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ANALISIS PERUBAHAN GARIS PANTAI DAN PENUTUPAN LAHAN ANTARA WAY PENET DAN WAY SEKAMPUNG, KABUPATEN LAMPUNG TIMUR Mulia Purba; Indra Jaya
Jurnal Ilmu-Ilmu Perairan dan Perikanan Indonesia Vol. 11 No. 2 (2004): Desember 2004
Publisher : Institut Pertanian Bogor

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Abstract

Analisis terhadap perubahan garis pantai dan penutupan lahan di pesisir Lampung Timur, antara Way Penet dan Way Sekampung dilakukan berdasarkan citra satelit LANDSAT-TM antara tahun 1991, 1999,2001 dan 2003. Observasi dan pengukuran kondisi pantai dan gelombang di lapangan dilakukan untuk mempelajari dinamika pantai. Dari rangkaian data citra satelit tersebut ditemukan bahwa garis pantai mengalami proses erosi dan sedimentasi yang cukup nyata pada bagian-bagian pantai tertentu. Erosi yang terjadi di bagian selatan di Desa Purworedjo, misalnya, bervariasi antara 90 - 600 m dalam kurun waktu 12 tahun (1991 - 2003). Sementara itu, ke arah utara dari desa ini proses sedimentasi bervariasi antara 90 - 550 m. Ke arah utaranya lagi, garis pantai mengalami erosi, kemudian sedimentasi. Bentuk morfologi garis pantai, variasi arah angin dan karakteristik gelombang ditelaah sebagai faktor yang berperan dalam perubahan garis pantai tersebut. Intensitas perubahan dan uraian dinamika pantai yang terjadi dapat digunakan sebagai acuan dalam menentukan tindakan mitigasi ekologi yang efektif untuk melindungi daerah tersebut.Kata kunci: dinamika garis pantai, citra satelit, Lampung Timur
VARIABILITAS ANOMALI TINGGI PARAS LAUT (TPL) DAN ARUS GEOSTROPIK PERMUKAAN ANTARA L. SULAWESI, S. MAKASSAR DAN S. LOMBOK DARI DATA ALTIMETER TOPEX/ERS Mulia Purba; Agus S . Atmadipoera
Jurnal Ilmu-Ilmu Perairan dan Perikanan Indonesia Vol. 12 No. 2 (2005): Desember 2005
Publisher : Institut Pertanian Bogor

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Abstract

Fluktuasi anomali tinggi paras laut (TPL) dari data altimeter TOPEX/ERS2 selama 4 tahun (April1998 - Maret 2002) sepanjang lintasan barat aliran Arus Lintas Indonesia (ARLINDO) antara L. Sulawesi, S. Makassar dan S. Lombok ditelaah dengan menggunakan analisis deret waktu. Fluktuasi anomali TPL dengan periode 2 - 6 bulanan terdapat di sepanjang lintasan Arlindo, sementara periode tahunan hanya terdapat di L.Flores dan kedua ujung S. Lombok. Spektral energi fluktuasi tertinggi terdapat di selatan S. Lombok, kemudian diikuti L. Flores dan L. Sulawesi serta yang terlemah di S. Makassar. Anomali TPL tahunan yang tinggi di selatan S. Lombok pada Desember Maret diperkirakan merupakan sinyal tibanya Arus Pantai Jawa (APJ).Anomali semi-tahunan yang tinggi di lokasi yang sama pada bulan Mei dan November diduga sinyal gelombang Kelvin. Anomali TPL tahunan yang rendah pada Juni - September di sisi selatan S. Lombok diperkirakan akibat menggesernya poros Arus Ekuator Selatan ke utara pada saat bertiupnya Angin Muson Tenggara. Kelihatannya pengaruh sistem Angin Muson lebih terasa di bagian selatan (kedua ujung S. Lombok) dari bagian utara (L. Sulawesi dan S. Makassar) dari lintasan barat aliran Arlindo. Perbedaan anomali TPL tegak lurus lintasan Arlindo dihitung pada posisi 4oS sejauh 166.1 km di S. Makassar untuk memperkirakan anomali arus geostropik permukaan dan apakah hasilnya dapat digunakan sebagai indikator proxy aliran Arlindo. Anomali arus geostropik permukan yang telah ditapis 30 hari bervariasi antara -9 cm/det (ke selatan) sampai +5.5 cm/det (ke utara) dengan periode fluktuasi antara 2 - 4bulanan. Aliran ke utara dan ke selatan hampir sebanding dengan aliran bersih selama 4 tahun ke selatan (-0.43 cm/det). Kelihatannya, anomali arus geostropik permukaan terlalu berfluktuasi dan tidak mengambarkan aliran Arlindo yang menurut pengamatan umumnya ke selatan dan terfokus di lapisan termoklin. Akan tetapi, seperti halnya karakter Arlindo, arus permukaan ini menguat ke selatan pada bulan Juni - Agustus dan aliran cenderung ke utara pada bulan Desember –Maret.Kata kunci: anomali Tinggi Permukaan Laut (TPL), Arus Lintas Indonesia (Arlindo), fluktuasi, anomali arusgeostropik permukaan.
KARAKTER DAN PERGERAKAN MASSA AIR DI SELAT LOMBOK BULAN JANUARI 2004 DAN JUNI 2005 Mulia Purba; Iriana N .Utami
Jurnal Ilmu-Ilmu Perairan dan Perikanan Indonesia Vol. 13 No. 2 (2006): Desember 2006
Publisher : Institut Pertanian Bogor

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Abstract

Data CTD pada Januari 2004 dan Juni 2005 dan data ADCP pada Juni 2005 hasil ekspedisi oseanografi program INSTANT (International Nusantara Stratification and Transport) di Selat Lombok dianalisis untuk mempelajari karakter dan pergerakan massa air. Karakter massa air pada lapisan permukaan dan massa air Northern Subtropical Lower Water (NSLW) pada lapisan termoklin memperlihatkan perbedaan yang jelas antara kedua pengukuran yang diperkirakan berkaitan dengan perubahan karakter dan pergerakan massa air di Laut Jawa dan Laut Flores. Akan tetapi karakter massa air North Pacific Intermediate Water (NPIW) dan massa air lapisan dalam tidak jauh berbeda. Arus geostropik yang ditentukan dari perbedaan kedalaman dinamik dari dua stasiun yang berdekatan menghasilkan variasi kecepatan yang terlalu besar dan kecepatan yang terlalu tinggi bila dibandingkan dengan kecepatan arus yang diukur secara langsung dengan ADCP. Kelihatannya jarak antar stasiun yang terlalu dekat (kurang dari 9 km) menyebabkan kecepatan arus yang tidak akurat.Kata kunci: karakter massa air, arus geostropik.
The researh for study relationship between phytoplankton abundance and environment parameters and determining contribuion each environment parameters on phytoplankton abundance discrimination had been conducted in 2005 in bagan rambo fishing ground at coastal water Barru Regency, Makassar Strait.  Environment parameters and phytoplankton abundance data collection were conducted on May (6 stations), June, July, September, October and November (9 stations).  Spatio-temporal distribution of environ Muh. Hatta; Richardus F Kaswadji; Mulia Purba; Daniel R. Monintja
Forum Pasca Sarjana Vol. 33 No. 1 (2010): Forum Pascasarjana
Publisher : Forum Pasca Sarjana

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Abstract

The researh for study relationship between phytoplankton abundance and environment parameters and determining contribuion each environment parameters on phytoplankton abundance discrimination had been conducted in 2005 in bagan rambo fishing ground at coastal water Barru Regency, Makassar Strait.  Environment parameters and phytoplankton abundance data collection were conducted on May (6 stations), June, July, September, October and November (9 stations).  Spatio-temporal distribution of environment parameters probably ralate to fresh water loading to stations inshore.  Phytoplankton abundance found in this research ranged from 431 to 5438 cels/liter.  Phytoplankton population dominated by diatom i.e: Bacteriatrum, Biddulphia, Chaetoceros, Coscinodiscus, Ditylum, Eucampia, Melosira, Navicula, Nitzschia, Rhizosolenia, Skeletonema, Thalassionema, Thalassiosira, dan Thalassiothrix.  Regression analysis result show significantly positive linear correlation between phytoplankton abundance with temperature and phosphate concentration, but low correlation coefficient R = 0,4366 (R2 = 0,1906).  Discriminant analysis result show that high average of phytoplankton abundance occured when high temperature and nitrat concentration, and moderate salinity, pH and phosphate concentration.  Phosphate concentration have higher contribution on discriminating phytoplankton abundance.  The contribution of nitrate and silicat concentration and pH are low.   Key words: phytoplankton, phytoplankton abundance, diatom, discriminant analysis, environment parameters
TEMPERATURE VARIABILITY AT SENUNU BAY, WEST SUMBAWA Syamsul Hidayat; Mulia Purba; Jorina Waworuntu
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 5 No. 2 (2013): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1167.451 KB) | DOI: 10.29244/jitkt.v5i2.7555

Abstract

The purposes of this study were to determine the variability of temperature and its relation to regional processes in the Senunu Bay. The result showed clear vertical stratifications i.e., mixed layer thickness about 39-119 m with isotherm of 27°C, thermocline layer thickness about 83-204 m with isotherm of 14–26°C, and  the deeper layer from the thermocline lower limit to the sea bottom with isotherm <13°C. Temperature and the thickness of each layers varied with season in which during the Northwest Monsoon the temperature was warmer and the mixed layer was thicker than those during Southeast Monsoon. During Southeast Monsoon, the thermocline layer rose  about 24 m. The 2001, 2006, and 2009 (weak La Nina years),  the Indonesia Throughflow (ITF) carried warmer water, deepening thermocline depth and reducing upwelling strength.  In 2003 and 2008 thickening of mixed layer occurred in transition season  was believed  associated with the  arrival of Kelvin Wave from the west. In 2002 and 2004 (weak El Nino period,) ITF carries colder water shallowing thermocline depth and enhancing upwelling strength. In 2007 was believed to be related with positive IODM where the sea surface temperature were decreasing due to intensification of southeast wind which induced strong upwelling. The temperature spectral density of mixed layer and thermocline was influenced by annual, semi-annual, intra-annual and inter-annual period fluctuations. The cross-correlation between wind and temperature showed significant value in the annual period.  Keywords: temperature, thermocline, variability, ENSO, IODM.
STUDY OF SHORELINE CHANGES AT JENEBERANG RIVER DELTA, MAKASSAR Sakka Sakka; Mulia Purba; I Wayan Nurjaya; Hidayat Pawitan; Vincentius P. Siregar
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 3 No. 2 (2011): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (568.813 KB) | DOI: 10.29244/jitkt.v3i2.7826

Abstract

The study of shoreline changes during 1990 - 2008 in the delta of the River Jeneberang, Makassar was conducted by evaluating sediment transport into and out of a cell. Longshore sediment transport was computed by considering the influence of heights and angles of the breaking waves. Results of calculation of sediment transport showed that the dominant of sediment transport was to the north during the arrival of the southwest and west waves, and to the south when the wave coming from the northwest. Comparison between shore profiles resulting from model and coastline satellite imagery showed similarity. The difference between the two tend to be occurred at the head land part of the shoreline. This was due to complexity of coastal dynamic at the area. The results of the 19 years shoreline simulation showed that there was a tendency of abrasion at the upsteam head land part as the wave energy tend to converge and accretion at the bay part as the wave energy tend to diverge. Abrasion mainly occurred at Tanjung Bunga (head land) where the coast retreat 181.1 m. Accretion occur in the bay area (Tanjung Merdeka) where the coast advance to the sea for about 59.8 m. The shoreline tend to be stable when the profile was straight such as Barombong Coast.Keywords: abrasion, accretion, sediment transport, shoreline changes.
INTRA-SEASONAL VARIABILITY OF NEAR-BOTTOM CURRENT IN THE HALMAHERA SEA Marlin C Wattimena; Agus S Atmadipoera; Mulia Purba; Ariane Koch-Larrouy
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 6 No. 2 (2014): Electronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1409.838 KB) | DOI: 10.29244/jitkt.v6i2.9003

Abstract

The secondary entry portal of the Indonesian Throughflow (ITF) from the Pacific to Indian Oceans is considered to be via the Halmahera Sea (HS). However, few ITF studies have been done within the passage. This motivated the Internal Tides and Mixing in the Indonesian Througflow (INDOMIX) program to conduct direct measurements of currents and its variability across the eastern path of the ITF. This study focused on the intra-seasonal variability of near-bottom current in HS (129°E, 0°S), its origin and correlation with surface zonal winds and sea surface height over the equatorial Pacific Ocean. The result showed a strong northwestward mean flow with velocity exceeding 40 cm/s, which represented the current-following topography with the northwest orientation. Meridional current component was much stronger than the zonal component. The energy of power spectral density (PSD) of the current peaked on 14-days and 27-days periods. The first period was presumably related to the tidal oscillation, but the latter may be associated with surface winds perturbation. Furthermore, cross-PSD revealed a significant coherency between the observed currents and the surface zonal winds in the central equatorial Pacific zonal winds (180°E-160°W), which corroborates westward propagation of intra-seasonal sea surface height signals along the 5°S with its mean phase speeds of 50 cm/s, depicting the low-latitude westward Rossby waves on intra-seasonal band. Keywords: current, equatorial Pacific Ocean,  zonal winds, sea surface height, Halmahera Sea