scholarly journals DANGER OF RIVERBED PROCESSES ON RUSSIAN RIVERS: ASSESSMENT CRITERIA, MAPPING, REGIONAL ANALYSIS

2021 ◽  
pp. 53-67
Author(s):  
Roman S. Chalov ◽  
◽  
Alexey V. Chernov ◽  
Nadezhda M. Mikhailova ◽  
◽  
...  
Keyword(s):  
Main Part ◽  
Regional Analysis ◽  
High Water ◽  
River Channel ◽  
Assessment Criteria ◽  
Natural Conditions ◽  
Channel Processes ◽  
Geographical Analysis ◽  
Full View

The article discusses the danger that channel processes – the processes creating the river channel and floodplain and those occurring in them – can pose to people. Riverbed processes are among the most dynamic ones in nature: the speed of their manifestation varies from the first decades to individual months in high water and floods, i.e. they develop in full view of people. This can significantly complicate life on the banks of rivers and the use of river resources. The article deals with dangerous manifestations of riverbed processes, their causes and consequences, but the main part of the paper is devoted to the cartographic method of assessing the danger of riverbed processes: determining the danger degree and various ways of displaying it on maps. There are given examples of showing danger on previously compiled maps. In conclusion, the article provides a brief geographical analysis of the distribution of various types and the manifestation degree of dangerous riverbed processes in a variety of natural conditions in Russia.

scholarly journals Influence of speed distribution in a rounded flow on the character of slopes erosion

2019 ◽  
Vol 20 (1) ◽  
pp. 85-95
Author(s):  
O. Ya. Maslikova ◽  
I. I. Gritsuk ◽  
D. N. Ionov ◽  
V. K. Debolskiy
Keyword(s):  
Reynolds Number ◽  
Reynolds Numbers ◽  
Hydraulic Structures ◽  
Natural Conditions ◽  
Channel Processes ◽  
Speed Distribution ◽  
Straight Line ◽  
River Hydraulics ◽  
Critical Reynolds Numbers ◽  
The Impact

One of the most important issues of river hydraulics is the movement of water and the formation of a channel in a stream that has a non-straight-line outline in the plan. Under natural conditions for rivers characteristic winding shape in the plan. The curvature of the jet occurs when the flow is divided into sleeves, at the inflow into the river, the confluence of flows, etc. Therefore, the study of channel processes in rivers is impossible without knowledge of the flow patterns at the curve of the channel. When designing hydraulic structures, including bridge crossings on the meandering sections of rivers, one should know the features of the dynamics of the channel in the sections of the flow turning. In winter, such areas may be narrowed due to the freezing of the channel, and during the period of ice thawing they are clogged with ice fragments. The narrowing of the canal causes an increase in the Reynolds number and a redistribution of velocity diagrams in the area under consideration, which causes a change in the erosion pattern. In laboratory conditions, the nature of the distribution of velocities and the formation of vortices on the installation, creating a rounded flow. It is shown that, at critical Reynolds numbers, a vortex countercurrent occurs in the rounded flow at the inner shore. The impact of this velocity distribution on the erosion pattern of the various slopes of the rounded flow was analyzed.

scholarly journals Navigational Atlas of the Selenga River section within Mongolian People’s Republic, 1925

2021 ◽  
Vol 885 (1) ◽  
pp. 012053
Author(s):  
E A Batotsyrenov
Keyword(s):  
River Channel ◽  
Geographical Information ◽  
River Section ◽  
Channel Processes ◽  
Technical Work ◽  
Selenga River ◽  
The North ◽  
Northern Mongolia

Abstract The article provides information on the manuscript atlas of the Selenga and Orkhon rivers within the Mongolian People’s Republic (MPR), compiled on the basis of data from 1924-1925. It was developed for the Selenga Technical Section of the Ministry of the River Fleet to guide navigation along the rivers of Mongolia. The shooting was carried out on a steam boat “Shilka”. The atlas is of interest for the dynamics of river channel processes in northern Mongolia. The materials provide information on where and how to carry out technical work to improve navigation. In addition to information on navigation, it provides economic and geographical information on the north of Mongolia in the 1920s.

scholarly journals Yakutsk Water Agglomeration at the Lena River – Channel Processes Problems: History, Current State, Prospect, and Possibilities of Control

2012 ◽  
pp. 44-56
Author(s):  
Keyword(s):  
Flow Line ◽  
River Channel ◽  
Main Trend ◽  
Channel Processes ◽  
Channel Deformations ◽  
Lena River ◽  
Current State ◽  
Valley Side ◽  
Predictive Assessment ◽  
The Right

The paper presents results of the analysis of the Lena River channel deformations near the Yakutsk City over the period exceeding the past 100 years. The data presented enables to conclude that the main trend of the channel development over that period has been a transformation of the adjoint braids pattern into the parallel arms pattern accompanied with directed migration of the main flow line towards the right valley side along the entire studied reach. Such a tendency of channel evolution creates an unfavorable situation for operations of the Yakutsk water industry and transportation facilities. The paper also gives a predictive assessment of the future channel deformations and proposes a set of channel regulation measures aimed at improving the situation.

scholarly journals Tolerance assessment of the aquatic invasive snail Potamopyrgus antipodarum to different post-dispersive conditions: implications for its invasive success

NeoBiota ◽  
2019 ◽  
Vol 44 ◽  
pp. 57-73 ◽  
Author(s):  
Alberto Romero-Blanco ◽  
Álvaro Alonso
Keyword(s):  
Aquatic Ecosystems ◽  
Exposure Period ◽  
High Water ◽  
Negative Consequences ◽  
Natural Conditions ◽  
Air Exposure ◽  
Abiotic Conditions ◽  
Normal Water ◽  
Chemical Conditions ◽  
Physical And Chemical

The New Zealand mudsnail (NZMS) Potamopyrgusantipodarum (Gray, 1843) (Tateidae, Mollusca) is a successful invasive species able to alter the functioning of the invaded ecosystems. However, to arrive and establish in new aquatic ecosystems, this snail must survive to the overland translocation through aerial exposure and must tolerate the new physical and chemical conditions of the recipient ecosystem. In this study, we simulated different conditions for the NZMS invasion by combining two air exposure treatments (0 and 20 h) with different physical and chemical conditions of the rehydration water (low and normal water temperatures and normal and high water conductivities). Mortality, behavior and neonate production were compared across treatments. Air exposure caused a high percentage of mortality but survivors tolerated the subsequent abiotic conditions. Low temperatures and high conductivities altered the behavior of adult snails, increasing significantly their reaction time (i.e. time to start normal movement). This may have negative consequences for the survival of this species under natural conditions. Finally, these conditions did not affect significantly the production of neonates. These results supported that the surviving NZMS to a brief period of air exposure possess the ability to acclimate to contrasting abiotic conditions with a potential establishment of new populations and that survivors can reproduce in different abiotic conditions after an air exposure period.

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