碩士 / 國立成功大學 / 水利及海洋工程學系專班 / 93 / Taiwan is surrounded by the ocean so that the marine transportation trading plays an important role in the economic development. The construction of international harbors is almost complete and now the government is actively developing the auxiliary harbors. For example, Ann-ping Harbor is the auxiliary harbor of Kaohsiung Harbor and the planning of this harbor requires accurate long-term ocean climate information. Because the basic information is so important in the subsequent engineering planning, the accuracy and precision of these sources is crucial. The study compiles ocean currents data from different agencies in Tainan city area to establish basic background information and further analyze these data by statistic methods, spectrum analysis, harmonic analysis, and numerical filtering. The mechanisms of ocean currents and their characteristics are generated for further use or reference during the coastal planning.
The current velocity over one knot is approximately 4% among all the registered entry. The direction is roughly parallel to the coast, namely NW-NNW during the floods and SE-SSE during the ebbs. The SSW-SW direction is about 40% during the measurements. Current velocity between 10~30 cm/s is about 51% and the maximum velocity is 91 cm/s during the observation. The average current velocity is 5~10 cm/s and the average direction is between 90 degrees to 200 degrees. The ocean current is dominated by M2 semi-diurnal period, the amplitude of current velocity appears to be seasonal, about 30~40 cm/s during May to Octorber and 15~30 cm/s during November to February. The longitudinal direction angel doen not change much and is about 147 degrees.
For the M2 semi-diurnal tide along the coast, time delays of -1 hour and +5 hours has a better relative coefficient. The phase difference is about 30 degrees, and differs from standing waves that have a 90 degrees phase angel. Therefore, the semi-diurnal tide does not appear a standing wave in Tainan area. Study of the influence of seasonal winds indicates that it usually correlates to the sudden change of the wind field nearby in a very short period. The change of sub-tide that parallels to the coast can be very severe that reaches 20~30 cm/s, but not limited to the wind field in the near shore of Tainan area.
| Identifer | oai:union.ndltd.org:TW/093NCKU5083044 |
| Date | January 2005 |
| Creators | Tzu-Hsing Lu, 呂賜興 |
| Contributors | Tai-Weu Hsu, Jaw-Feng Lee, 許泰文, 李兆芳 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 40 |
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