應用都市模型於因應海平面上升之空間調適策略

Abstract

自從20世紀末以來，全球氣候變遷的問題已引起世界各國的矚目。身為海島國家的臺灣，無可必免得面臨海平面上升的衝擊。當前因應氣候變遷主要有兩條取徑，其一是溫室氣體的減量，其二則是人類活動的調適。在國外的相關研究中，利用土地規劃來執行空間調適，已被認為是因應海平面上升威脅的有效手段。撤離區的設置，除了可以使整體都市獲得緩衝區域外，兼具生態與觀光遊憩的價值，創造濕地與親水空間。然而，當前臺灣的都市規劃仍停留在與河海爭地的思維之中，長此以往，決非良策。 本研究嘗試以臺北都會區為研究區域，利用都市模型模擬因應海平面上升而劃設的撤離區，對都會區內部人口流動的影響。研究結果顯示，撤離區劃設之後，人口傾向遷移到鄰近且發展程度較高的行政區。而臺北都會區內6 – 100公尺的地區對於人口遷移不具有特別的誘因，因此在住宅單位增加之後，人口未隨之有顯著的增長。 此外，本研究另以極端情境（海平面上升25公尺）來模擬整個台北都會區的人口流動，模擬結果顯示人口傾向落腳於臺北市周邊地區。

Over the past decade, global changing has aroused increasing interests around the world. Among various kinds of issues, accelerated sea level may post most critical threat to low-lying area. As an island country, people in Taiwan inevitably need to face the rising sea level and deal with the related impact. Up to now, there are two different measures to reduce the damage induced by global change: mitigation and adaptation. According to many researches, managed realignment, which could create a buffer zone and provide ecological and recreational benefits, has been proven as an effective adaptation. In Taiwan, however, the urban development policy reflects no awareness of the high cost and the potential risk of holding the line. This research aims at creating a suitable retreat area in Taipei metropolis and examining how it affects the population distribution inside the city by introducing urban simulation model. The result shows that, after executing retreat policy for 30 years, the amount of population will have substantial growth in the neighbor districts with higher development. Despite the abundant dwellings, the area ranges in height from 6 to 100m could not attract more residents. Besides, under the most critical scenario (sea level rise 25 m), with large area covered by water, the result shows that households tend to relocate in the neighborhood of Taipei City.