地理研究
Permanent URI for this collectionhttp://rportal.lib.ntnu.edu.tw/handle/20.500.12235/194
Browse
12 results
Search Results
Item 臺灣東北部福隆海灘類型和裂流分布之長期變動研究(地理學系, 2009-05-??) 林雪美; 黃翊翔; 沈淑敏巴西南部海灘研究顯示，海灘意外的成因中有90%是來自裂流帶來的危害。鑑於國內海灘意外事件頻傳，裂流既為海灘危險的重要因子，管理當局實有必要針對海 灘安全的議題加以探討。過去有關海灘模式研究的理論基礎和分類，主要來自Wright、Short 等多位學者於澳洲海灘進行的研究，其探討海灘營力機制對水下沙洲和裂流變化的影響。福隆海灘有雙溪注入，受到波浪、潮汐等海灘營力的影響，其海灘類型和裂 流分布勢必也會受到河口逕流的影響。本研究即以Wright 等人於1984 年發表的海灘模式理論為基礎，透過航照的判讀，來探討福隆海灘長期以來海灘類型和裂流分布的時空間變動，並討論造成其差異的原因。 就時間而論，福隆海灘冬季海灘類型以倒轉沙洲與裂流型（TBR）為主，夏季則以反射型（REF） 至低潮位階地型（LTT）為主。探討冬半年海灘類型較夏半年偏消散之因，為波浪營力的不同所致；河口附近受逕流切穿的影響，其河口海灘類型無法適用於 Wright 的海灘模式理論。本研究依河口逕流的流向為指標，對雙溪河口沙洲水下沙洲形態加以分類。結果發現福隆海灘冬季河口海灘類型不僅較偏消散的情形，其河口變化 遠大於夏季河口海灘形態的變化。就空間而論，相同拍攝時間內，海域南側海灘類型較北側偏消散；造成其差異的主要成因則是局部礁岩的影響，使得海床粒徑較 大，海灘類型因而偏向反射型，裂流頻數也比較低。然而不論任何時間，海域東南端受到河口切穿和人工堤防建造的影響，皆有固定離岸方向水流的存在，對於海灘 遊憩者而言，需避免到該地戲水。Item 臺灣東北部福隆海灘類型和裂流分布之長期變動研究(地理學系, 2009-05-??) 林雪美; 黃翊翔; 沈淑敏巴西南部海灘研究顯示，海灘意外的成因中有90%是來自裂流帶來的危害。鑑於國內海灘意外事件頻傳，裂流既為海灘危險的重要因子，管理當局實有必要針對海 灘安全的議題加以探討。過去有關海灘模式研究的理論基礎和分類，主要來自Wright、Short 等多位學者於澳洲海灘進行的研究，其探討海灘營力機制對水下沙洲和裂流變化的影響。福隆海灘有雙溪注入，受到波浪、潮汐等海灘營力的影響，其海灘類型和裂 流分布勢必也會受到河口逕流的影響。本研究即以Wright 等人於1984 年發表的海灘模式理論為基礎，透過航照的判讀，來探討福隆海灘長期以來海灘類型和裂流分布的時空間變動，並討論造成其差異的原因。 就時間而論，福隆海灘冬季海灘類型以倒轉沙洲與裂流型（TBR）為主，夏季則以反射型（REF） 至低潮位階地型（LTT）為主。探討冬半年海灘類型較夏半年偏消散之因，為波浪營力的不同所致；河口附近受逕流切穿的影響，其河口海灘類型無法適用於 Wright 的海灘模式理論。本研究依河口逕流的流向為指標，對雙溪河口沙洲水下沙洲形態加以分類。結果發現福隆海灘冬季河口海灘類型不僅較偏消散的情形，其河口變化 遠大於夏季河口海灘形態的變化。就空間而論，相同拍攝時間內，海域南側海灘類型較北側偏消散；造成其差異的主要成因則是局部礁岩的影響，使得海床粒徑較 大，海灘類型因而偏向反射型，裂流頻數也比較低。然而不論任何時間，海域東南端受到河口切穿和人工堤防建造的影響，皆有固定離岸方向水流的存在，對於海灘 遊憩者而言，需避免到該地戲水。Item 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.Item 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.Item 颱風事件對臺灣河口地形的影響分析(地理學系, 2002-11-??) 林雪美; 彭佳偉; 張喬盛河口地形的形成多依賴長期穩靜變動的河海營力，其平均能量對河口的形成與破壞是緩慢累積的，但是颱風、豪雨等突發事件所帶來的最大能量，其對河口塑形的重要性卻常遠較平均能量為大，往往造成河口地形在短時間內顯而易見的變動。本研究以中港溪口與水璉溪口為對象，利用野外沙洲剖線實測、粒度分析、數值地形等方法，探討研究期間颱風事件對河口沙洲的改變情形。主要目的在於了解河口在颱風事件的強烈能量下的反應情形，並比較不同規模與性質河口的差異性。期能藉由河口地形變動特性的認識，提供下游地區環境災害的預防及開發利用之參考。 研究得知水璉溪口經歷啟德和碧利斯兩個颱風後，河口沙洲被沖刷後退，兩岸沙洲壩變窄而陡；中港溪口在桃芝颱風後，河口沙洲形態變動幅度不大，但納莉颱風後，右岸河口沙洲幾乎全遭沖毀，殘餘的沙洲略有外海偏移的現象，河口沙洲坡度皆變得陡峭，顯示納利颱風對河口地形產生莫大的影響。比較中港溪與水璉溪河口地形對於颱風事件的反映差異，可以得知河口主導營力是重要因素。以潮汐為主控營力的中港溪口，受颱風事件的影響，「逕流+滿潮」的沖刷作用遠超過風浪增強來得重要；而水璉溪口在特殊事件下以風浪為主導營力，受颱風事件的影響，「風浪」的沖刷營力則遠超過逕流增加等作用。再者，水璉溪流域面積小，颱風事件後三個月已大致回復颱風前沙洲形態。而河口粒徑與水璉溪口相近的中港溪口，流域面積為其16倍，在納利颱風過後一年，河口沙洲形態仍未回復。則又說明河川規模是河口地形變動的重要因素；也說明不同事件所造成的河海營力規模，亦是河口地形變動的關鍵因子。Item 臺灣西部海岸沙丘之地形學研究(地理學系, 1993-06-??) 石再添; 張瑞津; 張政亮; 林雪美; 連偵欽Coastal sand dunes are widely distributed along the western coast of Taiwan from Touchien Hsi to Erhjen Hsi. Based on maps work, airphoto interpretation, particle size analysis, field investigation, etc, the study results are summarized as follows: 1. The form and the magnitude of the western coastal sand dunes have close relationship with the source of 13 rivers' sand supply, alongshore current and wave action, power and direction of wind, terrains, rainfall, evaporation and vegetation. 2. The coastal dunes develop well on riversides of Chung Kang His, Holung Hsi, Choshui Hsi and offshore bars along Chianan coast. Two principal types of these dunefield may be distinguished, namely, active dunes and stabilized dunes. The two dunefield types contain a variety of dune features, such as transverse dunes, barchans, longitudinal dunes, and dome dune etc. 3. The grain sizes of beach and dune sand are quite uniform. The Md φ and δ φ on average of the dune sand is smaller than the beach sand. This shows that wave process is stronger than wind process. 4. Comparing the maps published in 1926 and 1984. the change of coastal dunes is clear. Because the dunefield was used as fishery or watermelon and sugarcane planting, most of the sand dunes were leveled off entirely. Some of the residual sand dune still exist at present fixed by windbreak forest. For sand dunes have the function of protecting coasts, they had better be well-planned and well-used so as to main-tain the sustainable utilization of land souces.Item 臺灣東部河口地形的變動時距與循環(地理學系, 2001-05-??) 林雪美; 張喬盛The estuary represents a very unique environment. It's influenced by forces from the rivers, the land, and the sea. Within the dynamic system, the estuary is located at the transition zone in which sediment-laden flows both from the river and the sea. The estuarine landforms may change due to the vaious combinations of wave, river discharge and tidal conditions. This study focuses on three estuaries in eastern Taiwan. The main aim is to outlook the change of the estuarine landforms in the different time span. It is expected that better understanding of the estuarine behavior may be helpful when conducting the development schemes regarding to the estuaries. The depositional forms of estuaries have significant daily, monthly and annual change due to the river discharge, wind, tidal range, wave, and typhoon frequency. First, the forms of estuaries are stable in the long-germ scale. Three estuaries have only slight change during the period from 1904 to 1989, moving back and forth within the distance of few hundreds meters. Second, the forms of the estuaries in eastern Taiwan have significant annual change due to the seasonal differences of discharge and monsoon. In summer, the channels usually become wider and sandbars are gentler and extended seaward. In winter, however, these sandbars become narrower, steeper and extend toward right bank. There is an obvious cycle of the change in the moderate time span. Third, the form of the three estuaries has most significant change due to the typhoon and storm. The mouth of channels will be narrowed or even closed when typhoon comes. But, the recovery time is different among the three estuaries.Item 臺灣北部海岸沙丘之地形學研究(地理學系, 1992-03-??) 石再添; 張瑞津; 林雪美; 張政亮; 連偵欽Item 臺灣東北部福隆海灘類型和裂流分布之長期變動研究(地理學系, 2009-05-??) 林雪美; 黃翊翔; 沈淑敏巴西南部海灘研究顯示，海灘意外的成因中有90%是來自裂流帶來的危害。鑑於國內海灘意外事件頻傳，裂流既為海灘危險的重要因子，管理當局實有必要針對海 灘安全的議題加以探討。過去有關海灘模式研究的理論基礎和分類，主要來自Wright、Short 等多位學者於澳洲海灘進行的研究，其探討海灘營力機制對水下沙洲和裂流變化的影響。福隆海灘有雙溪注入，受到波浪、潮汐等海灘營力的影響，其海灘類型和裂 流分布勢必也會受到河口逕流的影響。本研究即以Wright 等人於1984 年發表的海灘模式理論為基礎，透過航照的判讀，來探討福隆海灘長期以來海灘類型和裂流分布的時空間變動，並討論造成其差異的原因。 就時間而論，福隆海灘冬季海灘類型以倒轉沙洲與裂流型（TBR）為主，夏季則以反射型（REF） 至低潮位階地型（LTT）為主。探討冬半年海灘類型較夏半年偏消散之因，為波浪營力的不同所致；河口附近受逕流切穿的影響，其河口海灘類型無法適用於 Wright 的海灘模式理論。本研究依河口逕流的流向為指標，對雙溪河口沙洲水下沙洲形態加以分類。結果發現福隆海灘冬季河口海灘類型不僅較偏消散的情形，其河口變化 遠大於夏季河口海灘形態的變化。就空間而論，相同拍攝時間內，海域南側海灘類型較北側偏消散；造成其差異的主要成因則是局部礁岩的影響，使得海床粒徑較 大，海灘類型因而偏向反射型，裂流頻數也比較低。然而不論任何時間，海域東南端受到河口切穿和人工堤防建造的影響，皆有固定離岸方向水流的存在，對於海灘 遊憩者而言，需避免到該地戲水。Item 臺灣地區近三十年自然災害的時空特性(地理學系, 2004-11-??) 林雪美