Responsive image
博碩士論文 etd-0713105-104144 詳細資訊
Title page for etd-0713105-104144
論文名稱
Title
潮汐與波浪之互動對邊界層之影響
The Combined Influence of Tides and Waves on the Benthic Boundary Layer
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
127
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2005-06-21
繳交日期
Date of Submission
2005-07-13
關鍵字
Keywords
懸浮沉積物、高屏陸棚、邊界層、浪流交互作用
wave-current interaction, boundary layer, suspended sediment concentration, continental shelves
統計
Statistics
本論文已被瀏覽 5673 次,被下載 1168
The thesis/dissertation has been browsed 5673 times, has been downloaded 1168 times.
中文摘要
陸源沉積物經由近岸到大洋的過程中,沉積物的運動受到水動力作用的主導,影響沉積物的傳輸及分佈;而沉積物的來源、傳輸方式與分佈範圍,對近岸的地形變化,與陸棚沉積物的堆積有很大的影響。而上述沉積物之侵淤均發生在邊界層中,並受到波浪場、流場及生物擾動等因素的影響,造成沉積物在邊界層中的傳輸或再懸浮,沿岸及近海地區主要營力潮流與波浪的影響。本研究之目的由潮流流速剖面及聲波回波強度(Echo Intensity, EI)剖面的觀察,近一步了解底床邊界層的特性,以研究潮流及波浪的變化對邊界層的影響。
本研究針對邊界層中流速剖面及回波強度剖面的特性做探討,為了了解近岸浪流交互作用對邊界層的影響,錨錠儀器進行定點的長時間連續觀測,於2004年4月16日至5月1日期間,佈放一四角架於高雄二港口外東南方處的大陸棚內側,觀測單點的水文資料及流場隨時間序列的變化,而ADCP所記錄的回波強度可反映懸浮沉積物濃度的變化,因此利用各動力與回波強度的變化,進而了解高屏陸棚上的水動力機制及邊界層的變化。
實驗地點位於近岸海域,海流大部分以潮流為主,由Form Number值可得知,此處為全日潮所主導的混合潮,潮汐能量高達95.38 %。由ADCP觀測資料發現流速剖面受到潮汐作用的影響,log layer層的厚度約為一至二公尺,將流速剖面及回波強度剖面進行EOF(Empirical Orthogonal Eigen Function)分析,得到流速剖面的特徵形式,主要受到潮汐變化的影響,以全日潮為主導,半日潮為輔,回波強度的特徵形式反映出回波強度亦是受到全日潮為主導,但有低頻流的影響,主要營力為流剪應力;流速剖面及回波強度剖面的特徵向量趨勢,發現兩者第一個模態的剖面十分相似。在邊界層中,將EI(代表懸浮沉積物濃度)與波浪場、流場與浪流交互作用的動力相比對,發現EI受到流場的影響較大,波浪場的影響較小。
利用粗糙長度(zo)討論底部微地形的變化,發現底部粗糙長度與流剪應速度呈現負相關。波邊界層厚度最大值為0.9公分,浪流邊界層厚度為1.24公分,將邊界層變化趨勢與粗糙長度相比對,當粗糙長度變大時,則邊界層厚度則減小。經由頻譜分析可以得知,波邊界層厚度的變化主要受低頻流的影響,其次為半日潮;浪流邊界層厚度變化則受到半日潮為主,其次為全日潮;底部粗糙長度的變化以半日潮為主導,但有一低頻流存在,其週期為39.89小時。
潮流與波浪之互動對邊界層的影響,主要以潮汐的影響較大,以半日潮流為主,使得邊界層厚度的變化呈現週期性變化,流速主要亦受到潮汐的影響,波浪場影響較小,但回波強度除了受到潮流的影響外,亦受到波浪輕微影響。
Abstract
Continental shelves connect land and the ocean and also play a major role through time in the storage and re-distribution of terrigenous sediments to the ocean. Most of the sediments which origin in land and very shallow waters are deposited on the continental shelf. Sediment entrainment and movement in the coastal ocean are dominated by the combined effect of waves and currents within the benthic boundary layer. Our study intends to examine the relation between currents, waves and acoustic echo intensity in a wave-current boundary layer.
The site of the study was located southeast off Kaohsiung Harbor entrance in southern Taiwan on the inner shelf. Between April 16 and May 1, 2004, a tetrapod was deployed with an upward-looking ADCP (Aquadopp Profiler), a CTD with an OBS (XR-420). Another downward-looking ADCP was mounted at 2 m above bed (mab). The interval of the data collection was one hour. Water samples were pumped in seven time-segments (4 in the neap tide, 3 in the spring tide) through the experimental period at 1 and 0.5 mab, respectively for suspended sediment concentration (SSC) analysis in the laboratory. Aquadopp Profiler not only records 3-D current data but also measures the echo intensity (EI). The echo intensity is proportional to the amount of backscattering particles in the water column. The acoustic intensity could be a useful reference for the total concentration of the suspended particles.
Our preliminary findings indicate strong tidal control on the dynamics of suspended particles in the benthic boundary layer. The wave field is also modified by the tidal. The form number of the observed tides is 1.87, which indicates mixed tides with a predominantly diurnal component. The data were analyzed using empirical orthogonal (eigen) function (EOF) analysis. The results indicate that the tidal current dominated the alongshore current. Its period is 24.67 hours. The echo intensity are dominated by the current shear velocity.
The observations show that the maximum thickness of wave boundary layer and wave-current boundary layer at the experiment site is about 0.9 cm and 1.24 cm respectively. Cross-correlation analysis results among the roughness length, the thickness of wave boundary layer, and the thickness of wave-current boundary layer show that the roughness length correlates negatively to the thickness of both boundary layer. The data were analyzed by spectrum analysis. The results indicate that wave boundary layer were dominated by the low frequency current. The wave-current boundary layer and the roughness length were dominated by the semidiurnal tides.
目次 Table of Contents
致謝…………………………………………………………………… Ⅰ
中文摘要………………………………………………………………Ⅲ
英文摘要………………………………………………………………Ⅴ
目錄……………………………………………………………………Ⅶ
圖目錄…………………………………………………………………Ⅸ
表目錄………………………………………………………………

第一章、序論……………………………………………………………1
第二章、研究區域………………………………………………………7
第三章、實驗設計與分析方法………………………………………14
第四章、觀測結果……………………………………………………32
第五章、討論…………………………………………………………61
第六章、結論…………………………………………………………108
第七章、參考文獻……………………………………………………110
附錄一、符號注釋……………………………………………………113
參考文獻 References
侯麗華,1995. 高雄一港口航道對近岸沉積物分佈的影響,國立中
山大學海洋地質及化學研究所碩士論文,共91頁。
國立高雄海事專科學校,1988. 旗津外海海況調查分析研究報告:
研究報告007,共181頁。
黃俊傑,2001. 從高屏峽谷水文之時空變化來探討懸浮沉積物質傳
輸的機制,國立中山大學海洋資源研究所,共101頁。
黃煌煇等人,1993. 高雄海域海氣象調查報告研究,台南水工試驗
所,研究試驗報告第140號。
Brown, J., A., Colling, D., Park, J., Philips, D.,
Rothery, and J., Wright, 1989, Waves, Tides and
Shallow-water Processes, Open University Press,
Oxford, 187p.
Drake, D.E., and D.A., Cacchione, 1986, Field observation
of bed shear stress and sediment resuspension on
continental shelves, Alaska and California,
Continental Shelf Research, Vol. 6, pp.415-429.
Dyer, K.R., 1997, Estuaries: A Physical Introduction, 2nd
ed. John Wiley and Sons, Chichester, UK, 195p.
Emery, W.J. and Thomson, R.E., 2004, Data analysis methods
in physical oceanography, Elsevier Press, New York,
638p.
Foreman, M.G.G., 1977, Manual for tidal heights analysis
and prediction, Pacific Marine Science Report 77-10,
Institute of Ocean Sciences, Patricia Bay, Victoria,
B.C. 97p.
Grant, W.D. and O.S., Madsen, 1979, Combined wave and
current interaction with a rough bottom, J. Geophys.
Res., Vol. 84, No. C4, pp.1797-1808.
Grant, W.D. and O.S., Madsen, 1986, The continental-shelf
bottom boundary layer, Ann. Rev. Fluid Mech., Vol.
18, pp.265-305.
Kagan, B.A., L., Tejedor, O., Alvarez, A., Izquierdo, B.,
Tejedor and R., Mananes, 2001, Weak wave-tide
interaction formulation and its application to Cadiz
Bay, Continental Shelf Research, Vol.21, pp.697-725.
Li, C.-N. and J.T., Liu, 2005, Spring and Neap Controls on
the Relationship between Nearshore Current and
Suspended Particles: Implication on the Benthic
Boundary Dynamics, 5th International Conference on
Coastal Dynamics.
Liu, J.T. and H.L., Lin, 2004, Sediment dynamics in a
submarine canyon: a case of river-sea interaction.
Marine Geology, Vol.207, No.1-4, pp.55-81.
Liu, J.T. and Hou, L.-h. 1997, Sediment trapping and
bypassing characteristics of a stable tidal inlet at
Kaohsiung Harbor, Taiwan, Vol. 140, No, 3-4, pp.367-
390.
Liu, J.T. and Zarillo, G.A., 1993, Simulation of grain-
size abundances on a barred upper shoreface, Marine
Geology, Vol.109, pp.237-251.
Lueck, R.G. and Y. Lu, 1997, The logarithmic layer in a
tidal channel, Continental Shelf Research, Vol. 17,
pp.1785-1801.
Niedoroda, A.W., D.J.P., Swift and T.S. Hopkins, 1985, The
shoreface in coastal sedimentary environments, Davis,
R.A., Spriager-Veelag, N.Y., pp.533-624.
Ogston, A.S., Guerra, J.V., Sternberg, R.W., 2004,
Interannual variability of nearbed sediment flux on
the Eel River, northern California, Continental Shelf
Research, Vol. 24, pp.117-136.
Schlichting, H., 1979, Boundary-Layer Theory, McGraw-Hill
Company Press, 817p.
Smith, J.D., 1977, Modelling of sediment transport on
continental shelves, In: Goldberg, E.D., McCave,
I.N., O’Brien, J.J. and Steele, J.H.(Eds.), The Sea,
Wiley-Interscience, New York, Vol.6, pp.539-576.
Smith, J.D. and McLean, S.R., 1977. Spatially averaged
flow over a wavy surface, J. Geophys. Res., Vol.82,
pp.1735-1746.
Wang, Y.H., W.F., Bohlen and J. O’Donnell, 2000, Storm
enhanced bottom shear stress and associated sediment
entrainment in a moderate energetic estuary, Journal
of Oceanography, Vol.56, No.3, pp.311-317.
Wright, L.D., 1995, Morphodynamics of Inner Continental
Shelves, CRC Press, Boca Raton, FL, 241p.
Wright, L.D. and C.A., Nittrouer, 1995, Dispersal of River
Sediment in Coastal Seas: ix Contrasting Cases.
Estuarine, Vol. 18, No. 3, pp.494-508
Wroblewski, J.S. and E.E., Hofmann, 1989, U.S.
interdisciplinary modeling studies of coastal-
offshore exchange process: Past and future. Progress
in Oceanography, Vol.23, pp.65-99.
Yu, H.S. and Chiang, C.S., 1997, Kaoping shelf: morphology
and tectonic siginificance. Journal of Asian Earth
Sciences, Vol.15, No.1, pp.9-18.
Zhang, H., O.S., Madsen, S.A., Sannasiraj and E.S., Chan,
2004, Hydrodynamic model with wave-current
interaction in coastal regions, Estuarine Coastal and
Shelf Science, Vol.61, pp.317-324.
電子全文 Fulltext
本電子全文僅授權使用者為學術研究之目的,進行個人非營利性質之檢索、閱讀、列印。請遵守中華民國著作權法之相關規定,切勿任意重製、散佈、改作、轉貼、播送,以免觸法。
論文使用權限 Thesis access permission:校內校外完全公開 unrestricted
開放時間 Available:
校內 Campus: 已公開 available
校外 Off-campus: 已公開 available


紙本論文 Printed copies
紙本論文的公開資訊在102學年度以後相對較為完整。如果需要查詢101學年度以前的紙本論文公開資訊,請聯繫圖資處紙本論文服務櫃台。如有不便之處敬請見諒。
開放時間 available 已公開 available

QR Code