Geomorphology Processes of Channel Planform Migration on Modern Meandering Rivers
doi: 10.14027/j.issn.1000-0550.2018.045
- Received Date: 2017-05-19
- Rev Recd Date: 2017-08-22
- Publish Date: 2018-06-10
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Key words:
- meandering channel /
- Geomorphology /
- migration patterns /
- structure elements /
- characterization parameters
Abstract: Geomorphological migration structures are the basis to reconstruct and restore sedimentary evolution of the paleochannel, as well as the premise to forecast migration trend of rivers. In order to figure out the regularity of geomorphology migration structures of meandering rivers, high-resolution historical satellite images are acquired primarily through Google Earth and ACME Mapper. Through the fine feature characterization for the Irtysh River and the Nowitna River, which are both well in preservation conditions of natural structures, 28 kinds of structure elements are utilized to depict the meandering channels. Moreover, 5 kinds of characterization parameters are proposed to make quantitative description on the channel structure, extraordinarily, the difference of along-current deflection angle (Δθ), the difference of counter-current deflection angle (Δθ'), and expansion coefficient (KM) are firstly brought forward and applied for introduction. In addition, the conception of sinuosity index (S) and curvature (C) are also different from previous original definition and more meticulous. By fine anatomy of the structure for 12 typical meander loops, S, C, Δθ, Δθ', KM factors are adopted to summarize for 6 kinds of planform migration structures:symmetrical expansion structure, upstream rotation expansion structure; downstream rotation expansion structure; symmetrical constriction structure; upstream rotation constriction structure; downstream rotation constriction structure. Ultimately, 9 meandering channel migration patterns are concluded and discussed. Combined with the idea of geomorphological quantitative characterization, the evolution of the meandering river has a certain degree of universal law and guiding role in order to promote the landscape morphology and fluvial sedimentology of common development.
Citation: | LIN ZhiPeng, SHAN JingFu, CHEN Le, SUN QianJun, WANG YiWu, WANG Fei. Geomorphology Processes of Channel Planform Migration on Modern Meandering Rivers[J]. Acta Sedimentologica Sinica, 2018, 36(3): 427-445. doi: 10.14027/j.issn.1000-0550.2018.045 |