2009年第8號颱風莫拉克帶給台灣中南部嚴重災害實況以死亡600多人的小林村與神木村隆華國小全毀的情形爲例

The Damage in Taiwan Caused by 2009 Typhoon No.8 (Morakot) Cases in Xiaolin-cun and Shenmu-cun

許華杞(Hwa-Chu Shen) ； 高治喜(Tr-Shi Kao) ； 今村遼平(Ryohei Mamura) ； 中筋章人(Akito Nakasuji)

《測量工程》 51卷3&4期 (2009/12) Pp. 45-53

https://doi.org/10.29983/JSE.200912.0004

摘要

2009年8月6日至11日，第8號颱風莫拉克侵襲台灣，在中南部降下200年一次機率的豪大雨，許多地區遭受空前的洪水與土石流災害，災情極爲嚴重。8月9日早晨，高雄縣甲仙鄉小林村因旗山溪兩岸大崩塌與堵塞旗山溪河道形成之堰塞湖潰決而被土石淹没或洪流冲失，有600多人死亡々同一天下午，南投縣信義鄉神木村隆華國民小學，也因堰塞湖潰決以致於全部被河水冲刷衝擊破壞，所幸因週日學校沒有學生而未造成人員傷亡。
導致這次災害的主因係連續3天高達2600mm的降雨量（台灣的年降雨量爲2500mm）。山地陡峭，而且山坡廣佈過去的崩積土，在持續豪大雨下，崩積地吸水達飽和狀態產生滑動而引發大崩塌以及堰塞湖潰堤。聚落和小學離河床之比較高度只有5-6m，位於低位河階上的這個因素是也不容忽視。筆者等於2009年10月2日至7日利用小林村和神木村兩地區災害前後之空照像片加以判讀並到現場實地勘查。

關鍵字

崩積土 ； 堰塞湖 ； 低位河階

並列摘要

Typhoon No.8 (Morakot) that hit the middle-southern part of Taiwan on August 6-11, 2009 caused a large number of deaths and flooding there while it passed by. The most severe damage occurred in two townships of Xiaolin-cun and Shenmu-cun, in Kaohsiung county and Nantou county respectively. Xiaolin village was completely destroyed and buried by landslides and floods. In Shenmu-cun, the floods triggered by the heavy rainfall swept away an elementary school.
The violent downpour, the probability of the same scale of rainfall as being once in 200 years, was no doubt the immediate cause of the floods and debris disasters, while the region's vulnerability to those calamities was directly due to the colluvium layers which thickly cover a wide area of the mountain slopes, and the geomorphologic characteristics of the terrain, where the devastated villages and the elementary school were located on low terraces at a relative height of 5-6m above the recent riverbed.

並列關鍵字

Colluvium ； lake by landslide dam ； lower terrace