Browsing by Author "劉明錡"

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新店溪河階之地形學研究
(地理學系, 2000-11-??) 張瑞津; 鄧國雄; 劉明錡
River terraces including six lateritic surfaces (LH、LT1-LT5) and three non-Iateritic surfaces (FT1-FT3) have been recognized along Hsin-tien River. Most of lateritic surfaces distributed concentrately at Ping-lin, Shen-chang-Pan and Hsin-tien. Comparatively speaking, surfaces LT4, LT5 and FT2 distributed more widely and continuously than the others. Under the effect of tilting, the channel tended to shift from south to north and became sinuos. Sinuosity increased to the maximum in the LT4 stage that imp1ied the river had a significant lateral erosion in relatively stable stage. FT terraces have been formed under the controlling effect eustatic fluctuation and subsidence of Taipei Basin. The meander cut occurred during the lowering base level stage (FT1-FT2). Referring the results of climatic and eustatic fluctuation, the LT5 and three FT surfaces have been formed respectively in high sea level around 40000, 10000, 6000 and 3000 years before present.
臺灣東部河口地區之地形學研究
(地理學系, 1995-10-??) 石再添; 張瑞津; 林雪美; 張政亮; 劉明錡; 陳政典
The vincinity of the estuaries is one of the most populated area in the world. In order to ultilize the resources of this area more reasonably, the understanding of its geomorphological, hydrological and sedimentary characteristics becomes a main and basic task. Since estuary is located on the interface of river and sea, the morphology of estuary is influenced by the factors coming from both environments. The drainage basin area, shoreline length, shape factor, channel gradient, runoff, sediments and monthly discharge, etc. are factors coming from land, while the wind, current, wave and tide etc. coming from the sea. This study focuses on eleven estuaries of the eastern coast of Taiwan. Based on the stream slope, number of channels, discharge, etc., these estuaries can be divided into straight and braided pattern. The former has sandbars or spurs, such as Hualien Hsi, Hsiukuluan Hsi and Kangkou Hsi, while the latter have braided channels, sandy-gravel sediments and changeable sandbars, such as Hoping Hsi, Liwu Hsi and the estuaries in Taitung coastal area. The eastern coast is classified as wave-dominated type according to average wave height and tidal range. The wave impacting upon the area between Hoping Hsi and Hsiukuluan Hsi is severer. The forms of the estuaries in eastern Taiwan have significant seasonal change due to the seasonal differences of discharge, monsoon and typhoon. In the summer, the channels usually become wider and the sandbars are gentler and extended seaward for most estuaries. In the winter, however, these sandbars become narrower, steeper and extend toward right bank. The mouth of channels will be narrowed or even closed when typhoon coming. The forms of estuaries are stable in the long-term scale. Eleven estuaries have only slight change during the period from 1904 to 1989, moving back and forth within the distance of 250m. The channel migration of most estuaries, however, is obvious.
臺灣西北部階地形特徵及其演育模式
(2004-01-01) 劉明錡; 張瑞津; 沈淑敏
臺灣西南部河口地區之地形學研究
(地理學系, 1995-03-??) 石再添; 張瑞津; 林雪美; 張政亮; 劉明錡; 陳政典
The vincinity of the estuaries is one of the most populated area in the world. In order to ultilize the resource of this area more reasonably, the understanding of geomorphogical, hydrological and sedimentary characteristics becomes a main and basic task. Since estuary is located on the interface of river and sea, the morphology of estuary is influenced by the factors coming from both environments. The drainage basin area, shoreline length, shape factor, channel gradient, opening form, runoff, sediments, and monthly discharge etc. coming from the land. While the wind current, wave and tide etc. coming from the sea. This study area focuses on 20 estuaries of the south-western coast of Taiwan. The five of them are gravel estuaries and the rest are sandy. By correlation grain size of sandy estuaries has relationship with channel gradient below 100m, width of opening and shape factor. The forms of sand bar on estuaries are changed seasonly. Most of them has a tendency migrating southward due to northern moonsoon. The 20 estuaries can be classified into the wave dominated type, the tide dominated type and the runoff dominated type according average wave height, specific discharge and tidal range. Comparing the location of 20 estuaries during the period from 1904 to 1990(85 years). Most estuaries tend to migrate westward. The changes of estuaries are controlled by the intensity of wave and precipitation, the influence of reservior and hydraulic engineering and the changes of land use.
苗栗丘陵河階之地形學研究
(地理學系, 1998-11-??) 張瑞津; 鄧國雄; 劉明錡
苗栗丘陵區之階地至今仍殘存者，概分三義、銅苗及通霄等三區。三義區主要為高位紅壤階地，其階面高度 590 ～ 350m，對比為 LH、LT1、LT2 等三段。銅苗區的階地分布於後龍溪及西湖溪兩側，其中高位紅壤階地的階面高度 300 ～ 150m，分為 LT3 ～ LT5三段，而非紅壤的低位階地分為 FT1 ～ FT3 三段；通霄區高位階地分布於南勢溪上游，階面高度 220 ～ 70m，分為 LT4、LT5 二段，低位階地分布於苑裡溪至大安溪之間。階地的紅壤礫層一般厚約數公尺至十數公尺，上覆於頭嵙山層，其與火炎山相礫層不易分出界面，但與香山相砂頁岩層之界面較為清楚。紅壤粒徑中數（ Md φ）大部份介於 6.5 φ～ 7.0φ，各階地紅壤粒度並無規律變化。階地受新期斷層、背斜、向斜構造之影響，部份階面產生變形。三義區階地向東及向北傾動，八甲一帶的階地呈向斜變位。通霄東南之階地於倒梯崎則成反斜崖現象。至於三義至銅鑼的階地西側陡崖有 100 ～ 330m 的落差，狀似斷層崖，再經侵蝕而成，但其斷層面可能發生在火炎山相巨厚的礫層中，故不易直接找到變位證據。依本區階地高度、紅壤粒度、礫石覆瓦的特徵，三義南段階地及通霄階地似為大安溪階地的殘面，而三義以北的階地由後龍溪逐次堆積而成。古後龍溪由南轉向北，階地可分為九階，紅壤六階，非紅壤三階，西湖溪為其舊流路。
頭前溪階地之地形學研究
(地理學系, 1999-11-??) 張瑞津; 鄧國雄; 劉明錡
頭前溪階地群至今仍殘存之紅壤階地可分為六階，非紅壤階地為三階。紅壤高位階地分布於頭前溪兩岸，以南岸的竹東至新竹間之竹東丘陵區最為發達，紅壤最高面為竹東面，高度280~250公尺，比高約130 ~100公尺，對比為LH。其次為寶山北面、竹東西面、高峰面、仙宮面與關東橋面，前二者之紅壤階面多已侵蝕殆盡，僅餘丘頂殘面，高度為250~230公尺與220~200公尺，階崖均達20公尺，分別對比為LT1與LT2；後三者高度分別為110~100公尺、90~80公尺、70~50公尺，階崖為20公尺、15公尺與10公尺，對比為LT3、LT4與LT5面；北岸之飛鳳山丘陵區最高為飛鳳山，高度462公尺，殘面對此為LH，其次為犁頭山頂部賤留三塊向西緩降的高位紅壤階地，高度由230~150公尺，對比為LT1。非紅壤低位階地則分布於頭前溪南、北兩岸，可分為三段階地，其中南岸的員山面及麻園肚面較廣，高度為55~40公尺、45~30公尺，階崖為5公尺、3~5公尺，對比為FT2與FT3面，而FT1之員崠子面殘留甚少。北岸之穹林面與竹北面高度分別100~90公尺及80~20公尺，階崖5~10公尺與3~5公尺，對比為FT1與FT3。本區階地受到新期構造如新竹斷層、新城斷層、竹東斷層與寶山背斜、青草湖背斜等的影響，其中以新竹斷層及新城斷層對階地的影響最為明顯，例如新城斷層通過LT3、LT4與LT5，各造成40公尺、35公尺與25公尺之斷層崖，至於低位階地FT2則有數公尺的斷崖；新竹斷層通過LT5與FT2面，各造成10公尺與2公尺的斷崖，且影響LT5階面向南傾動。本研究根據階地分布、地形特徵及地形面對比推測，頭前溪地形演育如下：更新世中期頭前溪形成LH面，因受台灣島新期構造運動的隆升，造成頭前溪向北依次遷移下切，而新期構造運動中，斷層活動則至少持續至FT2。