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題 名 | 蘭陽溪上游降雨事件形態分析=Rainfall Characteristics in the Upper Lan-Yang River Watershed |
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作 者 | 黃誌川; 徐美玲; 姜善鑫; | 書刊名 | 中國地理學會會刊 |
卷 期 | 28 2000.07[民89.07] |
頁 次 | 頁163-174 |
分類號 | 328.63 |
關鍵詞 | 降雨逕流歷線; 群集分析; 降雨型態; Rainfall; Runoff hydrograph; Cluster analysis; Rainfall type; |
語 文 | 中文(Chinese) |
中文摘要 | 逕流流量及洪峰的掌握為水文學的重點之一,然而在不同的大氣條件下,不同季節的降雨型態與水文臨前條件差異甚大。臺灣地區地形崎嶇,山區降雨變化甚大,且雨量站架設有限,因此對逕流流量及洪峰的推估有較多盲點,現今許多水文模式皆以降雨事件為輸入,然而在對降雨事件的考慮上大多以總雨量或總歷時為主要輸入,這樣的作法往往忽略了雨峰的特性及臨前條件,如能利用現有的雨量資料對各集水區的降雨型態加以分類將有助於逕流量的推估。本研究嘗試利用群集分析(cluster analysis)以1982至1997年各降雨事件的總降雨量、降雨歷時、降雨重心及臨前條件(距離前一場降雨事件的時間及前一場事件的降雨量)為降雨特性的代表特徵進行分析。 研究結果顯示,蘭陽溪上游之降雨形態大致可分為五類:Type I:降雨量約在5~11mm的單日零星降雨,通常在4~5天前有降雨。Type II:約28~43mm,歷時3日並無明顯雨峰。Type III:歷時約8日之前峰型降雨。Type IV:降雨強度極高的單日降雨。Type V:對稱型的3日降雨,距離前場降雨時間較長。研究發現,約有70%的Type III降雨為颱風所造成,其餘30%則為該地區在夏、秋兩季偶會發生之高強度、長延時之降雨。 |
英文摘要 | One of the key issues in hydrological study is the estimation of runoff rate and f1ood peak for storm events. Currently, most hydrological models use total rainfall and/or total duration to calculate runoff rates. They ignore not only the distribution of rainfall within each storm but also the pre-storm conditions of the hillslope. However, rainfall characteristics and the pre-storm characteristics of hillslope conditions have been recognized as two of the most influential factors in runoff generation. Since these factors vary with seasons and atmospheric conditions, it is important to identify various rainfall types for more accurate estimation of runoff generation. In order to differentiate rainfall types, all rainfall events which occurred during 1982 - 1997 are selected for further study. Rainfall characteristics including total amount, duration, and mass center of each rainfall event, as well as pre-storm conditions represented by the duration between the event and its precedents, and the rainfall amount of the previous one, are selected and cluster analyses are adopted for c1assification. Five rainfall types are distinguished: Type I: single-day type with rainfall ranging from 5 to 11 mm, usually preceded by 4 to 5 non-rainy days; Type II: uniform rainfall lasts for 3 days with rainfall ranging from 28 to 43 mm; Type III: consecutive 8 day rainfall with early peaks; Type IV: high intensity single-day rainfall; Type V: 3-day rainfall with symmetrical distribution, usually preceded by long non-rainy periods. It is discovered that 70% of the Type III rainfall events were induced by typhoons, while the rest are high-intensity, long-duration rainfalls occurring in summers and autumns. |
本系統中英文摘要資訊取自各篇刊載內容。