An Assessment of the Potential, Suitability and Sustainability of the Sand Mining Site in the Kemaman River Basin, Terengganu Using Acoustic Doppler Current Profiler

Sand mining from the catchment basin for building is a worldwide issue. The increasing demand for sand in the construction industry has led sand suppliers to look for alternative methods by which they can obtain source of sand from the riverbed. Floodplain and river slabs can be used as new sources of sand mining. In Sungai Kemaman, during September until March a high precipitation can cause high flow in river. This high flow can cause riverbank erosion which leads to instability of river. Therefore, river erosion can probably be reduced by identifying the potential area for sand mining. This research was conducted to analyse sand capability on floodplain and riverbed by integrating resistivity method and sediment transport loads using Acoustic Doppler Current Profiler (ADCP). Resistivity survey is used in determining the availability of potential soil at the study area and the equipment could measure subsurface profile up to 80 meters depth. Meanwhile, ADCP survey is utilized to make river profiler in term of velocity meshes and riverbed depth. The primary data collected was from 20 January 2014 to 19 February 2014. The findings found that the samples trapped in the Helly-Smith grabber were majority of the samples consisted more than 93% of gravel and sand materials and from the resistivity analysis, it is verified that the surrounding materials along the Sungai Kemaman is sandy material and high potential of the sand mining site.

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Kajian Pola Arus Laut dan Distribusi Sedimen Di Perairan Pantai Muara Kamal Jakarta Utara

Jurnal Rekayasa Hijau ◽

10.26760/jrh.v1i1.1335 ◽

2018 ◽

Vol 1 (1) ◽

Author(s):

Permana Ari Soerjawo ◽

Thonas Indra Maryanto

Keyword(s):

Current Velocity ◽

High Tide ◽

Clay Fraction ◽

Secondary Data ◽

Acoustic Doppler Current Profiler ◽

Google Earth ◽

Ocean Current ◽

Primary Data ◽

Sediment Distribution ◽

Current Profiler

ABSTRAKPola arus laut dan distribusi sedimen merupakan proses dinamika di suatu perairan yang mempunyai karakteristik berbeda-beda, sehingga berpengaruh terhadap pembentukan geomorfologi pantai di seluruh dunia. Penelitian ini bertujuan untuk mengetahui pola arus dan sedimen di perairan Pantai Muara Kamal Jakarta Utara di tahun 2012. Data yang digunakan merupakan data primer dan data sekunder, data primer meliputi data arus yang didapat dari pemasangan ADCP(Acoustic Doppler Current Profiler), data pasang surut dan sedimen perairan yang diambil dengan sedimen grab. Data sekunder berupa peta LPI (Lingkungan Pantai Indonesia) tahun 2000 skala 1:50.000 dari BIG (Badan Informasi Geospasial) dan citra satelit Google Earth tahun 2009. Hasil penelitian menunjukan bahwa kecepatan arus yang paling besar terdapat pada lapisan permukaan dengan kecepatan 0,242 m/s kearah barat daya (207,8o), kecepatan arus terkecil terdapat pada lapisan dasar yaitu 0,141 m/s kearah barat daya (207o). Hasil simulasi model hidrodinamika 2D, menunjukkan bahwa pada saat pasang arus laut mengarah ke daratan (selatan) dan pada saat surut arus laut mengarah ke laut lepas (barat laut). Berdasarkan kandungan ukuran butir sedimen di perairan Pantai Muara Kamal Jakarta Utara adalah pasir (64.98 - 72.15%) fraksi pasir tertinggi distasiun B(belakang geotekstil), lanau (24.56 - 29.36%) fraksi lanau tertinggi di stasiun C (depan geotekstil) dan Lempung (1.64 – 5.64%) fraksi lempung tertinggi di stasiun C (depan geotekstil). Kata kunci: Arus, Pantai Muara Kamal, Sedimen, model hidrodinamika 2D ABSTRACTOcean current and sediment distribution are the dynamic process that have different charactheristic and therefore influenced beach geomorfophology around the world. This research aims to understand both ocean current and sediment pattern in Muara Kamal North Jakarta in 2012. This research used primary and secondary data, primary data were consisted of current data from ADCP (Acoustic Doppler Current Profiler), tidal data and bottom sediment samples. Secondary data involved of Indonesia Coastline Environmental map of year 2000 with scale 1:50.000 from Geospatial information Agency and a satellite data from Google earth of year 2009. The results showed that greatest ocean current velocity contained in the surface layer at a speed of 0,242 m/s with to southwest direction (207.8o), the smallest current velocity was in bottom layer is 0.141 m/s with southwest directiont (207o). Based on 2D hydrodynamic model simulation indicated that when high tide ocean current was flowed to the mainland (south) when low tide the current was flowed to the open sea direction. Based on the content grain size of the sediment, the studi area consisted of sand (64.98 - 72.15%) the highest sand fraction at station B(rare of geotextile) , silt (24.56 - 29.36%) the highest silt fraction at station C (front of geotextile) andclay (1.64 – 5.64%) the highest clay fraction at station C(front of geotextile) Key Words: Current, Muara Kamal Shoreline, Sediment, 2D hydrodynamics model

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Spectral and Structure Function Estimates of Turbulence Dissipation Rates in a High-Flow Tidal Channel Using Broadband ADCPs

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-16-0131.1 ◽

2017 ◽

Vol 34 (1) ◽

pp. 5-20 ◽

Cited By ~ 9

Author(s):

Justine M. McMillan ◽

Alex E. Hay

Keyword(s):

Structure Function ◽

Dissipation Rate ◽

Acoustic Doppler Current Profiler ◽

Universal Constant ◽

Flow Speed ◽

High Flow ◽

Small Scale ◽

Order Structure ◽

Tidal Channel ◽

Current Profiler

AbstractSpectral and structure function methods are implemented to compute the dissipation rate ε from broadband, diverging-beam acoustic Doppler current profiler (ADCP) data collected at four sites in a high-flow tidal channel. This paper shows that middepth estimates of ε obtained from spectral and second-order structure function (SF2) methods are both lognormally distributed with comparable means and variances. Speed bin–averaged ε values agree to within 16%, depending on the site and tidal phase (ebb/flood). The close agreement between the two independent methods provides further support for the argument put forward by McMillan et al.: that is, that the factor-of-2 difference between shear probe and (spectral) ADCP estimates of ε was likely caused by spatial differences in turbulence levels. The agreement between the spectral and both second- and third-order structure function methods also supports the use of for the SF2 universal constant. Notably, however, the SF3 method was less robust for these data. Two additional aspects of the SF2 approach are examined in some detail: 1) the differences from upstream- and downstream-facing beams are shown to arise from the Reynolds stress and 2) the inability of the ADCP to resolve small-scale motions does not affect the estimates of ε but yields apparent Doppler noise levels that—counterintuitively—decrease with increasing flow speed and increasing dissipation rate. A modified SF2 method that accounts for the variance associated with the unresolved scales removes the flow speed dependence and yields noise level estimates that agree with the spectral values.

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