氣候變遷對坡地災害發生潛勢之影響評估

Effects of Climate Change on the Slopeland Hazard Potentials

楊智翔(Chih-Hsiang Yang)

指導教授 ： 范正成

國立臺灣大學/生物資源暨農學院/生物環境系統工程學研究所/博士(2013年)

https://doi.org/10.6342/NTU.2013.02237

摘要

就歷史資料的統計結果而言，目前氣候變遷導致之極端降雨事件的發生頻率確有逐漸上升的趨勢，而隨颱風、豪雨所觸發的坡地災害，如崩塌及土石流等之發生潛勢亦隨之提高。在面臨氣候變遷之趨勢已日漸顯著的同時，本研究期能藉由探討氣候變遷對高屏溪流域坡地災害發生潛勢之影響，提供後續相關研究或防災策略調整之參考。
為達成前述目的，本研究透過7種GCMs模式及3種未來情境，配合建置之崩塌及土石流發生潛勢評估模式，進行氣候變遷對研究區域內坡地災害發生潛勢之影響評估。研究結果顯示，CSMK3模式-A1B情境的模擬結果對區內未來防災衝擊較大且與近期(2005~2011年)區內實際災例的分布狀況較為相符。以此結果而言，研究區域內未來(2020~2039年)「極高」(發生頻率年小於5年)崩塌發生潛勢的面積與基期相比，增加175 km2 (70.8 %)之多；而「極高」土石流發生潛勢的溪流數量則是增加9條 (90.0 %)之多。另由區內防災潛勢分布圖之結果觀之，未來屬高防災潛勢區域的範圍有顯著增加的趨勢，本研究模擬未來短期土石流發生潛勢的結果與近年災例分佈情形相符，該結果應可提供高潛勢聚落劃設的參考。此外，現有避難處所位置與崩塌防災潛勢圖層套疊後發現，在未來有37處避難處所將處在高防災潛勢(崩塌)的區域內。此一結果說明未來在避難處所的選取方面，應綜合考量土石流災害影響範圍及崩塌潛勢區塊等兩項因素，才可使避難處所安全性的疑慮降至最低。

關鍵字

氣候變遷 ； 坡地災害發生潛勢 ； 崩塌 ； 土石流

並列摘要

From the statistical results in the near history, the frequencies of extreme rainfall events induced by climate change have increased. Accordingly, potentials of slopeland hazards such as landslides and debris flows have also increased. To reflect the apparent trend of climate change, in this study, the effect of climate change on the hazard potentials of the slopelands in the watersheds of Kao-Ping stream was investigated; and the results are expected to be useful for related studies and disaster prevention strategies in the future.
To achieve the above-mentioned goal, in this study, 7 GCMs models and 3 futrue scenarios were used and combined to establish two models for evaluating the hazard potentials of slopelands and analyzing the potentials of slopeland disasters in the future. The results showed that the impact of the CSMK3 model with the A1B scenario on the slopeland disaster potential in the study area was the most consistent with the distribution of the recently real disasters. For the simulated resultsof CSMK3 model with the A1B scenario (2020~2039), compared with the baseline (1980~1999), in the study area, the area of landslides with the return period less than 5 years increases by 175 km2 (70.8 %), and the number of potential debris flow torrents with the return period less than 5 years increases by 9 (90.0 %). From the potential distribution map of disaster prevention in the study area, it is found that there is a significant increasing trend for high potential of disaster prevention. It is also found that the evaluated potential of slopelands hazard in the periods of 2020 to 2039 is similar to that occurred in the recent years. Therefore, the findings in this study could be used as a reference for plotting the villages with high disaster potential. Apart from these, according to the maps of present shelter locations and high potential of disaster prevention (landslides) simulated in this study, the numbers of shelters located in the areas of high potential of disaster prevention (landslides) in the periods of 2020 to 2039 might increase up to 37. From this finding, it is suggested that while selecting the shelter locations in the future, potential zones of debris flows and landslides be considered so that the risks of shelter safety may be minimized.

並列關鍵字

Climate change ； Slopeland hazard potential ； Landslides ； Debris flows

參考文獻

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