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COASTAL UPWELLING UNDER THE INFLUENCE OF WESTERLY WIND BURST IN THE NORTH OF PAPUA CONTINENT, WESTERN PACIFIC Waas, Harold J.D.; Siregar, Vincentius P; Jaya, Indra; Gaol, Jonson Lumban
International Journal of Remote Sensing and Earth Sciences (IJReSES) Vol 9, No 2 (2012)
Publisher : National Institute of Aeronautics and Space of Indonesia (LAPAN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.ijreses.2012.v9.a1837

Abstract

Coastal upwelling play an important role in biological productivity and the carbon cycle in the ocean. This research aimed to examine the phenomenon of coastal upwelling that occur in the coastal waters north of Papua continent under the influence of Westerly Wind Burst(WWB) prior to the development of El Nino in the Pacific. Data consisted of sea surface temperature, vertical oceanic temperature, ocean color satellite image, wind stress and vector wind speed image, sea surface high, and Nino 3.4 index. Coastal upwelling events in the northern coastal waters of Papua continent occurred in response to westerly winds and westerly wind burst (WWBs) during December to March characterizing by low sea surface temperature (SST) (25 - 28C), negative sea surface high deviation and phytoplankton blooming, except during pre-development of the El Nino 2006/2007 where weak upwelling followed by positive sea surface high deviation. Strong coastal upwelling occurred during two WWBs in December and March1996/1997 with maximum wind speed in March produced a strong El Nino 1997/1998. Upwelling generally occurred along coastal waters of Jayapura to Papua New Guinea with more intensive in coastal waters north of Papua New Guinea indicated by Ekman transport and Ekman layer depth maximum.
AKURASI TEMATIK PETA SUBSTRAT DASAR DARI CITRA QUICKBIRD (STUDI KASUS GUSUNG KARANG LEBAR, KEPULAUAN SERIBU, JAKARTA) (THEMATIC ACCURACY OF BOTTOM SUBSTRATE MAP FROM QUICKBRID IMAGERY (CASE STUDY: GUSUNG KARANG LEBAR, KEPULAUAN SERIBU, JAKARTA)) Selamat, Muhammad Banda; Jaya, Indra; Siregar, Vincentius P; Hestirianoto, Totok
ILMU KELAUTAN: Indonesian Journal of Marine Sciences Vol 17, No 3 (2012): Ilmu Kelautan
Publisher : Marine Science Department Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2144.187 KB) | DOI: 10.14710/ik.ijms.17.3.132-140

Abstract

Salah satu kelemahan metode koreksi kolom air adalah dapat memunculkan bias dalam estimasi rasio koefisien attenuasi. Bias ini berkontribusi pada nilai akurasi tematik peta substrat dasar. Studi ini menggunakan pendekatan zonasi geomorfologi untuk meningkatkan akurasi tematik peta substrat yang dihasilkan dari metode koreksi kolom air. Nilai piksel citra Quickbird dikonversi ke radiansi dan dilanjutkan dengan koreksi kolom air untuk menghasilkan peta substrat dasar dengan tiga tema ekosistem, yaitu ekosistem pantai berpasir dengan substrat dominan pasir, ekosistem lamun dan terumbu karang. Data lapangan dikelompokkan menggunakan metode Bray curtis dan menjadi dasar bagi reklasifikasi. Profil geomorfologi pada citra satelit disadap dari gabungan kanal hijau dan merah, mengacu pada hasil survei batimetri. Pendekatan kombinasi ini terbukti dapat meningkatkan akurasi tematik peta substrat dasar hingga lebih dari 20%.Kata kunci: quickbird, substrat dasar, akurasi tematikBias may occur on attenuation coefficient ratio estimated from water column correction method. This bias then contribute to thematic accuracy of bottom substrate images. This study used geomorphologic spatial zonation to improve thematic accuracy of bottom substrate maps that produced from water column correction method. Quickbird pixel values were converted to the top of atmosphere radiance and followed by water column correction to make bottom substrate map with three themes ecosystem i.e. sandy ecosystem, seagrass ecosystem and coral reef ecosystem. Field data were grouped using Bray Curtis method and become basis of image reclassification. Geomorphological profile was extracted from green and red composite images, refer to a bathymetric survey. These combined approaches were significantly proved to improve thematic accuracy up to more than 20%.Key words: quickbird, bottom subtrate, thematic accuracy
PENGUKURAN KOEFISIEN ATENUASI DAN HUBUNGANNYA DENGAN KUALITAS AIR DI PERAIRAN KELURAHAN PULAU PANGGANG Meliani, Fanny; Siregar, Vincentius P; Hendiarti, Nani; Parwati, Ety
Jurnal Teknologi Perikanan dan Kelautan Vol 9 No 1 (2018): MEI 2018
Publisher : Fakultas Perikanan dan Ilmu Kelautan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1778.922 KB) | DOI: 10.24319/jtpk.9.73-81

Abstract

Koefisien atenuasi merupakan gambaran seberapa besar cahaya datang berkurang atau hilang dibandingkan dengan energi cahaya datang di permukaan. Pengurangan energi cahaya dikarenakan adanya proses absorpsi dan hamburan oleh kolom air dan materi yang terkandung di dalamnya seperti fitoplankton, padatan tersuspensi dan colored dissolved organic matter. Kuantitas cahaya yang mengalami atenuasi setara dengan jumlah cahaya yang diabsorpsi dan dihamburkan. Penelitian ini bertujuan untuk menganalisis hubungan antara koefisien atenuasi dengan kualitas air, serta mengkaji karakteristik optik perairan Kelurahan Pulau Panggang. Pengukuran spektral menggunakan TriOSRamses yang memiliki sensor irradiance dengan panjang gelombang antara 320 nm sampai 950 nm dan rentang kanal 3,3 nm. Perhitungan koefisien atenuasi (Kd) berdasarkan perubahan downwelling irradiance pada dua kedalaman berbeda. Korelasi Pearson digunakan untuk mengetahui hubungan antara Kd dengan kualitas air. Berdasarkan rentang panjang gelombang, Kd dibagi menjadi 4 yaitu Kd PAR, Kd biru, Kd hijau dan Kd merah. Kd biru dan Kd hijau memiliki hubungan paling erat dengan kecerahan sebesar 0,5406 dan 0,3990 serta bersifat negatif, sedangkan Kd PAR dan Kd merah paling erat hubungannya dengan muatan padatan tersuspensi sebesar 0,4015 dan 0,4073 dan bersifat positif. Perairan Kelurahan Pulau Panggang merupakan perairan turbid dengan nilai Kd PAR > 0,115 m-1.
ANALISIS REFLEKTANSI SPEKTRAL LAMUN MENGGUNAKAN SPEKTROMETER DI PULAU TUNDA SERANG, BANTEN Aziizah, Nunung Noer; Siregar, Vincentius P; Agus, Syamsul Bahri
Jurnal Teknologi Perikanan dan Kelautan Vol 6 No 2 (2015): NOVEMBER 2015
Publisher : Fakultas Perikanan dan Ilmu Kelautan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3585.397 KB) | DOI: 10.24319/jtpk.6.199-208

Abstract

Analisis reflektansi spektral suatu objek mulai banyak berkembang dan memberikan data atau informasi tentang pola spektral. Objek dalam penelitian ini adalah lamun, yang merupakan tanaman memiliki kemampuan untuk beradaptasi hidup di perairan dengan salinitas tinggi. Permasalahan yang muncul adalah sejauh mana pola spektral objek mampu memberikan gambaran yang sesuai dengan karakteristik objek di lapangan. Penelitian dilaksanakan di ekosistem lamun Pulau Tunda Kabupaten Serang pada bulan Agustus 2014 dan dilanjutkan bulan Maret 2015. Tujuan dari penelitian ini adalah mengetahui kurva reflektansi spektral lamun, karakteristik spektral, dan identifikasi panjang gelombang yang memberikan karakteristik berbeda dari setiap jenis lamun. Pengukuran reflektansi insitu menggunakan spektrometer USB4000 menghasilkan nilai intensitas dan dianalisis menggunakan algoritma reflektansi untuk menghasilkan kurva. Kurva reflektansi memiliki dua puncak pada panjang gelombang 500-650 nm dan 700-750 nm dengan nilai tertinggi adalah 22% dipuncak pertama dan 14% dipuncak kedua. Hasil dari analisis statistik menunjukkan nilai reflektansi dari lima spesies lamun di Pulau Tunda berbeda signifikan. Berdasarkan nilai reflektansi dari lima jenis lamun dan uji Tukey yang telah dilakukan, dapat diketahui panjang gelombang penciri karena lima jenis lamun memiliki perbedaan signifikan yaitu dipanjang gelombang hijau, kuning, merah tepi, dan NIR-2.
APLIKASI CITRA QUICKBIRD UNTUK PEMETAAN 3D SUBSTRAT DASAR DI GUSUNG KARANG Selamat, Muhammad Banda; Jaya, Indra; Siregar, Vincentius P; Hestirianoto, Totok
GEOMATIKA Vol 18, No 2 (2012)
Publisher : Badan Informasi Geospasial in Partnership with MAPIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24895/JIG.2012.18-2.183

Abstract

Salah satu masalah dalam pemetaan batimetri di perairan gusung terumbu karang adalah sulitnya aksesibilitas kapal survei oleh karena perairannya yang dangkal.  Di lain pihak, citra satelit sinar tampak telah umum digunakan untuk pemetaan habitat terumbu karang dan kedalaman perairan.  Studi ini bertujuan menghasilkan peta 3D substrat dasar di gusung terumbu karang dari citra Quickbird.Sejumlah 325 titik sampling menjadi acuan dalam penentuan tipe substrat dasar melalui pendekatan indeks kemiripan Bray Curtis.Setelah koreksi atmosferik, metode koreksi kolom air diaplikasikan pada citra dan ditingkatkan akurasinya dengan kombinasi profil geomorfologi. Pendekatan ini telah menghasilkan peta substrat dasar di gusung Karang Lebar dengan akurasi tematik 82%.  Sejumlah lebih 5700  titik perum di regresi dengan kanal hijau dan merah untuk mendapatkan model estimasi batimetri dari citra Quickbird berdasarkan tipe substrat.  Gabungan model regresi menghasilkan nilai koefisien determinasi=94% dan RMSE=0.4 meter.  Interpolasi data gabungan citra batimetri pasir dan data perum menghasilkan model 3D batimetri di Karang Lebar dengan ME=0.4 m dan RMSE=0.9 m.  Hasil ini menunjukkan peta batimetri yang dihasilkan belum dapat memenuhi persyaratan navigasi, meskipun demikian masih dapat digunakan untuk keperluan lainnya seperti pengelolaan sumberdaya, pemodelan oseanografi dan lain-lain.Kata kunci: substrat dasar, Quickbird, batimetriABSTRACTOne of the problems when conducting bathymetric mapping in patch reef environments is shallow water condition.The shallowness complicates the surveillance boat to access the location. Apart from this, using visible satellite imagery, ones still can map coral reefs and shallow water depth. This study goal was to produce 3D bottom substrate map from quickbird imagery.  About 325 sampling points wereselected to characterize bottom substrate based on the similarity index from Bray Curtis. After theatmospheric correction, a water-column correction method was implemented and then a geomorphologic profilingwas applied to improve the map’s thematic accuracy. Theapproach has resultedan accuracy 82% for bottom substrate map.  A bathymetric estimation model then wasbuilt from a regression analysis to 5700 sounding data and combination of green and red channel value of quickbird. The model has 0.4m RMSE value and 94% for itscoefficient determination The fusion of sand bathymetric image and sounding data results on the 3D bathymetric model of Karang Lebar with ME=0.4 m and RMSE=0.9 m.  This result shows that the produced bathymetric map was not fulfilled the navigation requirement, but still potential as an additional information for resource management, oceanographic modeling etc.Keywords: bottom substrate, Quickbird, bathymetry
PENGELOMPOKKAN HABITAT DASAR PERAIRAN DANGKAL BERBASIS DATA SATELIT QUICKBIRD MENGGUNAKAN ALGORITMA SELF ORGANISING MAP Asmadin, Asmadin; Siregar, Vincentius P; Wijanarto, Antonius Bambang
AQUASAINS Vol 1, No 1 (2012)
Publisher : Jurusan Perikanan dan Kelautan

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Pengembangan algoritma self organising map dalam penelitian ini bertujuan untuk mengelompokkan habitat perairan dangkal berbasis data satelit Quickbird. Data primer dikumpulkan melalui data penginderaan jauh dan survey lapang, sedangkan data sekunder dikumpulkan dari penelitian yang relevan. Hasil penelitian menunjukkan bahwa klasifikasi algoritma self organising map dapat mengklaster/ mengklasifikasi citra Quickbird dari berbagai kombinasi kanal. Dari berbagai kombinasi input data setelah direduksi kolom air dengan algoritma Lyzenga, Self organising map menunjukkan hasil klaster yang relatif baik. Algoritma Lyzenga dapat mengelompokkan habitat perairan dangkal 6 (enam) kelas habitat, yaitu karang mati (merah), karang hidup (hijau), lamun (orange), pasir (kuning), dan habitat campuran (hijau muda), daratan (hitam) dan perairan (biru). Setelah menggunakan self organising map secara visual terlihat 6 kelas habitat yang berbeda dari Lyzenga, yaitu karang mati (kuning), karang hidup (cyan), lamun (ungu), pasir (kuning), dan habitat campuran (biru), daratan (hijau) dan perairan (coklat). Algoritma self organising map dapat mengurangi kesalahan tematik habitat perairan dangkal dan sangat membantu proses ekstraksi ROI (region of interset) untuk reklasifikasi lebih lanjut dengan teknik klasifikasi supervised.
MANGROVE COVERAGE CHANGE DETECTION USING LANDSAT IMAGERIES BASED ON HYBRID CLASSIFICATION IN KEMBUNG RIVER, BENGKALIS ISLAND, RIAU PROVINCE Jhonnerie, Romie; Siregar, Vincentius P; Nababan, Bisman; Prasetyo, Lilik Budi; Wouthuyzen, Sam
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 | DOI: 10.29244/jitkt.v6i2.9024

Abstract

ABSTRACT The limited scientific information and lack of attention from stakeholders on the status of mangroves in Kembung River functioned as a basis of this study. Four series of Landsat data recorded in 1996, 2002, 2010, and 2013 were used to map mangrove land cover and changes detection. Hybrid classification technique, a combination of the object-based and random forest classifications, were applied in this study. The result showed that based on hybrid classification, mangrove coverage was detected within 82.6-88.4% overall accuracy. Change detection analyses showed that the mangrove area of Kembung River was relatively stable. For nearly two decades, we found mangrove loss about 197.2 ha, gain of 251.1 ha, and unchanged of 2904.9 ha. Changes in mangrove were generally caused by anthropogenic factors such as mangrove replanting, logging, changes over the function of mangroves into the road, embankment, settlement, shrimp farms, and natural growth. Serious attention from various parties are needed to maintain the existence and sustainablility of mangrove ecosystems in Kembung River.   Keywords: Mangrove, Sungai Kembung, monitoring, Landsat, hybrid classification
CHANGE DETECTION OF CORAL REEF HABITAT USING LANDSAT IMAGERY IN MOROTAI ISLAND NORTH MALUKU PROVINCE Wahiddin, Nurhalis; Siregar, Vincentius P; Nababan, Bisman; Jaya, Indra; Wouthuyzen, Sam
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 | DOI: 10.29244/jitkt.v6i2.9026

Abstract

ABSTRACT Scientific information on coral reef habitat changes of Morotai island is very limited to none. This study aimed to detect the change of coral reef habitats between 1996 and 2013, using Landsat imagery integrated with field data in 2012. The research was conducted in the coral reef ecosystem of Morotai Island in North Maluku province. Change detection analyses were conducted using supervised classifications and transformation depth invariant index (DII), with five habitat classes i.e., mixed-habitat, coral, seagrass, sand, and rubble. The result showed that in 1996-2002 there was a significant increase in the mix-habitat and rubble classes (11.3% and 32.5%), however,  there  was  a siginifcant decrease in the sand, seagrass, and coral classes of -14.1%, -14.9%, and -16.6%, respectively. In 2002-2013, mixed-habitat, sand, and seagrass classes were increase by 1.1%, 13.3%, and 24.78%, respectively.  Meanwhile, coral and rubble classes were decrease by -22.7% and -27.0%, respectively. Within the period of 1996-2013, there was about 43.6% loss of coral reef of Morotai island.  This was probably caused by the increase of seas surface temperature nad and the increase of human activities in the region. Keywords: coral reef habitats, Landsat, change detection, Morotai Island
LAND CARRYING CAPACITY FOR SETTLEMENT AND ITS IMPLICATIONS ON WATER QUALITY AT SMALL ISLANDS (CASE STUDY OF TIWORO STRAIT SMALL ISLANDS, WEST MUNA REGENCY) Ketjulan, Romy; Boer, Mennofatria; Imran, Zulhamsyah; Siregar, Vincentius P
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 11 No. 3 (2019): 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 | DOI: 10.29244/jitkt.v11i3.25731

Abstract

Small islands are an entity that has limitations to be used. This study aimed to analyze the land carrying capacity for settlement and its implication on water quality at small islands. The carrying capacity of land are determined based on an analysis of the minimum space requirements of each individual according to Indonesian National Standards (SNI) 03-1733-2004, while the implications for water quality are determined based on the nutrient load approach. The results of this research showed that the Tiworo archypelago have a total potential land approximately 198.94 ha and about 31.45 ha of this amount has been utilized. Although the land use is relatively small, however, there are also islands that have been used to exceed their carrying capacity. The human population density of each island has a positive correlation with the level of the land degradation. The total population currently is still tolerated by water bodies, but when the population is suitable with the land carrying capacity will increase the ammonia ratio by 0.086-0.550. This indicates that the land carrying capacity of the Tiworo chained Islands is not higher than the ability of the water body in assimilating the domestic waste.