洪災風險評估與災害風險稅課徵－－以台北市為例

Flood Risk Assessment and Hazardous Risk-Based Taxation – A Case Study in Taipei

隨人口迅速增長及災害敏感地區的過度開發，使洪災損失有增無減。由於災害敏感地區的超限開發，造成政府須投資更多的災害防救設施與成本。然基於效率原則，該等地區之土地開發應依受益付費原則及風險分擔概念，依開發行為隱含的災害風險程度，分擔政府增加的防救災成本。故本文提出災害風險稅課（risk-based taxation）之方式，以增加災害敏感區的開發成本，降低開發誘因的手段，以達到減災的目的。本文藉由災害管理及地方財政理論，建構災害風險稅課徵基礎。另應用分析階層程序法（AHP）建立土地開發之災害風險程度評估體系，以台北市為例，評估案例區內各地區的洪災風險分布特性與空間差異，並以之做為災害風險稅課徵負擔估計之基礎。最後估計納稅人應負擔的稅額，依分攤災害防救成本比率的差異，平均約為每戶每年4,167元～11,907元間。 The dramatic increase in natural disaster losses associated with fast population growth and over-development in hazardous sensitivity areas should be taken seriously. From an efficiency standpoint, developers developing land in hazardous sensitivity areas should have to pay for the costs of disaster prevention and mitigation. This concept is established by the mechanism of risk-sharing, that companies developing in hazard-prone areas should defray the costs of the potential risk resulting from their land development. In order to design a framework for haulting such development, a non-structure disaster mitigation measure of risk-based taxation is proposed. First, we establish a multi criteria evaluation system to assess the risk levels of each development area by using AHP analysis. In the case study of Taipei, the characteristics and heterogeneity of flood risk distribution over areas in the city were estimated and identified by GIS. Second, if a riskbased tax is levied, we estimate the expected average burdens of each household in the case study. The results show that the average burdens of each household are estimated at NT$4,167~NT$11,907 per year.