scholarly journals MODELING AND FIELD OBSERVATIONS OF CHANNEL PROCESSES OF THE SIBERIAN RIVERS. OB RIVER AT BARNAUL CITY SITE AS A CASE STUDY

2021 ◽  
Vol 4 (1) ◽  
pp. 126-136
Author(s):  
Alexander T. Zinoviev ◽  
Alexander V. Dyachenko ◽  
Konstantin B. Koshelev ◽  
Konstantin V. Marusin
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Large River ◽  
Channel Processes ◽  
Flood Peak ◽  
Ob River ◽  
Bed Erosion ◽  
River Bed ◽  
Time Period

Computer simulation of channel morphodynamic for the section of a large river in real unsteady hydrological conditions is conducted. The Ob river channel section at Barnaul city is investigated. At the site considered the channel processes cause serious hazard to some important structures such as the municipal water intake and the power line. The time of modeling covers the period from the flood peak to the low water stage. The simulation is implemented by means of Delft3D program suite. The sediment transport is calculated by two types of Van Rijn’s formula (1984 and 1993). The simulation results are verified by the field data collected at the study site over the same time period. These results show poor agreement with the field data. The river bed erosion spatial pattern modeled differs from the real one significantly. Probably a reason of this discrepancy is that the formula used can’t estimate the sediment transport value correctly.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

scholarly journals The Bed Flow Mathematical Simulation for Forecast of Impact of Construction on Floodplain for Major rivers Hydrological Regime (the Ob River as a study case)

2017 ◽  
Author(s):  
Keyword(s):  
Hydrological Regime ◽  
Water Levels ◽  
Ob River ◽  
Bed Erosion ◽  
River Bed ◽  
Study Case ◽  
Scientific Practical ◽  
Work Impact ◽  
The City ◽  
Construction Works

Issues of forecasting of construction works on floodplains impact on hydrological and bed processes at adjacent ranges of major rivers have been considered. Mathematical models of flows and bed processes at the river ranges with complicated morphometry of the bed and floodplain have proposed. Their application enables to solve a significant scientific/practical problem of assessment of the construction works impact on flooding floodplain territories and the Ob River bed erosion in the vicinity of the city of Barnaul. Calculations for the Ob River range under consideration have been done according a computer hydrodynamic model produced with the use of hydrological data, outcomes of bed surveying and geodesic investigations. The planning construction work impact on the water levels, flow velocities and the river bed erosion in case of different Ob River flows has been shown. The bed and hydrological processes impact on the site of the designed facility has been assessed.

scholarly journals Evaluation of Bearing Capacity of Caissons Subject to Scour

2018 ◽  
Vol 2 (3) ◽  
pp. 276
Author(s):  
Moamen E. Abd Elraof
Keyword(s):  
Bearing Capacity ◽  
Computer Model ◽  
Field Data ◽  
Continuous Monitoring ◽  
River Nile ◽  
Department Of Transportation ◽  
Contour Maps ◽  
River Bed ◽  
Florida Department

The construction of any river obstruction has some morphological impacts on the river bed and flow as it implies some disturbance to the river water flow. This disturbance causes local scour to occur due to bridge construction. For many reasons, there exists a need to protect these assets by continuous monitoring and maintenance. For this research, 6 th October Bridge was considered as a case study for bridges constructed on caissons along the River Nile. A field data (contour maps for the bed of the River Nile at year 1982and 2008) and computer model FDOT (developed by Florida Department of Transportation), was used to evaluate the depth of scour at the caissons of 6 th October Bridge. Conclusions and recommendations were highlighted.

Sediment characteristics at river confluences: a case study of the Mula-Kas confluence, Maharashtra, India

2009 ◽  
Vol 33 (2) ◽  
pp. 208-223 ◽  
Author(s):  
Maya G. Unde ◽  
Subash Dhakal
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Transport Processes ◽  
Main Stream ◽  
Sediment Characteristics ◽  
Channel Processes ◽  
Local Flow ◽  
River Bed ◽  
Floodplain Sediments

River bed and floodplain sediments are a direct reflection of river channel processes. This paper examines sediment transfer processes at river junctions, using as a case study the River Kas, a tributary of the River Mula, Godavari basin, Maharashtra, India. The study uses four cross-sections, two from upstream tributaries, one in the main confluence zone, and one downstream. Sediment samples are collected from each cross-section and adjacent banks. To understand the tributary impact on the main channel, variations in sand, silt and clay percentages and variations in the shape of sediment particles were recorded. Data suggest that the percentage of silt and clay increased away from the active channel towards banks along a cross-section, except for the mid-channel bar and the downstream segment of the confluence. The `a axis' and `c axis' lengths of particles increased for the samples on the confluence compared to upstream and downstream samples. Sediment characteristics between tributary and the main stream reflect both downstream distance from sediment source and the characteristics of the respective transport processes. The distribution of fine material at the tributary mouth suggests that there have been instances in the past where the mainstream flow has dominated the confluence and has led to slack water deposits on the tributary mouth. Construction of a weir for local flow regulation also affects the pattern and character of sediments. In this large, seasonal river, confluence sedimentology is a joint product of flow variation, confluence morphology and the additional effects of human activity. The study thus provides insights into confluence dynamics and characteristics which may not be revealed in the more intensively researched temperate confluences of smaller scale.

Investigation of Apron Setting on the Main Deep Trough of River Bed by 2D Unsteady Flow Simulation

2012 ◽  
Vol 212-213 ◽  
pp. 1182-1187
Author(s):  
Kuei Hsiang Cheng ◽  
Chih Hsien Lin ◽  
Cheng Chao
Keyword(s):  
Unsteady Flow ◽  
Flow Model ◽  
Peak Flow ◽  
Flow Simulation ◽  
Reliable Information ◽  
Flood Peak ◽  
Bow Wave ◽  
River Bed ◽  
Scour Protection

This study uses SMS-2D unsteady flow model to simulate apron setting and discuss its scour protection due to bow wave around the bridge pier on the main deep trough of 24-pier ChihShang Bridge and 3-pier Taitung Bridge in 100 years return flood peak flow, on the downstream BeiNan River in East-Taiwan as case study. Further, the topic of this study is to evaluate location-oriented scour likely result in accelerated erosion of critical piers by apron setting designed sizes in case of excessive cost, thus, providing reliable information and references for bridge engineers.

MODELLING LONG-TERM SHORELINE EVOLUTION: FIGUEIRA DA FOZ BEACH, PORTUGAL

2017 ◽  
pp. 17
Author(s):  
Carla Pereira ◽  
Carlos Coelho ◽  
Paulo A. Silva
Keyword(s):  
Sediment Transport ◽  
Numerical Models ◽  
Shoreline Position ◽  
Shoreline Evolution ◽  
Longshore Sediment Transport ◽  
Time Period ◽  
Accretion Rates ◽  
Time Periods

This work applies two different shoreline evolution numerical models (LTC and GENESIS) in two different time periods (1980 2010 and 2010-2014) to compare respectively the calibration and validation performance of the models. The models were applied to evaluate long-term shoreline position and longshore sediments transport evolution, considering as a case study a sandy beach stretch located updrift of the Figueira da Foz harbor jetty, on the Northwest Portuguese coast. Due to the jetty extension, this stretch exhibits a clear accretion trend during the analyzed time periods. For this region, the longshore sediment transport rate estimated by several authors varies between 200 and 1500x103m3/year. According to the modelling results, it was observed that both models reproduce reasonably well the shoreline evolution between 1980 and 2010. In average, the LTC model reproduces a 2010 shoreline position nearest the observed and GENESIS presents better approximation in the Northern part of the beach and also near the South (downdrift) border (just close to the Northern jetty of the harbor). The modeled shoreline average accretion rates for the considered stretch is quite similar and close to the values referred in the bibliography, which indicates that the beach presents 500 meters of maximum accretion width updrift the jetty (about 16.6m/year). In what concerns to the longshore sediment transport it was observed that numerical models generally indicate lower values than the bibliography, being GENESIS results higher and closer to the observed than the LTC. These results are common in the numerical modelling of shoreline evolution, showing that is difficult to simultaneously represent both the shoreline position and sediment transport volumes. After calibration, LTC validation was evaluated for the time period between 2010 and 2014 to allow confidence in the extrapolation of results to the future. Estimated deposition rates of about 350x103m3/year were obtained at the harbor entrance.

Key Construction Technologies for Large River-Crossing Slurry Shield Tunnel: Case Study

2021 ◽  
Vol 34 (2) ◽  
pp. 04020118
Author(s):  
Song Zhou ◽  
Guan-Lin Ye ◽  
Lei Han ◽  
Wang Jian-Hua
Keyword(s):  
Large River ◽  
Shield Tunnel ◽  
Slurry Shield

Field Observation and Simulation of Sediment Resuspension in a Shallow Lake

1988 ◽  
Vol 20 (6-7) ◽  
pp. 263-270 ◽  
Author(s):  
K. Otsubo ◽  
K. Muraoka
Keyword(s):  
Numerical Simulation ◽  
Shallow Lake ◽  
Water Wave ◽  
Field Data ◽  
Sediment Resuspension ◽  
Field Research ◽  
Lake Kasumigaura ◽  
Bed Erosion ◽  
Current Water ◽  
Good Agreement

The dispersion and resuspension of sediments in Takahamairi Bay basin of Lake Kasumigaura were studied by means of field research and numerical simulation. The field data on wind direction and velocity, lake current, water wave, and turbidity were shown. Based on these results, we discuss how precipitated sediments were resuspended in this shallow lake. To predict the turbidity and the depth of bed erosion, a simulation model was established for this lake. The calculated turbidity showed good agreement with the field data. According to the simulated results, the turbidity reaches 200 ppm, and the bed is eroded several millimeters deep when the wind velocity exceeds 12 m/s in the lake.

scholarly journals Getting information on suspended sediments in a large river from acoustic backscatter

2018 ◽  
Vol 40 ◽  
pp. 04017
Author(s):  
Adrien Vergne ◽  
Céline Berni ◽  
Jérôme Le Coz
Keyword(s):  
Suspended Sediment Concentration ◽  
Spatial Information ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Large River ◽  
Acoustic Backscatter ◽  
Qualitative Information ◽  
Sediment Size ◽  
The Common

There has been a growing interest in the last decade in extracting information on Suspended Sediment Concentration (SSC) from acoustic backscatter in rivers. Quantitative techniques are not yet effective, but acoustic backscatter already provides qualitative information on suspended sediments. In particular, in the common case of a bi-modal sediment size distribution, corrected acoustic backscatter can be used to look for sand particles in suspension and provide spatial information on their distribution throughout a river crosssection. This paper presents a case-study where these techniques have been applied.

scholarly journals The reasons women choose and stay in a geology major: a qualitative multi-case analysis

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ron E. Gray ◽  
Alexis T. Riche ◽  
Isabel J. Shinnick-Gordon ◽  
James C. Sample
Keyword(s):  
Role Models ◽  
Critical Incident ◽  
Earth Science ◽  
Time Period ◽  
The Usa ◽  
Data Source ◽  
Introductory Classes ◽  
Iterative Coding ◽  
As Relationship

AbstractDespite earning half of all science and engineering undergraduate degrees between 2007 and 2016 in the USA, women were awarded only 39% of earth science degrees in the same time period. In order to better understand why women are both choosing and staying in geology programs, we conducted a multi-case study of nine current female undergraduate geology majors at a large public university in the USA within a department that is at gender parity among its undergraduate majors. The main data source was audio-recorded critical incident interviews of each participant. Data from the interviews were analyzed through an iterative coding process using codes adapted from previous studies that focused on factors both internal and external to the department. The students said that personal interests, influence by others outside of the department, and introductory classes attracted them to the geology program, but once declared, departmental factors such as relationship with faculty caused them to stay. We also found an emphasis on female role models, especially those teaching introductory courses. We believe this study offers important insights into the ways in which factors leading to recruitment and retention play out in the lived experiences of female geology majors.

Sign in / Sign up

Export Citation Format

Share Document