부산대학교 도서관

The characteristics change of landslide disaster on slope land of Southern Taiwan can be positively related to the extremely heavy rainfall which were brought by Morakot typhoon on August, 2009. The accumulated rainfall amount within continuous 3 days was closed to 2,884mm according to the record of A-Li-San rainfall station at Chiayi. This heavy rainfall amount was occupied almost 82.4% of annual precipitation in Taiwan. Very serious large-scale landslides and debris flow were induced by this heavy rainfall event. As a result, we proposed this project mainly focuses on applying field investigations integrated with GPS/GIS/RS technique to analyze and investigate the characteristics, movement and mechanism of these landslide disasters. According to the satellite image analysis project was conducted by Soil and Water Conservation Bureau after Morakot event indicated that more than 10,904 sites of landslide with total sliding area of 18,113ha were found in this disaster area. Characteristics and mechanism of debris flow, landslide and large scale soil mass movement are collected on the basis of sediment related disasters recently happened on slope land located at Zengwen, Nanhua and Wusanto reservoir watersheds in the southwestern Taiwan. However, Nanhua reservoir was 1^(st) priority to be selected as a studied area due to its main purpose to play an important role of public water supply systems in southern Taiwan. In order to decrease the risk of large scale landslides on slope land, the strategy of land conservation, landslide control treatment, and sediment related disaster prevention should be executed as soon as possible. Meanwhile, consideration on the mechanism and behavior of large scale landslide disasters induced by heavy rainfall become an important issue which was seriously concerned by Taiwan government. The mechanism of large scale landslide disaster spatial analysis and watershed management under the condition of extreme rainfall resulted from climate change during the past 10 years (2007~2017) would be recognized as a critical issue by this research. Hopefully, all results can be used as references for the disaster prevention and hazard mitigation systems operated by Nanhua reservoir watershed agencies in southern Taiwan.