Coastline Change and Erosion-Accretion Evolution of the Sandwip Island, Bangladesh

2019 ◽  
pp. 434-447
Author(s):  
Al Emran ◽  
Md. Abdur Rob ◽  
Md. Humayun Kabir
Keyword(s):  
Water Depth ◽  
Water Pressure ◽  
Steep Slope ◽  
Erosion Processes ◽  
Coastline Change ◽  
The North ◽  
Topographic Slope ◽  
North Eastern ◽  
Near Shore ◽  
Different Parts

The study tries to analyze the morphological and hydrological changes and to establish their relationship in the Sandwip Island through the integration of Remote Sensing (RS) and Geographic Information Systems (GIS). The study concludes from the recent 30 years' data that the different parts of the island response different cycle of coastline change associated with hydrological dynamics. The resulted net loss of the coastline is about 6.98 km (0.23 km/y) and the net loss of the coastal area is about 23.99 km2 (0.8 km2/y). The erosion processes (increase in the water depth near shore) were active along the western and the south-western shores. This erosion of the island is facilitated by the steep slope of the bank, high tidal water pressure and loose bank materials. In contrast, the accretions (decrease in the water depth near shore) were taken place in the larger parts of the northern and the north-eastern shores of the island. This is due to the backwash sediment deposition with the favor of gentle topographic slope along shores.

Coastline Change and Erosion-Accretion Evolution of the Sandwip Island, Bangladesh

2019 ◽  
pp. 1497-1509
Author(s):  
Al Emran ◽  
Md. Abdur Rob ◽  
Md. Humayun Kabir
Keyword(s):  
Water Depth ◽  
Water Pressure ◽  
Steep Slope ◽  
Erosion Processes ◽  
Coastline Change ◽  
The North ◽  
Topographic Slope ◽  
North Eastern ◽  
Near Shore ◽  
Different Parts

The study tries to analyze the morphological and hydrological changes and to establish their relationship in the Sandwip Island through the integration of Remote Sensing (RS) and Geographic Information Systems (GIS). The study concludes from the recent 30 years' data that the different parts of the island response different cycle of coastline change associated with hydrological dynamics. The resulted net loss of the coastline is about 6.98 km (0.23 km/y) and the net loss of the coastal area is about 23.99 km2 (0.8 km2/y). The erosion processes (increase in the water depth near shore) were active along the western and the south-western shores. This erosion of the island is facilitated by the steep slope of the bank, high tidal water pressure and loose bank materials. In contrast, the accretions (decrease in the water depth near shore) were taken place in the larger parts of the northern and the north-eastern shores of the island. This is due to the backwash sediment deposition with the favor of gentle topographic slope along shores.

Coastline Change and Erosion-Accretion Evolution of the Sandwip Island, Bangladesh

2017 ◽  
Vol 8 (2) ◽  
pp. 33-44 ◽  
Author(s):  
Al Emran ◽  
Md. Abdur Rob ◽  
Md. Humayun Kabir
Keyword(s):  
Water Depth ◽  
Water Pressure ◽  
Erosion Processes ◽  
Coastline Change ◽  
The North ◽  
Topographic Slope ◽  
Tidal Water ◽  
North Eastern ◽  
Near Shore ◽  
Different Parts

The study tries to analyze the morphological and hydrological changes and to establish their relationship in the Sandwip Island through the integration of Remote Sensing (RS) and Geographic Information Systems (GIS). The study concludes from the recent 30 years' data that the different parts of the island response different cycle of coastline change associated with hydrological dynamics. The resulted net loss of the coastline is about 6.98 km (0.23 km/y) and the net loss of the coastal area is about 23.99 km2 (0.8 km2/y). The erosion processes (increase in the water depth near shore) were active along the western and the south-western shores. This erosion of the island is facilitated by the steep slope of the bank, high tidal water pressure and loose bank materials. In contrast, the accretions (decrease in the water depth near shore) were taken place in the larger parts of the northern and the north-eastern shores of the island. This is due to the backwash sediment deposition with the favor of gentle topographic slope along shores.

The Strength Analysis of Francis Turbine Runner Based on the Fluid-Solid Coupling

2014 ◽  
Vol 709 ◽  
pp. 41-45
Author(s):  
Kan Kan ◽  
Yuan Zheng ◽  
Xin Zhang ◽  
Bin Sun ◽  
Hui Wen Liu
Keyword(s):  
Water Pressure ◽  
Eastern China ◽  
Static Stress ◽  
Operating Conditions ◽  
Francis Turbine ◽  
Strength Analysis ◽  
Maximum Deformation ◽  
The North ◽  
North Eastern ◽  
Turbine Runner

This paper does unidirectional fluid-solid coupling calculation on the runner strength under three designed head loading conditions of a certain Francis turbine in the north-eastern China. The water pressure on the blade in the flow fields of different operating conditions is calculated by means of CFD software CFX. With the help of ansys workbench, the water pressure is loaded to the blade as structural load to conclude the static stress distribution and deformation of the runner under different operating conditions. The results show that the maximum static stress increases with the rise of the flow and appears near the influent side of the blade connected to the runner crown; the maximum deformation increases with the rise of the flow and appears on the band. The results provides effective basis for the structural design and safe operation of the Francis turbine.

The Selandian (Paleocene) mollusc fauna from Copenhagen, Denmark: the Poul Harder 1920 collection

2001 ◽  
pp. 1-85
Author(s):  
Kaj Ingemann Schnetler
Keyword(s):  
New Species ◽  
Water Depth ◽  
Historical Context ◽  
Fine Grained ◽  
The North ◽  
First Occurrence ◽  
Near Shore ◽  
The North Sea ◽  
Molluscan Fauna ◽  
Fine Grained Sand

NOTE: This monograph was published in a former series of GEUS Bulletin. Please use the original series name when citing this monograph. Schnetler, K. I. (2001). The Selandian (Paleocene) mollusc fauna from Copenhagen, Denmark: the Poul Harder 1920 collection. Geology of Denmark Survey Bulletin, 37, 1-85. https://doi.org/10.34194/dgub.v37.5021 A detailed study has been made of the molluscan fauna in the material collected by Poul Harder in 1920 from the classical Danish early Selandian (Late Paleocene) locality in the Lellinge Greensand at Sundkrogen (the harbour of Copenhagen). A description is also given of the now submerged locality.The Harder collection, which has remained virtually unstudied for more than 75 years, is discussed in the interesting historical context that it was not included in the monograph on the Paleocene of Copenhagen by J.P.J. Ravn in 1939. Ravn's study was based on material collected the same year from Sundkrogen by A. Rosenkrantz, and on material collected in the thirties from other localities in the Copenhagen area. Some material collected by A. Rosenkrantz and others, but not dealt with by J.P.J. Ravn, is also included in the present study. The long-lasting controversy about publication rights relating to the Sundkrogen material is recalled.Twenty-seven new species are introduced, viz. Portlandia (Yoldiella) nielseni n. sp., Plicatula selandica n. sp., Laternula (Laternulina) ravni n. sp., Dentalium (Dentalium) sundkrogensis n. sp., Solariella (Solariella) ravni n. sp., Solariella (Solariella) hauniensis n. sp., Teinostoma (Teinostoma) ledoni n. sp., Entomope kirstineae n. sp., Harrisianella subglabra n. sp., Bittium (Bittium) oedumi n. sp., Cerithiopsidella (Vatopsis) rasmusseni n. sp., Seila (Notoseila) heilmannclauseni n. sp., Seila (Notoseila) anderseni n. sp., Thereitis weinbrechti n. sp., Cirsotrema (Cirsotrema) hauniensis n. sp., Opalia (Pliciscala) thomseni n. sp., Charonia (Sassia) danica n. sp., Siphonalia arlejansseni n. sp., Astyris (Astyris) lappanni n. sp., Streptolathyrus danicus n. sp., Streptolathyrus lemchei n. sp., Cancellaria (sensu lato) jakobseni n. sp., Pseudocochlespira rosenkrantzi gen. et sp. n., Actaeopyramis marcusseni n. sp., Chrysallida (Parthenina) peterseni n. sp., Syrnola (Syrnola) granti n. sp. and Cingulina harderi n. sp. Within the Turridae, Pseudocochlespira n. gen. is established.A total of 182 taxons are listed. Of these, 36 are new for the Lellinge Greensand, and 60 have not previously been recorded from Sundkrogen. The study demonstrates that several genera have their first occurrence datum in the Selandian. The Selandian mollusc fauna from Sundkrogen and elsewhere in the Copenhagen area has no equivalent in the North Sea Basin, but faunas from boulders of Selandian age from the south-eastern part of Denmark and the southern part of Sweden demonstrate affinities with the Sundkrogen fauna, whereas the fauna from the Kerteminde Marl demonstrates a lesser degree of affinity.The palaeoenvironment is interpreted as a transgression of the Selandian Sea with erosion of the underlying Danian sediments. The near-shore environment was followed by gradually increasing water depth, resulting in deposits of fine-grained sand and finally dark clay. The dark clay was probably deposited in a deep inlet from the eastern margin of the Selandian Sea.

Present-day sediment dynamics and provenance of the Gornergletscher

2021 ◽  
Author(s):  
Fien De Doncker ◽  
Frédéric Herman ◽  
Günther Prasicek ◽  
Thierry Adatte ◽  
François Mettra ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Protective Layer ◽  
Suspended Sediments ◽  
Equilibrium Line Altitude ◽  
Glacial Erosion ◽  
Erosion Rates ◽  
Erosion Processes ◽  
The North ◽  
North Eastern ◽  
Western Side

<p>Glacial erosion processes shape the Earth’s surface. Nevertheless, the processes that drive glacial erosion and the subsequent export of sediments are poorly understood and quantified. These processes include ice sliding, which controls erosion by abrasion and quarrying, and meltwater availability, which is essential to flush out sediment stocks that form a protective layer of sediments impeding bedrock erosion. Mapping glacial erosion rates can help understand the role of these different processes through the spatial relationships between the subprocesses and erosion rates. Here we report timeseries of glacial erosion rate maps inferred from the inversion of suspended sediment loads and their provenance. Geographically, we focus on the Gornergletscher complex (VS, Switzerland) where we collected data for the summer of 2017. The erosion rate timeseries are then compared to records of temperature, precipitation and estimates of discharge and turbidity of the meltwater river. Erosional activity seems to increase with rising temperatures and meltwater discharge, leading to an increased proportion of suspended sediments coming from the north-eastern (and occasionally western) side of the glacier. Interestingly, the peak in sediments from the north-eastern side is always preceded by a peak in sediments from the western side of the glacier. Sediments of these two zones are predominant in the suspended load signal when the maximal temperature at the Equilibrium Line Altitude (ELA) is above 10°C and on the rising limb of the hydrograph. Furthermore, the obtained erosion rate maps suggest that sliding velocities are not the only explanatory factor of the erosion rate patterns. We therefore postulate from these preliminary results that the present-day sediment output of the Gornergletscher complex is largely influenced by short term variations in temperature and meltwater availability.</p>

scholarly journals Chlorinated hydrocarbons residues in milk fat of selected farm animals from the north-eastern part of Poland

2014 ◽  
Vol 58 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Renata Pietrzak-Fiećko ◽  
Michalina Gałgowska ◽  
Sylwia Bakuła ◽  
Barbara Felkner-Poźniakowska
Keyword(s):  
Milk Fat ◽  
Animal Species ◽  
Chlorinated Hydrocarbons ◽  
Farm Animals ◽  
Milk Samples ◽  
The North ◽  
North Eastern ◽  
North Eastern Part ◽  
Different Parts

Abstract The aim of the study was to determine and compare the concentrations of chlorinated hydrocarbons residues (DDT, DDE, DDD, γ-HCH) in the milk fat of selected species of farm animals. The experiment was carried out on cow’s, sheep’s, goat’s, and mare’s milk samples originating from different parts of north-eastern Poland. The samples were prepared using Röse-Gottlieb’s and Ludwicki’s methods. The determination of the compounds was conducted with gas chromatography. All tested samples contained the residues of chlorinated hydrocarbons. The results varied depending on the animal species as well as the places of sample collections. The highest content of γ-HCH and ΣDDT was determined in cow’s milk (22.75; 53.12 μg/kg of fat, respectively). The lowest level of γ-HCH and ΣDDT was observed in sheep’s milk (0.25; 5.94 μg/kg of fat, respectively). The content of chlorinated hydrocarbons did not exceed the maximum acceptable levels of these compounds.

High-Precision Relative Depth and Subsidence Mapping from Seafloor Water Pressure Measurements

SPE Journal ◽  
2006 ◽  
Vol 11 (03) ◽  
pp. 380-389 ◽  
Author(s):  
Torkjell Stenvold ◽  
Ola Eiken ◽  
Mark Zumberge ◽  
Glenn Sasagawa ◽  
Scott Nooner
Keyword(s):  
High Precision ◽  
Water Depth ◽  
Water Pressure ◽  
Large Field ◽  
Relative Depth ◽  
Remotely Operated Vehicle ◽  
Gas Field ◽  
Reservoir Compaction ◽  
The North ◽  
Single Station

Summary A method to accurately measure seafloor subsidence away from platform locations is presented. The method is based on seafloor water pressure, which is measured on top of predeployed benchmarks visited one after another using a remotely operated vehicle (ROV) and is at the same time measured continuously throughout the survey at one or more reference locations. Because no significant subsidence is expected during a few days of data acquisition, high-precision relative depths representative for the average time of the survey can be obtained. Accurate subsidence estimates between seafloor surveys are found assuming negligible subsidence at benchmarks located outside the field. Results from six seafloor surveys performed at two gas fields in the North Sea are presented. For an area of 1 km2 at 80 m water depth, single-measurement relative depth precision (standard deviation) of 0.4 cm was obtained. Correspondingly, for an area of 700 km2 at 295 to 345 m water depth, 0.6 cm was obtained. Single-station subsidence accuracy down to 1 cm is achieved from the two most recent pressure surveys at the large field. A subsidence signal is seen for this difference, and it is compared with modeled subsidence. Error budgets for depth precision and subsidence, incorporating instrumental and environmental errors, are discussed. Introduction Reservoir compaction caused by the extraction of hydrocarbons usually results in surface subsidence. The most vulnerable fields are those with thick and soft reservoir formations being exposed to a large drop in pore pressure. For such fields, reservoir compaction can be a major energy drive for production that enhances the recovery of the field (Merle et al. 1976). Reservoir compaction can also lead to a reduction in permeability. When significant subsidence occurs, it can cause well failures and costly repairs of surface structures such as platforms and pipelines (Bruno 1992). Subsidence monitoring can improve the safety of field installations, and it may also be used to estimate reservoir behavior and formation properties. Marchina (1996) reported examples of high-accuracy leveling data from the Groningen gas field used to estimate pressure depletion in the aquifer by solving a linear inverse problem, and Nagel (1998) used bathymetry data from the Ekofisk field to achieve estimates of overburden properties.

scholarly journals THE SEAFLOOR MORPHOLOGHY OF SUNDA STRAIT FOR LAYING THE UNDERWATER CABLES

2016 ◽  
Vol 25 (2) ◽  
pp. 103
Author(s):  
Yogi Noviadi
Keyword(s):  
Water Depth ◽  
Fine Fraction ◽  
Steep Slope ◽  
Submarine Cable ◽  
Coastal Morphology ◽  
Seafloor Morphology ◽  
Industrial Activities ◽  
Line Spacing ◽  
Near Shore ◽  
Underwater Cables

The coastal and offshore areas around the Sunda Strait will be developed to be a submarine cable corridor connecting between Java and Sumatra Islands. There are some requirements that should be considered before laying the underwater cables. One of these considerations is to understand the seafloor morphology of the Sunda Strait. The study was conducted based on six of track lines with 1 km line spacing and 4 Cross lines. The water depth obtained then was corrected to the depth of water from the Lowest Water Level (LWL). The seabed condition in the near shore area of Sumatra side is very flat and is influenced by 2 km offshore tide activity. The coast line is characterized by mangrove and fine fraction of sediments (mud and clay). At the Java side, the coastal morphology is characterized by the very steep slope and most of the area is occupied by the industrial activities. Keywords: seafloor morphology, under water cables, Sunda Strait Area pantai dan perairan Selat Sunda akan dikembangkan sebagai bagian dalam penempatan kabel bawah laut yang menghubungkan Pulau Jawa dan Pulau Sumatera. Rencana penempatan kabel bawah laut ini membutuhkan beberapa persyaratan teknis yang harus dipertimbangkan. Salah satu pertimbangan untuk peletakan kabel bawah laut adalah memahami morfologi dasar laut selat Sunda. Penelitian dilakukan berdasarkan 6 lintasan pemeruman dengan jarak antar lintasan 1 km, dan 4 lintasan memotong lintasan utama. Kedalaman laut yang diperoleh kemudian dikoreksi dengan muka laut terendah. Kondisi permukaan dasar laut di sisi pantai Sumatra sangat datar serta sejauh 2 km ke arah laut lepas masih dipengaruhi oleh aktifitas pasang surut. Garis pantainya dicirikan oleh tanaman bakau dan fraksi sedimen halus (lumpur dan lempung). Pada sisi Jawa, morfologi pantai dicirikan oleh kemiringan lereng yang curam dan kebanyakan area ditempati oleh aktivitas industri. Kata kunci: morfologi dasar laut, kabel bawah laut, Selat Sunda

Discussion on “The grinding wheel and production” at the North-Eastern Section of the Institution

1942 ◽  
Vol 21 (8) ◽  
pp. 315
Author(s):  
Bowen ◽  
Vickery ◽  
Buchanan ◽  
Swallow ◽  
Perks ◽  
...  
Keyword(s):  
Grinding Wheel ◽  
The North ◽  
North Eastern

The influence of submesoscale eddies on hydrochemical parameters and structural and functional characteristics of phytoplankton in the north-eastern part of the Black Sea

2019 ◽  
pp. 24-40
Author(s):  
Sergey B. Kuklev ◽  
Vladimir A. Silkin ◽  
Valeriy K. Chasovnikov ◽  
Andrey G. Zatsepin ◽  
Larisa A. Pautova ◽  
...  
Keyword(s):  
Anticyclonic Eddy ◽  
The Black Sea ◽  
Hydrochemical Parameters ◽  
North East ◽  
The North ◽  
Seasonal Thermocline ◽  
North Eastern ◽  
Quantitative Indicators ◽  
The City ◽  
North Eastern Part

On June 7, 2018, a sub-mesoscale anticyclonic eddy induced by the wind (north-east) was registered on the shelf in the area of the city of Gelendzhik. With the help of field multidisciplinary expedition ship surveys, it was shown that this eddy exists in the layer above the seasonal thermocline. At the periphery of the eddy weak variability of hydrochemical parameters and quantitative indicators of phytoplankton were recorded. The result of the formation of such eddy structure was a shift in the structure of phytoplankton – the annual observed coccolithophores bloom was not registered.

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