Effect of alternate expansion and contraction of width on the river morphology

2020 ◽  
pp. 574-581
Author(s):  
T. Karmaker ◽  
D.N. Ratha ◽  
H. Singh ◽  
J. Singh ◽  
J. Mangla ◽  
...  
Keyword(s):  
1993 ◽  
Vol 101 (4) ◽  
pp. 451-466 ◽  
Author(s):  
Dru Germanoski ◽  
S. A. Schumm

2018 ◽  
Vol 40 ◽  
pp. 05044
Author(s):  
Andrés Vargas-Luna ◽  
Alessandra Crosato ◽  
Protogene Byishimo ◽  
Wim Uijttewaal

Alluvial rivers are shaped by sequences of water flows excavating their channels. Observations show that besides the magnitude, also the frequency and duration of streamflow oscillations might be important for the river channel formation. In addition, the river morphology appears influenced also by both size and degree of uniformity of the sediment. Nevertheless, many morphodynamic studies still represent the flow regime with a single value of the discharge, often corresponding to the bankfull condition, and the sediment with its median grain size. This work investigates the effects of streamflow variability and sediment characteristics on channel width formation, analysing the evolution of experimental streams with different sediments and discharge hydrographs. Results show that the formative condition of the channel width is not the geometric bankfull flow but a rather frequent peak flow. Remarkably different channel configurations arise from different sediment characteristics in the laboratory, where sediment non-uniformity produces more stable banks.


2018 ◽  
Vol 12 (2) ◽  
pp. 627-633 ◽  
Author(s):  
Knut Alfredsen ◽  
Christian Haas ◽  
Jeffrey A. Tuhtan ◽  
Peggy Zinke

Abstract. In cold climate regions, the formation and break-up of river ice is important for river morphology, winter water supply, and riparian and instream ecology as well as for hydraulic engineering. Data on river ice is therefore significant, both to understand river ice processes directly and to assess ice effects on other systems. Ice measurement is complicated due to difficult site access, the inherent complexity of ice formations, and the potential danger involved in carrying out on-ice measurements. Remote sensing methods are therefore highly useful, and data from satellite-based sensors and, increasingly, aerial and terrestrial imagery are currently applied. Access to low cost drone systems with quality cameras and structure from motion software opens up a new possibility for mapping complex ice formations. Through this method, a georeferenced surface model can be built and data on ice thickness, spatial distribution, and volume can be extracted without accessing the ice, and with considerably fewer measurement efforts compared to traditional surveying methods. A methodology applied to ice mapping is outlined here, and examples are shown of how to successfully derive quantitative data on ice processes.


2014 ◽  
pp. 1261-1267
Author(s):  
A Constain ◽  
D Mesa ◽  
J Corredor ◽  
C Peña-Guzmán

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