amandangi hastuti

Coastal areas are one of the essential regions for the ecosystem. Consequently, monitoring and detecting the changes of coastal areas is thus necessary in order to provide valuable information for future mitigation and adaptation. Recently, the utilization of satellite images for coastal areas has been used widely and effectively as a viable alternative to in-situ observation and monitoring. In this study, multi-temporal satellite imagery data from Sentinel-2 have been used to find out the changes in the coastal area of Gianyar and Klungkung Regency - Bali, considering the capability which has good resolution with a wide swath and high revisit time. Sentinel-2 imagery data taken from 2016 and 2019 at an interval of about 4 years were collected to determine coastline changes. There are two main steps to detect the coastline. First is image classification by supervised classification where each pixel has been labeled with one or three classes. And the second is to make border segmentation between sand and water by applying the Modified Normalized Difference Water Index (MNDWI). The areas that are experiencing erosion and accretion were determined by using the overlay method between two satellite images. Results show that about 9,248 m2of coastline were eroded in Gianyar Regency and 121,000 m2in Klungkung Regency for the period of 2016 to 2019. Meanwhile, the accretion area reached 158,615 m2in Gianyar and 32,159 m2in Klungkung Regency.

Coastal zones are considered to be highly vulnerable to the effects of climate change, such as erosion, flooding, and storms, including sea level rise (SLR). The effects of rising sea levels endanger several nations, including Indonesia, and it potentially affects the coastal population and natural environment. Quantification is needed to determine the degree of vulnerability experienced by a coast since measuring vulnerability is a fundamental phase towards effective risk reduction. Therefore, the main objective of this research is to identify how vulnerable the coastal zone of Bali Province by develop a Coastal Vulnerability Index (CVI) of areas exposed to the sea-level rise on regional scales using remote sensing and Geographic Information System (GIS) approaches. This study was conducted in Bali Province, Indonesia, which has a beach length of ~640 km, and six parameters were considered in the creation to measure the degree of coastal vulnerability by CVI: geomorphology, shoreli...

Land areas in the territorial waters will often be affected by sea-level flooding or commonly referred to as rob. This research was conducted to see the physical condition of the waters and to do a hydrodynamic model (2D) in the waters of the Tembesi Reservoir, Batam, Indonesia. This research was conducted using primary and secondary data to produce physical conditions of waters and hydrodynamic (2D) models. The results showed the depth of waters has a minimum value of depth of -1.05 meters and a maximum value of depth of -5.95 meters. The percentage of wind speed below 1 Knot is 3.23%, and the independent variable in the percentage of wind data processing is 1.61%, with the lowest wind speed in the range of 0.1-1 Knots. Water level models produced in conditions during the filling process before the water discharge from the outlet is 0.023 meters and relatively small currents range from 0.0012 cm/s. Elevation of the final water level to the final flow when the conditions during the filling process before the water is discharged, resulting in highest water elevation, compared to when the water condition in the reservoir has been discharged from the outlet into the sea.

Mangrove vegetation is one of the forest ecosystems that offers a potential of substantial greenhouse gases (GHG) emission mitigation, due to its ability to sink the amount of CO2 in the atmosphere through the photosynthesis process. Mangroves have been providing multiple benefits either as the source of food, the habitat of wildlife, the coastline protectors as well as the CO2 absorber, higher than other forest types. To explore the role of mangrove vegetation in sequestering the carbon stock, the study on the use of remotely sensed data in estimating carbon stock was applied. This paper describes an examination of the use of remote sensing data particularly Landsat-data with the main objective to estimate carbon stock of mangrove vegetation in Perancak Estuary, Jembrana, Bali. The carbon stock was estimated by analyzing the relationship between NDVI, Above Ground Biomass (AGB) and Below Ground Biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with...

During Marine Science Summer Course 2017, a continuous 24-h conductivity-temperature-depth (CTD) “yoyo” measurement has been carried out at the entrance of Padangbai Lombok Strait to investigate seawater properties variations on semidiurnal tidal-scale which is dominant in the strait. The SBE CTD 19 plus is equipped with optional sensors such as pH, turbidity and chlorophyll-a derived-fluoro. During 24-h field observation, 15 CTD casts from sea surface to about 60 m depth have been acquired. It is shown that observed seawater properties fluctuate strongly four times a day, following semidiurnal-tide period with two flood-tide and two ebb-tide conditions. During flood-tide, water mass is derived from open strait with colder, saltier, denser and low dissolved oxygen characteristics. In contrast, during ebb-tide, local water mass is recirculated back from the inner bay to the open strait. It is interesting to note that fluctuation of chlorophyll-a indicates a diurnal signal. In additio...

Pesisir selatan Yogyakarta merupakan daerah yang cukup penting bagi masyarakat pesisir baik dari segi ekonomi maupun konservasi. Apabila sebagian besar wilayah dari pesisir pantai tersebut mengalami kerusakan akibat kenaikan muka laut, maka akan menimbulkan kerugian. Oleh karena itu, diperlukan suatu studi mengenai analisis kerentanan pesisir terhadap ancaman muka laut untuk menjadi bahan pertimbangan dalam pengelolaan wilayah pesisir sehingga dapat mengurangi kerugian harta benda dan korban jiwa. Penelitian dengan judul Analisis Kerentanan Pesisir Terhadap Ancaman Kenaikan Muka Laut di Selatan Yogyakarta dilaksanakan pada Juni 2011 sampai Januari 2012 di pesisir selatan Yogyakarta dan pengolahan data dilakukan di Laboratorium Pengolahan Data Oseanografi, Departemen Ilmu dan Teknologi Kelautan, Fakultas Perikanan dan Ilmu Kelautan, Institut Pertanian Bogor. Parameter yang digunakan untuk menganalisis tingkat kerentanan pesisir adalah geomorfologi, perubahan garis pantai, elevasi, kenaikan muka laut relatif, tunggang pasang surut rata-rata dan tinggi gelombang. Zona kerentanan diperoleh dari pengolahan parameter tersebut yang kemudian diberi skor. Setelah seluruh parameter tersebut memiliki skor, maka untuk mengetahui tingkat kerentanan pesisir dilakukan penghitungan dengan menggunakan persamaan umum indeks kerentanan pesisir (Coastal Vulnerability Index). Hasil perhitungan CVI tersebut selanjutnya dikelompokan menjadi wilayah dengan tingkat kerentanan tidak rentan, sedang, dan sangat rentan. Pembagian indeks ini didasarkan pada persen dengan kisaran antar kelas adalah 33 persen. Wilayah pesisir yang termasuk kategori tidak rentan terdapat di Kecamatan Panjatan, kategori sedang di Kecamatan Temon dan Wates, sedangkan wilayah pesisir yang rentan di Kecamatan Galur dan Srandakan. Berdasarkan distribusi tingkat kerentanan skala lokal, panjang garis pantai yang termasuk dalam kategori tidak rentan adalah sepanjang 7 km (26,92% dari total panjang garis pantai), panjang garis pantai yang termasuk dalam kategori sedang adalah 10 km (38,46% dari total panjang garis pantai), dan panjang garis pantai yang termasuk dalam kategori rentan terhadap perubahan kenaikan muka laut adalah 9 km (34,62% dari total panjang garis pantai). Hasil penghitungan variabel proses fisik yakni geomorfologi, perubahan garis pantai, elevasi, kenaikan muka laut relatif, tunggang pasang surut rata-rata dan tinggi gelombang menunjukkan bahwa parameter yang memberi pengaruh besar terhadap kerentanan wilayah pesisir di selatan Yogyakarta adalah perubahan garis pantai. Perubahan garis pantai akan memberikan pengaruh negatif terhadap daerah pesisir apabila perubahannya tersebut berupa pengurangan luas daratan (abrasi). Kecepatan perubahan garis pantai juga dipengaruhi oleh faktor geomorfologi. Geomorfologi pesisir selatan Yogyakarta yang berupa gumuk pasir memberikan pengaruh terhadap kecepatan perubahan garis pantai.

Mangrove vegetation is one of the forest ecosystems that offers a potential of substantial greenhouse gases (GHG) emission mitigation, due to its ability to sink the amount of CO2 in the atmosphere through the photosynthesis process. Mangroves have been providing multiple benefits either as the source of food, the habitat of wildlife, the coastline protectors as well as the CO2 absorber, higher than other forest types.To explore the role of mangrove vegetation in sequestering the carbon stock, the study on the use of remotely sensed data in estimating carbon stock was applied. This paper describes an examination of the use of remote sensing data particularly Landsat-data with the main objective to estimate carbon stock of mangrove vegetation in Perancak Estuary, Jembrana, Bali. The carbon stock was estimated by analyzing the relationship between NDVI, Above Ground Biomass (AGB) and Below Ground Biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with the carbon organic value of 0.47. The study results show that the total accumulated biomass obtained from remote sensing data in Perancak Estuary in 2015 is about 47.20±25.03 ton ha-1 with total carbon stock of about 22.18±11.76 tonC ha-1and CO2 sequestration 81.41±43.18 tonC ha-1.

Pesisir selatan Yogyakarta merupakan daerah yang cukup penting bagi masyarakat pesisir baik dari segi ekonomi maupun konservasi. Apabila sebagian besar wilayah dari pesisir pantai tersebut mengalami kerusakan akibat kenaikan muka laut, maka akan menimbulkan kerugian. Oleh karena itu, diperlukan suatu studi mengenai analisis kerentanan pesisir terhadap ancaman muka laut untuk menjadi bahan pertimbangan dalam pengelolaan wilayah pesisir sehingga dapat mengurangi kerugian harta benda dan korban jiwa. Penelitian dengan judul Analisis Kerentanan Pesisir Terhadap Ancaman Kenaikan Muka Laut di Selatan Yogyakarta dilaksanakan pada Juni 2011 sampai Januari 2012 di pesisir selatan Yogyakarta dan pengolahan data dilakukan di Laboratorium Pengolahan Data Oseanografi, Departemen Ilmu dan Teknologi Kelautan, Fakultas Perikanan dan Ilmu Kelautan, Institut Pertanian Bogor. Parameter yang digunakan untuk menganalisis tingkat kerentanan pesisir adalah geomorfologi, perubahan garis pantai, elevasi, kenaikan muka laut relatif, tunggang pasang surut rata-rata dan tinggi gelombang. Zona kerentanan diperoleh dari pengolahan parameter tersebut yang kemudian diberi skor. Setelah seluruh parameter tersebut memiliki skor, maka untuk mengetahui tingkat kerentanan pesisir dilakukan penghitungan dengan menggunakan persamaan umum indeks kerentanan pesisir (Coastal Vulnerability Index). Hasil perhitungan CVI tersebut selanjutnya dikelompokan menjadi wilayah dengan tingkat kerentanan tidak rentan, sedang, dan sangat rentan. Pembagian indeks ini didasarkan pada persen dengan kisaran antar kelas adalah 33 persen. Wilayah pesisir yang termasuk kategori tidak rentan terdapat di Kecamatan Panjatan, kategori sedang di Kecamatan Temon dan Wates, sedangkan wilayah pesisir yang rentan di Kecamatan Galur dan Srandakan. Berdasarkan distribusi tingkat kerentanan skala lokal, panjang garis pantai yang termasuk dalam kategori tidak rentan adalah sepanjang 7 km (26,92% dari total panjang garis pantai), panjang garis pantai yang termasuk dalam kategori sedang adalah 10 km (38,46% dari total panjang garis pantai), dan panjang garis pantai yang termasuk dalam kategori rentan terhadap perubahan kenaikan muka laut adalah 9 km (34,62% dari total panjang garis pantai). Hasil penghitungan variabel proses fisik yakni geomorfologi, perubahan garis pantai, elevasi, kenaikan muka laut relatif, tunggang pasang surut rata-rata dan tinggi gelombang menunjukkan bahwa parameter yang memberi pengaruh besar terhadap kerentanan wilayah pesisir di selatan Yogyakarta adalah perubahan garis pantai. Perubahan garis pantai akan memberikan pengaruh negatif terhadap daerah pesisir apabila perubahannya tersebut berupa pengurangan luas daratan (abrasi). Kecepatan perubahan garis pantai juga dipengaruhi oleh faktor geomorfologi. Geomorfologi pesisir selatan Yogyakarta yang berupa gumuk pasir memberikan pengaruh terhadap kecepatan perubahan garis pantai.

Indonesian Fisheries Management Area (FMA) 711 is an important area for pelagic fishing in Indonesia.  FMA-711 is one of the outermost regions of the Exclusive Economic Zone (EEZ) and is bordered with Malaysia, Singapore, and Vietnam. This FMA-711 covering South China Sea, Natuna Sea and Strait of Karimata.  Potential fishing areas can be predicted using thermal front indicator and chlorophyll-a concentration.  The aim of this study is to determine the monthly variation of potential fishing areas at FMA-711 in 2015 derived from Terra/Aqua MODIS satellite imagery and its relationship with fishing vessel distribution analyzed from Radarsat-2 data.  To find out the relationship, monthly potential fishing areas then overlayed with fishing vessel distribution.  Monthly overlayed result shows that fishing vessel distribution area mostly located around the potential fishing area, with the highest accuration occur in May (86.74%) and the lowest accuration occur in January (13.02%).
Keywords: Indonesian Fisheries Management Area 711, potential fishing ground, Terra/Aqua MODIS, fishing vessel distribution, Radarsat-2

Plankton plays an important role in a body of water as the primary producers and the beginning of the chain in the food web (food chain) causes the plankton used as a measure of fertility an ecosystem scale. This study aims to analyze the diversity and community structure of plankton in order to describe the condition of waters in the estuary Perancak, Bali.. This research was conducted by field surveys in September 2015 (transitional season II), consisting of three location , namely data collection Loloan River (north), Dermaga Perancak (middle) and Muara Perancak (south). Based on the results, both plankton abundance of phytoplankton and zooplankton ranged between 300-20100 ind/m3 and 300-28500 ind/m3. An abundance of plankton in the Estuary Perancak influenced by the water quality, especially the concentration of nutrients (phosphate, silicate and nitrate). Ecological index showed that species diversity of phytoplankton in the Estuary Perancak was categorized as low diversity (0,98≤H'≤ 1.38) and no species of phytoplankton dominating (0,55≤E≤0,77) with uniformity kind of approaching a stable and tend evenly (0,32≤ D≤0,48). While the index showed that diverisity index of zooplankton is low (1,06≤H'≤1,29), with the distribution species are fairly uniform and relatively similar (0,54≤E≤1), and dominant species is not present (0,33≤D≤0,51). These results indicate that Perancak Estuary is moderate levels of water pollution. It is known from the low diversity index of phytoplankton and zooplankton in the waters of  Perancak Estuary.
Keywords: plankton community structure, Perancak Estuary, abundance, diversity, dominance index.

Pada saat muson tenggara perairan selatan Jawa, Bali dan Nusa Tenggara mengalami upwelling yang berpengaruh ke perairan selat Bali disebut sebagai in-direct upwelling. Pengaruh upwelling ini bisa dilihat dari perubahan parameter fisika, kimia dan biologi perairan seperti suhu, klorofil-a dan nutrien. Penelitian ini bertujuan untuk mengetahui pengaruh terjadinya upwelling terhadap distribusi suhu, klorofil-a dan nutrien terutama nitrat,
fosfat, dan silika di Selat Bali dari hasil observasi bulan Juni-September 2012. Lokasi penelitian di koordinat 8,4 LS – 8,85 LS dan 114,40 BT – 115,5 BT. Metode yang digunakan adalah observasi lapangan saat terjadinya upwelling. Pengukuran parameter suhu dan klorofil-a menggunakan Conductivity Temperature Depth (CTD). Sampel nutrien
diambil tiap layer kedalaman dari permukaan sampai 100 m dibagi menjadi 3 zona mewakili karaketristik perairan utara (Laut Bali), tengah (Selat Bali) dan selatan (Samudera Hindia). Hasil penelitian menunjukkan terjadi peningkatan konsentrasi nutrien yang terlihat dari peningkatan konsentrasi nitrat, fosfat, silikat dan klorofil-a serta penurunan suhu. Konsentrasi klorofil-a maksimum di kedalaman 20 m zona selatan yang berhubungan langsung dengan Samudera Hindia dan terjadi kenaikan massa air dingin dikedalaman 70 m serta peningkatan konsentrasi fosfat di kedalaman 60 m, hal ini memperkuat bahwa pada bulan Juni-September perairan selat Bali mendapatkan pengaruh upwelling kuat dari Samudera Hindia.
Kata kunci : in-direct upwelling, suhu, klorofil-a, nutrien

Mangrove vegetation is one of the forest ecosystems that offers a potential of substantial greenhouse gases (GHG) emission mitigation, due to its ability to sink the amount of CO2 in the atmosphere through the photosynthesis process. Mangroves have been providing multiple benefits either as the source of food, the habitat of wildlife, the coastline protectors as well as the CO2 absorber, higher than other forest types. To explore the role of mangrove vegetation in sequestering the carbon stock, the study on the use of remotely sensed data in estimating carbon stock was applied. This paper describes an examination of the use of remote sensing data particularly Landsatdata with the main objective to estimate carbon stock of mangrove vegetation in Perancak Estuary, Jembrana, Bali. The carbon stock was estimated by analyzing the relationship between NDVI, Above Ground Biomass (AGB) and Below Ground Biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with the carbon organic value of 0.47. The study results show that the total accumulated biomass obtained from remote sensing data in Perancak Estuary in 2015 is about 47.20±25.03 ton ha-1 with total carbon stock of about 22.18±11.76 tonC ha-1and CO2 sequestration 81.41±43.18 tonC ha-1.

Keywords: Perancak Estuary, carbon stock estimation, mangrove, CO2 sequestration, NDVI