頁籤選單縮合
題 名 | 以河川乾旱指標評估臺灣北部區域乾旱特性=SDI for Regional Drought Characteristics of the Northern Taiwan |
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作 者 | 葉振峰; 葉信富; 李哲瑋; 李振誥; | 書刊名 | 農業工程學報 |
卷 期 | 61:4 2015.12[民104.12] |
頁 次 | 頁80-92 |
分類號 | 328.633 |
關鍵詞 | 河川乾旱指數; 馬可夫鏈法; 水文型乾旱; 乾旱預測; SDI; Markov chains; Hydrological drought; Drought prediction; |
語 文 | 中文(Chinese) |
中文摘要 | 近年來全球受到氣候變遷影響使得降雨型態發生改變,造成降雨時空分佈不均且逐漸出現降雨兩極化的現象。台灣位於亞熱帶氣候區,屬乾濕季分明之地區,因此降雨兩極化的現象更加的明顯,而河川流量受到降雨量影響甚巨,使得河川流量於豐水期及枯水期流量的差異更加的擴大,造成水文型乾旱事件發生。因此,為了有效管理日益短缺之水資源,須針對河川流量之乾旱特性進行探討及評估。本研究以河川乾旱指數及馬可夫鏈分析台灣北部區域之乾旱特性,由分析結果顯示,2002年為蘭陽溪流域及宜蘭河流域乾旱事件強度的轉折時間點,蘭陽溪流域於 2002年後潮濕事件強度增大,宜蘭河流域則為乾旱事件強度有逐漸增強的趨勢。探討乾旱事件強度時,以 3個月(11月-1月)和 6個月(11月-4月)所分析之結果能顯現出明顯的乾旱事件特性。另外,利用馬可夫鏈法分析乾旱事件之發生機率結果可觀察出,蘭陽溪流域發生乾旱事件之機率較宜蘭河流域高,尤其極端事件發生之機率,蘭陽溪流域於枯水期(11至 4月)發生極端乾旱的機率為 20.6%,宜蘭河流域則為 3.4%。本研究結果顯示,分析乾旱及潮濕事件發生機率時,可由馬可夫鏈法以短時間之乾旱事件強度的發生頻率及機率的結果,預測長時間乾旱及潮濕事件強度之發生機率。 |
英文摘要 | The impact of global climate change in recent years has led to changes in rainfall patterns, resulting in uneven rainfall distribution and the birth of polarized rainfalls. Taiwan is a region located in a subtropical climate zone and one that is characterized by distinct wet and dry seasons; such a characteristic has created a comparatively more severe polarized rainfall situation in which streamflow is drastically influenced by amount of rainfall. This has created considerable differences in streamflow between wet and dry seasons and instances of hydrological droughts are prevalent. Therefore, to effectively manage the increasingly scarce water resources, streamflow characteristics during dry seasons must be explored and assessed. In this study, streamflow characteristics of the Northern region of Taiwan were analyzed using the streamflow drought index (SDI) and the Markov chains, in which results showed that 2002 marked the turning point from which the severity of droughts increased in both the Lanyang River and Yilan River basins; in 2002, the severity of wet condition in the Lanyang River basin increased, whereas the severity of droughts in the Yilan River basin increased. When investigating droughts, the 3-month (Nov. to Jan.) and 6-month (Nov. to Apr.) analysis results may be used to show the drought characteristics. A drought probability analysis made using the Markov chains indicated that the probability of dry and wet conditions in the Lanyang River basin are all higher than that of the Yilan River basin. In particular, during dry seasons (from Nov. to Apr.), the likelihood of the Lanyang River basin to experience severe droughts is 20.6%, whereas that of the Yilan River basin is 3.4%. This study also found that the short-term probability, severity, and frequency of dry and wet conditions may be analyzed using the Markov chains, and that the said results can be used to predict the severity and probability of long-term dry and wet conditions. |
本系統中英文摘要資訊取自各篇刊載內容。