南臺灣嘉南偏遠山區聚落環境土砂災害潛勢風險調查分析

Investigation and Analysis on the Sediment Disasters Occurred at Remote Mountainous Communities of Chia-Nan Aera in Southern Taiwan

蔡光榮(Kuang-Jung, Tsai) ； 李明熹(Ming-Hsi Lee) ； 蔡雨����(Yu-Ling Tsai) ； 李佳諠(Jia-Xuan Li)

《臺灣鑛業》 73卷2期 (2021/06) Pp. 1-19

摘要

臺灣地處環太平洋地震帶與北太平洋副熱帶季風區，近年來，更因全球氣候變遷，引致極端降雨事件頻傳，每年襲臺的颱風暴雨次數逐年增加。致使坡地大規模土砂災害大規模山崩、地滑、土石流等日益加劇，尤其以具高潛勢致災風險之臺灣偏遠山區聚落環境受創最為嚴重。依據行政院災害防救委員會（2012）報告，全臺灣共計有12個縣市具有偏鄉山地聚落，以南投縣67處聚落最多，占全省17%，而南臺灣所轄嘉南等三縣市之偏遠山區聚落約占全臺灣之18%，共計有83處，依據成功大學防災中心（2015）之統計資料顯示，南臺灣偏遠山區聚落周圍之崩塌處數由2011年之359處已逐年增加至2015年之652處，崩塌總面積高達1,078.4公頃，單筆最大崩塌面積約達37.3～45.4公頃，此對偏遠山區聚落環境安全與災情即時快速傳遞確實造成極大威脅，另依水土保持局統計2007－2018年間之土砂災害分布資訊獲知南臺灣偏遠山區發生重大受災情形至為嚴重。且近年來大規模土砂災害亦大多集中發生於南臺灣之偏遠山區聚落，尤其以嘉義、臺南、高雄、屏東等地區為重災區，因此為期降低大規模土砂災害對於南臺灣嘉南等三縣市偏遠山區聚落居民之生命財產危害度，相關偏鄉聚落居住環境安全調查評估、災害發生類型與誘因、災害風險評估等防減災策略均為目前迫切需要進行調查研究之主要課題，且必須更進一步採取必要之防災因應對策，俾期提升南臺灣嘉南三縣市所轄偏遠山區聚落之自主防災／耐災力。

關鍵字

氣候變遷 ； 極端降雨 ； 土砂災害 ； 偏遠山區聚落

並列摘要

Taiwan is located at Pacific-rim area and belongs to the sub-tropic to tropic weather characteristics. Recently, extreme rainfall amount and intensity resulted from climate change to induce serious sediment related disasters, such as large-scale landslide and debris flow, are critical in Taiwan. There are almost 18% of total remoted mountainous communities in Taiwan were occupied by Chiayi & Tainan counties/cities with the amount of 83 remote communities in southern Taiwan. Most of these communities were frequently attacked by typhoons such as Morakot typhoon (2009), which brought the accumulated rainfall more than 2450 mm within continuous 48 hours. This extreme rainfall has triggered compound disasters to destroy the environment systems, human lifes, and public facilities. More than 608 landslides with total area of 968.2ha were induced by these disasters which were based on the field investigations conducted by Disaster Prevention and Research Center (DPRC, 2015), National Cheng Kung University. In order to reduce the risk of multi-sediment related disasters (MSD) attack these remoted mountainous areas, the adaption strategy of environmental conservation, new technology of field investigation and environmental disaster risk assessment should be executed as soon as possible. According to the historical record (2007-2018) from Soil &Water Conservation Bureau indicated that most of the remote mountainous communities located at southern Taiwan attacked by these compound disasters are significant. Meanwhile, study on the behavior of sediment disasters induced by extremely heavy rainfall become an important issue which was seriously concerned by Taiwan government. Investigation on sediment related disaster occurrence and disaster risk analysis would be positively concerned as an important issue by this research. Hopefully, all results can be used to enhance the disaster prevention capability for all remote mountainous communities in southern Taiwan.

並列關鍵字

Climate change ； Extreme rainfall ； Sediment disasters ； Remote mountainous community