Meandering Process and Migration Architecture: Based on the Nowitna River

Le Chen,Zhipeng Lin,Qianjun Sun,Jingfu Shan,Taiju Yin,Fei Wang

doi:10.5539/esr.v6n2p76

Abstract

The meandering process has always been the topic through years and still remains a lot of unsolved mysteries. One of the most important focus is the migration architectures and models that the meandering channels follow. This article chooses the Nowitna River as the study object of the typical meandering river with high migratory processes. Though the high-resolution historical satellite images by the techniques of Google Earth and ACME Mapper, 50 meanders in the river is studied and 6 of which are chosen for meticulous characterization. During the process, the planform structure of meandering channel is re-examined and 29 kinds of architecture elements are systematically established. More importantly, in order to make a fine quantitative characterization of the channel structure of meandering river, 5 kinds of characterization parameters are proposed, extraordinarily, the parameters of the difference of along-current deflection angle, a difference of counter-current deflection angle, and expansion coefficient, these three are firstly brought forward and applied introduction. In addition, the conception of sinuosity index and curvature are also different from the original definition. Though these architectures elements the meandering process and migration structure of the Nowitna River is demonstrated. 6 kinds of planform migration structures is revealed with the quantitative characterization of characterization parameters and 9 species of meandering channel migration patterns are concluded and discussed.

Highlights

Many classical articles at home and abroad try to analyze the three-dimensional dynamic structure of the river from the aspects of scale estimation, numerical simulation, and hydrodynamics, such as Leopold and Maddock(1953), had made some achievements on river hydrodynamic characteristics, meandering structure, pattern(1957) and geomorphological features(1960) and so on. Wolman and Miller(1960) thought that the periodicity of flow change is an important factor in controlling the geomorphology through the analysis of the geomorphic process, and followed the examples of tracking the evolution of the meandering process
This paper crucially aims to focus on four targets, (1) A comprehensive scheme for characterizes the morphological elements of planform architecture of meandering rivers; (2) New method of characterization factors, including descriptive elements and dynamic parameters; (3) Geomorphology process and migration characteristics of different meandering channels; (4) a comprehensive set of model for channel migration structure of meandering rivers
According to the planform migration architecture of NR2 and characterization parameters of NR3, we can see that the value of S is 2.21, C is 0.0033, reflecting that the bending degree is in general; ∆θ is -2° and ∆θ' is 2°, indicating that the symmetry of the meander is relatively great, with a slight trend of along-current rotation

Summary

Introduction

Many classical articles at home and abroad try to analyze the three-dimensional dynamic structure of the river from the aspects of scale estimation, numerical simulation, and hydrodynamics, such as Leopold and Maddock(1953), had made some achievements on river hydrodynamic characteristics, meandering structure, pattern(1957) and geomorphological features(1960) and so on. Wolman and Miller(1960) thought that the periodicity of flow change is an important factor in controlling the geomorphology through the analysis of the geomorphic process, and followed the examples of tracking the evolution of the meandering process. Many classical articles at home and abroad try to analyze the three-dimensional dynamic structure of the river from the aspects of scale estimation, numerical simulation, and hydrodynamics, such as Leopold and Maddock(1953), had made some achievements on river hydrodynamic characteristics, meandering structure, pattern(1957) and geomorphological features(1960) and so on. Wolman and Miller(1960) thought that the periodicity of flow change is an important factor in controlling the geomorphology through the analysis of the geomorphic process, and followed the examples of tracking the evolution of the meandering process. Through the three-dimensional model of simulating the migration process of meandering, Willis and Tang(2010) further demonstrated the translation, rotation, expansion and complex patterns of the meandering loops. Ielpi(2014), Ghinassi(2014) and Wu(2016) and others recently have begun to try to reconstruct the esr.ccsenet.org

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