碩士 / 國立海洋大學 / 海洋科學系 / 90 / Abstract
During the past years, the investigation of the thermal plume off the nuclear power plants at northern Taiwan provides an opportunity to study the effects of the various shapes of bays upon the coastal currents. Due to the complex of those currents, observations were made by the ADP or ADCP (Acoustic Doppler Current Profiler) scanning over the inside and outside areas of the bays. Thus the data must be processed in synoptic manner. And then, after the objective analysis, those measurements of the currents may be in further presented in grids. The time series of the flow charts overlapped with streamlines of stream functions becomes easy to read and understand.
The alternation of the flood and ebb currents shows a nice regularity in region about one kilometer offshore near the northwest tip of Taiwan. Such a region moves further offshore for where is closed to the northeast corner of Taiwan, maybe due to the complexity of the coastal features. For instance, it moves to about four kilometers from the shore at Yehliu Bay. For the same reason, the near shore currents are characterized by eddies mostly initiated inside the bay. Those eddies then move away offshore along with tide motion. And new eddies will be generated inside the bay while the tide alters. Nevertheless, while waters transported by those flood or ebb currents towards the coast of a bay cape might produce a local transient upwelling inside the bay. Its returned surface flow may encounter the strong thermal plume to sometimes render a significant front, along which surface debris or foams etc. are clustered as a very natural phenomenon.
The alternation of tidal currents inside the bays of Shimen and Yehliu where the Nuclear Power Plants I and II reside always leads about one to two hours to the tides. According to several observations of moored current meter and the GPS drifter tracking, the current field within the Santiao Bay where the Plant IV is under construction is characterized by the difference of the surface 1 m flow and the subsurface flow. The recent ADP observation indicates again the consistency of the northward surface flow while the subsurface flow shows the reversing of tide components, evidencing the returned surface flow system by local upwelling as that in Yehliu Bay.
| Identifer | oai:union.ndltd.org:TW/090NTOU0276005 |
| Date | January 2002 |
| Creators | Chun-Hung Chang, 張俊鋐 |
| Contributors | Jian-Hwa Hu, 胡健驊 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 138 |
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