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Article

Nda Muhammad, Mohd Shalahuddin Adnan, Mohd Azlan Mohd Yosuff and Kabiru Abdullahi Ahmad

Sediment measurement is usually accessible on a periodic or distinct basis. The measurement of sediment (suspended and bedload), especially in the field, is vital in…

Abstract

Purpose

Sediment measurement is usually accessible on a periodic or distinct basis. The measurement of sediment (suspended and bedload), especially in the field, is vital in keeping essential data of sediment transport and deposition. Various techniques for measuring sediment have been used over time each with its merits and demerits. The techniques discussed in this paper for suspended sediment include bottle, acoustic, pump, laser diffraction, nuclear and optical. Other techniques for bedload measurement are; River bedload trap (RBT), CSU/FU bedload trap, Helley–Smith, Polish Hydrological Services (PIHM) device, pit and trough, vortex tube, radioactive traces and bedload–surrogate technologies. However, the choice of technique depends on multiple factors ranging from budget constraint, availability of equipment, manpower and data requirement. The purpose of this paper is to present valuable information on selected techniques used in sediment measurement, to aid researchers/practitioners in the choice of sediment measurement technique.

Design/methodology/approach

This paper presents a general review of selected field techniques used in sediment measurement (suspended and bedload). Each techniques mode of operation, merits and demerits are discussed.

Findings

This paper highlights that each technique has its peculiar merits and demerits. However, two techniques are generally preferred over others; the bottle sampling and the Helley–Smith sampler for measuring suspended and bedload sediment. This is because the applicability of these techniques is quite widespread and time-tested.

Originality/value

This review paper provides an in-depth description and comparison of selected existing field sediment measurement techniques. The objective is to ease decision-making about the choice of technique, as well as to identify the suitability and applicability of the chosen technique.

Details

World Journal of Engineering, vol. 16 no. 1
Type: Research Article
ISSN: 1708-5284

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Article

Chung Dang Huu

The paper aims to present a study on the effects of temperature and salinity on the vertical distribution of suspended sand concentration and transport rate on the basis…

Abstract

Purpose

The paper aims to present a study on the effects of temperature and salinity on the vertical distribution of suspended sand concentration and transport rate on the basis of 1DV model.

Design/methodology/approach

The finite difference method based on the implicit scheme of Crank‐Nicolson with an irregular grid was used for the fluid flow equation and the implicit upwind scheme with a staggered grid for the equation of concentration diffusion. The model was applied to five tests of the data sets from the Delta Flume with three different cases of temperature and salinity on the basis of parameterisation of the kinematic viscosity, the turbulence‐related sediment mixing coefficient and the concentration at the reference level.

Findings

The computed results showed that the vertical distributions of suspended sand concentration depend on salinity and specially, on temperature. When temperature increases or salinity decreases, the settling process of particles occurs considerably faster. For fine sand, the discrepancy on suspended sand transport rates due to temperature or salinity decreases with wave height. For coarse sand, the effect of temperature and salinity is not much affected by the wave height.

Originality/value

The quantitative evaluation of the roles of salinity, especially temperature once again confirmed their importance for the sediment transport and the process of coastal morphology. The further sense from this research may suggest some new ideas on the tendency of evolution of sea bed due to the warming of the earth in the future.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 5
Type: Research Article
ISSN: 0961-5539

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Abstract

Although there have been extensive studies on the hydrological and erosional impacts of logging, relatively little is known about the impacts of conversion into agricultural plantation (namely rubber and oil palm). Furthermore, studies on morphological impacts, sediment-bound chemistry and forensic attribution of deposited sediment to their respective sources are scarcer. This chapter introduces the potential for using the multi-proxy sediment fingerprinting technique in this context. Featuring pilot projects in two major flood-prone river systems in Malaysia, the studies explore application of geochemistry-based sediment source ascription. The geochemical signatures of sediment mixtures on floodplains were compared to sediments from upstream source tributaries. The tributaries were hypothesised to have different geochemical signatures in response to dominant land management. The first case study took place in the Segama River system (4,023 km2) of Sabah, Malaysian Borneo where a mixture of primary forest, logged-forests and oil palm plantations were predominant. The second case study was in the Kelantan River Basin (13,100 km2) with two major tributaries (Galas River and Lebir River) where logged-forests and rubber and oil palm plantations are dominant land-uses. Both case studies demonstrated the applicability of this method in ascribing floodplain deposited sediment to their respective upstream sources. Preliminary results showed that trace elements associated with fertilisers (e.g. copper and vanadium) contribute to agricultural catchment signatures. Alkaline and alkaline-earth elements were linked to recently established oil palm plantations due to soil turnover. Mixing model outputs showed that contributions from smaller, more severely disturbed catchment are higher than those from larger but milder disturbed catchments. This method capitalises on flood events to counter its adverse impacts by identifying high-priority sediment source areas for efficient and effective management.

Details

Improving Flood Management, Prediction and Monitoring
Type: Book
ISBN: 978-1-78756-552-4

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Article

Stênio de Sousa Venâncio, Swami Marcondes Villela, José Luís da Silva Pinho and José Manuel Pereira Vieira

The purpose of this paper is to construct a numerical model for the numerical analysis of the hydraulic transient profile in Trabalhador channel for filling and emptying…

Abstract

Purpose

The purpose of this paper is to construct a numerical model for the numerical analysis of the hydraulic transient profile in Trabalhador channel for filling and emptying maneuvers and to determine the water level in time. Model results support operational managers in the decision-making process.

Design/methodology/approach

Physical data were provided for the construction and calibration of the numerical model. The equations of Saint-Venant were approximated by a finite difference scheme and the numerical model was written in Fortran. The results of filling and emptying of the channel simulations were compared with the measured water levels.

Findings

Measured water levels and those simulated by the numerical model have shown good correlation. The time recorded for the filling and emptying of the canal was also close between the measured and simulated data. The simulation design flow pointed to inundation in the channel banks. Simulation water levels were slightly higher than those measured.

Research limitations/implications

In this model, the combination of canals and pressure conduits was not considered.

Practical implications

The findings confirm the measured time for filling and emptying of the canal, as well as inundation of canal banks for the maximum design flow. These results help in the management process.

Originality/value

This paper presents a numerical model for hydraulic transient analysis in channels with good agreement with the field data.

Details

Management of Environmental Quality: An International Journal, vol. 28 no. 2
Type: Research Article
ISSN: 1477-7835

Keywords

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Article

Érika Silva Fabri, Maurício Antônio Carneiro and Mariangela Garcia Praça Leite

The purpose of this research is to determine the major environmental impacts and, especially, to evaluate the geochemical characteristics of water of the lakes formed in…

Abstract

Purpose

The purpose of this research is to determine the major environmental impacts and, especially, to evaluate the geochemical characteristics of water of the lakes formed in abandoned quarries of ornamental rock of the Campo Belo Metamorphic Complex.

Design/methodology/approach

To do so, 12 quarries were chosen to be studied. They were mapped in a detail scale and their rocks were described and sampled for petrography analysis. Whenever present, the lakes were evaluated too. In situ measurements included pH, Eh, conductivity, resistivity, total dissolved solids and temperature. Water samples were collected to determine alkalinity, sulfates, chlorates, turbidity, suspended sediments and the concentrations of major and trace elements using the ICP‐OES.

Findings

Abandoned open‐pit mining operations have resulted in the creation of numerous pit lakes. About 90 per cent of the quarries visited and studied were abandoned or interdicted by environmental organs, what will probably lead to its subsequent abandonment. The quarries Borges and Gêmeos were two quarries of the abandoned quarries in the region, which has a lake formed in its trench. Gêmeos and Borges pit lakes analytical data shows clear correlation between the chemical compositions of the solute and the geological characteristics of the quarries. In spite of the differences found, the results showed a relatively quality water according to Brazilian legislation control values.

Originality/value

This was the first study done of pit lakes formed in abandoned ornamental rock quarries of Campo Belo Metamorphic Complex/Minas Gerais – Brazil. This research provides a better understanding of the gneisses pit lakes hydrogeochemistry, a subject neglected in scientific literature.

Details

Management of Environmental Quality: An International Journal, vol. 24 no. 1
Type: Research Article
ISSN: 1477-7835

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Article

Dang Huu Chung and Dieter P. Eppel

The aim is to investigate in detail the sensitivity of sediment transport and bed morphology with respect to some parameters including bed slope, non‐hydrostatic pressure…

Abstract

Purpose

The aim is to investigate in detail the sensitivity of sediment transport and bed morphology with respect to some parameters including bed slope, non‐hydrostatic pressure term, sand grain size, temperature, salinity and lower boundary conditions for suspended sand concentration on a regional scale through numerical simulations based on a mathematical model.

Design/methodology/approach

The numerical model consists of a 3D hydrodynamic code amended by a sediment transport module. At the same time, the influence of wave action has been taken into account. The model is applied to the Sylt‐Romo tidal bay covering approximately 20 × 30 km2 spanned by about 2.7 × 106 active grid points with the constant wind and wave fields.

Findings

The computed results of seven different cases over 150 h show that the effect of bed slope correction is very strong, especially in case of largely changeable bathymetry and depends on the horizontal grid resolution. Sand grain size strongly influences the vertical distribution of suspended sediment and then sedimentation. The impact of sea water temperature is relatively clear despite being less powerful than two former parameters. Non‐hydrostatic pressure perturbations of the flow field and the kind of the lower boundary condition as well as salinity are negligible allowing for considerable savings of CPU time when the numerical simulation is carried out for a large area and for a very long‐time period.

Originality/value

The results of the study demonstrate that the geometrical factor of coastal bed and the range of sand particle size on the bottom contribute to the tendency of bed evolution in some measure. Additionally, the increase of temperature of sea water due to global warming may also make a considerable change to the mechanism of sediment transport and sedimentation in future. Therefore, the human intervention in the process of natural evolution is possible through the behaviour to the nature. At the same time, this is also interesting and useful information and it can consolidate the idea for coastal engineering projects.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 18 no. 5
Type: Research Article
ISSN: 0961-5539

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Article

Thomas Rowan and Mohammed Seaid

The purpose of this paper is to present a new numerical model for shallow water flows over heterogeneous sedimentary layers. It is already several years since the…

Abstract

Purpose

The purpose of this paper is to present a new numerical model for shallow water flows over heterogeneous sedimentary layers. It is already several years since the single-layered models have been used to model shallow water flows over erodible beds. Although such models present a real opportunity for shallow water flows over movable beds, this paper is the first to propose a multilayered solver for this class of flow problems.

Design/methodology/approach

Multilayered beds formed with different erodible soils are considered in this study. The governing equations consist of the well-established shallow water equations for the flow, a transport equation for the suspended sediments, an Exner-type equation for the bed load and a set of empirical equations for erosion and deposition terms. For the numerical solution of the coupled system, the authors consider a non-homogeneous Riemann solver equipped with interface-tracking tools to resolve discontinuous soil properties in the multilayered bed. The solver consists of a predictor stage for the discretization of gradient terms and a corrector stage for the treatment of source terms.

Findings

This paper reveals that modeling shallow water flows over multilayered sedimentary topography can be achieved by using a coupled system of partial differential equations governing sediment transport. The obtained results demonstrate that the proposed numerical model preserves the conservation property, and it provides accurate results, avoiding numerical oscillations and numerical dissipation in the approximated solutions.

Originality/value

A novel implementation of sediment handling is presented where both averaged and separate values for sediment species are used to ensure speed and precision in the simulations.

Details

Engineering Computations, vol. 37 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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Article

Fikru Damte, Bogale G_Mariam, Melkamu Teshome Ayana, Tarun Kumar Lohani, Gaurav Dhiman and Mohammad Shabaz

The change in sediment transport phenomenon and morphological characteristics of Kulfo River in the southern part of Ethiopia is estimated using one-dimensional hydraulic…

Abstract

Purpose

The change in sediment transport phenomenon and morphological characteristics of Kulfo River in the southern part of Ethiopia is estimated using one-dimensional hydraulic modelling. The purpose of this study is to predict erosion and sedimentation using hydrological engineering center-river analysis system (HEC-RAS) model.

Design/methodology/approach

Geometrical survey data of 2005 and 2019 were used to assess the impact of flood depth with 100 years of return per period on the morphology of the river. The bed and bank materials at selected sites of the river were sampled to estimate the grain size using manning roughness coefficient. Discharge and suspended sediment concentration were sampled thrice per day for a stretch of three months to develop a rating curve.

Findings

HEC-RAS model indicates that flood depth with 100 years return period had a significant inundated area during 2019 in comparison to 2005 demonstrating a temporary change in the morphology of the river. Acker and White method in HEC-RAS was used extensively to calculate the sediment load and subsequently calibrated. In the upper reach of the study area, there was aggradation and degradation, whereas the only degradation was noted in the middle to the downstream reach of the channel. Seasonal flood during peak flow due to a rise in bed level is most prevalent during the aggradation period.

Originality/value

Comparison of a flood depth inundating the catchment and sediment deposition has been intricately analyzed by using HEC-RAS model.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

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Article

Marcus Vinicius Estigoni, Renato Billia Miranda and Frederico Fabio Mauad

Finer sediment particles (silt and clay) transported by rivers carry the major part of nutrient loads by absorption; thus, sediment settling can remove nutrients from the…

Abstract

Purpose

Finer sediment particles (silt and clay) transported by rivers carry the major part of nutrient loads by absorption; thus, sediment settling can remove nutrients from the water column. The purpose of this paper is to analyze the relation between reservoir sedimentation and water quality by assessing the reservoir sedimentation process and the sediments’ characteristics.

Design/methodology/approach

Bathymetric surveys from 2004 to 2014 were analyzed to assess the sedimentation process. Core samples provided information on a layer-by-layer basis of the sediment deposits, and water samples near the surface and near the bottom provided information on sediment concentration, and adsorbed and dissolved nutrients.

Findings

The upstream region of a reservoir is already silted. From 2004 to 2014, the delta evoluted approximately 500 m downstream and the deposits were mainly composed of clay. An area of approximately 1,000 m between the delta and the dam should still be able to continue allowing sediment deposition in the coming years. Most of the nutrients were absorbed into the sediment particles, except for the nitrogen measured in the dry season.

Research limitations/implications

Although analyses of the full cycle of the nutrients were not carried out, the constant sediment trapping of finer sediments and the high rate of absorbed nutrients in the suspended sediment support the hypothesis that the reservoir has removed nutrients from aqueous media by adsorption into sediments.

Practical implications

In the studied case, reservoir sedimentation has led to better water quality downstream.

Originality/value

It is shown in this study that reservoir sedimentation may have positive effects on river water quality.

Details

Management of Environmental Quality: An International Journal, vol. 28 no. 1
Type: Research Article
ISSN: 1477-7835

Keywords

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Article

Marco Ostoich, Marco Carcereri and Jvan Barbaro

The tannery industry impacts strongly on water bodies due to the presence of chemical substances, such as chlorides, sulphates, chromium and other pollutants. This study…

Abstract

Purpose

The tannery industry impacts strongly on water bodies due to the presence of chemical substances, such as chlorides, sulphates, chromium and other pollutants. This study has been carried out with a view to enhance the environmental compatibility of the Arzignano tannery district (northern Italy) which is the largest in Italy, by improving the quality of the Fratta-Gorzone River. Sediment quality, according to the driving forces-pressure-state-impact-response (DPSIR) scheme, has been developed as a significant impact indicator to be applied at basin level. The purpose of this paper is to discuss the above issues.

Design/methodology/approach

Data were produced during institutional monitoring and control activities carried out by ARPAV (Veneto Region Environmental Prevention and Protection Agency) according to official methods. To define the environmental impacts on the river basin, a statistical assessment was performed on water and sediment quality data to establish the degree of correlation for the main pollutants along the river stem.

Findings

In the basin considered, sediment quality presents high levels of contamination from heavy metals – in particular chromium (Cr) (III) – as well as organic pollutants. Investigation of the pressure sources revealed that the discharge from the Arzignano tannery district is the main source of Cr (III), according to background studies performed in the same area.

Practical implications

The quality of river sediments must be improved in order to avoid the re-suspension/solubility of pollutants; dredged materials with high polluting substances must be managed with specific precautions in order to safeguard the environment.

Originality/value

The river studied is currently the only significant water body in which sediment monitoring has been performed in the Veneto Region (Italy) since 2002. This study presents issues linked to the characterization of river sediment and the correlation between sediment quality and water pollution and prior and current pressure sources.

Details

Management of Environmental Quality: An International Journal, vol. 25 no. 4
Type: Research Article
ISSN: 1477-7835

Keywords

1 – 10 of 269