scholarly journals Sediment Movements in Estuary of Siak River, Riau Basin, Indonesia

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Mubarak Mubarak ◽  
Ahmad Nurhuda
Keyword(s):  
Sediment Transport ◽  
Total Solid ◽  
Flood Tide ◽  
Clear Understanding ◽  
Sediment Distribution ◽  
Organic Matters ◽  
Many Sources

Siak river has a long history as a transportation lane in the east of Sumatera. From traditional to timber transportations are dependent on this river. Now the river is a severe suffering pollutant spill from many sources. Anthropological activities were higher contributions in the degradation of river environments. Many works were reported about pollution in Siak river. But how the distribution of model sediment transport in the mouth of the river is less to be explained. We consider hydrodynamics model of the mouth of Siak river for modeling the sediment distribution. This simulation gives a fundamental and clear understanding of how total solid sediment (TSS) distribution when flood and ebb tide happens. At ebb tide, TSS dispersion is higher than at flood tide. There is found that the sediment is concentrated in the plume of Siak river in Bengkalis strait. The composition of the sediment is dominated by organic matters.

scholarly journals SEDIMENT DISTRIBUTION BASED ON GRAIN SIZE ANALYSES IN WEDA BAY, NORTHERN MALUKU

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Septriono Hari Nugroho ◽  
Abdul Basit
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Size Distribution ◽  
Deposition Process ◽  
General Information ◽  
Current Speed ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
Sea Floor ◽  
Integrated Study

<p>An integrated study of sediment distribution was conducted in Weda Bay, Northern Maluku to provide general information on transportation and deposition process based on sediment grain size distribution. The study was conducted during the Weda Bay Expedition using the “Baruna Jaya VII” research vessel in March 13<sup>th</sup> –22<sup>th</sup> 2013. Sieving method (granulometric) was used to analyze the grain size. The results indicated that in general the pattern of sea floor sediment distribution was dominated by clay – sand grain-sized. The current speed influenced the sediment transport, deposition, and distribution.  Larger fractions of sediment were quickly settled on the sea floor due to stronger currents around Southern area (Widi islands), meanwhile the lesser fractions of the transported away into other places with weaker currents conditions.</p> <p>Keywords: current, the Weda Bay expedition, granulometric, grain size, sediment distribution</p>

Self-consistency of the regolith hypothesis for the mid-Pleistocene Transition

2021 ◽  
Author(s):  
Matthew Drew ◽  
Lev Tarasov
Keyword(s):  
Sediment Transport ◽  
State Of The Art ◽  
Flow Line ◽  
Ice Sheets ◽  
Balance Model ◽  
Clear Understanding ◽  
Ice Dynamics ◽  
Ice Volume ◽  
Systems Model ◽  
Fully Coupled

&lt;p&gt;Is the regolith hypothesis consistent with the physics of glacial removal of mechanically weak surface material?&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The&amp;#160; mid-Pleistocene transition (MPT) from small 40 kyr glacial cycles to large, abruptly terminating 100 kyr ones represents a major climate system reorganization for which a clear understanding is lacking. A leading mechanism for this transition is a stabilization of ice sheets due to a shift to higher friction substrate. The Pleistocene saw the removal of deformable regolith -- laying bare hard higher-friction bedrock that would help preserve regional ice during warm interstadials. This is the regolith hypothesis.&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The removal of regolith by Pleistocene ice sheets remains poorly constrained. To date, only models with a forced change in area of regolith cover or 1D flow line models with simplistic sediment transport have been used to probe the role of regolith in the MPT. It is therefore unclear if the appropriate amount of regolith removal can occur within the time-frame of the MPT.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;To properly test the hypothesis, at least three components are required: capable model, observational constraint, and a probe of uncertainties. A capable model must explicitly represent relevant processes in a fully coupled self-consistent manner. We have therefore configured a state of the art 3D glacial systems model (GSM). The GSM incorporates a state-of-the-art fully coupled sediment production/transport model, subglacial hydrology, visco-elastic glacial isostatic adjustment, 3D thermomechanically coupled hybrid shallow ice/shallow shelf ice dynamics, and internal climate solution from an energy balance model. The model generates sediment by quarrying and abrasion, and both subglacial and englacial sediment transport. The subglacial hydrology model employs a linked-cavity system with a flux based switch to tunnel drainage, giving dynamic effective pressure needed for realistic sediment and sliding processes. The coupled model is driven only by prescribed atmospheric CO2 and orbitally derived insolation.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The required observational constraints include present-day regolith distribution and inferred Pleistocene ice volume from proxy records.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The final component is&amp;#160; a large ensemble of full Pleistocene simulations that probe both initial regolith distribution uncertainties and model parametric uncertainties. We present the results of such an ensemble, examining both rates of computed regolith removal and changes in ice volume cycling across the MPT interval.&lt;/p&gt;

Coastal Hydrodynamic and Sediment-Salinity Transport Simulations for Southwest Louisiana Using Measured Vegetation Data

2015 ◽  
Author(s):  
Xiao Han ◽  
Ning Zhang
Keyword(s):  
Sediment Transport ◽  
Storm Surge ◽  
Water System ◽  
Water Systems ◽  
Vegetation Coverage ◽  
Target Area ◽  
Sediment Distribution ◽  
Entire Area ◽  
Lake Charles ◽  
The City

Storm-surge flood is a major thread to the inhabitants and the health of the marshes in Southwest Louisiana. The floods caused direct damages to the area, but also indirectly caused excessive sedimentations in the water system, especially in Calcasieu Ship Channel which is a vital industrial water way connecting the City of Lake Charles to the Gulf. It is well known that coastal wetlands and marshes have significant impacts on the prevention and reduction of coastal floods. The wetland vegetation creates larger frictions to the flooding water and acts as the first line of defense against any storm surge floods. In this study, we center Calcasieu Ship Channel, and hydrodynamic and sediment transport simulations were conducted for Calcasieu Ship Channel and surrounding areas. The target area ranges from the city of Lake Charles as the north end and the Gulf of Mexico as the south end, and includes three connected water systems, Calcaiseu Lake, Prien Lake and Lake Charles. The entire Calcasieu Ship Channel running from north to south is included in the domain along with the Gulf Intracoastal Waterway (GIWW) in east and west directions. In authors’ previous study, only the area of south portion of the ship channel, Calcasieu Lake and its surrounding wetlands was simulated and studied. This study is a major upgrade to the model, which provides more complete understanding of the flow and sediment transport in the entire area, as well as the interactions among all water systems surrounding the ship channel. There are wetlands (two National Wild Life Refuges, one in the west and one in the east) surrounding Calcaiseu Lake, while there are various of vegetated and non-vegetated areas surrounding Prien Lake and Lake Charles. The standard 2-D depth averaged shallow water solver was utilized for the simulation of the flow phase and a standard Eulerian scalar transport equation was solved for the sediment and salinity phases. In the sediment phase, the sediment deposition and re-suspension effects are included, while in the salinity phase, the precipitation and evaporation are included. A realistic vegetation model was implemented to represent various types of vegetation coverage in the target area, and appropriate friction values were assigned to different non-vegetated areas. Measured and observed vegetation data were utilized. A coastal storm surge flood was simulated, and effects of vegetation on flood reduction and sediment distribution were investigated. The total flooded area, the flood speed, and the distribution of the flooding water and sediments were compared between vegetated and non-vegetated areas to show the differences between different types of surfaces.

3D numerical studies on stratification and mixing processes affecting fine sediment transport in the pre-dam of the Dhünn reservoir in Germany

2020 ◽  
Author(s):  
Wendy Gonzalez ◽  
Irina Klassen ◽  
Anne Jakobs ◽  
Frank Seidel
Keyword(s):  
Sediment Transport ◽  
Input Data ◽  
Measurement Data ◽  
Fine Sediment ◽  
Transport Processes ◽  
Transport Modeling ◽  
Wind Effects ◽  
Sediment Distribution ◽  
Vertical Diffusivity ◽  
The Impact

&lt;p&gt;Fine sediment transport processes and the thermodynamics in reservoirs are key processes governing the water quality of reservoirs. With regard to a sustainable sediment management of reservoirs, the prediction of sediment transport and deposition is becoming increasingly important.&lt;/p&gt;&lt;p&gt;The subject of the present work was the 3D numerical simulation of fine sediment transport in a reservoir taking into account stratification and mixing effects which in turn are caused by temperature gradients and wind effects. In order to understand and investigate the driving factors for stratification processes and their impact on fine sediment distribution, the great pre-dam of the Dh&amp;#252;nn reservoir in Germany served as case study. The investigations were conducted in sensitivity analyses adopting a 3D sediment transport model with Delft 3D. The impact of various physical and numerical parameters on temperature and fine sediment transport modeling was examined: the number of vertical layers, the input data for the heat model (e.g. relative humidity, air temperature, cloud coverage, solar radiation), the vertical diffusivity and wind effects. The sensitivity studies showed that the input data for the heat model have a minor impact on the temperature and sediment transport modeling within the tested range of parameters. However, the vertical diffusivity and especially the inclusion of wind showed a greater influence on the simulated temperature and suspended sediment concentration gradients. The temperature modeling results by inclusion/exclusion of wind were qualitatively compared with temperature data from literature and with measurement data over a period of one month. Hereby, the simulations showed a good agreement with measurement data by exclusion of wind effects.&lt;/p&gt;&lt;p&gt;The results of the studies provide a solid basis for the development of further models in fields where fine sediment transport is affected by stratification processes and can also be very useful in terms of a better understanding of the interactions between temperature, wind and fine sediment transport.&lt;/p&gt;

Analysis for the Characteristics of Sediment in Tarim River

2014 ◽  
Vol 641-642 ◽  
pp. 25-28
Author(s):  
Shao Yun Deng
Keyword(s):  
Sediment Transport ◽  
Sediment Load ◽  
Sediment Concentration ◽  
Annual Runoff ◽  
Tarim River ◽  
Main Stream ◽  
Water Network ◽  
Annual Average ◽  
Sediment Distribution ◽  
Annual Sediment

The author had given a brief introduction of Tarim River, and the analysis of its water network and the surrounding environmental features, and a few important representative of Tarim River tributaries and the main stream of the four major hydrological stations measured runoff for many years, the annual runoff, the average annual sediment load, the annual sediment load, the annual average sediment concentration, the annual sediment concentration, the average annual sediment transport modulus, the annual sediment transport modulus index data were analyzed. And on this basis, the author had given the further analysis of Tarim River stream sediment distribution characteristics, and had described the sediment source and characteristics of Tarim River.

scholarly journals SEDIMENT TRANSPORT ON THE SOUTH-EAST AUSTRALIAN CONTINENTAL SHELF

1984 ◽  
Vol 1 (19) ◽  
pp. 131 ◽  
Author(s):  
Angus D. Gordon ◽  
John G. Hoffman
Keyword(s):  
Sediment Transport ◽  
Continental Shelf ◽  
Suspended Sediment ◽  
Transport System ◽  
Sediment Concentration ◽  
High Energy ◽  
Sediment Distribution ◽  
Sediment Movement ◽  
Shelf Sediment ◽  
Sea Bed

Engineering projects on the continental shelf off Sydney, Australia, have stimulated investigation into the sediment transport system of the shelf. Investigation activities associated with these projects have included: definition of sea bed morphology, sediment distribution and bedform characteristics; monitoring of steady and wave induced currents; wind data collection; suspended sediment sampling; bottom camera sediment movement investigations and analytical studies of sediment reaction to sea bed forcing functions. Sea bed velocity exceedence relationships for both wave oscillations and steady currents have been determined at depths of 24 m, 60 m and 80 m. Thresholds of sediment movement have been defined. Relative sediment transport computations have been undertaken and studies of suspended sediment concentration profiles are in progress so that absolute transport rates can be determined. The prevailing conditions, which include a mainly south bound current, are seldom sufficient to induce entrainment of shelf sediments. Transport events mainly result from major storms in the Tasman Sea which produce both high energy waves and north bound currents. Although these events are rare and short lived, the combined wave and current shear produced at the sea bed during the events gives rise to entrainment conditions which result in their dominance of the shelf sediment transport system.

scholarly journals Response of tidal flow regime and sediment transport in North Male' Atoll, Maldives to coastal modification and sea level rise

2020 ◽  
Author(s):  
Shuaib Rasheed ◽  
Simon C. Warder ◽  
Yves Plancherel ◽  
Matthew D. Piggott
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Sea Level Rise ◽  
Sea Level ◽  
Land Reclamation ◽  
Tidal Flow ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
Time Periods ◽  
The Impact

Abstract. Changes to coastlines and bathymetry alter tidal dynamics and associated sediment transport process, impacting upon a number of threats facing coastal regions, including flood risk and erosion. Especially vulnerable are coral atolls such as those that make up the Maldives archipelago which has undergone significant land reclamation in recent years and decades, and is also particularly exposed to sea level rise. Here we develop a tidal model of Male' Atoll, Maldives, and use it to assess potential changes to sediment grain size distributions under sea level rise and coastline alteration scenarios. The results indicate that the impact of coastline modification over the last two decades at the island scale is not limited to the immediate vicinity of the modified island, but can also significantly impact the sediment grain size distribution across the wider atoll basin. Additionally, the degree of change in sediment distribution which can be associated with sea level rise that is projected to occur over relatively long time periods is predicted to occur over far shorter time periods with coastline changes, highlighting the need to better understand, predict and mitigate the impact of land reclamation and other coastal modifications before conducting such activities.

Water-sediment distribution and behaviour of Polonium (²¹⁰Po) in a shallow coastal area with high concentration of dissolved organic matters in water, North Vietnam

2016 ◽  
Vol 6 (2) ◽  
pp. 1-14
Author(s):  
Thi Van Tran ◽  
Duc Tam Nguyen ◽  
Duc Nhan Dang ◽  
Quang Long Nguyen ◽  
Van Thang Duong ◽  
...  
Keyword(s):  
Coastal Region ◽  
Dry Season ◽  
High Concentration ◽  
Sediment Distribution ◽  
Organic Matters ◽  
Suspended Particulates ◽  
Total Suspended Particulates ◽  
Dissolved Organic Matters ◽  
North Vietnam

The behaviour and water-sediment distribution of particle-reactive Polonium-210 in the marine environment with high concentration of total suspended particulates (TSP) and dissolved organic matters (DOC) along the coast of the Tonkin Gulf (North Vietnam) were investigated. It was revealed that the water-sediment distribution coefficient, Kd(s), of 210Po varied from 2.39x103 to 1.9x104 (L kg-1) and from 7x103to 2.5x105 (L kg-1), respectively, in the rainy and dry season. This implies that in the aquatic environment 210Po tends to be of high affinity to suspended particulates. The 210Po Kd(s) was positively correlated with salinity in both rainy and dry seasons. With DOC the Kd(s) was positively correlated in the rainy season, but in the dry season the relationship tended to be reverse. This behaviour of 210Po in the coastal region was explained by the variation of pH of seawater and by the complexation of the isotope with DOC. The Kd(s) found in this study was in an order lower compared to that reported by Malaysian researchers for the Thailand Gulf. The most important source of 210Po was suggested to be from in-situ generation by the decay of its grand-parent 210Pb which mainly derived from the atmospheric fall-out.  

Application of ATR-FTIR spectroscopy for the identification of chemical functional groups in kerogens and fossil resins.

2020 ◽  
Author(s):  
Yen Yu Chen ◽  
Ying Ju Chang
Keyword(s):  
Functional Groups ◽  
Organic Matters ◽  
Analytical Technique ◽  
Similar Chemical ◽  
Stretching Vibration ◽  
Infrared Spectrometer ◽  
Reflectance Ftir ◽  
The Many ◽  
Many Sources ◽  
Fossil Resins

&lt;p&gt;Organic matters, such as oil, kerogen, fossil resins have different chemical functional groups. The complexity of chemical functional groups derives from the many sources of original contributing organic matter and long-term chemical and physical changes over geologic time. Fourier transform infrared spectrometer attenuated total reflectance (FTIR-ATR) can quantify the abundance of chemical functional groups and is a sensitive, high resolution and non-destructive analytical technique. The aim of this study was to characterize the spectral behavior and chemical structure of organic matters. In order to correlate organic matters of different types with its infrared spectra. The results show that FTIR-ATR spectra of oil contain intense aliphatic C-H stretching vibration in 2960 cm&lt;sup&gt;-1&lt;/sup&gt;,2925 cm&lt;sup&gt;-1&lt;/sup&gt;,2850 cm&lt;sup&gt;-1&lt;/sup&gt; region relative to the C&amp;#8211;H (CH&lt;sub&gt;3&lt;/sub&gt;) scissoring vibration at 1470 cm&lt;sup&gt;-1&lt;/sup&gt; and C=C aromatic ring stretching vibration at 1640 cm&lt;sup&gt;-1&lt;/sup&gt;. We apply FTIR-ATR analyses for evaluating oil potential of kerogens. The longest aliphatic chains having the least amount of branching testifying to the highest oil generating potential. The similar locality of fossil resins has a similar chemical vibration ratio of C-H stretching (2925 cm&lt;sup&gt;-1&lt;/sup&gt;,2850 cm&lt;sup&gt;-1&lt;/sup&gt;) and C-H scissoring (1470 cm&lt;sup&gt;-1&lt;/sup&gt;). In consequence, the analysis providing a rapid means of assessing organic matters and oil potential, and it can also rapidly identification the botanical origin of fossil resins.&lt;/p&gt;&lt;p&gt;&lt;/p&gt;

Modelling sediment accumulation and dispersion of contaminants in Lake Ijsselmeer (The Netherlands)

1998 ◽  
Vol 37 (6-7) ◽  
pp. 17-24 ◽  
Author(s):  
G. Blom ◽  
H. J. Winkels
Keyword(s):  
Sediment Transport ◽  
Suspended Solids ◽  
Sediment Accumulation ◽  
Quality Model ◽  
Sediment Distribution ◽  
Transport Dynamics ◽  
Solids Concentration ◽  
Sedimentation Flux ◽  
Ijsselmeer Area ◽  
One Year

In this study two models are integrated for the simulation of sediment distribution and quality in the Lake IJsselmeer area. STRESS-2d, a two dimensional dynamic model for simulation of sediment transport due to resuspension, erosion, sedimentation and horizontal advection and dispersion is used to simulate the sediment transport dynamics for a period of one year. The model is calibrated on water level, suspended solids concentration and sedimentation flux measurements. The model has a high spatial and temporal resolution. The model DIASPORA, which is based on STRESS-2d results, simulates the effects of sediment transport on morphology and contaminant concentrations in the sediment for a period of decades. DIASPORA also simulates dilution by internally produced CaCO3 and consolidation of sediment layers. The models produce a reasonable reconstruction of suspended solids concentrations and long term accumulation of sediments in deep areas within the lake. Also the temporal and spatial variability in the contaminant concentration in sediments in Lake IJsselmeer is reconstructed with sufficient quality. Model simulations show that internal redistribution of old deposits in the IJsselmeer area and internal production of CaCO3 are diluting the contaminated solids supplied by the river IJssel.

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