石門水庫集水區崩塌原因之探討

Abstract

2004年之艾利颱風及2005年之馬莎颱風通過台灣上空時，帶來豐沛雨量，造成石門水庫集水區發生數量相當可觀之崩塌及土石流災害，大量土砂在水流運搬之下，除增加水庫集水區大量鬆動土石外，由於細顆粒泥砂導致之原水濁度過高，使得桃園地區停水分別長達十餘天及數天。本研究為瞭解崩塌之原因，蒐集1986、1998、2003、2004及2005年之崩塌地，與地質、坡度、坡向、土地利用、土地權屬、溪流道路、聚落及降雨等特性因子進行比較，以探討造成崩塌之主因，結果顯示造成石門水庫集水區崩塌之原因應與累積降雨及地質兩項因子有關。

When the typhoon Aere and Matsa passed through the north of Taiwan in 2004 and 2005, the extremely rainfall cause the huge landslides and debris-flow disasters in the Shihmen reservoir watershed. A large number of sand cause the reservoir to deposited and because the water muddied, there is no water to use for ten more days in Taoyuan. In order to understand the reason of the landslide, we compare with the landslide data included the years of 1986, 1998, 2003, 2004, 2005 and the factors of geology, slope, direction of the slope, land-used, river, road, village, rainfall in relationship. The reason of landslide in the Shihmen reservoir watershed was because of the geology condition and cumulative precipitation.