Letteratura scientifica selezionata sul tema "Sediment"
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Articoli di riviste sul tema "Sediment"
1
Kamiludin, Udaya, e Yudi Darlan. "KARAKTERISTIK PASIR DI PANTAI DAN LEPAS PANTAI BINUANGEUN, LEBAK-BANTEN". JURNAL GEOLOGI KELAUTAN 11, n. 2 (16 febbraio 2016): 79. http://dx.doi.org/10.32693/jgk.11.2.2013.235.
Testo completoAbstract (sommario):
Pasir merupakan sesuatu penomena yang menarik karena padanya tersimpan misteri bagaimana partikel itu terendapkan sesuai dengan lingkungannya, apakah merupakan pasir pada lingkungan marin, pantai atau sungai. Untuk mengetahui lingkungan pengendapan tersebut maka dilakukan identifikasi karakteristik pasirnya. Metoda penelitan meliputi pengambilan contoh, analisis besar butir, klasifikasi nomenklatur sedimen dan parameter statistik. Klasifikasi nomenklatur sedimen pada endapan sedimen permukaan dasar laut, gisik pasir, tanggul gisik dan endapan sungai aktif didapat pasir sebanyak, masing masing 19, 35, 15 dan 3 percontoh. Ke empat jenis endapan mempunyai ukuran butir rata-rata (mean) relatif seragam, yaitu pasir halus (2 Φ - 3 Φ). Begitu juga ukuran pasirnya berupa pasir halus dengan kurva distribusi persen berat fluktuatif. Perbedaan terlihat pada ukuran pasir sedimen permukaan dasar laut dan sedimen sungai aktif, selain pasir halus hadir pula pasir menengah (1 Φ - 2 Φ). Klasifikasi lingkungan pasir memperlihatkan bahwa ke empat endapan mempunyai kesesuaian lingkungan pengendapan disertai adanya muatan partikel yang mengkasar dan menghalus dengan bentuk kurtosis leptokurtik dan platikurtik monomodal. Sumber batuan asal sedimen diduga berasal dari hasil abrasi batugamping terumbu yang tersingkap di pantai bagian tengah daerah penelitian dan pengerjaan ulang batuan gunungapi dan batuan sedimen asal volkanik yang umum tersingkap di utara daerah penelitian.
Kata Kunci : Sedimen permukaan dasar laut, gisik pasir, tanggul gisik, sedimen sungai aktif, lingkungan pengendapan pasir, sumber batuan.
Sand sediment is something interesting phenomenon because the sand is stored in the mystery of how the sand particles sedimented according to the deposition environment, what is the sand that was deposited in marine, beach or river environment. The identification of sand sediment characteristic is used for the determination of depositional environment. Study methods include sediment sampling, grain size analysis of sediment, sediment nomenclature classification and computing the statistical parameters. Sediment nomenclature classification results on the seafloor surface sediment, sand beach sediment, berm sediment and active stream sediment derived as much sand sediment types, respectively 19, 35, 15 and 3 samples. The four types of sediment deposition that has mean is relatively uniform, which falls on the fine sand (Φ 2 - Φ 3). While the size of sand fall in the fine sand with fluctuating weight percent distribution curve. The difference was in the size of the sand on the sea floor sediments and active stream sediments, in addition to fine sand also present medium sand (Φ1 - Φ2). Sand environment classification showed that all four types of the sediments have suitability depositional environment be accompanied excess coarse and fine particles with curved kurtosis leptokurtic and platykurtic monomodal. Source rocks of the sediments probably derived from the abrasion of coralreef limestone exposed in the central coast of study area and rework volcanic rocks and sedimentary rocks of volcanic origin are commonly exposed in the northern of study area.
Key words: Seafloor surface sediment, sand beach, berm, active stream sediment, sand depositional environment, source rocks.
2
Ooi, Jieun Lin, Lee Woen Ean, Bashar S. Mohammed, M. A. Malek, Leong Sing Wong, Chao Wei Tang e He Qing Chua. "Study on the Properties of Compressed Bricks Using Cameron Highlands Reservoir Sediment as Primary Material". Applied Mechanics and Materials 710 (gennaio 2015): 25–29. http://dx.doi.org/10.4028/www.scientific.net/amm.710.25.
Testo completoAbstract (sommario):
This research is to investigate the properties of compressed building bricks producedfrom Cameron Highlands reservoir sediment. The particle size distribution of the sediments are graded as silt and sand. The sediments used were as total replacement of the normal soils used in the compressed soil bricks. This paper presents the compilation of experimental brick properties; compressive strength, water absorption, microstructure and heavy metal leachingof the compressed sediment bricks. The experimental results shows that increasing use of reservoir sediments decrease the compressive strength andincrease the water absorption. The heavy metal concentrations of the leachates from the leaching test are all within the regulatory limits. The optimum mix is derives from the compressive strength and the water absorption in which in this research is Mix 4, 70% sedimenta, 20% sedimentb and 10% cement,complying with ASTM C129 – Non Load Bearing Bricks [1].
3
Hasteti, Mita, Tri Apriadi e Winny Retna Melani. "Komposisi dan Kepadatan Mikroplastik di Sedimen Perairan Pulau Los, Kota Tanjungpinang, Kepulauan Riau". Journal of Marine Research 12, n. 3 (23 maggio 2023): 455–64. http://dx.doi.org/10.14710/jmr.v12i3.36691.
Testo completoAbstract (sommario):
Penelitian ini dilatarbelakangi oleh adanya keberadaan sampah plastik di sedimen perairan Pulau Los, Kota Tanjungpinang. Tujuan dari penelitian ini adalah untuk mengetahui komposisi dan kepadatan jenis mikroplastik serta perbedaan antara nilai rata-rata kepadatan mikroplastik pada setiap jenis sedimen di Pulau Los, Kota Tanjungpinang. Penelitian ini dilaksanakan pada bulan Mei-Juli 2022. Pengambilan sampel menggunakan metode Random Sampling di 30 titik dengan satu kali pengambilan sampel. Sampel sedimen diambil menggunakan transek kuadran ukuran 0,5x0,5 m pada kedalaman 5 cm. Sampel sedimen kemudian dikeringkan dengan oven, setelah kering sampel diberi larutan H2O2 30% untuk menghancurkan bahan organik serta larutan ZnCl2 untuk memisahkan partikel mikroplastik dengan non-plastik. Selanjutnya sampel diidentifikasi di laboratorium menggunakan mikroskop stereo. Komposisi mikroplastik di sedimen berpasir dan pasir berlumpur terdiri dari jenis fiber, fragmen, dan film sedangkan untuk jenis foam dan pelet tidak dijumpai dalam penelitian ini. Kepadatan mikroplastik jenis fiber mempunyai nilai rata-rata yang lebih tinggi di sedimen pasir berlumpur yaitu sebesar 6,75 partikel/25 gram sedimen kering dibandingkan dengan sedimen berpasir yang hanya sebesar 5,83 partikel/25 gram sedimen kering. Fragmen merupakan jenis mikroplastik yang nilai rata-rata kepadatannya hampir mendekati antara sedimen pasir berlumpur yang memperoleh nilai sebesar 5,58 partikel/25 gram sedimen kering dengan sedimen berpasir sebesar 5,22 partikel/25 gram sedimen kering. Mikroplastik jenis film mempunyai nilai rata-rata kepadatan yang lebih tinggi di sedimen pasir berlumpur yaitu sebesar 5,08 partikel/25 gram sedimen kering dibandingkan dengan sedimen berpasir yang hanya sebesar 3,83 partikel/25 gram sedimen kering. Hasil uji Kruskal Wallis dan uji ANOVA menunjukkan tidak terdapat perbedaan secara nyata antara kepadatan jenis mikroplastik pada sedimen berpasir dan pasir berlumpur di Pulau Los, Kota Tanjungpinang. This research is based on the presence of plastic waste in the sediments of the waters of Los Island, Tanjungpinang City. The objective of this study was to determine the composition and density of microplastics along the differences between the average values of microplastic density in each type of sediment on Los Island, Tanjungpinang City.This research was conducted in May-July 2022. Sampling used the Random Sampling method at 30 points with one sampling. Sediment samples were taken using a 0,5x0,5 m quadrant transect at a depth of 5 cm. The sediment sample was then dried in an oven, after drying the sample was given a 30% H2O2 solution to destroy organic matter and a ZnCl2 solution to separate microplastic particles from non-microplastics. The samples were then identified in the laboratory using a stereo microscope. The composition of microplastics in sandy and muddy sand sediments consisted of fiber, fragments, and films, while foam and pellet types were not found in this study. The density of fiber-type microplastics has a higher average value in muddy sand sediments, which is 6,75 particles/25 grams of dry sediment compared to sandy sediments which are only 5,83 particles/25 grams of dry sediment. Fragments are a type of microplastic with an average density value close to that of silty sand sediments with a value of 5,58 particles/25 grams of dry sediment and sandy sediments of 5,22 particles/25 grams of dry sediment. Film-type microplastics have a higher average density value in muddy sand sediments namely 5,08 particles/25 grams of dry sediment compared to sandy sediments which are only 3,83 particles/25 grams of dry sediment. The results of the Kruskal Wallis test and the ANOVA test showed that there was no significant difference between the densities of microplastic species in sandy and muddy sand sediments on Los Island, Tanjungpinang City.
4
Hasteti, Mita, Tri Apriadi e Winny Retna Melani. "Komposisi dan Kepadatan Mikroplastik di Sedimen Perairan Pulau Los, Kota Tanjungpinang, Kepulauan Riau". Journal of Marine Research 12, n. 3 (23 maggio 2023): 455–64. http://dx.doi.org/10.14710/jmr.v12i3.36691.
Testo completoAbstract (sommario):
Penelitian ini dilatarbelakangi oleh adanya keberadaan sampah plastik di sedimen perairan Pulau Los, Kota Tanjungpinang. Tujuan dari penelitian ini adalah untuk mengetahui komposisi dan kepadatan jenis mikroplastik serta perbedaan antara nilai rata-rata kepadatan mikroplastik pada setiap jenis sedimen di Pulau Los, Kota Tanjungpinang. Penelitian ini dilaksanakan pada bulan Mei-Juli 2022. Pengambilan sampel menggunakan metode Random Sampling di 30 titik dengan satu kali pengambilan sampel. Sampel sedimen diambil menggunakan transek kuadran ukuran 0,5x0,5 m pada kedalaman 5 cm. Sampel sedimen kemudian dikeringkan dengan oven, setelah kering sampel diberi larutan H2O2 30% untuk menghancurkan bahan organik serta larutan ZnCl2 untuk memisahkan partikel mikroplastik dengan non-plastik. Selanjutnya sampel diidentifikasi di laboratorium menggunakan mikroskop stereo. Komposisi mikroplastik di sedimen berpasir dan pasir berlumpur terdiri dari jenis fiber, fragmen, dan film sedangkan untuk jenis foam dan pelet tidak dijumpai dalam penelitian ini. Kepadatan mikroplastik jenis fiber mempunyai nilai rata-rata yang lebih tinggi di sedimen pasir berlumpur yaitu sebesar 6,75 partikel/25 gram sedimen kering dibandingkan dengan sedimen berpasir yang hanya sebesar 5,83 partikel/25 gram sedimen kering. Fragmen merupakan jenis mikroplastik yang nilai rata-rata kepadatannya hampir mendekati antara sedimen pasir berlumpur yang memperoleh nilai sebesar 5,58 partikel/25 gram sedimen kering dengan sedimen berpasir sebesar 5,22 partikel/25 gram sedimen kering. Mikroplastik jenis film mempunyai nilai rata-rata kepadatan yang lebih tinggi di sedimen pasir berlumpur yaitu sebesar 5,08 partikel/25 gram sedimen kering dibandingkan dengan sedimen berpasir yang hanya sebesar 3,83 partikel/25 gram sedimen kering. Hasil uji Kruskal Wallis dan uji ANOVA menunjukkan tidak terdapat perbedaan secara nyata antara kepadatan jenis mikroplastik pada sedimen berpasir dan pasir berlumpur di Pulau Los, Kota Tanjungpinang. This research is based on the presence of plastic waste in the sediments of the waters of Los Island, Tanjungpinang City. The objective of this study was to determine the composition and density of microplastics along the differences between the average values of microplastic density in each type of sediment on Los Island, Tanjungpinang City.This research was conducted in May-July 2022. Sampling used the Random Sampling method at 30 points with one sampling. Sediment samples were taken using a 0,5x0,5 m quadrant transect at a depth of 5 cm. The sediment sample was then dried in an oven, after drying the sample was given a 30% H2O2 solution to destroy organic matter and a ZnCl2 solution to separate microplastic particles from non-microplastics. The samples were then identified in the laboratory using a stereo microscope. The composition of microplastics in sandy and muddy sand sediments consisted of fiber, fragments, and films, while foam and pellet types were not found in this study. The density of fiber-type microplastics has a higher average value in muddy sand sediments, which is 6,75 particles/25 grams of dry sediment compared to sandy sediments which are only 5,83 particles/25 grams of dry sediment. Fragments are a type of microplastic with an average density value close to that of silty sand sediments with a value of 5,58 particles/25 grams of dry sediment and sandy sediments of 5,22 particles/25 grams of dry sediment. Film-type microplastics have a higher average density value in muddy sand sediments namely 5,08 particles/25 grams of dry sediment compared to sandy sediments which are only 3,83 particles/25 grams of dry sediment. The results of the Kruskal Wallis test and the ANOVA test showed that there was no significant difference between the densities of microplastic species in sandy and muddy sand sediments on Los Island, Tanjungpinang City.
5
Kurnio, Hananto, e Noor C. D. Aryanto. "THE RELATIONSHIP OF SEAFLOOR SURFACIAL SEDIMENT WITH SEABOTTOM MORPHOLOGY OF LEMKUTAN ISLAND WATER, WEST KALIMANTAN". BULLETIN OF THE MARINE GEOLOGY 28, n. 2 (15 febbraio 2016): 13. http://dx.doi.org/10.32693/bomg.28.2.2013.56.
Testo completoAbstract (sommario):
Sea floor sediment surrounding Lemukutan Island, West Kalimantan is distributed on rather steep sea bottom morphology. The steep bottom seems a continuation of rugged morphology of the island, especially at the northeast and southeast parts. This paper discusses the relation between sediment grain sizes and the steepness of sea bottom morphology. Grain size analyses of sediment shows various sediment types such as slightly gravelly muddy sand, gravel mostly composed of coral and lithic, and gravelly sand. Results show that steepness of sea bottom slope control deposited sediment types, coarse fraction sediments tend to settle on the area of high slope angle as at the northeastern and southeastern of the island. On the other hand, high energy marine environment, such as at the sea in front of north headland of Lemukutan Island, tends to accumulate coarse sediments. High percentages of organism shells in marine sediments obviously are deposited at those two domains.
Keywords: sea bottom morphology, sediment, Lemukutan Island, West Kalimantan.
Sedimen dasar laut sekitar Pulau Lemukutan, Kalimantan Barat tersebar pada morfologi yang agak curam. Permukaan dasar laut yang curam tampaknya merupakan kelanjutan morfologi kasar pulau tersebut, terutama pada bagian timur laut dan tenggara. Makalah ini membahas hubungan antara besar butir sedimen dan kecuraman morfologi dasar laut. Analisis besar butir sedimen memperlihatkan jenis sedimen yang bervariasi, seperti pasir lumpuran sedikit krikilan, kerikil umumnya terdiri koral dan fragmen batuan, dan pasir krikilan. Hasil kajian menunjukkan bahwa kecuraman lereng dasar laut mengontrol tipe sedimen yang diendapkan, sedimen fraksi kasar cenderung mengendap pada daerah dengan sudut lereng tinggi seperti di bagian timur laut dan tenggara Pulau Lemukutan. Di samping itu, lingkungan laut enerji tinggi, seperti di bagian utara pulau, cenderung mengakumulasikan sedimen kasar. Prosentase tinggi dari cangkang organisma dalam sedimen laut tampak nyata diendapkan pada kedua lingkungan tersebut.
Kata kunci: morfologi dasar laut, sedimen, Pulau Lemukutan, Kalimantan Barat.
6
Hernawan, Undang, e Kris Budiono. "KARAKTERISTIK DAN DISTRIBUSI LUMPUR SIDOARJO SEPANJANG SUNGAI, ESTUARI DAN PERAIRAN PORONG". JURNAL GEOLOGI KELAUTAN 11, n. 2 (16 febbraio 2016): 91. http://dx.doi.org/10.32693/jgk.11.2.2013.234.
Testo completoAbstract (sommario):
Semburan lumpur Sidoarjo (Lusi) di daerah Porong menambah fungsi Sungai Porong menjadi sarana untuk mengalirkan lumpur ke arah laut, karena kemampuan tanggul – tanggul penghalang di sekitar lokasi semburan sangat terbatas. Kondisi ini berdampak pula terhadap terbawanya lumpur lapindo ke perairan Porong. Penelitian ini bermaksud untuk mengetahui sebaran sedimen di sungai, muara dan perairan sekitar Porong terutama yang bersumber dari luapan lumpur Sidoarjo.
Materi yang digunakan dalam penelitian ini adalah sebanyak 30 sampel sedimen hasil sampling yang diambil di lokasi sungai – muara sungai Porong dan 30 sampel sedimen permukaan dasar laut di perairan sekitar muara sungai Porong.
Distribusi umum sebaran sedimen di perairan Porong menunjukkan sedimen lumpur ditemukan di pinggir sungai dan sedimen pasir ditemukan di bagian tengah sungai. Distribusi umum sedimen dasar perairan di sekitar muara Porong berupa pasir, lempung dan lempung lanau pasiran. Hasil analisis mikroskopik dan SEM menunjukkan bahwa sedimen yang berasal dari luapan lumpur Sidoarjo ditemukan di sepanjang aliran Sungai Porong sampai muara, namun belum ditemukan di perairan luar sekitar muara Porong. Sedimen Lusi yang sampai ke muara Porong berukuran butir sampai 2,5 mikron. Deskripsi megaskopis menunjukkan sedimen Lusi pasir - kerikil umumnya berbentuk pipih (halus– agak halus). Hasil SEM menunjukkan bahwa sedimen yang berasal dari lumpur Sidoarjo umumnya seragam dan didominasi berupa smectite. Berbeda dengan sedimen sungai, hasil SEM yang diperoleh dari sampel laut yang menunjukkan sedimennya beragam, berupa montmorilonite, kaolinite dan illite.
Kata Kunci : Sedimen, Porong, lumpur Sidoarjo
The Sidoarjo mudflow in the Porong area increases the functions of Porong River as media to drain the muds towards the sea, because the ability of embankments in the area as a barrier is very limited. This condition intends to determine the presence and distribution of sediment in rivers, estuaries and waters originating from the Lusi mudflow.
The materials used in this study are the sediment sampling results as many as 30 samples taken from the river and off the river mouth and 30 samples of sea surface sediments in the surrounding waters.
General distribution of sediments in the Porong River shows the form of mud sediments are generally found in the riverside and sandy sediment found in the middle of the river, while the distribution of sediments in waters Porong form of sand, clay and sandy silt clay. The results of microscopic and SEM analysis showed that the sediments derived from the Lusi mudflow found along Porong River till estuaries, but they have not reach surrounding water of Porong estuary. The Lusi sediment that reached the estuary Porong sized to 2.5 micron. General megascopic description show the shape of the Lusi sediment as sand-gravel is a flat-shaped (rounded - sub rounded). SEM results showed that the sediments derived from the Lusi is generally uniform and dominated by smectite. In contrast to stream sediments, the SEM results obtained from marine sediment samples show a variety of sediments, in the form of montmorillonite, caolinite and illite.
Key words: Sediment, Porong, Sidoarjo, Mud Overflow (Lusi)
7
Hamidah, Siti, Sugeng Widada, Sri Yulina Wulandari e Lilik Maslukah. "Sebaran Sedimen Dasar Di Perairan Teluk Awur Jepara, Jawa Tengah". Buletin Oseanografi Marina 13, n. 2 (3 maggio 2024): 261–70. http://dx.doi.org/10.14710/buloma.v13i2.53955.
Testo completoAbstract (sommario):
Berbagai aktivitas manusia di Pesisir Teluk Awur yang berupa kegiatan pertambakan, pariwisata, pemukiman, pertanian dan operasional kampus pendidikan (Marine Science Teckno Park/MSTP) berpengaruh terhadap proses geomorfologi pantai dan masukan bahan pencemar ke perairan. Proses geomorfologi pantai dan sebaran bahan pencemar tersebut dipengaruh oleh sedimen yang tertranport dan terendapkan sebagai sedimen dasar. Oleh karena itu perlu dipetakan sebaran sedimen dasar di Perairan Teluk Awur tersebut yang ditetapkan sebagai tujuan dalam penelitian ini. Penelitian ini dilakukan pada Bulan Oktober 2022 dengan mengambil 30 titik sampling yang ditentukan secara semi purposive. Sampel sedimen dasar diambil dengan alat sediment grab dan dianalisis granulometri secara gravimetri. Nama sedimen ditentukan dengan metode Segitiga Shepard. Data pendukung yang digunakan dalam penelitian ini meliputi data arus (hasil model), data angin, pasang surut (Ipasoet), batimetri, dan peta Rupa Bumi Indonesia. Hasil penelitian menunjukkan sedimen dasar di Perairan Teluk Awur berupa pasir, lanau, lanau pasiran, dan lempung. Sedimen pasir mendominasi jenis sedimen yang ada dengan sebaran terutama pada area dekat dengan pantai. Hasil analisis diagram hjulstrom menunjukan bahwa sedimen ini terendapkan pada kecepatan arus 0,0044-0,18 m/s. Pada saat penelitian arus bergerak menuju laut dengan kecepatan 0,003-0,14 m/s. Hal ini mengindikasikan bahwa proses pengendapan sedimen dasar yang dijumpai sudah berlangsung sebelum pengambilan sampel sedimen dilakukan. Various human activities on the Gulf of Awur Coast in the form of aquaculture, tourism, settlement, agriculture, and educational campus operations (Marine Science Teckno Park / MSTP) affect the coastal geomorphological process and the input of pollutants into the water. The geomorphological process of the beach and the distribution of pollutants are influenced by transported sediments and immersion as seabed sediments. Therefore, it is necessary to map the distribution of seabed sediments in the waters of Teluk Awur which is set as the goal of this study. This study was conducted in October 2022 by taking 30 semi-purposive determined sampling points. Base sediment samples were taken with a sediment grab device and gravimetrically analyzed granulometrically. The name of the sediment is determined by the Shepard Triangle method. The supporting data used in this study include current data (model results), wind data, tides (Ipasoet), bathymetry, and maps of Indonesia. The results showed bottom sediments in the waters of Teluk Awur in the form of sand, silt, sand silt, and clay. Sand sediments dominate the type of sediment that exists with distribution, especially in areas close to the coast. The results of the Hjulstrom diagram analysis show that this sediment was deposited at a current speed of 0.0044-0.18 m/s. At the time of the study, the current moved towards the sea at a speed of 0.003-0.14 m/s. This indicates that the deposition process of the bottom sediment found was already underway before sediment sampling was carried out
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Najamuddin, Najamuddin, Irmalita Tahir, Rustam E. Paembonan e Inayah Inayah. "Pengaruh Karakteristik Sedimen terhadap Distribusi dan Akumulasi Logam Berat Pb dan Zn di Perairan Sungai, Estuaria, dan Pantai". Jurnal Kelautan Tropis 23, n. 1 (13 febbraio 2020): 1. http://dx.doi.org/10.14710/jkt.v23i1.5315.
Testo completoAbstract (sommario):
The purpose of the study was to analyze the effect of surface sediment characteristics including texture, organic carbon content, and redox potential of sediments on the distribution and accumulation of heavy metals Pb and Zn in three different water zones of each river, estuary and coast. Sediment texture was determined by pipette method, organic carbon content in sediments using Walkley and Black method, redox potential of sediments measured by Eh Meter, and concentrations of heavy metals Pb and Zn in sediments with Atomic Absorption Spectrophotometer with graphite furnace system. The results showed that the distribution and accumulation pattern of heavy metals Pb was similar to Zn where the highest concentration was in the coastal waters zone and the lowest was in the estuary waters zone. Sediment texture in the three zones of the dominant was sand. The percentage of organic carbon content in sediments ranges from 1.63-3.25% and the sediment redox potential was classified as reduction and transition zones. The parameters of texture, organic carbon content, and sediment redox potential have a significant influence on the distribution and accumulation of heavy metals Pb and Zn in sediments in all three water zones. Tujuan penelitian adalah menganalisis pengaruh karakteristik sedimen permukaan meliputi tekstur, kandungan karbon organik, dan potensial redoks sedimen terhadap distribusi dan akumulasi logam berat Pb dan Zn di tiga zona perairan berbeda masing-masing sungai, estuaria, dan pantai. Tekstur sedimen ditentukan dengan metode pipet, kandungan karbon organik dalam sedimen dengan metode Walkley and Black, potensial redoks sedimen diukur dengan Eh Meter, dan konsentrasi logam berat Pb dan Zn dalam sedimen dengan Spektrofotometer Serapan Atom dengan sistem graphite furnace. Hasil penelitian menunjukkan pola distribusi dan akumulasi logam berat Pb serupa dengan Zn dimana konsentrasi tertinggi di zona perairan pantai dan terendah zona perairan estuaria. Tekstur sedimen pada tiga zona perairan dominan berupa fraksi pasir (sand). Persentase kandungan karbon organik dalam sedimen berkisar antara 1,63-3,25 % dan nilai potensial redoks sedimen termasuk kategori zona reduksi dan transisi. Parameter tekstur, kandungan karbon organik, dan potensial redoks sedimen memberikan pengaruh nyata terhadap distribusi dan akumulasi logam berat Pb dan Zn dalam sedimen pada ketiga zona perairan.
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Setiady, Deny, e Ediar Usman. "KANDUNGAN MINERAL PADA SEDIMEN PANTAI DAN LAUT, HUBUNGANNYA DENGAN BATUAN SUMBER DI PESISIR KABUPATEN REMBANG, JAWA TENGAH". JURNAL GEOLOGI KELAUTAN 9, n. 3 (16 febbraio 2016): 135. http://dx.doi.org/10.32693/jgk.9.3.2011.206.
Testo completoAbstract (sommario):
Sedimen di sepanjang pantai Kabupaten Rembang terdiri atas sedimen muda (aluvial) dan sedimen tua (breksi dan batugamping). Sedimen muda merupakan sedimen lepas dan terdapat di daerah sedimentasi. Sedimen tua berupa sedimen kompak yang secara fisik mempunyai resisitensi tinggi terhadap abrasi
Batuan yang terdapat di kawasan pesisir adalah: pasir kuarsa, andesit, tras kaolin, batugamping, batubara dan lempung. Peta sebaran sedimen dasar laut perairan Kabupaten Rembang, menunjukkan dominasi endapan pasir, lanau (pasir halus) dan lanau pasiran (pasir halus - kasar).
Kandungan mineral yang terdapat di perairan Kabupaten Rembang terdiri dari: magnetit, pirit, hematit, zirkon, ilmenit diopsid, augit, hornblende, kuarsa, biotit, muskovit dan dolomit
Kata Kunci: sedimen, mineral, Rembang
The coastal sediment along the coastal of Rembang District consists of young sediment (alluvium) and old sediment (breccias and limestones). Young sediment is placer sediment that occupies the sedimentation area. Old sediment is massive sediment that has a high resistance to abrasion
Rocks content in the coastal zone area consist of quarzt sand, andesite, caoline, limestone, trass, coal and clay. Seafloor surficial sediments map of the Rembang water area shows the domination of sand deposits, silt (fine sand) and sandy silt (fine to medium sand).
Mineral content in Rembang waters area consists of magnetites, pyrites, hematites, zircons, ilmenite diopsides, augitse, hornblendas, quartzs, biotitse, muskovites and dolomites.
Keywords: sediment, mineral, Rembang
10
Suryono, Chrisna Adhi, Ibnu Pratikto e Ajeng Rusmaharani. "Logam Berat Anthropogenik Pb dan Cu pada Lapisan Sedimen Permukaan dan Dasar Muara Sungai di Kota Semarang, Jawa Tengah Indonesia". Jurnal Kelautan Tropis 22, n. 1 (13 aprile 2019): 87. http://dx.doi.org/10.14710/jkt.v22i1.3223.
Testo completoAbstract (sommario):
Semarang coastal areas as specially on river down stream have been develop to industrial, dumpping areas and human settlement. Its will be caused increasing sedimentation and anthropogenic heavy metals accumulation in sediments. In order to assess Pb, and Cu on diferent layers of sediments on three down stream rivers on Semarang, samples of surface and bed sediment were collected for analyzed by ICPMS. The result showed that the heavy metal of Pb on bed layer was higher than Pb on surface sediment, on the other hand Cu on surface sediment was higher than Cu on bed sediments. Unfraternally the heavy metal concentration on surface and beds sediments they do not correlation with totals organic carbon and combination silt and clay in sediment on three down stream rivers on Semarang. Wilayah pesisir Semarang terutama di daerah muara sungai telah berkembang menjadi kawasan industri, penimbunan dan hunian. Hal tersebut menyebabkan peningkatan sedimentasi dan akumulasi antropogenik logam berat dalam sedimen. Untuk mengetahui logam berat Pb dan Cu dalam permukaan dan dasar sedimen di tiga muara sungai Semarang. Maka sampel pada permukaan dan dasar sedimen diambil dan dianalisa dengan ICPMS. Hasil pengukuran menunjukan bahwa konsentrasi logam Pb pada lapisan dasar lebih tinggi dari pada lapisan permukaan sedimen, sebaliknya konsentrasi logam Cu pada lapisan permukaan lebih tinggi dari pada lapisan dasar sedimen. Namun keseluruhan antropogenik logam berat Pb dan Cu pada lapisan permukaan maupun bawah sedimen tidak ada korelasinya dengan kandungan total bahan organik karbon dan kombinasi antara silt dan clay dalam sedimen di ketiga mura sungai di Semarang.
Tesi sul tema "Sediment"
1
Bornemann, André, Thomas C. Brachert e Werner Ehrmann. "SEDIMENT 2011 Sediments: Archives of the Earth System: SEDIMENT 2011Sediments: Archives of the Earth System". ?, 2011. https://ul.qucosa.de/id/qucosa%3A11218.
Testo completoAbstract (sommario):
This volume comprises ninety-one contributions to the Sediment 2011 conference of the Central European section of the Society for Sedimentary Geology (SEPM-CES) and the Geologische Vereinigung (GV) at the University of Leipzig held in June 2011. The central theme of this meeting was “Sediments: Archives of the Earth System” in order to bring together young and established researchers from all fields of soft-rock geology and beyond to shape a stimulating interdisciplinary program on the role of sediments in understanding the System Earth and the evolution of paleoenvironments and climate through time.
2
Sherwood, Christopher R. "Measurements and modeling of suspended-sediment transport on the northern California continental shelf /". Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/11014.
Testo completo
3
Guerra, Josefa Varela. "Interannual variability of nearbed sediment flux and associated physical processes on the Eel River shelf, Northern California, USA /". Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/11000.
Testo completo
4
Suedel, Burton C. (Burton Craig). "Sediment Characteristics and Bioavailability of Sorbed Neutral Organic Compounds". Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc500652/.
Testo completoAbstract (sommario):
Several sediment characteristics were analyzed to determine their suitability for use as potential normalization factors for the bioavailability of neutral organic compounds sorbed to sediments. Percent organic carbon, cation exchange capacity and particle surface area were measured sediment characteristics that varied sufficiently to encompass the range in observed sediment toxicity. Laboratory sediment toxicity test data using fluoranthene suggest that there is no biologically significant correlation between sediment toxicity and sediment characteristics (organic carbon, cation exchange capacity, particle size distribution, particle surface area). Fluoranthene amended sediments with similar organic carbon contents do not yield similar toxicities due to sorbed fluoranthene and thus do not support the organic carbon normalization approach for evaluating sediment quality or for sediment criteria development.
5
Franz, Claudia. "Sediments in a fast urbanizing catchment in Central Brazil – an analysis of anthropogenic impacts on sediment geochemistry and sediment sources". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-171959.
Testo completoAbstract (sommario):
Over the last decades, fast urban sprawl and accelerated land use change have drastically increased the pressure on water resources of the capital Brasília and its surrounding area. The water supply of the metropolitan region of Brasília depends largely on surface water collected in reservoirs. There are increasing concerns regarding water shortages due to sediment aggradations, and of water quality due to geochemical modification of sediments from human activities. The complexity of various socio-environmental problems, such as non-point source pollution, soil erosion or silting of water reservoirs within urban catchments evoked the need for more effective and sustainable strategies to use land and water resources. Accurate identification and management of sediment source areas, however, is hampered by the lack of reliable information on the primary sources of sediment and on sediment geochemistry. The fingerprinting approach and a multivariate mixing model have been proven to be a valuable sediment source tracing technique across the globe and for various environmental settings. A multi-component methodology, including geochemical and geophysical analyses of representative sediment source and alluvial sediment samples, statistical analyses and a multivariate mixing model, was utilized to obtain the impact of different anthropogenic activities on sediment and water quality and to identify the major sources of sediments within the Lago Paranoá catchment. However, sediment source appointment and geochemical signatures of sediments in urbanized tropical regions, such as the Lago Paranoá catchment in the DF, are hampered by severe challenges; (i) the presence of various types of land use and heavy urbanized areas, (ii) large differences between sub-catchments and (iii) model structural failures in representing the sediment source contribution within urban tropical river basins. The present cumulative thesis addresses the challenges in geochemical analyses of different types of source and alluvial sediments, and in sediment source appointment for the Lago Paranoá catchment and it´s five sub-catchments. The aim of the study was to assess the distribution of chemical elements and geochemical/physical properties of potential sediment sources in the Lago Paranoá catchment. Principal component analysis and hierarchical cluster analysis were used to investigate the influence of different land use types on the geochemistry of sediments. Geochemical fingerprints of anthropogenic activities were developed based on the results of the cluster analysis grouping. The anthropogenic input of land use specific geochemical elements was examined and quantified by the calculation of enrichment factors using the local geological background as reference. The existing findings suggest a strong relationship between land use and quantifiable features of sediment geochemistry, and identified the combined effects of specific anthropogenic activities and metal enrichment in source and alluvial sediments. Through comparison of the geochemical signature of potential sediment sources and alluvial sediments of the Lago Paranoá and sub-catchments, the relative contribution of land use specific sediment sources to the sediment deposition of the main water reservoir were estimated. This assessment indicated that urban land use had the greatest responsibility for recent silting in the Lago Paranoá. In fact, one of the most challenging issues within the scope of IWRM is to quantify the contribution of sediment sources within fast urbanizing, mixed used, tropical catchments. Therefore, statistically verified composite fingerprints and a modified multivariate mixing model have been used to identify the main land use specific sources of sediment deposited in the silting zones of the Lago Paranoá, Central Brazil. Because of the great variability of urban land use types within the Lago Paranoá sub-catchments, the fingerprinting approach was additionally undertaking for the Riacho Fundo sub-catchment. This sediment source tracing technique provides valuable information on the response of the main sediment sources in a fast growing agglomeration with respect to specific land uses and human activities and allowed to examine the uncertainty in model prediction. The main contributions from individual source types (i.e. surface materials from residential areas, constructions sites, road deposited sediment, cultivated areas, pasture, farm tracks, woodland and natural gullies) varied between the whole catchment and the Riacho Fundo sub-catchment, reflecting the different proportions of land uses. The sediments deposited in the silting zones of the Lago Paranoá originate largely from urban sources (85±4%). Areas with (semi-) natural vegetation and natural gullies contribute 10±2% of the sediment yield. Agricultural sites have only a minor sediment contribution of about 5±4 % within the whole catchment. However, there is no mechanism considered to reflect seasonality in the tropics, e.g. phenological change of the vegetation between wet and dry season, or and temporal changes in land use, e.g. construction sites, which influence model estimates. Nevertheless, the study reveals that even 58 % of the land remains in (semi-) natural state, the main sediment source are urban areas. Beside the analyses of sediments, it was found that metal concentrations in surface water of the main tributaries to the Lago Paranoá are generally low, but show seasonal variability. Terrestrial inputs of metals occur during the rainy season and depend largely on the influence of urban land use. The present thesis shows the great influence of anthropogenic activities on sediment generation, and at least to some degree, on sediment associated pollution loads. It depicts region specific challenges, but also provides essential information to guide management responses towards more effective sediment source-reduction strategiesIm Gebiet des Bundesdistrikts Brasilien ist ein erheblicher Druck auf die Wasserressourcen zu beobachten, der vorwiegend durch starkes Bevölkerungswachstum, ungeplante Suburbanisierung und Landnutzungsänderungen innerhalb der letzten Jahrzehnte ausgeübt wird. Die Wasserversorgung der jungen Hauptstadt Brasília und seiner suburbanen Räume wird im Wesentlichen durch in Stauseen gesammeltes Oberflächenwasser gewährleistet. Durch die voranschreitende Ausdehnung von urbanen und landwirtschaftlichen Flächen spielen insbesondere Sedimenteinträge in die Stauanlagen sowie sedimentgebundene Stoffbelastungen durch anthropogene Aktivitäten für die verfügbare Wasserquantität und Wasserqualität eine bedeutende Rolle. Damit verbundene negative Umweltauswirkungen sowie die daraus resultierenden sozioökonomische Konsequenzen erfordern daher dringend wirksame und nachhaltige Strategien im Land-und Wasserressourcenmanagement. Eine deutliche Minimierung der Sedimenteinträge und Stoffbelastungen in das Gewässernetz ist jedoch nur mit Kenntnis der Primärquellen von Sedimenten und der Sedimentgeochemie zu erreichen. Der "Fingerprinting"-Ansatz und der Einsatz eines "Multivariate Mixing-Modell", sind geeignete Werkzeuge um den Einfluss anthropogener Eingriffe in das landschaftsökologische Prozessgefüge der Sedimentgenerierung zu klären. Die vorliegende kumulative Dissertation zeigt dies anhand der Anwendung einer Multikomponenten-Methodik. Diese beinhaltet sowohl geochemische und geophysikalische Analysen repräsentativer Sedimentproben der Sedimentquellen und der finalen Senken (Auenbereiche und Bereiche der Zuflüsse zum Lago Paranoá) als auch umfassende statistische Analysen sowie die Anwendung eines modifizierten "Multivariate Mixing-Modells". Der Einsatzder "Fingerprinting" Methodik in urbanen Einzugsgebieten der wechselfeuchten Tropen, wie das des Lago Paranoá in Zentralbrasilien, ist jedoch mit erheblichen Herausforderungen verbunden. Das betrifft insbesondere die Heterogenität der Landnutzungstypen innerhalb einer Landnutzungsklasse (urban, landwirtschaftlich, semi-natürlich) und die Unterschiede der Landnutzungsanteile zwischen den einzelnen Teileinzugsgebieten als auch modelstruktureller Unzulänglichkeiten bei der Sedimentherkunftsberechnung für urbane Einzugsgebiete. Eine Hauptkomponentenanalyse und hierarchische Clusteranalyse wurden verwendet, um den Einfluss der verschiedenen Landnutzungstypen auf der Geochemie der Sedimente zu untersuchen. Geochemische Fingerprints verschiedener anthropogener Aktivitäten wurden auf der Grundlage der Ergebnisse der Clusteranalyse ("grouping") entwickelt. Die Berechnung von Anreicherungsfaktoren ("Enrichmentfactors") auf Basis der gemessenen Elementgehalte, mit dem lokalen geologischen Hintergrundwerten als Referenz, ermöglichte die Quantifizierung des Einflusses der verschiedenen Landnutzungen auf die Metalleinträge in die Sedimente. Die vorhandenen Ergebnisse legen nahe, dass eine direkte Beziehung zwischen Landnutzung und quantifizierbarer Merkmale der Sedimentgeochemie existiert. Ein Vergleich der geochemischen Signatur von potentiellen Sedimentquellen und mit jenen der alluvialen Sedimente unterstützt die Hypothese, dass urbane Gebiete einen beachtlichen Beitrag zur Sedimentgenerierung und letztendlich zur Sedimentablagerung in den Auen- und Zuflussbereichen des Lago Paranoá leisten. Da diese relative Betrachtung von Elementzusammensetzungen der Sedimente keine quantitativen Aussagen zur Bedeutung der einzelnen Sedimentquellen zulässt, wurden statistisch verifizierte "composite fingerprints" und ein an urbane Bedingungen modifiziertes multivariate mixing-Modell (Hybrid) entwickelt und angewendet. Die Modellberechnungen erfolgten für das gesamte Einzugsgebiet des Lago Paranoá und separat für das Riacho Fundo Teileinzugsgebiet, welches Die angepassten Modellschätzungen zeigten, dass die in den Verlandungszonen des Lago Paranoá abgelagerten Sedimente weitgehend aus urbane Räumen (85 ± 4%) generiert wurden. Dahingegen stammen nur 10 ± 2% der Sedimente aus Gebieten mit (semi-) natürlicher Vegetation, obwohl 58 % der gesamten Einzugsgebietsfläche des Lago Paranoá stets (semi-) natürliche Verhältnisse aufweist. Landwirtschaftliche Gebiete haben generell nur einen geringen Anteil von etwa 5 ± 4% am Sedimenteintrag. Die Unterschiede in den Sedimentbeträgen sowohl zwischen den verschiedenen Sedimentquelltypen als auch zwischen den einzelnen Teileinzugsgebieten scheinen maßgeblich von den Flächennutzungsanteilen (urban, landwirtschaftlich, semi-natürlich) in dem jeweiligen Teileinzugsgebiet abhängig zu sein. Trotz umfassender Probennahme, Probenanalytik, Modellanpassung und Unsicherheitsanalyse sind die Ergebnisse nur für den Beprobungszeitraum, für die analysierte Stoffgruppe (organische Stoffeinträge sind im Rahmen dieser Dissertation nicht erfasst) und für die ausgewählten Lokalitäten repräsentativ. Zeitliche Einflussgrößen wie die Saisonalität in den Tropen oder Änderungen der Landnutzung, wie z.B. temporäre Baustellen, konnten mit den hier verwendeten Methoden nicht erfasst werden. Um die hohe räumliche und zeitliche Variabilität der Sedimentdynamik und eine deutliche Minimierung der Sedimenteinträge in das Gewässernetz zu erzielen, sind demnach die Einrichtung und der Betrieb eines langfristigen Monitoring-Netzwerkes für Sedimente im Einzugsgebiet des Lago Paranoá von hoher Priorität. Die vorliegende Dissertation bringt neue Einsichten in verschiedene wichtige Aspekte der geochemischen Beeinflussung von Sedimenten durch anthropogene Aktivitäten und liefert erstmalig quantitative Aussagen zu den Sedimentquellgebieten im Einzugsgebiet des Lago Paranoá. Sie stellt regionsspezifische Herausforderungen heraus, liefert gleichzeitig aber auch wichtige Informationen zu Sedimentbelastungen und -Einträgen und damit einen wichtigen Beitrag als Entscheidungsunterstützung im Rahmen eines Sedimentmanagementplans
6
Tarekegn, Tesfaye Haimanot. "Downstream suspended sediment dynamics of reservoir sediment flushing". Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/12963.
Testo completoAbstract (sommario):
Reservoir sediment flushing is increasingly considered beneficial to reduce sedimentation of reservoirs and maintain sediment supply downstream of impounded rivers. Nevertheless, flushing of the accumulated sediments downstream of the dam also bears numerous negative impacts. In this study, first the most important downstream impacts of fine sediment releases of flushing were identified based on previously published research of twenty case studies in eleven countries. The results showed that the long-term as well as short term biological and physical impacts decreased with distance from the dam. The temporal scale of impacts on macro-invertebrates could span from few weeks or a month to several months while the effect on fish could last for a number of years. The impacts on downstream vegetation dynamics is driven by many years of flushing activities. The study also enabled proposing generic management strategies aimed to reduce the impacts. Second, fine sediment transport in coarse immobile bed, which is a common phenomenon downstream of dams during flushing releases, dam removal and also in many mountain and canyon rivers, was investigated. Particularly, the dynamics of the downstream erosion and transport of fine sediments released during sediment flushing was investigated based on a series of flume experiments that were carried out in immobile gravel bed and using a one-dimensional (1-D) suspended sediment transport model developed in the present study. In the framework of the flume experiment, firstly gravel bed roughness, porosity and roughness density were exclusively extracted from gravel surface elevation data in which developing a spatial filter to overcome elevation errors was carried out. Secondly a new technique to acquire fine sediment erosion in immobile coarse bed in running water condition was developed. The method proved to be the back bone of all fine sediment erosion experiments conducted in the present study and could be used for similar studies. This study presents a first work of direct measurement of erosion rate and characterizing its spatial heterogeneity in gravel bed. The experimental data of erosion rate of fine sediments showed that it varied spatially with high erosion rate on the stoss side of gravels and less on the lee side conforming to sweeps and ejections characteristics in coherent flow structure of gravel bed flows. Erosion rate was significantly affected by increase in roughness of immobile gravel bed with high erosion rate noticed when sand level was reduced although the effect on stream-wise velocity was not significant. The vertical profile of erosion rate was found to decrease linearly and showed an exponential decay in time in the gravel matrix. Third, a new non-equilibrium erosion rate relation is proposed. Drag force profile in the interfacial sublayer of clean gravel bed was found to be scaled well with roughness density and allowed predicting the effective shear stress distribution available for fine sediment entrainment with an empirical equation. vi The new relation is a modified version of the pick-up rate function of van Rijn (1984b) in which the predicted shear stress in the roughness layer was implemented. The most important finding was that if the shear stress distribution in the interfacial sublayer is predicted, a relation for sand bed condition can be applied to predict fine sediment erosion rate in immobile gravel bed. This approach is conceptually superior to previous approaches where erosion rate in sand bed condition was scaled empirically for various fine sediment bed level within the interfacial sublayer. Finally, the effect of the interaction between hydrodynamic and sediment wave dynamics of sediment flushing on spatial pattern of sediment deposition was investigated. The 1-D model was developed to include major processes observed in sediment flushing: sediment wave celerity correction, variable bed roughness, bed exchange in immobile bed, hindered settling velocity and rough bed porosity. The proposed erosion rate relation showed encouraging results when implemented in the 1-D model. The wave celerity factor did not show significant effect on the spatial lag in immobile bed condition although was significant in sand bed condition. Variable bed roughness modified both the flow field and sediment deposition in which larger length of sediment deposit was noted. The immobile bed porosity allowed modelling clogged depth of fine sediments. The model was also found to be very valuable to investigate flushing scenarios that reduce significant deposition through the analysis of the dependence of deposition on peak-to-base flow and intermittence of releases. The highest peak-to-base flows produced the longest and thickest region of deposition while those with the lowest ratio produced the shortest and thinnest. A single flushing release followed by clear water release reduced area or length of sediment deposition more than intermittent flushing followed by inter- and post-flushing clear water releases. In the latter case, the peak of concentration reduced but remained higher for longer duration than the former, which suggests that a large quantity of clear water release has to be available. Overall, the present research represents a step forward in understanding relevant processes involved in the downstream transport of fine sediments released during sediment flushing and the associated impacts that can help the development of better management strategies and predictive tools.
7
Tarekegn, Tesfaye Haimanot. "Downstream suspended sediment dynamics of reservoir sediment flushing". Doctoral thesis, Università degli studi di Trento, 2015. https://hdl.handle.net/11572/369112.
Testo completoAbstract (sommario):
Reservoir sediment flushing is increasingly considered beneficial to reduce sedimentation of reservoirs and maintain sediment supply downstream of impounded rivers. Nevertheless, flushing of the accumulated sediments downstream of the dam also bears numerous negative impacts. In this study, first the most important downstream impacts of fine sediment releases of flushing were identified based on previously published research of twenty case studies in eleven countries. The results showed that the long-term as well as short term biological and physical impacts decreased with distance from the dam. The temporal scale of impacts on macro-invertebrates could span from few weeks or a month to several months while the effect on fish could last for a number of years. The impacts on downstream vegetation dynamics is driven by many years of flushing activities. The study also enabled proposing generic management strategies aimed to reduce the impacts. Second, fine sediment transport in coarse immobile bed, which is a common phenomenon downstream of dams during flushing releases, dam removal and also in many mountain and canyon rivers, was investigated. Particularly, the dynamics of the downstream erosion and transport of fine sediments released during sediment flushing was investigated based on a series of flume experiments that were carried out in immobile gravel bed and using a one-dimensional (1-D) suspended sediment transport model developed in the present study. In the framework of the flume experiment, firstly gravel bed roughness, porosity and roughness density were exclusively extracted from gravel surface elevation data in which developing a spatial filter to overcome elevation errors was carried out. Secondly a new technique to acquire fine sediment erosion in immobile coarse bed in running water condition was developed. The method proved to be the back bone of all fine sediment erosion experiments conducted in the present study and could be used for similar studies. This study presents a first work of direct measurement of erosion rate and characterizing its spatial heterogeneity in gravel bed. The experimental data of erosion rate of fine sediments showed that it varied spatially with high erosion rate on the stoss side of gravels and less on the lee side conforming to sweeps and ejections characteristics in coherent flow structure of gravel bed flows. Erosion rate was significantly affected by increase in roughness of immobile gravel bed with high erosion rate noticed when sand level was reduced although the effect on stream-wise velocity was not significant. The vertical profile of erosion rate was found to decrease linearly and showed an exponential decay in time in the gravel matrix.
Third, a new non-equilibrium erosion rate relation is proposed. Drag force profile in the interfacial sublayer of clean gravel bed was found to be scaled well with roughness density and allowed predicting the effective shear stress distribution available for fine sediment entrainment with an empirical equation. The new relation is a modified version of the pick-up rate function of van Rijn (1984b) in which the predicted shear stress in the roughness layer was implemented. The most important finding was that if the shear stress distribution in the interfacial sublayer is predicted, a relation for sand bed condition can be applied to predict fine sediment erosion rate in immobile gravel bed. This approach is conceptually superior to previous approaches where erosion rate in sand bed condition was scaled empirically for various fine sediment bed level within the interfacial sublayer. Finally, the effect of the interaction between hydrodynamic and sediment wave dynamics of sediment flushing on spatial pattern of sediment deposition was investigated. The 1-D model was developed to include major processes observed in sediment flushing: sediment wave celerity correction, variable bed roughness, bed exchange in immobile bed, hindered settling velocity and rough bed porosity. The proposed erosion rate relation showed encouraging results when implemented in the 1-D model. The wave celerity factor did not show significant effect on the spatial lag in immobile bed condition although was significant in sand bed condition. Variable bed roughness modified both the flow field and sediment deposition in which larger length of sediment deposit was noted. The immobile bed porosity allowed modelling clogged depth of fine sediments. The model was also found to be very valuable to investigate flushing scenarios that reduce significant deposition through the analysis of the dependence of deposition on peak-to-base flow and intermittence of releases. The highest peak-to-base flows produced the longest and thickest region of deposition while those with the lowest ratio produced the shortest and thinnest. A single flushing release followed by clear water release reduced area or length of sediment deposition more than intermittent flushing followed by inter- and post-flushing clear water releases. In the latter case, the peak of concentration reduced but remained higher for longer duration than the former, which suggests that a large quantity of clear water release has to be available.
Overall, the present research represents a step forward in understanding relevant processes involved in the downstream transport of fine sediments released during sediment flushing and the associated impacts that can help the development of better management strategies and predictive tools.
8
Tarekegn, Tesfaye Haimanot. "Downstream suspended sediment dynamics of reservoir sediment flushing". Doctoral thesis, University of Trento, 2015. http://eprints-phd.biblio.unitn.it/1646/1/TesfayeTarekegn_PhDThesis_2015.pdf.
Testo completoAbstract (sommario):
Reservoir sediment flushing is increasingly considered beneficial to reduce sedimentation of reservoirs and maintain sediment supply downstream of impounded rivers. Nevertheless, flushing of the accumulated sediments downstream of the dam also bears numerous negative impacts. In this study, first the most important downstream impacts of fine sediment releases of flushing were identified based on previously published research of twenty case studies in eleven countries. The results showed that the long-term as well as short term biological and physical impacts decreased with distance from the dam. The temporal scale of impacts on macro-invertebrates could span from few weeks or a month to several months while the effect on fish could last for a number of years. The impacts on downstream vegetation dynamics is driven by many years of flushing activities. The study also enabled proposing generic management strategies aimed to reduce the impacts. Second, fine sediment transport in coarse immobile bed, which is a common phenomenon downstream of dams during flushing releases, dam removal and also in many mountain and canyon rivers, was investigated. Particularly, the dynamics of the downstream erosion and transport of fine sediments released during sediment flushing was investigated based on a series of flume experiments that were carried out in immobile gravel bed and using a one-dimensional (1-D) suspended sediment transport model developed in the present study. In the framework of the flume experiment, firstly gravel bed roughness, porosity and roughness density were exclusively extracted from gravel surface elevation data in which developing a spatial filter to overcome elevation errors was carried out. Secondly a new technique to acquire fine sediment erosion in immobile coarse bed in running water condition was developed. The method proved to be the back bone of all fine sediment erosion experiments conducted in the present study and could be used for similar studies. This study presents a first work of direct measurement of erosion rate and characterizing its spatial heterogeneity in gravel bed. The experimental data of erosion rate of fine sediments showed that it varied spatially with high erosion rate on the stoss side of gravels and less on the lee side conforming to sweeps and ejections characteristics in coherent flow structure of gravel bed flows. Erosion rate was significantly affected by increase in roughness of immobile gravel bed with high erosion rate noticed when sand level was reduced although the effect on stream-wise velocity was not significant. The vertical profile of erosion rate was found to decrease linearly and showed an exponential decay in time in the gravel matrix.
Third, a new non-equilibrium erosion rate relation is proposed. Drag force profile in the interfacial sublayer of clean gravel bed was found to be scaled well with roughness density and allowed predicting the effective shear stress distribution available for fine sediment entrainment with an empirical equation. The new relation is a modified version of the pick-up rate function of van Rijn (1984b) in which the predicted shear stress in the roughness layer was implemented. The most important finding was that if the shear stress distribution in the interfacial sublayer is predicted, a relation for sand bed condition can be applied to predict fine sediment erosion rate in immobile gravel bed. This approach is conceptually superior to previous approaches where erosion rate in sand bed condition was scaled empirically for various fine sediment bed level within the interfacial sublayer. Finally, the effect of the interaction between hydrodynamic and sediment wave dynamics of sediment flushing on spatial pattern of sediment deposition was investigated. The 1-D model was developed to include major processes observed in sediment flushing: sediment wave celerity correction, variable bed roughness, bed exchange in immobile bed, hindered settling velocity and rough bed porosity. The proposed erosion rate relation showed encouraging results when implemented in the 1-D model. The wave celerity factor did not show significant effect on the spatial lag in immobile bed condition although was significant in sand bed condition. Variable bed roughness modified both the flow field and sediment deposition in which larger length of sediment deposit was noted. The immobile bed porosity allowed modelling clogged depth of fine sediments. The model was also found to be very valuable to investigate flushing scenarios that reduce significant deposition through the analysis of the dependence of deposition on peak-to-base flow and intermittence of releases. The highest peak-to-base flows produced the longest and thickest region of deposition while those with the lowest ratio produced the shortest and thinnest. A single flushing release followed by clear water release reduced area or length of sediment deposition more than intermittent flushing followed by inter- and post-flushing clear water releases. In the latter case, the peak of concentration reduced but remained higher for longer duration than the former, which suggests that a large quantity of clear water release has to be available.
Overall, the present research represents a step forward in understanding relevant processes involved in the downstream transport of fine sediments released during sediment flushing and the associated impacts that can help the development of better management strategies and predictive tools.
9
Kularatne, Kottabogoda Angidigedera Samantha Rangajeewa. "Factors influencing sediment re-suspension and cross-shore suspended sediment flux in the frequency domain". University of Western Australia. School of Environmental Systems Engineering, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0005.
Testo completoAbstract (sommario):
[Truncated abstract] With rapidly increasing population densities along coastlines and rising global sea levels, coastal protection has become a major concern for coastal communities. Predicting sediment transport in nearshore regions, however, is one of the most challenging tasks faced by coastal researchers in designing coastal structures or beach nourishment schemes. Although nearshore sediment transport mainly occurs in the longshore direction, cross-shore sediment transport is crucial in determining the shoreline evolution and beach morphology . . . This study investigated the factors influencing sediment re-suspension and cross-shore suspended sediment flux in the frequency domain through a series of field measurements conducted at several different locations and a numerical model. Only oscillatory flow components were examined and the mean flow components were not considered. Although many different factors such as cross-shore location with respect to breaker line, significant wave height to water depth ratio (Hs/h), normalised horizontal velocity skewness (
10
Sell, Karen S. "Temporal influences of seasonal hypoxia on sediment biogeochemistry in coastal sediments". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/1142.
Testo completoAbstract (sommario):
Bottom water hypoxia and its influence on the environment have been topics of increasing concern for many coastal regions. This research addresses both spatial and temporal variability in sediment biogeochemistry at the southeastern region of Corpus Christi Bay, TX, where seasonal (summer) hypoxia occurs. Traditional techniques for determination of a variety of dissolved and solid components, benthic oxygen demand, and sulfate reduction rates were augmented by measurements using solid state microelectrodes to simultaneously determine concentrations of dissolved O2, Mn2+, Fe2+, and [sigma]H2S in multiple small - interval (1 mm) depth profiles of sediment microcosms. Oxygen concentrations in the overlying water were manipulated in the sediment microcosms and electrode depth profile measurements were made over ~ 500 hours of experimentation. Laboratory and field microelectrode results were in good agreement for both norm - oxic and anoxic time periods. Results indicated that iron (Fe2+) and sulfide ([sigma]H2S) were the redox reactive species in these sediments. During hypoxic conditions an upward migration of dissolved Fe2+and [sigma]H2S through the sediment column and, at times, into the overlying water was observed as the dissolved oxygen concentrations decreased. A corresponding decline in the vertical extent of these redox species occurred when the overlying water was re-oxidized. When both dissolved iron and sulfide coexisted, FeS minerals were formed in the sediment, preventing sulfide diffusion into the overlying water. However, after a long duration of hypoxia (> 200 hours) this buffering capacity was exceeded and both iron and sulfide penetrated into the overlying waters. Results indicated that iron may have a greater influence on hypoxia than sulfide because its concentration in the overlying waters during induced hypoxia was an order of magnitude greater than those of sulfide. Moreover, in the southeastern region of the Bay, where mixing was minimal and the water column was shallow, the sediments alone may have caused the onset of the hypoxic event in a relatively short time period (< 5.5 days). These results demonstrated that in shallow marine environments where seasonal hypoxia occurs, such as Corpus Christi Bay, the associated major changes that take place in the sediment biogeochemistry must be included in benthic - pelagic models for overlying water hypoxia.
Libri sul tema "Sediment"
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Rose, William J. Sediment transport, particle size, and loads in North Fish Creek in Bayfield County, Wisconsin, water years 1990-91. Madison, Wis: U.S. Dept. of the Interior, U.S. Geological Survey, 1996.
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Banasik, Kazimierz. Model sedymentogramu wezbrania opadowego w małej zlewni rolniczej. Warszawa: Wydawn. SGGW, 1994.
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Partheniades, Emmanuel. Cohesive sediments in open channels: Properties, transport, and applications. Burlington: Butterworth-Heinemann, 2009.
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1951-, Gray John R., Glysson G. Douglas e Geological Survey (U.S.), a cura di. Introduction to suspended-sediment sampling. [Reston, Va.]: U.S. Geological Survey, 2005.
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Burkham, D. E. An approach for appraising the accuracy of suspended-sediment data. Washington [D.C.]: U.S. G.P.O., 1985.
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Burkham, D. E. An approach for appraising the accuracy of suspended-sediment data. [Reston, Va.?]: Dept. of the Interior, U.S. Geological Survey, 1985.
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Neuendorf, Josefine. Urine Sediment. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-15911-5.
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Burt, Timothy P., e Robert J. Allison, a cura di. Sediment Cascades. Chichester, UK: John Wiley & Sons, Ltd, 2010. http://dx.doi.org/10.1002/9780470682876.
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Heininger, Peter, e Johannes Cullmann, a cura di. Sediment Matters. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14696-6.
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Ginsberg, Silvia Susana. Sediment transport. Rijeka, Croatia: INTECH, 2014.
Cerca il testo completoCapitoli di libri sul tema "Sediment"
1
Boyd, Claude E. "Sediment". In Bottom Soils, Sediment, and Pond Aquaculture, 219–52. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-1785-6_7.
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Gooch, Jan W. "Sediment". In Encyclopedic Dictionary of Polymers, 652. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_10420.
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Riedler, P., e Karl Donabaum. "Sediment". In The Alte Donau: Successful Restoration and Sustainable Management, 69–85. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-93270-5_7.
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Bährle-Rapp, Marina. "Sediment". In Springer Lexikon Kosmetik und Körperpflege, 497. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_9250.
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Schmieder, Robert William. "Sediment". In Heard Island, 345–64. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-20343-5_15.
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Pikelj, Kristina, e Nina Furčić. "Impact of cliff erosion on marine sediment composition - indication of local coastline evolution (Vrgada Island, Croatia)". In Proceedings e report, 462–68. Florence: Firenze University Press, 2020. http://dx.doi.org/10.36253/978-88-5518-147-1.46.
Testo completoAbstract (sommario):
Erosive coastal cliffs formed in soft-rocks sediments along the generally carbonaceous Eastern Adriatic are a rare feature. The one from the Vrgada Island gave rise to the idea that local seabed surface sediment may reflect the composition of the cliff sediment. First results of sedimentological analyses showed that sediment samples collected on both sides of the cliff contain material eroded mostly from the eastern side of the cliff. Subsequent longshore drift caused by dominant waves likely sort fallen material, transporting its finer fractions to the northern side and further into the sea.
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Cullmann, Johannes, e Peter Heininger. "Introduction". In Sediment Matters, 1–10. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14696-6_1.
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Lalk, Petra, Marlene Haimann e Helmut Habersack. "Application of a New Monitoring Strategy and Analysis Concept of Suspended Sediments in Austrian Rivers". In Sediment Matters, 153–67. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14696-6_10.
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Netshitungulwana, Robert, Bisrat Yibas, Christoph Gauert, Danie Vermeulen, Obed Novhe e Tshepa Motlakeng. "Investigation of the Metal Contamination in the Upper Olifants Primary Catchment by Using Stream Sediment Geochemistry, Witbank Coalfield, South Africa". In Sediment Matters, 169–84. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14696-6_11.
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Wild, Thomas B., e Daniel P. Loucks. "An Approach to Simulating Sediment Management in the Mekong River Basin". In Sediment Matters, 187–99. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14696-6_12.
Testo completoAtti di convegni sul tema "Sediment"
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Mohr, Henning, Scott Draper e David White. "Free Field Sediment Mobility on Australia’s North West Shelf". In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11490.
Testo completoAbstract (sommario):
Under cyclonic conditions, sediment on the North West Shelf (NWS) of Australia may become mobile in shallow water due to classical sediment transport or local liquefaction, and this can affect, for example, the on-bottom stability of subsea pipelines. In this paper, three calcareous sediments sampled from the NWS are analysed, together with realistic metocean data, to illustrate this potential for sediment mobility on the NWS. Specifically, experiments are performed in a recirculating flume (known as an O-Tube) to measure the erosional behaviour and an additional series of experiments are performed using a shaking table, on which each of the sediments have been liquefied and excess pore pressure measurements recorded to back calculate the consolidation coefficient. Soil characterisation data, threshold velocity measurements and shaking table results have then combined to illustrate the potential for sediment mobility for each of the NWS sediments. Best practice models are used to calculate wave and current combined shear stress at the seabed and excess pore pressure accumulation. We find that for these sediments, freshly deposited in laboratory samples, mobility due to sediment transport or liquefaction is very likely in cyclonic conditions on the NWS. Liquefaction is most likely for loosely packed silt, whilst sediment transport is most likely for sand. However, we also show that in more extreme cyclonic conditions there are a subset of sediments that can become mobile due to both sediment transport and liquefaction.
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Catianis, Irina, Adriana Maria Constantinescu, Dan-Lucian Vasiliu, Bogdan-Adrian Ispas e Dumitru Grosu. "PHYSICAL AND CHEMICAL CHARACTERISTICS OF TATARU AND MERHEI LACUSTRINE SEDIMENTS, FROM THE DANUBE DELTA, ROMANIA". In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/5.1/s20.042.
Testo completoAbstract (sommario):
The quality and quantity of delta lakes� sediment depend on fluvial input and in-situ bio-geo-chemical processes. The present study investigates the quality of lacustrine sediments collected from two lakes - Tataru and Merhei, situated in different hydrodynamic environments within the Danube Delta, Romania, but both connected to fluvial input of water and sediment of the Danube. The following physical and chemical analyses have been carried out on several lake-bottom sediment samples: the main lithological components (total organic matter-TOM%, total carbonates-CAR% and siliciclastic fraction-SIL%), particle size analysis and technophilic element contents. The lithological analysis reveals a considerable variation related to the TOM%, CAR% and SIL% fractions. From this perspective, the investigated lacustrine sediments are generally characterized as organic-rich sediments (endogenous input). The grain size analysis shows the predominance of sandy silt sediments in both lakes. The data regarding the content of technophilic elements in the bed-sediment samples is given in comparison with their natural geochemical background reference value and their acceptable limits provided by the national reference standard. The general characterization of the investigated sediments reveals slight differences among the two investigated lakes in terms of the sediment input from the Danube River. The acquired results contribute to improve the knowledge about physical and chemical characteristics of lacustrine sediments and to plan management strategies of the deltaic lakes for future conservation perspectives, considering the great international importance of the Danube Delta Biosphere Reserve.
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Zhang, Ning, Anpeng He, Jeff Corbino, Paul Schroeder e Johnathan Bolton. "The Impacts of Confined Disposal Facilities on Calcasieu Ship Channel Sedimentation". In ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16160.
Testo completoAbstract (sommario):
The confined disposal facilities (CDFs) are the areas along Calcasieu Ship Channel to store dredged sediments from the ship channel. As the sediments settle in the CDFs, the low concentration sediment flows are discharged into the open water adjacent to the CDFs. The paper demonstrates flow and sediment transport characteristics in the open water due to the CDF discharge. The sediment distributions in all three dimensions in the water are revealed. The lake current effects were also investigated. A commercial CFD package ANSYS-FLUENT is used to simulate all cases in this study.
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Ong, Muk Chen, Lars Erik Holmedal e Dag Myrhaug. "Numerical Computation of Suspended Sediment Around a Marine Pipeline Close to the Flat Seabed". In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49111.
Testo completoAbstract (sommario):
The purpose of this paper is to investigate suspended sediment transport around a marine pipeline near the seabed by solving the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with the standard k-ε model. High Reynolds number flow simulations are considered in the present study. The suspended sediments are seeded upstream of the pipeline. Particle trajectories of the suspended sediments downstream of the pipeline have been visualized by using a Lagrangian approach. Effects of the gap (i.e. the normal distance between the pipeline and the seabed) and the sediment weight (i.e. taking into account sediment settling velocity) have been investigated and discussed.
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Maherzi, Walid, Mahfoud Benzerzour, Nor-Edine Abriak e Ahmed Senouci. "Marine Dredging Sediments Valorization in Self-Compacting Concretes". In The 2nd International Conference on Civil Infrastructure and Construction. Qatar University Press, 2023. http://dx.doi.org/10.29117/cic.2023.0086.
Testo completoAbstract (sommario):
Rock and eroded soil are transported by wind, tide, and human action (development works), and deposited as sediment in ports, estuaries, and rivers. The sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. As a result, dredging is necessary to reduce sediment deposits and restore the natural environment for proper port functioning. At the national level, the maintenance of the 6,500-kilometer French coastline would require the extraction of about fifty million cubic meters of marine sediment every year. These dredged sediments have been used in civil engineering applications for about ten years, in order to reduce their economic and environmental impact. The proposed study addresses the potential use of sediments to produce accropode blocks for maritime public works applications. It consists in developing concrete mixtures using dredged marine sediment treated to protect against erosion. A study of material characterization, optimization of the composition of the concrete formulation, as well as a determination of the mechanical, physical and durability properties of the concrete were necessary to validate the technical feasibility of this new solution. Around 700 small accropode blocks were then prepared to better analyze the structure stability against swell effects. The obtained results show that the sediments could not produce Self Compacting Concrete (SCC). However, sediment treatment with 6% by weight of cement has enabled the production of SCC. It is worth noting that the use of superplasticizer was essential to ensure concrete workability. Increasing the cement percentage has also improved the composite workability. Finally, a concrete compressive strength greater than 40 MPa has been achieved when using 300 kg/m3 of treated sediments.
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Vrålstad, Torbjørn, Ragnhild Skorpa e Arild Saasen. "Rheological Properties of Barite Sediments in Water-Based Drilling Fluids". In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78695.
Testo completoAbstract (sommario):
When a drilling fluid column remains static over a timeframe of several years, the drilling fluid separates into different sediment phases due to gravity separation. These heavy sediments, entitled “settled barite”, are the cause of significant operational problems several years after drilling. An important problem caused by settled barite occurs when performing casing cut-and-pull operations during slot recovery and well abandonment: the casing is “stuck” due to the sediments in the annulus outside the casing. The consistency and rheological properties of the sediments determine how easily the casing is removed. In this paper, we report a preliminary study were we have artificially prepared gravity sediment phases for two different types of water-based drilling fluids; one KCl/polymer-based fluid and one bentonite-based fluid. By studying the rheological properties of the obtained sediment phases, we see that there are considerable differences between the sediments for these different drilling fluids.
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Chechko, Vladimir, Vladimir Chechko, Boris Chubarenko e Boris Chubarenko. "SEDIMENT BALANCE OF THE VISTULA LAGOON". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b94303c55f9.63278465.
Testo completoAbstract (sommario):
Vistula Lagoon is the second largest lagoon in the Baltic Sea with maximum depth 5.2 m and average depth 2.7 m. Water volume and area are 2.3 km3 and 838 km2. Lagoon is connected with the Baltic Sea by single inlet 400 m wide and 10-12 m deep. Sediment budget estimation were made using literature sources, results of field measurements (hydrology, suspended sediment content, upper layer sediment structure, direct measurements of sedimentation in summer and winter conditions). The budget for terrigene and biogenic components of sediments were made, considering their contributions from the rivers, inflow from the Baltic Sea, coastal erosion and aerial flux, biological production within the lagoon, totally - ca. 730 thousands ton per year. Nearly half of total gain is washed out (105 and 244 thousands ton per year of terrigene and biogenic components), another half is dissolved and mineralized (biogenic component), and only 10% is deposited on the bottom, resulting in rather low sedimentation rate - 0.4 mm/year during last 100 years. Paper explain the reason of difference with estimation made in (Chubarenko&Chubarenko, 2002) and concludes that the clarification of estimates of the amounts of sediments transported from the lagoon to the Baltic Sea is a critical element for understanding the evolution of the Vistula Lagoon as a sedimentation system.
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Chechko, Vladimir, Vladimir Chechko, Boris Chubarenko e Boris Chubarenko. "SEDIMENT BALANCE OF THE VISTULA LAGOON". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b43153db8ae.
Testo completoAbstract (sommario):
Vistula Lagoon is the second largest lagoon in the Baltic Sea with maximum depth 5.2 m and average depth 2.7 m. Water volume and area are 2.3 km3 and 838 km2. Lagoon is connected with the Baltic Sea by single inlet 400 m wide and 10-12 m deep. Sediment budget estimation were made using literature sources, results of field measurements (hydrology, suspended sediment content, upper layer sediment structure, direct measurements of sedimentation in summer and winter conditions). The budget for terrigene and biogenic components of sediments were made, considering their contributions from the rivers, inflow from the Baltic Sea, coastal erosion and aerial flux, biological production within the lagoon, totally - ca. 730 thousands ton per year. Nearly half of total gain is washed out (105 and 244 thousands ton per year of terrigene and biogenic components), another half is dissolved and mineralized (biogenic component), and only 10% is deposited on the bottom, resulting in rather low sedimentation rate - 0.4 mm/year during last 100 years. Paper explain the reason of difference with estimation made in (Chubarenko&Chubarenko, 2002) and concludes that the clarification of estimates of the amounts of sediments transported from the lagoon to the Baltic Sea is a critical element for understanding the evolution of the Vistula Lagoon as a sedimentation system.
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Chi, Sang-Bum, Wonnyon Kim, Cheong-Kee Park, Chanmin Yoo, Youngtak Ko e Jai-Woon Moon. "Relationship Between Manganese Nodule Distribution and Deep-Sea Sediment Properties in the Northeastern Pacific". In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83773.
Testo completoAbstract (sommario):
In order to identify a potential relationship between the spatial distribution of Mn-nodule and deep-sea sediment properties in the Clarion-Clipperton fracture zone of the northeastern Pacific, physico-chemical properties of deep-sea sediments and photos of sea-floor are analyzed. In general, sediment types in the area show dramatic changes with latitude. Compared to the middle sector (8–12°N) covered with biogenic siliceous sediments, the northern (16–17°N) and southern (5–6°N) areas are dominated by pelagic red clays and calcareous sediments, respectively. Such a difference in sediment types probably produces regional-scale variations in Mn-nodule occurrence with latitude (5–17°N) along longitude (131.5°W). According to the photographic examination, manganese nodules are well exposed on the sea floor in the latitude of >8°N. In connection with the dominant oceanic environment, such observation indicates that calcareous sediments cover the diagenic nodules due to higher primary productivity and sedimentation rate in the latitude of <8°N. In addition, sediments in the latitude of 8–12°N show relatively high shear strength. Considering the operation of miner and environmental effect, highly consolidated B2 and C1 areas (8–12°N), showing higher nodule contents and relatively lower primary productivity, are the most plausible site for commercial mining.
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Abduev, M. A. "ANTHROPOGENIC TRANSFORMATION OF THE STOCK OF WEIGHED WEIGHTS OF THE MOUNTAIN RIVERS OF AZERBAIJAN". In Prirodopol'zovanie i ohrana prirody: Ohrana pamjatnikov prirody, biologicheskogo i landshaftnogo raznoobrazija Tomskogo Priob'ja i drugih regionov Rossii. Izdatel'stvo Tomskogo gosudarstvennogo universiteta, 2020. http://dx.doi.org/10.17223/978-5-94621-954-9-2020-60.
Testo completoAbstract (sommario):
Based on the data of network hydrometric observations over a multi-year period, the transformation of suspended sediments of mountain rivers of Azerbaijan into the stock has been estimated. To quantify the anthropogenic transformation of suspended sediment runoff, we analyzed the dependences of the average annual flow rates of suspended sediment and water, Rg = f (Qg); It was revealed that in connection with the construction of reservoirs, the natural regime of sediment runoff has radically changed.
Rapporti di organizzazioni sul tema "Sediment"
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Kuehl, Steven A. Extension of Sediment Geochronology to Coarse-Grained Sediments. Fort Belvoir, VA: Defense Technical Information Center, settembre 2005. http://dx.doi.org/10.21236/ada572615.
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Li, Honghai, Carter Rucker, Lihwa Lin e Kevin Conner. Use of sediment tracers to evaluate sediment plume at Beaufort Inlet and Adjacent Beaches, North Carolina. Engineer Research and Development Center (U.S.), aprile 2024. http://dx.doi.org/10.21079/11681/48379.
Testo completoAbstract (sommario):
This report documents a numerical modeling investigation on the transport of sediment material placed on designated disposal sites adjacent to Beaufort Inlet, North Carolina. Historical and newly collected wave and hydrodynamic data around the inlet are assembled and analyzed. The data sets are used to calibrate and validate a coastal wave, hydrodynamic and sediment transport model, the Coastal Modeling System. Model alternatives are developed corresponding to different material placement sites. Sediment transport and sediment plume distribution are evaluated within and around the immediate vicinity of the Beaufort Inlet estuarine system for a representative summer and winter month. Results of model simulations show that high flows occur along navigation channels and low flows occur outside the inlet in open ocean area. Sand materials placed in nearshore sites tend to be trapped in and move along navigation channels entering the inlet. In offshore placement sites the sediment plume shows slow spreading and no significant sand migration from its release locations. Simulations for the summer and winter month present similar distribution patterns of sediments originating from placement sites.
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Li, Honghai, Carter Rucker, Lihwa Lin e Kevin Conner. Use of sediment tracers to evaluate sediment plume at Cape Fear River Inlet and Adjacent Beaches, North Carolina. Engineer Research and Development Center (U.S.), aprile 2024. http://dx.doi.org/10.21079/11681/48380.
Testo completoAbstract (sommario):
This report documents a numerical modeling investigation on the transport of sediment material placed on designated disposal sites adjacent to Cape Fear River Inlet, North Carolina. Historical and newly collected wave and hydrodynamic data around the inlet are assembled and analyzed. The data sets are used to calibrate and validate a coastal wave, hydrodynamic, and sediment transport model, the Coastal Modeling System. Model alternatives are developed corresponding to different material placement sites. Sediment transport and sediment plume distribution are evaluated within and around the immediate vicinity of Cape Fear River Inlet estuarine system for a representative summer and a winter month. Results of model simulations show that high flows occur along navigation channels and low flows occur outside the inlet in open ocean area. Sand materials placed in disposal sites tend to be trapped in and move along navigation channel and in these offshore placement sites sediment plume shows slow spreading and no significant sand migration from its release locations. Simulations for the summer and winter month present similar distribution patterns of sediments originating from placement sites.
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Perkey, David W., Anthony M. Priestas, Jeffrey M. Corbino, Gary L. Brown, Michael A. Hartman, Danielle R. N. Tarpley e Loung Phu V. Sediment Provenance Studies of the Calcasieu Ship Channel, Louisiana : A Synopsis Report. U.S. Army Engineer Research and Development Center, luglio 2022. http://dx.doi.org/10.21079/11681/44905.
Testo completoAbstract (sommario):
To maintain the navigability of the Calcasieu Ship Channel (CSC), the US Army Corps of Engineers annually dredges millions of cubic yards of sediment from the inland channel. To assess sources of channel shoaling, a previous study examined river and bankline erosion as inputs. Results from that study accounted for approximately 20% of dredged volumes. Through the support of the Regional Sediment Management Program, a follow-up investigation reviewed prior sediment budgets, identified potential missing sediment sources, modeled potential sediment pathways, and utilized geochemical fingerprinting to discern primary shoaling sources to the channel. The missing sediment sources from the original budget include coastally derived sediment from the Gulf of Mexico and terrestrially derived sediment from Lake Calcasieu and surrounding wetlands. Results from geochemical fingerprinting of various potential sediment sources indicate the Calcasieu River and the Gulf of Mexico are primary contributors of sediment to the CSC, and sediments sourced from bankline erosion, Lake Calcasieu bed, and interior wetlands are secondary in nature. These results suggest that engineering solutions to control shoaling in the CSC should be focused on sources originating from the Gulf of Mexico and river headwaters as opposed to Lake Calcasieu, channel banklines, and surrounding wetlands.
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Perkey, David, David Yearwood, Brian McFall, Brian Harris, Christopher Hardy, Timothy Welp, Adrienne Eckstein e Zachary Tyler. Hydraulic sorting of dredged sediment in a pipeline : an evaluation of the sediment distribution pipe. Engineer Research and Development Center (U.S.), febbraio 2024. http://dx.doi.org/10.21079/11681/48219.
Testo completoAbstract (sommario):
The US Army Corps of Engineers (USACE) recently established a goal to beneficially use 70% of material dredged from the nation’s navigable waterways by the year 2030. Most of the sediments dredged by the USACE are heterogeneous mixtures of mud and sand, which can limit beneficial use of dredged material (BUDM) applications. Innovative technologies that can sort material during the dredging process are needed to help increase BUDM practices. This investigation sought to evaluate the ability of a sediment distribution pipe (SDP) to sort particles during transport in a pipeline. Field demonstrations were conducted during dredged material placements at Sturgeon Island, New Jersey. Velocity within the pipeline was found to be inadequate for efficient hydraulic sorting of fines (<75 μm) and produced inconclusive results. Small scale laboratory SDP experiments found that effluent from the SDP holes had an altered sediment texture compared to the initial slurry and that hydraulic sorting was occurring within the pipeline. However, outflow from the SDP holes was inconsistent, and typically >90% of the sediment mass was discharged out the end of the pipeline. Sorting efficiency of the SDP could not be accurately assessed in the current experimental configuration.
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Brown, Gary L., e Luong Phu V. Investigation of Sources of Sediment Associated with Deposition in the Calcasieu Ship Channel. U.S. Army Engineer Research and Development Center, luglio 2022. http://dx.doi.org/10.21079/11681/44907.
Testo completoAbstract (sommario):
The Calcasieu Ship Channel (CSC) is a deep-draft federal channel located in southwest Louisiana. It is the channelized lowermost segment of the Calcasieu River, connecting Lake Charles to the Gulf of Mexico. With support from the Regional Sediment Management Program, the US Army Corps of Engineers, New Orleans District, requested that the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, perform an investigation of the potential sources of sediment associated with dredging in the CSC. A previous study had quantified sediment from known sources, indicating that the known sediment sources contribute approximately only 21% of the volume that is regularly dredged from the channel. This technical report details the results of the current study, which employed multiple methods, including numerical analysis, to identify potential additional sources of sediment by first examining the available literature and the modeled energetics and flow pathways, and then estimating the quantities of sediment associated with these identified sources that may be contributing to the shoaling of the CSC. The results of these efforts were used to update the original sediment budget with estimates of the contributions from two additional sources: the erosion of interior wetlands and coastally derived sediments.
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Gwiazda, R., G. Wiemer, D. H. Lee e Y. H. Noh. Sediment coring. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2016. http://dx.doi.org/10.4095/297873.
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Benoit, N., e A. J. M. Pugin. Sediment thickness. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2016. http://dx.doi.org/10.4095/298888.
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Stoll, Robert D. Sediment Acoustics. Fort Belvoir, VA: Defense Technical Information Center, settembre 1997. http://dx.doi.org/10.21236/ada627985.
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Stoll, Robert D. Sediment Acoustics. Fort Belvoir, VA: Defense Technical Information Center, settembre 1999. http://dx.doi.org/10.21236/ada630275.
Testo completo