Satellite Observations on the Oil Spill in the Waters Adjacent to Taiwan

• Main Authors: Shu-Chang Liu, 劉書彰
• Other Authors: Chung-Ru Ho
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/30653733677799410895

碩士 === 國立臺灣海洋大學 === 海洋科學系 === 93 === Abstract The purpose of this thesis is to investigate the situation of oil spill from ship navigations in the waters adjacent to Taiwan by satellite imagery. About 136 Synthetic Aperture Radar (SAR) images from the European Remote Sensing Satellite (ERS) taken from 1993 to 1997 are used to perform this study. There are 46 images showing the possibility of oil spill, based on the position and the shape of the discharge, the path of the ship, the sea characteristics of the area, and the weather conditions. The result shows that oil spill occurs most frequently in spring and least in winter. One possible reason is that navigation conditions are better during spring and summer, and as such, traffics of fishing boats, and oil and cargo freighters increasing at this time. The sea area off eastern Taiwan has a probability which far surpassed the other areas, followed by the western sea area, the northern sea area, and the southern sea area. This can be explained by the fact that navigations and weather conditions are well in the eastern sea area all year round, resulting in increasing marine activity. Also, the eastern sea area contains many international waterways, frequently navigated by large-scale oil and cargo freighters. For these reasons, the high probability for oil spill in the area is understandable. Regarding the oil spill in the different regions with the distance to the shore, the oil spill in the western sea area, with an average distance of 28 nautical miles (50 kilometers), is closer than those in the other areas. Possible explanations are: navigation conditions in the western sea area are constantly poor, the tonnage of the working fishing boats in the area is smaller, or the distance of the fishing area and the fishery is closer to shore. All of those factors can help to explain the proximity of the oil spill to the shore in the western sea area. The statistical analysis demonstrates that the oil spill around Taiwan mostly occurred over 24 nautical miles (44 kilometers) away from shore. Therefore, it is obvious that the probability of oil spill occurring as a ship leaves the harbor is not high. Instead, the majority of oil spill takes place from middle to long distance navigating fishing boats and from oil and cargo freighters navigating international waterways. Keywords: SAR, Oil spill, Taiwan sea area, Remote sensing