Mudslide Potential Zoning - A Case Study in Alishan Township,Chiayi County,Taiwan

• Main Authors: Chia-Hsiang Fan, 范家翔
• Other Authors: Tung-Lin Tsai
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/ksj23a

碩士 === 國立嘉義大學 === 土木與水資源工程學系研究所 === 106 === In the wake of global warming effects, extreme rainfall events have become unprecedented and unpredictable in the recent years. Top economic entities in the world provide government-funded insurance as an essential countermeasure of adaptation of climate change, such as the US flood insurance system, the French system and Spanish system of natural catastrophe insurance. The UK system operated by the member of Association of British Insurers (ABI) has been supported by the UK government and finally became funded in 2015. In 1969 mudslide areas were regulated as Zone M and became insurable in US National Flood Insurance Program. However, there is almost no real case of Zone M delineation due to the difficulty in detailed hydraulic analysis and the confusion of mudslide, mudflow and landslide. This study is based on the definition of mudslide by US National Academy of Science as a flow-induced motion accompanied with mud and rocks. The application case in this study is based on the investigation and survey data of Taiwan Forestry Bureau in 5 Villages in Alisan Forest District in 2010. By applying TRIGRS model with 500 mm rainfall intensity of 24 hour duration, areas with 50 percents changes or higher are marked as high potential collapse areas. The numbers and areas of simulated collapse sites are marked and counted in order to define 3 different potential collapse areas: High, Middle, and Low. With the application of ArcGIS software, potential collapse areas defined by collapse sites or collapse areas are both feasible in risk forecasting and management. Throughout investigation of vegetation, soil and rock conditions will be helpful in future study, and a detailed risk delineation in collapse area will be very helpful in land management, but not very helpful in defining insurance rates since a complicated rate scheme can be very difficult to explain in insurance sales.