高雄市復興堰塞壩溢流破壞評估研究

Evaluation study of overtopping failure for Fuxing landslide dam in Kaohsiung, Taiwan

趙恩廷(En-Ting Zhao)；陳天健(Tien-Chien Chen)；陳昆廷(Kun-Ting Chen)

復興堰塞湖 ； 崩塌 ； 溢流破壞 ； 氣候變遷 ； Fuxing landslide dam ； Landslide ； Overtopping failure ； Climate changes

中華防災學刊

16卷2期（2024 / 09 / 01）

175 - 182

繁體中文;英文

由於全球氣候變遷影響，使得極端降雨事件發生機率和強度上升，使得崩塌、地滑、土石流以及堰塞湖坡地災害形成常態。2009年8月莫拉克颱風帶來長延時、強降雨、範圍廣之極端降雨事件，造成臺灣山坡地多處大規模崩塌，崩塌土體阻塞河道後，形成多處堰塞湖。多數堰塞湖在形成後短時間內受降雨影響而直接產生溢流破壞。而高雄市桃源區拉克斯溪上游復興堰塞湖為莫拉克颱風後唯一存在之案例，因此本研究為了探討復興堰塞湖之存在因素，以及了解未來發生溢流破壞之降雨條件，藉由水文水理、入流、滲流等分析，結合歷年降雨事件和衛星影像，評估復興堰塞湖未來發生溢流之時機。由研究成果可知，若不考慮土砂淤積條件，復興堰塞湖未來發生溢流破壞之降雨重現期距需超過200年，而在小於此降雨特性下，可進一步針對湖區水體水資源再利用進行規劃。

The impacts of global climate change have increased the incidence and intensity of extreme rainfall events, causing landslides, debris flows, and landslide dams becomes the norm. In August 2009, Typhoon Morakot brought an extreme rainfall event with long duration, heavy rainfall and wide coverage, which caused massive landslides in many parts of Taiwan, and a number of landslide dams were formed after the landslide masses blocked the river channels. Most dams are affected by rainfall within a short period of time after their formation, resulting in direct overtopping failure. Fuxing landslide dam is the only case that exists after Typhoon Morakot in Taiwan. Therefore, in order to investigate the reason for existence of the Fuxing landslide dam and to understand the rainfall conditions for future overtopping failure, this study evaluates the timing of future overflow of the Fuxing landslide dam by analyzing the hydrology, inflow, and seepage, as well as by combining the rainfall events of the past years and the satellite images. From the study results, the rainfall recurrence period for the future overtopping failure of the dam would need to be more than 200 years, and with less than this rainfall characteristic, further planning can be carried out for the reuse of the water resources of the landslide-dammed lake.