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系統識別號 U0026-0907202012511800
論文名稱(中文) 水砂量影響辮狀河川形貌演化之大型物理實驗及二維模式模擬
論文名稱(英文) Morphological Evolution of Braided Channels in response to Flow and Sediment: Physical Experiments and 2D Model Simulation
校院名稱 成功大學
系所名稱(中) 水利及海洋工程學系
系所名稱(英) Department of Hydraulics & Ocean Engineering
學年度 108
學期 2
出版年 109
研究生(中文) 石軒寧
研究生(英文) Hsuan-Ning Shih
學號 N86074071
學位類別 碩士
語文別 中文
論文頁數 183頁
口試委員 口試委員-陳樹群
口試委員-吳富春
口試委員-卡艾瑋
指導教授-賴悅仁
中文關鍵字 辮狀河川  水砂量  大型物理實驗  二維水理模式 
英文關鍵字 Braided channels  flow and sediment  experiments  model 
學科別分類
中文摘要 以往的辮狀河川實驗較少討論泥砂量對於辮狀河川形貌演化的影響,本研究以一系列的大型物理模型實驗探討供砂量對於辮狀河川的影響,而另一系列實驗考慮供砂量達到輸砂平衡時,不同流量對辮狀河川的影響。RiverFlow2D 模式部分則輸入實驗之 DEM 並給定實驗中率定之流量、砂量等參數進行不同輸砂公式之模擬。
實驗研究結果顯示,本研究的辮狀河川之辮狀強度指數高於以往的辮狀河川實驗許多,而辮狀比率皆趨近於平衡值 0.4,整體趨勢仍具有辮狀強度指數與無因次河川功率成正相關之關係,因此,我們認為本研究數據可能為辮狀河川的新領域。本研究亦開發了人工及影像自動判釋辮狀河川的砂洲形態,得到的砂洲形態吻合由現地及實驗數據所建立的回歸趨勢,表示本研究之砂洲型態與天然河川具有高度相似性。最重要的是,在本研究中隨著供砂量或是流量增加,辮狀強度指數及河道濕寬都是隨之增加,因此我們認定除了流量之外,砂量亦是影響辮狀河川形貌的重要因素之一。
模式模擬部分則是以模式設定及模擬經驗較有貢獻,鑑於模擬結果而歸納出本研究模擬誤差之原因可能是 RiverFlow2D 模擬物理實驗時,應多加考慮水槽粗糙度和河道砂材的粗糙度是否一致,或是因為RiverFlow2D 較不適用於辮狀河川的模擬。
英文摘要 There was little discussion about braided channel morphology in response to sediment supply. Due to this reason, we study the influence of sediment supply to the braided evolution in three experiments. And also, we study the evolutions in response to increased discharge in other three experiments. We build DEM and orthophoto for analysis and model simulation by using Matlab.
The results indicate the total/active braiding intensity in our experiments are higher than those in previous braided experiments, and the braiding ratio is also closed to the equilibrium value 0.4. In our research, braiding intensity is in proportional to dimensionless stream power, we think that our data may be a new region of several-thread braided channels. We also develop bar interpretations of orthophoto to get the shape parameters. Bar parameters here are similar to nature braided river and other experiments. The most important is that braiding intensity and wetted width are in proportional to sediment supply or discharge in this research, so we suggest that sediment supply is one of the significant factors to braided morphology.
With respect to simulation, this research contributes to the basic setting and experiences for RiverFlow2D. According to the results, we think that RiverFlow2D may not be suitable to braided experiments.
論文目次 摘要 I
致謝 XII
目錄 XIV
表目錄 XVIII
圖目錄 XX
第一章 緒論 1
1-1 研究動機 1
1-2 文獻回顧 4
1-2-1 物理實驗之相關文獻 4
1-2-2 二維水理模式之文獻回顧 9
1-3 研究問題 11
第二章 實驗配置 12
2-1 實驗水槽 12
2-1-1 水槽配置 12
2-1-2 供水供砂系統 13
2-1-3 排水排砂系統 17
2-1-4 測量及記錄系統 18
2-2 實驗砂材 20
2-3 實驗組數及參數 22
2-4 實驗流程 24
第三章 數位影像處理 25
3-1 影像分析 25
3-1-1 影像校正 25
3-1-2 影片轉檔 29
3-1-3 影像處理 29
i 挑選實驗區段內相片 29
ii 使用濾波器及測試亮度門檻值 30
iii 實驗觀察區段圈選 31
iv 批次套用濾波器、亮度門檻值及實驗觀察區段範圍 32
v 抓取雷射線並歸位 32
3-2 數值高程模型建置 33
3-2-1 由二維平面雷射線轉換成三維空間點位 33
3-2-2 點位X座標歸位 33
3-2-3 地形內插 34
3-2-4 輸出地形資料 36
第四章 二維模式 (RiverFlow2D) 理論及方法 37
4-1 模式理論 38
4-1-1 流體動力學模式的假設 38
4-1-2 水理模式 38
4-1-3 輸砂模組的假設 40
4-1-4 輸砂模式 40
4-1-5 底床載輸砂公式 42
4-2 模式設定 43
4-2-1 模擬網格建置 43
4-2-2 設定出入流邊界條件 44
4-2-3 設定模擬範圍之曼寧n值 46
4-2-4 設定模擬條件 47
第五章 實驗結果 50
5-1 地形呈現 50
5-1-1 數值高程模型 50
5-1-2 光源陰影圖 (hillshade map) 53
i 系列A – 相同流量下砂量改變之辮狀河道演化 53
ii 系列B – 輸砂平衡條件下流量改變之辮狀河道演化 57
5-1-3 正攝影像圖 (orthophoto) 61
5-2 地形分析 76
5-2-1 數值高程差異圖 (DEM of Difference, DoD) 76
i 各階段地形和初始地形之高程差異圖 76
ii 各階段地形相減之高程差異圖 79
5-2-2 體積變化量比較 83
i 由DoD求出體積變化量 83
ii 實驗率定參數計算體積變化量 88
5-2-3 縱剖面坡度分析 90
5-3 河寬變化分析 96
5-4 穩定性理論預測河道機制 102
5-5 辮狀強度指數分析 106
5-5-1 辮狀強度指數基本定義 106
5-5-2 活躍辮狀強度指數分析方法 107
5-5-3 總辮狀強度指數分析方法 110
5-5-4 辮狀強度指數分析結果 111
5-6 砂洲分析 116
5-6-1 人工判釋 116
5-6-2 自動化判釋 125
5-7 無因次河川功率 144
第六章 二維模式成果展示及討論 148
6-1 模式初步測試 148
6-2 模擬參數討論 151
i 底床載輸砂公式討論 151
ii 封閉式邊界 (external closed boundary) 粗糙度討論 159
第七章 問題與討論 167
7-1 無因次河川功率和辮狀強度指數的關係 167
7-2 無因次河川功率和乾寬比的關係 175
7-3 供砂量如何影響辮狀河川形貌 176
7-4 各個無因次河川功率公式的適用性 178
第八章 結論與建議 179
參考文獻 181
參考文獻 1.Ashmore, P., Bertoldi, W., & Tobias Gardner, J. (2011). Active width of gravel‐bed braided rivers. Earth Surface Processes and Landforms, 36(11), 1510-1521.
2.Bertoldi, W., Ashmore, P., & Tubino, M. (2009). A method for estimating the mean bed load flux in braided rivers. Geomorphology, 103(3), 330-340.
3.Bertoldi, W., Zanoni, L., & Tubino, M. (2009). Planform dynamics of braided streams. Earth Surface Processes and Landforms, 34(4), 547-557.
4.Brice, J. C. (1964). Channel patterns and terraces of the Loup Rivers in Nebraska: US Government Printing Office.
5.Coluccio, K., & Morgan, L. K. (2019). A review of methods for measuring groundwater–surface water exchange in braided rivers. Hydrology and Earth System Sciences, 23(10), 4397-4417.
6.Egozi, & Ashmore. (2008). Defining and measuring braiding intensity. Earth Surface Processes and Landforms, 33(14), 2121-2138.
7.Egozi, & Ashmore. (2009). Experimental analysis of braided channel pattern response to increased discharge. Journal of Geophysical Research: Earth Surface, 114(F2).
8.Ferguson, R., & Church, M. (2004). A simple universal equation for grain settling velocity. Journal of Sedimentary Research, 74(6), 933-937.
9.Foreman, B. Z., Lai, S. Y., Komatsu, Y., & Paola, C. (2015). Braiding of submarine channels controlled by aspect ratio similar to rivers. Nature Geoscience, 8(9), 700-703.
10.Garcia Lugo, G. A., Bertoldi, W., Henshaw, A., & Gurnell, A. (2015). The effect of lateral confinement on gravel bed river morphology. Water Resources Research, 51(9), 7145-7158.
11.Germanoski, D., & Schumm, S. (1993). Changes in braided river morphology resulting from aggradation and degradation. The Journal of Geology, 101(4), 451-466.
12.Hong, L. B., & Davies, T.R.H. (1979). A study of stream braiding. Geological Society of America Bulletin, Part II, 90, 1839-1859.
13.Howard, A. D., Keetch, M. E., & Vincent, C. L. (1970). Topological and geometrical properties of braided streams. Water Resources Research, 6(6), 1674-1688.
14.Kelly, S. (2006). Scaling and hierarchy in braided rivers and their deposits: examples and implications for reservoir modelling. Braided rivers: Process, deposits, ecology and management, 36, 75-106.
15.Lai, S. Y., Hung, S. S., Foreman, B. Z., Limaye, A. B., Grimaud, J. L., & Paola, C. (2017). Stream power controls the braiding intensity of submarine channels similarly to rivers. Geophysical Research Letters, 44(10), 5062-5070.
16.Lane, E. W. (1957). A Study of the shape of channels formed by natural streams flowing in erodible material. Missouri River Division Sediment Series, 9, U.S. Army Engineer Div., Missoouri River.
17.Nicholas, A., Ashworth, P., Sambrook Smith, G., & Sandbach (2013). Numerical simulation of bar and island morphodynamics in anabranching megarivers. Journal of Geophysical Research, 118(4), 2019-2044.
18.Parker, G. (1976). On the cause and characteristic scales of meandering and braiding in rivers. Journal of Fluid Mechanics, 76(3), 457-480.
19.Peirce, S., Ashmore, P., & Leduc, P. (2018). The variability in the morphological active width: Results from physical models of gravel-bed braided rivers. Earth Surface Processes and Landforms, 43(11), 2371-2383. doi:10.1002/esp.4400
20.Rust, B. R. (1977). A classification of alluvial channel systems. Canadian Society of Petroleum Geologists, M emoir, 5, 187-198.
21.Schuurman, F., & Kleinhans, M. G. (2015). Bar dynamics and bifurcation evolution in a modelled braided sand‐bed river. Earth Surface Processes and Landforms, 40(10), 1318-1333.
22.Schuurman, F., Marra, W. A., & Kleinhans, M. G. (2013). Physics‐based modeling of large braided sand‐bed rivers: Bar pattern formation, dynamics, and sensitivity. Journal of Geophysical Research: Earth Surface, 118(4), 2509-2527.
23.Williams, R., Measures, R., Hicks, D., & Brasington, J. (2016). Assessment of a numerical model to reproduce event‐scale erosion and deposition distributions in a braided river. Water Resources Research, 52(8), 6621-6642.
24.洪世哲,2015,「以實驗方法探究海下受異重流影響之辮狀河道」,成功大學水利及海洋工程學系學位論文,1-90。
25.唐高晴,2018 ,「河寬及水流功率影響海底辮狀河道之實驗研究」,成功大學水利及海洋工程學系學位論文,1-100。
26.張棠羽,2019,「以實驗方法探究向下丁壩對河道形貌之影響」,成功大學水利及海洋工程學系學位論文,1-111。
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