七二水災引致坡地崩塌之因子研究

Landslide Characteristics Induced by Heavy Rainfall on July 2, 2004 Taiwan

陳天健(Tien-Chien Chen) ； 王晉倫(Chin-Lun Wang) ； 許中立(Chung-Li Hsu)

《坡地防災學報》 3卷2期 (2004/12) Pp. 69-80

https://doi.org/10.29995/JSHR.200412.0006

摘要

民國93年6月29日敏督利颱風颱風侵襲台灣，7月1日上午由淡水附近進入台灣海峽，以北北西的方向進入東海，此颱風雖然已經離開，但是卻引進強烈西南氣流，為本島於7月2日至4日間帶來巨量降雨，重創颱風台灣中部與南部地區，造成極嚴重之坡地崩塌、土石流及淹水災害，簡稱『七二水災』。本文比對颱風路徑與土石災害記錄，同時配合現地勘查及遙測相關之資料，檢討降雨所造成崩塌與土石災害之特性。結果顯示，颱風路徑與坡地災害息息相關；颱風帶來之高降雨量與降雨強度、以及921集集大地震坡地崩積土體是造成中部地區崩塌與土石災害之主要因素。本文亦針對防治工法相關性進行分析，初步推斷防治措施之施作對於土石流災害之抑制有其正面之助益。

關鍵字

敏督利颱風 ； 七二水災 ； 降雨 ； 崩塌 ； 土石流 ； 921地震

並列摘要

The severe Typhoon Mindulle ended on Jun 29, 2004 introduced with a high-intensity and -accumulation storm that dumped more than 2000 mm of rain during July 2 to July 4 in central and south Taiwan. The high-intensity and–accumulation event caused flooding and triggered more than 1000 soils slips and debris flows and large, complex landslides. Slope failures caused severe damage to roads, private homes, and agriculture. Through the interpretation of the 800 more disaster reports covering an area of slopeland in west Taiwan, we identified the rainfall conditions that triggered landslides under cumulative- and the peak intensity rainfall data, combined with detailed information on the spatial distribution of landslide. We also collected information about Chi-Chi earthquake (1999) event that occurred on September 21, 1999 and illustrated the after-earthquake effect in this event. A comparison of mitigation facility and the recent debris-flow events indicated that the mitigations are helpful for reducing the occurrence of debris-flow event.

並列關鍵字

Typhoon Mindulle ； landslides ； hazards ； rainfall ； Chi Chi earthquake