氣候變遷對臺灣颱風警報天數影響之研究

Abstract

氣候變遷是一個重要的研究議題，國際間研究氣候變遷下對颱風的影響更是受到許多學者高度重視。在颱風期間內，颱風所帶來的暴雨、洪水及土石流等災害在臺灣經常導致人民生命及財產損失。首先，本研究為探討氣候變遷下臺灣颱風警報天數之未來變化趨勢，使用氣候變數資料為NCEP/NCAR再分析資料和在SRES排放情境下之大氣環流模式 (General Circulation Model, GCM) 模擬資料，包括海平面氣壓、地表之緯向風速和地表之經向風速三種氣候變數。其次，以支援向量機建立多個氣候變數和颱風警報天數之間的非線性關係。最後，根據不同的未來氣候情境之各種GCM模擬資料輸入模式，進而推估在不同的氣候情境下臺灣颱風警報天數之未來可能變化趨勢。由結果顯示，所使用之三種氣候變數對於推估颱風警報天數皆具有一定程度的描述能力，而綜合所有氣候變數之模式表現皆優於由各別單一氣候變數所建立之模式。除此之外，不論是海上或陸上颱風警報天數，所使用之GCM資料推估未來中、長期在不同情境下普遍呈現減少趨勢。本研究結果可作為氣候變遷下颱風相關研究之重要參考，期望可供相關研究單位進行後續研究。

Climate change is an important issue. During typhoons, serious disasters, such as heavy rainfall, flood, and debris flow, often result in loss of life and property damage. The objective of this study is to investigate the influence of climate change on the change of typhoon warning days. Firstly, three climate variables, sea level pressure, zonal surface wind speed and meridional surface wind speed, are collected from the National Center for Environmental Prediction (NCEP) /National Center for Atmospheric Research (NCAR) reanalysis data. Then, a support-vector-machine-based model is proposed to estimate the typhoon warning days. Thirdly, according to the future simulations of these three climate variables from general circulation models (GCMs) for SRES emission scenarios 20C3M, A1B, A2, and B1, the estimation of future typhoon warning days are obtained. The results indicate that three climate variables used in this study are effective for estimating typhoon warning days. As compared to models using only single climate variable, the model using all climate variables yields the best performance. In addition, the future typhoon warning days generally decrease for various scenarios regardless of sea or land warning. The results of this study are expected to be an important reference of similar studies on climate change.