Putri Island, Nongsa is the outer and frontier island of NKRI region bordering Singapore. Its existence is very important both economically and politically. The management of  Putri Island should consider the coastal characteristic that describes character and physical of the beach as the result of interaction between marine influence and coastal condition, geophysical and anthropogenic elements. The purposes of the study are mapping the coastal characteristics as an effort to manage frontier island and describing the abrasion hazard that occurred in this area. The study area is Putri Island, Nongsa. Field survey was conducted in May 2014. Coastal characteristic method wes conducted through geological observation, coastal morphology and coastline character. Bathymetry measurement conducted by echosounder, tidal observation by peilschaal and wind observation by a weather station. The study results show the type of tide is mixed predominantly semi diurnal. The dominant current direction is to the northeastern. The bathymetry conditions between Putri and Batam Island have a depth of up to 20 with a slope of 2.50 and towards the Singapore Strait has a depth of up to 70 m with a slope of > 100. Coastal characteristics of Putri Island is divided into 5 types, ie sandy beaches, mangroves, coral, rocky and cliff. Generally, sandy beaches, mangroves, rocky, rocky have flat morphology and consist of sand, mangroves, coral reefs, gravel and boulder. Low-cliff beaches consist of conglomerates of various materials that are not well consolidated. The abrasion hazard threatens the Putri Island, Nongsa, especially in the north-western part of the island. The abrasion of Putri Island should be managed and performed based on the coastal characteristics of the area.

Kondisi lingkungan dapat diketahui berdasarkan jejak karbon organik dalam sedimen inti. Penelitian bertujuan untuk mengetahui perubahan lingkungan saat sedimen terendapkan. Lokasi penelitian berada di perairan utara Pulau Lembata, Laut Flores. Bahan yang digunakan adalah sampel sedimen inti yang diambil menggunakan penginti jatuh bebas pada 7 (tujuh) lokasi dengan sayatan oles. Karakteristik sedimen bagian timur didominasi fragmen biogenik dan sedimen lebih halus. Bagian tengah memiliki komposisi relatif sama antara fragmen batuan dengan biogenik. Bagian barat didominasi oleh fragmen biogenik. Persentase material organik antara 2.496-11.133%, CaCO 3 (karbonat) 16.365-79.910% dan total organik karbon 0.999-4.453%. Distribusi karbon organik dalam sedimen inti menunjukkan perubahan dinamis di wilayah perairan tengah dibandingkan dengan bagian barat dan timur. Perubahan distribusi karbon organik terjadi karena adanya perbedaan sumber asal sedimen, perbedaan morfologi dasar laut, perubahan kekuatan dinamika perairan, pemanfaatan kesuburan perairan, dan perbedaan produktivitas perairan saat material karbon organik terendapkan.

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)

The central Kalimantan has envolved into a new oil and gas industry area where potential impact on environmental need to be anticipated comprehensively for environmental protection from oil spill. The locations are East Barito District, South Barito District and Kapuas District (Tamiang Layang, Buntok and surrounding area), Central Kalimantan Province. The main problem of this study is determining areas of sensitive and vulnerability to oil spill. The aims of study were to identify the factors and components that affect the level of ESI to oil spill and analyse and establish environmental sensitivity rank for oil spill contingency plan. The methodology of study carried out by identifying and assessing each landuse unit and analyse performed by GIS method with ESI formula. Interpretation and classification of landuse used Landsat TM imagery that acquired in 2014 and updated in 2018 and field survey in October 2014. The result of analysis showed environmental sensitivity index divided into four categories, dominated by high sensitive (40,8%) due to the presence of protected and conservation forest, less sensitive (31,9%), moderately sensitive (14,6%), and insensitive (12,8%). General condition of study area is lowland and swamp area and potential to flood. The environmental protection from oil spill should be mitigated and prioritized for sustainable development.

Tanjung Berikat Coast in Central Bangka, is a part of the Southeast Asian tin belt. We conducted four Ground-Penetrating Radar (GPR) survey lines and 13 hand auger coring to understand sediment deposition and composition. Two similar units were determined from GPR lines BLG 01–BLG 03: Unit A at the top part, reflected by parallel and continuous reflector configuration, weak–strong electromagnetic wave. Underneath Unit A is Unit B, characterized by subparallel configuration, not continuous–chaotic, weak–medium electromagnetic wave. Unit B is absent in BLG 04. We identify another two units from BLG 04 and BLG 03, Unit C, characterized by subparallel reflector configuration, not continuous– chaotic, weak–strong electromagnetic wave. It exhibits distinctive modulating contact with Unit D. Unit D is characterized by chaotic reflector configuration, relatively stronger electromagnetic wave that might be correlated to the granite intrusion Tanjung Klabat. Sediment deposit is composed of fine–coarse sand, consisting mostly of clastic plutonic and clastic biogenic (coral and mollusk fragments), which increase downward. This indicates marine-fluvial influence, which suggests that sea-level changes strongly influence sedimentation process. Unit A from GPR is correlated to these sediment deposits, the other three units might be correlated to weathering of older insitu deposit.

Nongsa Isle belongs to Putri Islands in Batam, is the outermost island that need to be protected either from natural hazards and anthropogenic factor. Therefore, this study was conducted by performing Ground Penetrating Radar analysis, in order to understand the geological condition particularly sedimentology and its process. We used Sirveyor 20 GPR equipment type with MLF antenna frequency 40 Mhz and Radan 5 as processing software, which include time zero correction, spatial filter, deconvolution, migration and adjustment of amplitude and signal gain. Data interpretation was conducted based on radar facies methodology that describes georadar image/radargram. The study result showed differences of sedimentary facies based on three differences of radar facies units, with the first layer (unit 1) is the youngest unit has thicknesses ranging from 3.5 – 5 m that characterized by parallel, strong reflector, high amplitude and continuous reflector configurations, unit 2 from 5 – 11 meter of depth, indicates parallel reflector pattern with medium-high amplitude and continuous, and unit 3 which is the oldest unit with thickness until penetration limit (11 – 20 m), characterized by a configuration of sub parallel – hummocky reflectors that are undulating, low-medium amplitude reflectors. Based on radar facies characteristics such as reflector configuration, reflection amplitude, and reflection continuity, the differencies of depositional facies are changes from fluvial – coastal plain.

The Georadar (GPR) as a non-destructive technique has been used extensively for geological research. The study was conducted in order to identify coastal sediment characteristics of northern Obi coastal area by performing GPR radar facies analysis. The model of GPR used was Sirveyor 20 with MLF antenna frequency 40 Mhz, penetration depth was 10 meter, and Radan 5 as processing software which include time zero correction, spatial filtering, deconvolution, migration, adjustment amplitude and signal gain. Data interpretation describes georadar image/radargram based on radar facies methodology. The result showed three differences of radar facies unit. The radar facies unit can be divided into 2 facies units in which there are 2 other sub-units, namely unit 1A, 1B, 2A and 2B. Radar facies characterized by medium-high amplitude, continuous parallel-subparallel, medium-weak reflector. At the top part down to 3.75 m is Unit 1A that intersects with 1B. Below 3.75 – 7.75 m depth interval is Unit 2A, and unit 2B is from 7.75-10 meter depth interval. Unit 1 is interpreted as Quartenary alluvium (Qa) and unit B is Woi Formation (Tmpw). Radar facies characteristic indicated the differences of the geological unit.

The southern part of Bintuni Bay with highly sensitive ecosystem conditions has evolved into an oil and gas industry where potential impacts on coastal and offshore environments need to be anticipated and planned comprehensively for environmental protection from oil spills. The main problem is the determination of areas that are sensitive and vulnerable to oil spills. This study is to analyze the factors and components that affect the level of environmental sensitivity and mapping Environment Sensitivity Index (ESI) to the oil spill.  The study was carried out by identifying and assessing each land units of its and use. Land use and land cover are interpreted through the use of satellite imagery with classification methods of guided satellite imagery. Field survey was also conducted in order to improve the accuracy of land use interpretation. Data analysis was performed by spatially by GIS method. The result indicated that ESI can be divided into five categories, are very sensitive (2,395.98 hectares or 2.38%), sensitive (13,133.53 hectares or 13.07%), moderately sensitive (17,902.78 hectares or 17.81%), low sensitive (52,409.14 hectares or 52.14%) and not sensitive (14,681.48 hectares or 14.61%). Although the study area is dominated by low sensitivity category, however the coastal protection from oil spill still should be prioritized.Keywords:  coastal protection, Environmental Sensitivity Index, Oil Spill, Bintuni Bay Wilayah bagian selatan Teluk Bintuni dengan kondisi ekosistem yang sangat sensitif telah berkembang menjadi industri minyak dan gas dimana potensi dampaknya terhadap lingkungan pesisir dan lepas pantai  perlu diantisipasi dan terencana secara komprehensif untuk perlindungan lingkungan dari kemungkinan tumpahan minyak. Masalah utamanya adalah penentuan daerah yang sensitif dan rentan terhadap tumpahan minyak. Penelitian ini menganalisis faktor dan komponen yang berpengaruh terhadap tingkat sensitivitas lingkungan dan pemetaan Indeks Sensitivitas Lingkungan (ISL) terhadap tumpahan minyak. Studi ini dilakukan dengan cara identifikasi dan penilaian unit lahan pada setiap penggunaan lahan. Penggunaan dan penutup lahan diinterpretasikan melalui penggunaan citra satelit dengan metode klasifikasi citra satelit terbimbing. Guna meningkatkan akurasi interpretasi penggunaan lahan juga dilaksanakan survei lapangan. Analisis data hasil penilaian unit identifikasi dilakukan secara spasial dengan metode SIG. Hasil penelitian menunjukkan bahwa ESI dapat dibagi menjadi lima kategori, yaitu sangat sensitif (2.395,98 hektar atau 2,38%), sensitif (13.133,53 hektar atau 13,07%), cukup sensitif (17.902,78 hektar atau 17,81%), sensitif rendah (52,409.14 hektar atau 52,14% dan tidak sensitif (14.681,48 hektar atau 14,61. Meskipun sebagian besar daerah daerah penelitian termasuk dalam kategori sensitif rendah, namun demikian perlindungan dari tumpahan minyak harus tetap diprioritaskan.Kata Kunci: perlindungan pantai, Indeks Sensitivits Lingkungan, tumpahan minyak, Teluk Bintuni