611水災高雄市桃源區復興里災害成因分析

Disaster Cause Analysis on 611 Flood Disasters at Fuxing Village in Taoyuan District of Kaohsing County

許中立(Chung-Li Hsu) ； 葉師杏(Shih- Sing Ye)

《坡地防災學報》 12卷1期 (2013/06) Pp. 1-11

摘要

荖濃溪支流布唐布那斯溪因岩性相對軟弱、節理和破碎較多，遇豪大雨就有土石流出的情形，因此被編為土石流潛勢溪流。2009年莫拉克風災對於高屏地區影響甚大，該地區更形成堰塞湖並潰決釀災且災情相當嚴重，其上、下游的公路、堤岸與村落安全受到威脅，雖經緊急災害復建但至今引發之後續災害問題仍使災民生命財產與生活品質受到影響。本文以該土石流潛勢溪流上游的高雄市桃源區復興里為調查區域，以資料蒐集、實地調查與周邊災害影響比對方式，運移探討其於2012年611水災時21戶房屋受災的成因。分析結果得知復興里下游的布唐布那斯溪發生大規模崩塌後形成土石流，沖入荖濃溪淤積阻斷了溪水流形成了堰塞湖，造成溪水泥砂往上游回淤而抬高既有河床。也使得復興里旁荖濃溪支流拉庫斯溪之溪水泥砂因回淤無法排出，且河道完全淤滿並喪失排洪功能，造成溪水改道溢流沖入村落而淘刷釀災。調查結果發現布唐布那斯溪的崩塌仍在持續，匯入荖濃溪河段易形成堰塞湖，必須儘早監控、調查與妥善安置影響區域民眾。

關鍵字

611水災 ； 土石流 ； 堰塞湖 ； 回淤 ； 淘刷

並列摘要

The Butangbunasu Stream was one of the tributaries in Laonong River watershed, which lithology was relatively weak, joints and broken more. Case of heavy rain there mudslide situation, thus was incorporated as a potential debris flow streams. Typhoon Morakot seriously hit Kaohsiung and Pingtung areas in 2009. There was the formation of landslide lake break disaster brewing and very serious disaster on downstream load embankment and villages of security was threatened. Although despite emergency disaster rehabilitation, but the triggered subsequent disasters were still affected life and property and life quality of the victims. In this paper the test site located in Fuxing Village, Taoyuan District, Kaohsing County of the debris flow potential river upstream for the survey area, data collection, field investigation with neighboring disasters than migration to explore the causes of the 21 houses affected 611 flood event in 2012. The analysis results showed the Butangbunasu Stream in the downstream of Fuxing village that numerous sediment of debris flow from its upstream landslides into the Laonong River formed a landslide lake to silt and block the river, resulting river upstream back silting and raise riverbed nearby Fuxing Village. Thus, it can not be discharged due to back silting the river completely overwhelmed and the loss of the drainage function in the Laonong River tributaries Lakusi Stream, causing the stream diversions flood flow into the village and scour riverbank let disaster brewing. Butangbunasu Stream upstream continually have landslide accurse, the threat of backed silting in Laonong River still exists, must as soon as possible to monitor the proper placement of affected area people.

並列關鍵字

611 flood event ； Debris flow ； Landslide lake ； Back silting ； Scour