都市空間中「熱」的不平等：臺北盆地熱島效應、都市型態與社會脆弱度之關聯分析

Abstract

全球暖化下，都會區的都市熱島效應逐漸增強。不同社會經濟條件的都市居民，也面臨熱曝險的不平等分配，形塑熱的社會不平等。本研究針對此議題，發展了三階段分析，目標是提出能調節臺北盆地都市熱島效應，並發展能減緩熱的社會不平等的都市規劃策略。 首先，本研究使用空間迴歸分析臺北盆地中地表溫度與都市型態的關係，發現建物形狀與密度顯著影響熱島強度。路網上高集中性的建物會強化地表熱島效應，而高可及性的路網設計可調節地表溫度。綠地則對地表溫度有最大的影響，可顯著降低地表溫度。其次，本研究用F’ANP架構評估臺北盆地各里的社會脆弱度，發現家戶所得是決定脆弱度最重要變數。最後，使用地表溫度與脆弱度數值，本研究辨識出臺北盆地中高熱曝險且高脆弱度的里，並以臺北市萬華區糖廍里為案例，模擬不同都市更新情境下的地表溫度。結果顯示，建造配有綠地的集合式公寓來取代低樓層且緊湊建物群，可降低更新街廓4.2%地表溫度。 本研究對亞洲都會區的都市規劃提出實務與熱島研究上重要意涵。分析結果顯示，除了改變建物與路網的型態規劃，增設綠基盤 (公園等開放式綠地) 也可調節都市熱島效應。此外，本研究提出了社會脆弱度評估方法，可協助以參與式決策討論都市的災害管理或氣候調適政策，協助政府或其他重要利害關係人辨識都市中的脆弱區域，達成具環境正義的都市氣候治理。

In a warming climate, urban heat island (UHI) effects have intensified and result in unequal distribution of heat exposure for urban population with different socio-economic statuses. In response, this research conducted a three-stage analysis to mitigate UHI and thermal inequality in Taipei Basin via spatially targeted urban planning. First, this research analyzed the relationship between land surface temperature (LST) and urban morphology in Taipei Basin using spatial regression and found that shape irregularity and density of buildings affected UHI. Road networks with close buildings would intensify UHI, while higher network accessibility mitigated UHI intensity. Green cover was found to have the largest impact on UHI. Second, this research estimated social vulnerability using F’ANP method and found household income as the most important determinant of vulnerability. Third, this research identified neighborhoods exposed to high UHI intensity and vulnerability and simulated urban renewal scenarios in Tangbu Li, Taipei City. Based on the current building cover ratio, simulation results indicate that replacing low-rise building clusters with condominiums and green spaces could reduce 4.2% LST in renewed blocks. This research has implications for urban climate governance with adaptive urban renewals in Asian metropolises. The result suggests that UHI could be mitigated not only via optimizing the configuration of buildings and networks, but also by implementing green spaces. In addition, this research provides a social vulnerability assessment that effectively identifies vulnerable neighborhoods in a city. By incorporating vulnerability assessment in participatory planning procedure, stakeholders could examine the feasibility of adaptation plannings to achieve environmental justice and eliminate climate gaps.