本文提出大規模崩塌影響範圍之劃設方法，以提供大規模崩塌災害風險管理使用。一般來說崩塌的影響範圍分為三部分：發生區、運動區及堆積區。在發生區部分，目前可透過高精度之數值地形進行劃設，而運動區及堆積區則因崩塌土體之運動型態而有所不同。本研究針對運動與堆積區之劃設方法，透過歷史資料之彙整提出重力堆積型、土石流型及堰塞湖型等三種分類。這些分類可藉由潛在崩塌區之崩塌體積、崩塌位置、坡趾地形等參數進行分類。另外本研究考慮不同防減災目的提出兩種影響範圍之劃設方法。針對全國尺度之可能致災對象的清查，可以透過容易操作的經驗統計法做為主要劃設工具。針對較高致災可能之潛勢區，再以數值模擬法進行較精緻的影響範圍劃設。本研究所提劃設方法均與實際發生案例進行比對以確定方法之可行性。

An evaluation method of large-scale landslide affecting area was proposed in this research. To setup the mitigation system, the defined of the affecting area is the most important work. The affecting area of landslide could divide into source, transporting, and deposition area. The source area, could be identify with the high solution DEM. The transportation and deposition area could be identified with the movement process of the landslide. In this research, three types could be defined for the transportation and deposition area, which are landslide type, debris flow type, and landslide dam type. The interpretation of three types are based on the volume, location, and the topography of the hill foot. There are two stages to quantity the affecting area of large-scale landslide. For the first stage, national wide work, the empirical method was used. From the area of source area, the volume, the movement distance could be evaluated. With the comparison between the movement distance and hill foot topography and interpretation process, the affecting area could be quantity quickly. The possible dangers village could be find out by the first stage result. For the high risk village, the numeral simulation method was applied as second stage. All the methods were verified with historical events.