Geologic Characteristics of Costal Zone along Taoyuan, Hsinchu and Miaoli in western Taiwan

• Main Authors: Wen-Hsin Wang, 王玟心
• Other Authors: Ho-Shing Yu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/54771865933519495937

碩士 === 國立臺灣大學 === 海洋研究所 === 92 === The coastal zone is one of the most important fields of human’s economic activities. Due to it matters much in modern human living and lives, the research of the coastal zone is necessarily inevitable. Only through the understanding of the characteristics of the coastal zone then we can best ultilize, manage and preserve the coastal zone. This thesis adapts the software of GIS to integrate all the data, including depths of maritime space and heights of the land space into a cross-sectional view of the coastal zone. And then analyzing the features and characteristics of the topography combined with the field research to find out the characteristics and the distribution of the sediment of the beaches. The coastal zone of Taoyuan, Hsinchu and Miaoli is alongside the north western part of Taiwan, approximately 118 kilometers in length. Since the lack of the information of sudden tides, the upper limit of the coastal line is regarded as the upper limit of beaches’ distribution and locations in the area of land. As the lower limit of the coastal line, it is defined as around the surf zone, namely 30 meters under water in depth. The width of coastal zone is nearly 4 to 9 kilometers, and drop height is about under 45 meters between the sea limit and land limit. Base on grain size analysis results of sediment’s granular structure, the sand in Taoyuan’s beaches is categrorized as middle-size granule, the reflecting color of the beaches is apricot-yellow. Hsinchu’s beaches are basically consisted of middle-size granule and the tide gravel-bed with sandal-mud, the reflecting color of the beaches is dark-gray. As for Miaoli’s sand is tiny-size granule and has fine sorting, and the reflecting color is apricot-yellow. The compositions of the beach are all sand. Because of the natured phenomenon of the erosion as well as deposit occurred by turns, most of the terrain containing lagoons, sand bars, spits and bays are belongs to deposition shore. The cross-section view of the coastal zone in Taoyuan, Hsinchu and Miaoli shows that the slope of the beaches are gradual and gentle, and there are troughs and sand bars. Only in Yongan fishing port, the lagoons and offshore bars occur.