- 期刊
大鐵杉－塔塔加鞍部－玉山群峰地區之崩塌地初步調查
Landslide along the Yushan Mountain Pathway-A Preliminary Investigation
摘要
九二一集集大地震使得台灣中部地區受創嚴重，位於震央附近的玉山國家公園更是深受影響。本研究的目的，是為了調查九二一集集大地震後玉山國家公園內邊坡崩塌的情形與分佈狀況，瞭解崩塌地發生的原因，以及環境變遷的情形與影響。 野外調查工作主要是沿著大鐵杉－塔塔加鞍部－玉山群峰之間登山步道進行。由於缺乏航空相片與衛星影像的輔助，調查工作僅能從既有的相片基本圖、地形圖與野外觀察中獲得初步的觀察資料，記錄於崩塌地調查表。 從調查資料中得知，研究區內的崩塌地集中在三個地方，分別是大鐵杉至塔塔加鞍部之間的林道（編號l－6號崩塌地）、塔塔加鞍部至玉山前峰附近（編號7－11號崩塌地）與玉山西峰一帶（編號12－16 號崩塌地）。從調查結果可知，地質破碎、逕流集中與道路開挖關係是造成本區發生崩塌主要的原因。崩塌類型的不同則明顯受到岩性軟硬的控制，而不同崩塌類型的分佈狀況也反映出軟硬岩體在空間上分佈的情形。 由於缺乏航空相片與衛星影像，無法進行玉山地區大規模的崩塌地調查工作，僅能沿著登山步道獲得線的崩塌資料。缺乏面的資料使探討崩塌地的空間分佈特性時可能會有所偏失。因此，儘速取得航空相片與衛星影像資料，進行全面性的調查工作，將是接下來的工作之一。
並列摘要
This study tried to understand the conditions, distribution and causes of landslides that happened after Chi-Chi earthquake on 21(superscript st) September 1999 in the Yushan National Park. We investigated the landslides with basic maps, topographic maps and field facilities along the Yushan mountain pathway (Big Hemlock to Yushan), and recorded data in the landslide surveying sheets. 16 landslides were clustered at three places. They were located between the Big Hemlock to Tatajia (landslide No.l-No.6), Tatajia to Yushan front peak (landslide No.7-No.l1) and Yushan western peak (landslide No.12-No.16). Landslides along the pathway were induced by geological condition, runoff concentration and road excavation. We could obviously find out that different types of landslide were controlled by hardness of rock, and so do their spatial contribution. This study didn't investigate landslides in the whole area of Yushan National Park because of lacking aero-photograph and satellite images of the area. It is better to infer the spatial distribution character and caution of landslide from planar data than line data. What we are going to do is to collect aero-photograph and satellite images of the study area for further landslide analysis.