DOI: 10.5194/hess-24-3513-2020
论文题名: Automatic identification of alternating morphological units in river channels using wavelet analysis and ridge extraction
作者: Mahdade M. ; Le Moine N. ; Moussa R. ; Navratil O. ; Ribstein P.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2020
卷: 24, 期: 7 起始页码: 3513
结束页码: 3537
语种: 英语
Scopus关键词: Automation
; Degrees of freedom (mechanics)
; Extraction
; Geometry
; Hydraulic models
; Shear flow
; Shear stress
; Wavelet analysis
; Continuous approach
; Cross sectional parameter
; Crosssectional geometry
; Geomorphic analysis
; High frequency variabilities
; Hydrographic networks
; Morphological variability
; Objective identification
; Rivers
; automation
; bathymetric survey
; design method
; drainage water
; geomorphological response
; hydraulic conductivity
; hydrological modeling
; identification method
; river channel
; wavelength
; wavelet analysis
; France
英文摘要: pThe accuracy of hydraulic models depends on the quality of the bathymetric data they are based on, whatever the scale at which they are applied. The along-stream (longitudinal) and cross-sectional geometry of inatural/i rivers is known to vary at the scale of the hydrographic network (e.g., generally decreasing slope, increasing width in the downstream direction), allowing parameterizations of main cross-sectional parameters with large-scale proxies such as drainage area or bankfull discharge (an approach coined downstream hydraulic geometry, DHG). However, higher-frequency morphological variability (i.e., at river reach scale) is known to occur for many stream types, associated with varying flow conditions along a given reach, such as the alternate bars or the pool-riffle sequences and meanders. To consider this high-frequency variability of the geometry in the hydraulic models, a first step is to design robust methods to characterize the scales at which it occurs. In this paper, we introduce new wavelet analysis tools in the field of geomorphic analysis (namely, wavelet ridge extraction) to identify the pseudo-periodicity of alternating morphological units from a general point of view (focusing on pool-riffle sequences) for six small French rivers. This analysis can be performed on a single variable (univariate case) but also on multiple variables (multivariate case). In this study, we choose a set of four variables describing the flow degrees of freedom: velocity, hydraulic radius, bed shear stress, and a planform descriptor that quantifies the local deviation of the channel from its mean direction. Finally, this method is compared with the bedform differencing technique (BDT), by computing the mean, median, and standard deviation of their longitudinal spacings. The two methods show agreement in the estimation of the wavelength in all reaches except one. The method aims to extract a pseudo-periodicity of the alternating bedforms that allow objective identification of morphological units in a continuous approach with the maintenance of correlations between variables (i.e., at many station hydraulic geometry, AMHG) without the need to define a prior threshold for each variable to characterize the transition from one unit to another. © 2020 EDP Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162644
Appears in Collections: 气候变化与战略
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作者单位: Mahdade, M., Sorbonne Université, CNRS, EPHE, Milieux Environnementaux, Transferts et Interaction dans les Hydrosystèmes et les Sols, METIS, Paris, 75005, France; Le Moine, N., Sorbonne Université, CNRS, EPHE, Milieux Environnementaux, Transferts et Interaction dans les Hydrosystèmes et les Sols, METIS, Paris, 75005, France; Moussa, R., INRA, UMR LISAH, 2 Place Pierre Viala, Montpellier, 34060, France; Navratil, O., University of Lyon, Lumiá°1/2re Lyon 2, Department of Geography, CNRS 5600 EVS, Lyon, France; Ribstein, P., Sorbonne Université, CNRS, EPHE, Milieux Environnementaux, Transferts et Interaction dans les Hydrosystèmes et les Sols, METIS, Paris, 75005, France
Recommended Citation:
Mahdade M.,Le Moine N.,Moussa R.,et al. Automatic identification of alternating morphological units in river channels using wavelet analysis and ridge extraction[J]. Hydrology and Earth System Sciences,2020-01-01,24(7)