應用調和兩階段流動搜尋法分析臺北市地震短期避難場所之空間可及性與公平性

Analyzing Spatial Accessibility and Equity of an Earthquake Evacuation Site in Taipei City Based on the Harmonized Two- Step Floating Catchment Area Method

地震是臺灣常見的自然災害且不易預測，因此，震災的整備格外重要。本研究以臺北市為研究範圍，從空間可及性的角度探討避難空間不足與空間分布不均的問題。提出調和兩階段流動搜尋法（Harmonized Two-Step Floating Catchment Area，Ha-2SFCA），不僅考量避難場所的容量，更考量避難者步行可及性的限制，合理的計算避難場所的空間可及性，並應用吉尼係數（Gini Coefficient）量化避難空間可及性的公平性。本研究比較四種避難規劃方案所計算的空間可及性結果顯示，部分低人口密度區域仍存在顯著的可及性缺口，另外，依現行所有避難場所再增加建議之公立大專院校空間後，整體公平性達到94%。綜合而言，Ha-2SFCA可廣泛應用於長期防災規劃，提供決策者具科學性的數據支持，使避難空間的分配朝向更均衡的方向發展。

Earthquakes are a common and unpredictable natural disaster in Taiwan, so disaster preparedness is particularly critical. This study focuses on Taipei and examines the issues of insufficient and unevenly distributed evacuation sites from a spatial accessibility perspective. To address these challenges, we propose the Harmonized Two-Step Floating Catchment Area (Ha- 2SFCA) method, which not only considers the capacity of evacuation sites but also accounts for the limitations of pedestrian accessibility. This approach makes a more reasonable assessment of the spatial accessibility of evacuation sites possible. Additionally, the Gini coefficient is applied to quantify the equity of evacuation site accessibility. The results of the spatial accessibility analysis, based on four different evacuation site planning scenarios, reveal that certain low-population areas still face significant accessibility gaps. However, by supplementing existing evacuation site facilities with the proposed use of public universities, overall equity is improved reaching 94%. The Ha-2SFCA method can be widely applied to long-term disaster prevention planning, thus providing decision-makers with scientific data enough to support more balanced evacuation site space allocation.