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Title: 台灣高山凍融作用與冰緣地形分布之研究
Freeze-thaw Processes and Periglacial Landforms of High Mountain in Taiwan
Authors: 陳毅青
Contributors: 地理學系
Keywords: 南湖大山;高山地形;凍融作用;冰緣地形;垂直分布帶
Nanhuta Shan;Alpine landscapes;Freeze-thaw processes;Periglacial landforms;Vertical distribution
Date: 2007
Issue Date: 2015-04-29T04:08:07Z
Publisher: 國立台灣大學
Abstract: 寒凍為高山與冰緣氣候中,常見的環境因子,凍融作用亦是其中最重要的地形營力。台灣高山地區易發生凍融風化與寒凍潛移等作用,而對其地形演育甚為重要。本研究蒐集南湖大山氣溫及地溫資料,利用經驗與統計模型,推估凍融作用的規模、頻率與發生的時間,以及應用野外調查的結果,繪製高山地區之冰緣地貌圖。
Frost action is one of the important environmental factors in alpine and periglacial climate. Among them, freeze-thaw process is the most influential geomorphologic process in the area. Freeze-thaw weathering and gelifluction movement shapes the landform in high mountain area of Taiwan. In this study, the air and ground temperature data of 2, 10 and 20 cm depth of Mt. Nanhu was used to model the magnitude, frequency and distribution of freeze-thaw process. Besides, field investigation was also conducted to depict the geomorphological map in Mt. Nanhu area.
According to ground temperature data in Mt. Nanhuta collected from 2001 to 2005, frequency of freeze-thaw processes at depth of 2 , 10 and 20cm was 55, 8.75 and 1.25 times per year respectively. The freeze-thaw process was weak at depth of 20cm. It was most frequent in autumn and spring but not few in winter for freeze and snow cover in that period.
At the depth of 10 cm in the ground, there are about 2 months of frozen period per year in average. The measured and estimated ground temperature data are highly correlated, the R-square value is 0.7875, and the numbers of freeze-thaw from measurement and estimation by the model are identical.
The relationship between elevation and freeze-thaw cycle is in logarithm regression by the estimation of the model. However, the relationship between freeze-thaw cycle and forest line in Mt. Nanhuta is not clear.
According to field investigation, there are some periglacial landforms in the Mt. Nanhuta and Mt. Hehuan, including turf-banked lobes terraces, talus accumulation and talus slopes. Turf-banked lobes terrace are crescent shape terrace developed in Mt. Sheimajuei and the saddle between main peak and east peak of Mt. Nanhuta. Talus accumulation is developed in the saddle between main peak and east peak of Mt. Nanhuta. Talus slope is accumulated a lot of frost-wedging rock which is located at east of upper-cirque. It shows that freeze-thaw processes are active in the Mt. Nanhuta, so there are many periglacial landscapes between 3200-4000m above sea level.
Relation: 碩士; 國立台灣大學地理環境資源學所
Appears in Collections:[地理學系] 專書

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