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http://dx.doi.org/10.3741/JKWRA.2021.54.8.553

Identification of shear layer at river confluence using (RGB) aerial imagery  

Noh, Hyoseob (Department of Civil and Environmental Engineering, Seoul National University)
Park, Yong Sung (Department of Civil and Environmental Engineering, Seoul National University)
Publication Information
Journal of Korea Water Resources Association / v.54, no.8, 2021 , pp. 553-566 More about this Journal
Abstract
River confluence is often characterized by shear layer and the associated strong mixing. In natural rivers, the main channel and its tributary can be separated by the shear layer using contrasting colors. The shear layer can be easily observed using aerial images from satellite or unmanned aerial vehicles. This study proposes a low-cost identification method extracting geographic features of the shear layer using RGB aerial image. The method consists of three stages. At first, in order to identify the shear layer, it performs image segmentation using a Gaussian mixture model and extracts the water bodies of the main channel and tributary. Next, the self-organizing map simplifies the flow line of the water bodies into the 1-dimensional curve grid. After that, the curvilinear coordinate transformation is performed using the water body pixels and the curve grid. As a result, the shear layer identification method was successfully applied to the confluence between Nakdong River and Nam River to extract geometric shear layer features (confluence angle, upstream- and downstream- channel widths, shear layer length, maximum shear layer thickness).
Keywords
Aerial imagery; Confluence; Gaussian Mixture Model (GMM); Remote sensing; Self-Organizing Map (SOM); Shear layer;
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1 Dixon, S.J., Sambrook Smith, G.H., Best, J.L., Nicholas, A.P., Bull, J.M., Vardy, M.E., Sarker, M.H., and Goodbred, S. (2018). "The planform mobility of river channel confluences: Insights from analysis of remotely sensed imagery." Earth-Science Reviews, Vol. 176, pp. 1-18.   DOI
2 Gualtieri, C., Ianniruberto, M., and Filizola, N. (2019). "On the mixing of rivers with a difference in density: The case of the Negro/Solimoes confluence, Brazil." Journal of Hydrology, Vol. 578, 124029.   DOI
3 Hackney, C., and Carling, P. (2011). "The occurrence of obtuse junction angles and changes in channel width below tributaries along the Mekong River, South-east Asia." Earth Surface Processes and Landforms, Vol. 36, No. 12, pp. 1563-1576.   DOI
4 Jung, S.H., Seo, I.W., Kim, Y.D., and Park, I. (2019). "Feasibility of velocity-based method for transverse mixing coefficients in river mixing analysis." Journal of Hydraulic Engineering, Vol. 145, No. 11, 04019040.   DOI
5 Ashworth, P.J., and Lewin, J. (2012). "How do big rivers come to be different?" Earth-Science Reviews, Vol. 114, No. 1-2, pp. 84-107.   DOI
6 Gaudet, J.M., and Roy, A.G. (1995). "Effect of bed morphology on flow mixing length at river confluences." Nature, Vol. 373, No. 6510, pp. 138-139.   DOI
7 Best, J.L. (1987). "Flow dynamics at river channel confluences: Implications for sediment transport and bed morphology." Edited by Ethridge, F.G., Flores, R.M., and Harvey, M.D., SEPM Special Publication 39, Recent Developments in Fluvial Sedimentology. Society of Economic Paleontologists and Mineralogists, Tulsa, OK, U.S., pp. 27-35.
8 Best, J.L., and Ashworth, P.J. (1997). "Scour in large braided rivers and the recognition of sequence stratigraphic boundaries." Nature, Vol. 387, No. 6630, pp. 275-277.   DOI
9 Bishop, C.M. (2006). Pattern recognition and machine learning. springer, Berlin, Germany.
10 Brosinsky, A., Foerster, S., Segl, K., Lopez-Tarazon, J.A., Pique, G., and Bronstert, A. (2014). "Spectral fingerprinting: Characterizing suspended sediment sources by the use of VNIR-SWIR spectral information." Journal of Soils and Sediments, Vol. 14, No. 12, pp. 1965-1981.   DOI
11 Ban, Z., Liu, J., and Cao, L. (2018). "Superpixel segmentation using Gaussian mixture model." IEEE Transactions on Image Processing, Vol. 27, No. 8, pp. 4105-4117.   DOI
12 De Serres, B., Roy, A.G., Biron, P.M., and Best, J.L. (1999). "Three-dimensional structure of flow at a confluence of river channels with discordant beds." Geomorphology, Vol. 26, No. 4, pp. 313-335.   DOI
13 Dempster, A.P., Laird, N.M., and Rubin, D.B. (1977). "Maximum likelihood from incomplete data via the EM algorithm." Journal of the Royal Statistical Society: Series B (Methodological), Vol. 39, No. 1, pp. 1-22.   DOI
14 Ji, Z., Huang, Y., Xia, Y., and Zheng, Y. (2017). "A robust modified Gaussian mixture model with rough set for image segmentation." Neurocomputing, Vol. 266, pp. 550-565.   DOI
15 Kohonen, T. (1990). "The self-organizing map." Proceedings of the IEEE, Vol. 78, No. 9, pp. 1464-1480.   DOI
16 Kohonen, T. (2001). Self-organizing maps (3rd ed.), Springer, Berlin-Heidelberg, Germany.
17 Konsoer, K.M., and Rhoads, B.L. (2014). "Spatial - temporal structure of mixing interface turbulence at two large river confluences." Environmental Fluid Mechanics, Vol. 14, No. 5, pp. 1043-1070.   DOI
18 Lewin, J., and Ashworth, P.J. (2014). "Defining large river channel patterns: Alluvial exchange and plurality." Geomorphology, Vol. 215, pp. 83-98.   DOI
19 Kwon, S., Seo, I. W., and Beak, D. (2021). "Development of suspended solid concentration measurement technique based on multi-spectral satellite imagery in Nakdong River using machine learning model." Journal of Korea Water Resources Association, Vol. 54, No. 2, pp. 121-133.
20 Constantinescu, G., Miyawaki, S., Rhoads, B., and Sukhodolov, A. (2016). "Influence of planform geometry and momentum ratio on thermal mixing at a stream confluence with a concordant bed." Environmental Fluid Mechanics, Vol. 16, No. 4, pp. 845-873.   DOI
21 Lewis, Q.W., and Rhoads, B.L. (2018). "LSPIV measurements of two-dimensional flow structure in streams using small unmanned aerial systems: 2. Hydrodynamic mapping at river confluences." Water Resources Research, Vol. 54, No. 10, pp. 7981-7999.   DOI
22 Nikou, C., Galatsanos, N.P., and Likas, A.C. (2007). "A class-adaptive spatially variant mixture model for image segmentation." IEEE Transactions on Image Processing, Vol. 16, No. 4, pp. 1121-1130.   DOI
23 Novo, E.M.M., Hansom, J.D., and Curran, P.J. (1989). "The effect of sediment type on the relationship between reflectance and suspended sediment concentration." Remote Sensing, Vol. 10, No. 7, pp. 1283-1289.   DOI
24 Permuter, H., Francos, J., and Jermyn, I. (2006). "A study of Gaussian mixture models of color and texture features for image classification and segmentation." Pattern Recognition, Vol. 39, No. 4, pp. 695-706.   DOI
25 Pham, Q.V., Ha, N.T.T., Pahlevan, N., Oanh, L.T., Nguyen, T.B., and Nguyen, N.T. (2018). "Using landsat-8 images for quantifying suspended sediment concentration in red river (Northern Vietnam)." Remote Sensing, Vol. 10, No. 11, 1841.   DOI
26 Rhoads, B.L., and Sukhodolov, A.N. (2004). "Spatial and temporal structure of shear layer turbulence at a stream confluence." Water Resources Research, Vol. 40, No. 6.
27 Ramon, C.L., Hoyer, A.B., Armengol, J., Dolz, J., and Rueda, F.J. (2013). "Mixing and circulation at the confluence of two rivers entering a meandering reservoir." Water Resources Research, Vol. 49, No. 3, pp. 1429-1445.   DOI
28 Rhoads, B.L. (1987). "Changes in stream channel characteristics at tributary junctions." Physical Geography, Vol. 8, No. 4, pp. 346-361.   DOI
29 Rhoads, B.L. (1996). "Mean structure of transport-effective flows at an asymmetrical confluence when the main stream is dominant." Coherent Flow Structures in Open Channels, Edited by Ashworth, P., Bennett, S.J., Best, J.L., and McLelland, S.J., Wiley, Chichester, U.K., pp. 491-517.
30 Rhoads, B.L., and Sukhodolov, A.N. (2001). "Field investigation of three-dimensional flow structure at stream confluences: 1. Thermal mixing and time-averaged velocities." Water Resources Research, Vol. 37, No. 9, pp. 2393-2410.   DOI
31 Seo, I.W., and Park, I. (2013). "Determination of ecological flow at the confluence of Nakdong River and Gumho River using river2D." Journal of The Korean Society of Civil Engineers, Vol. 33, No. 3, pp. 947-956.   DOI
32 Shi, X., Li, Y., and Zhao, Q. (2020). "Flexible hierarchical Gaussian mixture model for high-resolution remote sensing image segmentation." Remote Sensing, Vol. 12, No. 7, 1219.   DOI
33 Sukhodolov, A.N., and Rhoads, B.L. (2001). "Field investigation of three-dimensional flow structure at stream confluences: 2. Turbulence." Water Resources Research, Vol. 37, No. 9, pp. 2411-2424.   DOI
34 Sukhodolov, A.N., Krick, J., Sukhodolova, T.A., Cheng, Z., Rhoads, B.L., and Constantinescu, G.S. (2017). "Turbulent flow structure at a discordant river confluence: Asymmetric jet dynamics with implications for channel morphology." Journal of Geophysical Research: Earth Surface, Vol. 122, No. 6, pp. 1278-1293.   DOI
35 Yuan, S., Tang, H., Xiao, Y., Qiu, X., and Xia, Y. (2018). "Water flow and sediment transport at open-channel confluences: An experimental study." Journal of Hydraulic Research, Vol. 56, No. 3, pp. 333-350.   DOI
36 Sukhodolov, A.N., Schnauder, I., and Uijttewaal, W.S. (2010). "Dynamics of shallow lateral shear layers: Experimental study in a river with a sandy bed." Water Resources Research, Vol. 46, No. 11.
37 Trigg, M.A., Bates, P.D., Wilson, M.D., Schumann, G., and Baugh, C. (2012). "Floodplain channel morphology and networks of the middle Amazon River." Water Resources Research, Vol. 48, No. 10.
38 Umar, M., Rhoads, B.L., and Greenberg, J.A. (2018). "Use of multispectral satellite remote sensing to assess mixing of suspended sediment downstream of large river confluences." Journal of Hydrology, Vol. 556, pp. 325-338.   DOI
39 Yuan, S., Tang, H., Xiao, Y., Qiu, X., Zhang, H., and Yu, D. (2016). "Turbulent flow structure at a 90-degree open channel confluence: Accounting for the distortion of the shear layer." Journal of Hydro-environment Research, Vol. 12, pp. 130-147.   DOI
40 Zhang, Y., Brady, M., and Smith, S. (2001). "Segmentation of brain MR images through a hidden Markov random field model and the expectation-maximization algorithm." IEEE Transactions on Medical Imaging, Vol. 20, No. 1, pp. 45-57.   DOI
41 Winant, C.D., and Browand, F.K. (1974). "Vortex pairing: The mechanism of turbulent mixing-layer growth at moderate Reynolds number." Journal of Fluid Mechanics, Vol. 63, No. 2, pp. 237-255.   DOI
42 Ullah, M.S., Bhattacharya, J.P., and Dupre, W.R. (2015). "Confluence scours versus incised valleys: Examples from the cretaceous Ferron Notom Delta, Southeastern Utah, U.S.A." Journal of Sedimentary Research, Vol. 85, No. 5, pp. 445-458.   DOI
43 Constantinescu, G., Miyawaki, S., Rhoads, B., and Sukhodolov, A. (2012). "Numerical analysis of the effect of momentum ratio on the dynamics and sediment-entrainment capacity of coherent flow structures at a stream confluence." Journal of Geophysical Research: Earth Surface, Vol. 117, No. F4, F04028.
44 Mount, N.J., Tate, N.J., Sarker, M.H., and Thorne, C.R. (2013). "Evolutionary, multi-scale analysis of river bank line retreat using continuous wavelet transforms: Jamuna River, Bangladesh." Geomorphology, Vol. 183, pp. 82-95.   DOI
45 Rhoads, B.L., and Sukhodolov, A.N. (2008). "Lateral momentum flux and the spatial evolution of flow within a confluence mixing interface." Water Resources Research, Vol. 44, No. 8.
46 Son, G., Kim, D., Kwak, S., Kim, Y.D., and Lyu, S. (2021). "Characterizing three-dimensional mixing process in river confluence using acoustical backscatter as surrogate of suspended sediment." Journal of Korea Water Resources Association, Vol. 54, No. 3, pp. 167-179.   DOI