研究顯示地球的平均溫度正逐年上升，而都市化城市變暖的速度快於其周圍農村地區之現象稱為都市熱島效應 (UHI)，UHI導因於都市地區之人為活動，其可能在區域或全球範圍內影響天氣和氣候。因此本研究目的在探討 UHI 對臺北地區水文變化、雷雨和地下水位的影響，以作為都市發展規劃的參考依據。為了從時域和頻率探討不同因子間非線性關係的具體細節和趨勢，本研究採用了希爾伯特-黃變換（HHT），在數個測站之間比較 HHT分析結果；亦透由經驗正交函數（EOF）萃取臺北市午後雷雨的主要空間分布特徵。結果顯示，臺北市都市化過程使過去 57 年來 UHI 的強度增加了 1.5°C，臺北地區各測站20年來以10年14.7%的速率從0.2°C增加到1.1°C；根據EOF分析結果，自1998年以來，42.36%的雷雨發生在市區而非其他地區，而市區地下水位總體呈上升趨勢，隨著雷雨事件的增加，都市內發生淹水事件的機率將增加，因此需要適當的應對政策及措施。;Each year, average of Earth’s temperature rises and the urbanized cities are warming at a significant rate than its surrounding rural area. This phenomenon is called Urban Heat Island (UHI). UHI is a consequence of human activities in urban area and it has possibilities to impact weather and climate on regional or global scale. The objective of this study is to understand UHI impact to hydrological variations, thunderstorms and groundwater level, in Taipei area in order to be an input of consideration for urban development. In order to reveal specific details and trend of non-linear relation from both time domain and frequency, Hilbert-Huang Transform (HHT) is adopted in this study. The HHT trend results are later compared between each station. Later, empirical orthogonal function (EOF) also being used to extract main spatial pattern of afternoon thunderstorm in Taipei city. The results show that the urbanization in Taipei city contribute to increase of UHI intensity for the past 57 years with 1.5 oC. While the increase of various stations in Taipei area for 20 years starts from 0.2 to 1.1 oC and also the increasement of 14,7%/decades. According to EOF analysis, there is 42.36% of thunderstorm that initiated and happened in the urban areas rather than in other area since 1998. While overall of groundwater level in urban areas has increasing trend. Proper mitigation is needed as the possibilities of sudden flooding in the urban will rises along with increasing of thunderstorms events.
