台灣因位於副熱帶季風氣候及熱帶季風氣候範圍內,基本上全年有雨,現又因氣候變遷導致極端氣候成為常態,導致常有偶發性強降雨發生,使生命與財產安全受到威脅。洪災為目前發生頻率、影響人數及財產損失最高的環境災害,因此洪汎風險為我們必須面對的議題之一。台灣之防汛政策從建設防災設施如雨水抽水站、下水道系統之設置,逐漸走向前端洪汎預測、災害避險及觀念宣導,達到全民防災的階段;如台北市亦於2015年底公布降雨淹水潛勢圖,宣導可能之積淹水範圍以利市民提前警戒,但亦有部分民眾擔憂公開洪汎資訊是否將衝擊房價?以環境經濟的角度,常有研究以探討住宅價格來分析該區域之整體經濟走勢,故本研究將以特徵價格理論估計此洪汎風險之於住宅價格的隱含價值,並使用空間分析工具納入環境特徵於迴歸模型中。洪汎風險部分,除了探討其環境影響,我們亦揭示公開淹水圖對住宅價格的衝擊。 研究結果顯示,站在全域分析(Global analysis)的角度,於固定效果模型(Fixed effect model)中洪汎風險之於住宅價格存在負面影響,且洪汎變數之結構轉變發生於公布降雨淹水模擬圖後;於地方分析(Local analysis)中,地理加權迴歸模型(Geographically Weighted Regression Model)揭示洪汎風險之影響程度因地理位置不同而有差異。 不論固定效果模型抑或是地理加權迴歸模型,皆點出洪汎風險確實對住宅價格產生負面影響,在公布降雨淹水潛勢圖後雖使房價市場受到衝擊,但民眾因接收到洪汎資訊而能提前自主防災,進而降低洪災風險。在公開資料與資訊衝擊間取得平衡,如何讓經濟衝擊降到最小,為後續防汛政策的首要項目。
Taiwan locates in subtropics area with plenty of rain, high temperature and humid weather. Climate change makes heavy rainfall become a serious treat tohuman lives and property. In this research we use hedonic price analysis to estimate the implicit price of flood hazards on residential property values. Also, the price effect of pumping station is identified by the hedonic price method. GIS applications is used tocharacterize the environment features. The flood potential maps used in this study is published by Taipei City Government in September 2015. The result shows that the effect of flood hazards has a negative impact on real estate prices. The result of fixed effect model shows that a significant impact occurs after the disclosure of the flood potential map. And the Geographically Weighted Regression (GWR) model is applied to identify the areas with high sensitivity about flood hazard. This study indicates that flood potential hazards indeed affects housing price in Taipei City. Although this kind of information disclosure may have some impact on the housing market, it helps in acknowledging the risk, and even reducing the flood risk in advance. It is the government’s responsibility to correctly acknowledge the environmental impacts in the future, and balances between the positive and negative effects .