; Regional drought frequency analysis; Standardized precipitation index; Self-organizing map; L-moment; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究之目的是應用自組織映射圖(self-organizing map, SOM)網路與線性動差 法(L-moment)於台灣地區乾旱頻率分析之研究。首先,本研究選用全台灣81 個雨量 測站,各測站之紀錄年限均超過30 年,並以標準化降雨指標(standardized precipi tation index, SPI)定義各測站於紀錄期限內之乾旱事件,將其乾旱特性資料與地文因 子經由SOM 網路進行分群。由SOM 網路之二維密度圖可知,81 個雨量測站可被分 成6 群,因此可將台灣地區劃分成6 個均ㄧ性區域。再者,經由以線性動差為基礎 的不一致估量(discordancy measure)及異質性估量(heterogeneity measure)評估同一群 集之乾旱資料是否具有一致性及均一性,結果顯示這6 個群集均通過測試。接著以 適合度估量(goodness-of-fit measure)選取各群集最適合之機率分佈,以乾旱量而言, 屬於通用帕雷托分佈(generalized Pareto distribution, GPA)共計三個群集;屬於三參數 對數常態分佈(three-parameter lognormal distribution, LN3)共計兩個群集;屬於皮爾遜 第III 型分佈(Pearson type III distribution, PE3)則只有一個群集。以乾旱延時而言,分 別各有三個群集屬於PE3 及GPA 分佈。最後,本研究分別推估各群集重現期距分別 為5、10、20、50 及100 年之頻率乾旱量及乾旱延時,此區域乾旱頻率分析之結果 將可作為未來台灣地區水利設施規劃設計時之參考。 |
英文摘要 | The purpose of this paper is to carry out the regional drought frequency analysis in Taiwan using self-organizing map (SOM) and L-moments. First, the 81 rainfall data with over 30-year record length in Taiwan are available. In this paper, standardized precipitation index (SPI) is used to define droughts. Based on the SPI and the geographic characters of the gauges, the SOM is used to group the rain gauges into specific clusters. According to the two-dimensional density map resulting from SOM, it is observed that the rain gauges can be grouped into 6 clusters. Moreover, the L-moment based discordancy and heterogeneity measures are used to test whether clusters may be acceptable as being homogeneous. The results show that the 6 clusters are sufficiently homogeneous. Then, the goodness-of-fit measure is used to select the best regional probability distributions of droughts. For drought magnitude, the results show that the best regional probability distribution for 3 regions is the generalized Pareto (GPA) distribution, the three-parameter lognormal (LN3) distribution is the best distribution for 2 regions, and the Pearson type III (PE3) distribution is the best distributions for only one region. For drought duration, the PE3 and GPA distributions are the best distributions for 3 regions, respectively. Finally, the drought magnitudes and drought durations with various return periods for each cluster are estimated. The results will provide a reference for the future design of hydraulic structures in Taiwan. |
本系統中英文摘要資訊取自各篇刊載內容。