scholarly journals KONDISI HIDRODINAMIKA PERAIRAN SUNGAI LIAT BANGKA BERDASARKAN MODEL MIKE 21-HD-AD SEHUBUNGAN DENGAN MORFOLOGI AKIBAT PENAMBANGAN DI LAUT

2016 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Franto Novico ◽  
Citrawan Sinaga
Keyword(s):  
Numerical Model ◽  
River Mouth ◽  
Mining Operation ◽  
Hydrodynamic Condition ◽  
Hydrodynamic Conditions ◽  
Sea Floor ◽  
Mine Dumps ◽  
The North ◽  
Maximum Current ◽  
Mike 21

Penambangan timah di perairan sekitar Sungai Liat- Bangka oleh kapal keruk dan hisap telah menyebabkan terjadinya perubahan kondisi dasar laut yang sangat besar dengan ditemukannya batimetri yang sangat tidak beraturan di sekitar wilayah foreshore, terutama pada bagian barat muarasungai. Pendekatan model numerik dengan menggunakan software Mike 21 HD-AD menjadi metode pilihan untuk mendapatkan gambaran kondisi hidrodinamika sekitar muara dan garis pantai sekitar Sungai Liat. Berdasarkan hasil simulasi didapatkan bahwa dengan perkiraan pelaksanaan kegiatan penambangan 24 jam sehari selama 15 hari model operasi maka kondisi sebaran buangan akan terbawa hingga jarak terjauh 15 km ke arah selatan, sementara sebaran bergerak ke arah utara sejauh 5 km dari lokasi sumber buangan. Waktu yang dibutuhkan untuk sebaran mencapai garis pantaiadalah 27 jam setelah penambangan dioperasikan. Sementara nilai kecepatan arus maksimum pada saat bulan penuh sebesar 1.5 m/det dengan arah arus dominan ke utara sementara pada saat bulan mati kecepatan maksimum sebesar 1.2 m/det dengan arah arus dominan ke tenggara. Kata kunci : Kondisi Hidrodinamika Sungai Liat, Model Numerik, Buangan Tambang The mining activities using dredging vessel and suction vessel that have done near river mouth of Sungai Liat and along coast line yielded a big deformation of sea floor bathymetry at foreshore especially west side a river mouth. Mike 21 HD-AD software as numerical model was selected as method to describe hydrodynamic conditions around river mouth and along coastline near the Sungai Liat River. Based on simulations where the mining operation is predicted 24 hours a day within 15 days operation model therefore a range of outsource dispersion of 15 km to south while 5 km flows to the north from the mine dumps position. A dispersion of mine dumps would be achieve a coastline in 27 hours since the mining begun. In addition, maximum current in spring time shows 1.5 m/sec to the north direction whereas in neap time the current shows 1.2 m/sec to the southeast direction. Keywords: Hydrodynamic Condition, Sungai Liat, Numerical Model, Mine dumps

scholarly journals Hydrodynamic Modelling of Wave Overtopping over a Block-Covered Flood Defence

2022 ◽  
Vol 10 (1) ◽  
pp. 89
Author(s):  
Luuk Barendse ◽  
Vera M. van Bergeijk ◽  
Weiqiu Chen ◽  
Jord J. Warmink ◽  
Aroen Mughal ◽  
...  
Keyword(s):  
Numerical Model ◽  
Porous Layer ◽  
Hydrodynamic Condition ◽  
Hydrodynamic Conditions ◽  
Physical Test ◽  
Wave Overtopping ◽  
Physical Tests ◽  
Run Up ◽  
Resistance Coefficients ◽  
Flow Velocities

Wave overtopping can cause erosion on the landward slope due to high flow velocities and turbulence that cause high stresses on the cover. Innovative block revetments such as Grassblocks protect the subsoil of the dike against erosion. The blocks are permeable, which reduces the flow velocity and the pressures along the landward slope. The performance of these blocks is assessed in physical tests, which provides insights into the stability of the blocks. However, such experiments are expensive and accurate measurements are difficult due to highly turbulent conditions. Therefore, the goal of this study is to determine the hydrodynamic conditions at the dike cover caused by the wave run-up on the seaward slope and by the overtopping flow over the crest and landward slope. The geometry and wave conditions from the physical test at the Deltares Delta flume are implemented in an OpenFOAM® numerical model. Using the porousWaveFoam solver, a porous layer on the crest and landward slope is implemented, where the flow resistance of this porous layer largely depends on the resistance coefficients α [-] and β [-]. The numerical model is calibrated based on resistance coefficients as introduced earlier in the literature, which showed that the resistance coefficients of α=500 and β=2.0 performed best for the peak flow velocities and the peak pressures. The numerical model is evaluated by using these resistance coefficients in other time series of the physical tests. The evaluated model is then used to determine the hydrodynamic conditions on the landward slope, which showed that the pressure was the most influential hydrodynamic condition at the time of failure. Finally, the model showed that a porosity of n=0.6 and the porous layer thickness η=36mm reduced the peak pressure the most.

scholarly journals MODEL SEDERHANA 2-DIMENSI ARAH PERGERAKAN SEDIMEN DI SUNGAI PORONG JAWA TIMUR

2016 ◽  
Vol 9 (3) ◽  
pp. 175
Author(s):  
Huda Bachtiar ◽  
Franto Novico ◽  
Fitri Riandini
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
River Mouth ◽  
Sediment Concentration ◽  
Dry Season ◽  
Observation Data ◽  
Wet Season ◽  
Level Data ◽  
Water Level Data ◽  
Mike 21

Model numerik MIKE 21 modul transport sedimen digunakan untuk mengetahui respon pergerakan lumpur Sidoarjo pada saat musim hujan dan musim kemarau dan pengaruh tanggul yang berada di muara Sungai Porong. Data yang digunakan adalah pasang surut muka air laut, kedalaman air, debit sungai, arus dan konsentrasi sedimen. Simulasi dilakukan dengan membuat dua skenario, yaitu pada saat kondisi musim hujan dan pada saat musim kemarau. Hasil simulasi model hidrodinamika di verifikasi dengan data lapangan untuk mendapatkan nilai korelasi. Verifikasi meliputi data muka air dan kecepatan arus baik arah –x maupun –y. Berdasarkan hasil verifikasi didapatkan nilai korelasi muka air sebesar 0.8641 sementara arus bernilai 0.1493 untuk sumbu –x dan 0.1917 untuk sumbu –y. Selanjutnya hasil simulasi model menunjukkan konsentrasi sedimen pada tanggal 27 November 2007 merupakan puncak tertinggi dengan nilai 3.2x10-3 kg/m3 untuk musim hujan sementara untuk musim kemarau konsentrasi sedimen bernilai 0.0x10-3 kg/m3. Kata kunci : Model Numerik, Pergerakan Lumpur, Sungai Porong. Numerical model of MIKE 21 sediment transport module was applied to recognize the response of mud flow respective in rainy and dry season and also to get information of dike effect at the river mouth. Data that used in this simulation was tide, water depth, river discharge, current and sediment concentration. The simulations were created for two scenarios, therefore dry season and wet season. The result of the simulation model verified with observation data to see the correlation value. The verification are covering water level data and current magnitude of –x and –y axis. Based on the verification result, the correlation value of water level has a value 0.8641 meanwhile for the current the correlation value have magnitude 0.1493 of x-axis and 0.1917of y-axis. Moreover, the maximum value of sediment concentration could be seen at November 27th 2007 with 3.2x10-3 kg/m3 at the wet season and 0.0x10-3 kg/m3 for dry season. Keywords: Numerical Model, Mud Movement, Porong River

Assessment of Turbulent Processes in Lake Kinneret by the Two-Dimensional Reservoir Water Quality Model “Better”

1993 ◽  
Vol 27 (7-8) ◽  
pp. 381-385 ◽  
Author(s):  
Y. Oziransky ◽  
B. Shteinman
Keyword(s):  
Water Body ◽  
River Mouth ◽  
Temporal Distribution ◽  
Lake Kinneret ◽  
Toxic Substances ◽  
Two Dimensional ◽  
Quality Model ◽  
Reservoir Water ◽  
The North ◽  
Longitudinal Gradients

Data of high spatial and temporal resolution, and a special sampling program are essential for successful application of mathematical models designed to reproduce observed seasonal patterns of temperature, dissolved oxygen, nutrients, pH, and algal biomass for both vertical and longitudinal gradients in a water body. Lake Kinneret suspended solids are of great potential value for estimating transport, exposure to water body elements, and fate of many toxic substances. Therefore the distribution of admixtures in two longitudinal and five vertical segmentation schemes were examined with the two-dimensional water body quality box model “BETTER” (Bender et al, 1990). The transects were taken in the north-western part of Lake Kinneret close to the Jordan River mouth and the National Water Carrier (NWC) head pumping station. The outflow volumes were given according to regular sampling of natural speed of water outflow from different lake layers under calm conditions. Temporal distribution of mixing concentrations as well as turbulent diffusion horizontal coefficients due to the spatial distribution of turbulent scale were obtained during the model's run with the December 1991 data.

scholarly journals Influence of the North Branch of the Qingshuigou River on the Lower Reaches of Yellow River Based on Two-dimensional Numerical Model

2021 ◽  
Vol 1885 (2) ◽  
pp. 022043
Author(s):  
Caodong Jiang ◽  
Liangchao Ma ◽  
Dongfeng Li ◽  
Hongwu Zhang ◽  
Zihao Li
Keyword(s):  
Numerical Model ◽  
Yellow River ◽  
Two Dimensional ◽  
The North

Episodes of sea-floor spreading recorded by the North Atlantic basement

1971 ◽  
Vol 12 (3) ◽  
pp. 211-234 ◽  
Author(s):  
P.R. Vogt ◽  
G.L. Johnson ◽  
T.L. Holcombe ◽  
J.G. Gilg ◽  
O.E. Avery
Keyword(s):  
North Atlantic ◽  
Sea Floor ◽  
The North ◽  
The North Atlantic ◽  
Sea Floor Spreading

Data assimilation with the ensemble Kalman filter in a numerical model of the North Sea

2016 ◽  
Vol 66 (8) ◽  
pp. 955-971 ◽  
Author(s):  
Stéphanie Ponsar ◽  
Patrick Luyten ◽  
Valérie Dulière
Keyword(s):  
Kalman Filter ◽  
Numerical Model ◽  
Data Assimilation ◽  
North Sea ◽  
Ensemble Kalman Filter ◽  
The North ◽  
The North Sea

AN OCEAN BOTTOM, D COMPONENT MAGNETOMETER

Geophysics ◽  
1967 ◽  
Vol 32 (6) ◽  
pp. 978-987 ◽  
Author(s):  
J. H. Filloux
Keyword(s):  
Electric Field ◽  
Dynamic Range ◽  
North Pacific Ocean ◽  
Mooring Line ◽  
Ocean Bottom ◽  
Magnetic Fluctuations ◽  
Sea Floor ◽  
The North ◽  
Low Profile ◽  
Optical Lever

The distribution of electric conductivity in the crustal and upper mantle materials beneath the ocean may be estimated from measurements of the relationship between the magnetic fluctuations and the induced electric field at the ocean bottom. Techniques for the measurement of the electric field have been available for a few years. The horizontal magnetic fluctuations to the magnetic east, usually called D, can be recorded with a simple instrument placed on the sea floor at any depth. This instrument uses a magnet pair which orients itself among the main horizontal field H. The coupling of the magnets to the mirror of a sensitive optical lever is delayed until the instrument has reached the bottom. There is no need to perform any orientation in situ. The instrument resolves 1 γ or less and has a dynamic range of at least 2500 γ. It is capable of recording for approximately 40 days at the rate of 30 readings per hour on self‐contained dry cells. It is lowered to the sea floor and recovered by means of a mooring line connected to a surface float. The low‐profile supporting tripod is effectively decoupled from the mooring tackle as evidenced by the lack of motion of the magnetometer during 26 days of recording. A sample of the observed fluctuations on the floor of the North Pacific Ocean, 600 km offshore, is given.

scholarly journals The North Atlantic Eddy Heat Transport and Its Relation with the Vertical Tilting of the Gulf Stream Axis

2017 ◽  
Vol 47 (6) ◽  
pp. 1281-1289 ◽  
Author(s):  
A. M. Treguier ◽  
C. Lique ◽  
J. Deshayes ◽  
J. M. Molines
Keyword(s):  
Numerical Model ◽  
Heat Transport ◽  
North Atlantic ◽  
Gulf Stream ◽  
Mean Flow ◽  
The North ◽  
Spatial Shift ◽  
Eddy Heat Flux ◽  
Eddy Heat Transport ◽  
The North Atlantic

AbstractCorrelations between temperature and velocity fluctuations are a significant contribution to the North Atlantic meridional heat transport, especially at the northern boundary of the subtropical gyre. In satellite observations and in a numerical model at ⅞° resolution, a localized pattern of positive eddy heat flux is found northwest of the Gulf Stream, downstream of its separation at Cape Hatteras. It is confined to the upper 500 m. A simple kinematic model of a meandering jet can explain the surface eddy flux, taking into account a spatial shift between the maximum velocity of the jet and the maximum cross-jet temperature gradient. In the Gulf Stream such a spatial shift results from the nonlinear temperature profile and the vertical tilting of the velocity profile with depth. The numerical model suggests that the meandering of the Gulf Stream could account, at least in part, for the large eddy heat transport (of order 0.3 PW) near 36°N in the North Atlantic and for its compensation by the mean flow.

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