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The problems in bathymetry measurement often have gaps or ‘holes’ within the data. As a result, hydrographic surveyors often have sparse data, and even though the data is dense and equal distances, there is still a gap in time. This paper present coastal depth extraction from satellite images. The problem encountered during the bathymetry derivation process and the problem related to the space, distribution and quantity of the Single-beam echo sounder (SBES) data. Therefore, the idea of using spatial interpolation could be a suitable approach in solving the problems. This study intends to produce Satellite-Derived Bathymetry (SDB) from Landsat 8 images at Pantai Tok Jembal, Terengganu, Malaysia. The proposed method by first interpolating the SBES point in the calibration data using spatial predictors, i.e. Inverse Distance Weightage, Thin-Plate Spline, Spline with Tension, Universal Kriging, Natural Neighbor, and Topo to Raster. Second, the raster output created from the interpolation process then converts into the point shapefile. Third, intersect function use to eliminate the point whereby not in the domain. Finally, the newly generated SBES points in calibration data ready to apply at the SDB computation process, generating SDB. In continuation, a comparative analysis conducted between six SDB results generated using each different newly generated calibration data. The result indicates SDB utilizes with Universal Kriging-newly generated calibration data (RMSE: 0.718 m) was the best result. To summarise, this study has successfully attained the research objectives by utilizing the newly generated calibration data in generating SDB. The task of spatial interpolation recreates the SBES data from irregular space and short data to uniform space and long data, which facilitate in pixel to point value extraction and help refine the bathymetry derivation process. Furthermore, the proposed method suitable to be used when the data are not applicable or limited.

Mangroves have many benefits, both for humans and for the surrounding ecosystem. One of the most benefits from mangroves is that mangroves have coastal blue carbon reserves up to five times greater than the total carbon storage of temperate, taiga, and tropical forests. But recently, mangroves have decreased in extent by 20-35% due to both anthropogenic and naturogenic factors. One of the naturogenic factors that impact mangroves is sea-level rise. Mangroves cannot survive if sediment accumulation cannot keep pace with sea-level rise. This can result in mangrove death or zonal shifts in plant communities.The decline in mangrove areas has resulted in increases in carbon emissions. This increase in carbon costs $US6-24 billion in economic damage annually. Indonesia experienced the highest increase in carbon dioxide emissions in the world in 1990-2010. Whereas in the Paris agreement, 2015, countries in the world including Indonesia have committed to reducing emissions by 29-41% by 2030. Therefore, rehabilitation and restoration of mangroves need to be undertaken, as well as identification of those mangroves most under threat.The aim of this study is to model future sea-level rise and the impact of its exposure on land suitability for mangrove rehabilitation and restoration in Indonesia. This study uses the integration of remote sensing, statistical, and future climate model data combined with GIS methods to produce a sea-level rise model. This study also uses several scenarios both climate and temporal to predict sea-level rise.The results of this study indicate that there are several areas that have high exposure caused by sea-level rise. This is exacerbated by low rates of sedimentation or land subsidence in some areas. In contrast, several other areas experienced high rates of accretion and thus are at less risk. Changes in rates of inundation caused by sea-level rise have caused some areas suitable for planting mangroves to become unsuitable. Therefore, if planting is carried out in the area now, it is very likely that the mangrove will be submerged by excessive tidal inundation and any rehabilitation and restoration carried out will fail.This study is expected to be taken into consideration in driving new policy based on the results of the model. This study can also be used as a guide to consider which areas are suitable for mangrove rehabilitation and restoration without the threat of a sea-level rise in the future.

This study's purpose is to gain knowledge and information on the hydrodynamic condition in the Java Sea, North Subang Region. The data was compiled from ECMWF for wind data and TMD for tide constituent data as a hydrodynamic model generator and the field data taken from a field survey in 2020 and 4 tide station BIG (Jakarta (3) and Cirebon (1)). The software developed by Deltares (DELFT3D) was used for hydrodynamic simulation to simulate hydrodynamic conditions (water level and current). A structured rectangular grid was used to construct domain boundary model on the north coast of West Java Province. The bathymetry data from BATNAS (BIG) has been processed to produce a 100 m resolution to accommodate the high-resolution bathymetry data in the coastal areas, especially in Patimban Port. The result shows the water level fluctuation and current movement on the north coast of the West Java Sea during 2020. The model verification shows that the tidal phase already has a similar pattern, especially on the western side of the West Java Sea. RMSE values for stations in Jakarta Sea are 0.2, 0.04, 0.21, and 0.39 with coefficient correlation are 0.94, 0.91, 0.93, and 0.69 for Pondok Dayung, Sunda Kelapa, Kolinamil, and Cirebon respectively. The monsoon seasonal phenomena affected the current condition in the study area. However, the tidal model amplitude needs to be tuned in, so that it can fit with the field data. The study of the hydrodynamic condition is necessary for Patimban Port development which is currently under construction.

How the tsunami hazard affecting life in Palabuhanratu District is investigated in this paper. By considering this district as a tourist area that is visited by many tourists, the coastal activity is quite high compared to other areas. In the southern region of Java Island, or more precisely Pelabuhanratu, there is an active tectonic zone that can cause underwater earthquakes with a potential strength of up to 8.7 Mw. An underwater earthquake of this magnitude can cause a large tsunami potential, which will greatly affect or even paralyze community activities in coastal areas. This study is conducted to analyze the impact of a potential tsunami that could occur on community activities in the area. To achieve this, it is necessary to do tsunami modeling with numerical methods using the COMCOT v1.7 software on two scenarios. Then the results of the visualization of the inundation will be overlaid with land cover data and buildings data in Palabuhanratu District. The results of this study indicate that the tsunami immersion height in the first scenario modeling is much higher than the second scenario, which is more than 30 m. Meanwhile, for the second scenario, it reaches more than 4 m. The potential for this tsunami caused several losses to the residents, namely the residential area of 917.51 ha is submerged and 17,709 buildings affected in the first scenario, as well as the residential area of 260.54 ha is submerged and 2,779 buildings affected in the second scenario.

The Sunda Strait Tsunami that occurred on 22 December 2018 was an extraordinary event. This event began with an increase in the volcanic activity of Mount Anak Krakatau on 29 June 2018 that occurred in the form of a series of eruptions and earthquakes that continually caused landslides of Mount Anak Krakatau. The landslide of Mount Anak Krakatau's body that entered the sea generated tsunami waves and hit several areas in the Sunda Strait. Tsunami reconstruction is done by numerical modeling of tsunami wave formation, propagation of tsunami waves, and tsunami inundation using COMCOT software. Data used in tsunami reconstruction are topographical and bathymetry data in the Sunda Strait region and landslide parameters in the form of snapshots (time phases) of landslide movements as tsunami wave generators. Tsunami reconstruction generates information about the propagation of tsunami waves from sources to coastal areas and the height of the tsunami inundation in the area affected by the tsunami. This study also validated the results of the tsunami reconstruction compared with actual events using BIG tide station data in the Sunda Strait area, the results of the study by Syamsidik et al. (2019) [1], and the arrival time of the tsunami originating from BMKG. Validation shows that the waves resulting from reconstruction are larger and the periods are faster than the actual events, but the height of tsunami inundation results from reconstruction is lower and the tsunami arrival time is slower than the actual event.

The decreasing area of mangroves is an ongoing problem since, between 1980 and 2005, one-third of the world’s mangroves were lost. Rehabilitation and restoration strategies are required to address this situation. However, mangroves do not always respond well to these strategies and have high mortality due to several growth limiting parameters. This study developed a land suitability map for new mangrove plantations in different Southeast Asian countries for both current and future climates at a 250-m resolution. Hydrodynamic, geomorphological, climatic, and socio-economic parameters and three representative concentration pathway (RCP) scenarios (RCP 2.6, 4.5, and 8.5) for 2050 and 2070 with two global climate model datasets (the Centre National de Recherches Météorologiques Climate model version 5 [CNRM-CM5.1] and the Model for Interdisciplinary Research on Climate [MIROC5]) were used to predict suitable areas for mangrove planting. An analytical hierarchy process (AHP) was used to determine the level of importance for each parameter. To test the accuracy of the results, the mangrove land suitability analysis were further compared using different weights in every parameter. The sensitivity test using the Wilcoxon test was also carried out to test which variables had changed with the first weight and the AHP weight. The land suitability products from this study were compared with those from previous studies. The differences in land suitability for each country in Southeast Asia in 2050 and 2070 to analyze the differences in each RCP scenario and their effects on the mangrove land suitability were also assessed. Currently, there is 398,000 ha of potentially suitable land for mangrove planting in Southeast Asia, and this study shows that it will increase between now and 2070. Indonesia account for 67.34% of the total land area in the “very suitable” and “suitable” class categories. The RCP 8.5 scenario in 2070, with both the MIROC5 and CNRM-CM5.1 models, resulted in the largest area of a “very suitable” class category for mangrove planting. This study provides information for the migration of mangrove forests to the land, alleviating many drawbacks, especially for ecosystems.

Bathymetric data could be extracted by means of remote sensing techniques from satellite sensors known as satellite derived bathymetry (SDB). This study applies the use of remote sensing data for extraction of bathymetry within a specified time range. Logarithmic and linear analytical methods are applied to Sentinel 2A and Landsat 8 imagery to retrieve bathymetry data. We intend to analyse the pattern of error in regards to depth and epoch. The collection of satellite image, the corresponding storage, and processing makes use of Google Earth Engine (GEE). The result shows that the root mean square error (RMSE) of depth is ranging from 1.6 m to 5.4 m from both sources of imageries. Better accuracy is obtained by applying logarithmic method to Landsat imagery.

The provision of more comprehensive bathymetric data, for not just apply to the modern marine application but also the development of national data infrastructure. This demand has created a series of development in bathymetric data acquisition throughout the year from the lead line, ship-borne sounding, to air-borne Lidar. However, it has pros and cons in each bathymetric data acquisition related to cost, time, manpower and accessibility. The integration idea drives from the successful of Satellite-Derived Bathymetry technique in solving the problem, moreover, this the way to achieve the data with a uniform resolution in acceptable time and cost. Therefore, this study conducted to generate bathymetric mapping at '‘Pantai Tok Jembal'’ using Single Band Algorithm (SBA) for two visible bands (Blue and Green) and Green Band Algorithm (GBA). Two comparative analysis conducted in this study first is between SBA-Blue and SBA-Green to evaluate the ability of each band to estimate bathymetry at '‘Pantai Tok Jembal'’ shallow-coastal water area and while second is between SBA-Green and GBA method to evaluate the ability of each statistical approach in computing absolute water depth. Further, the result evaluated using SBES ground truth data. The root mean square error (RMSE) and R-squared (R2) computed between Single Beam Echo Sounding (SBES) data and Satellite-Derived Bathymetry (SBA and GBA), and the result shows that SBA-Green stand out in both analysis; moreover, this study successfully produces 49.69 km2 area (Extended Area) bathymetric mapping at '‘Pantai Tok Jembal'’, Terengganu, Malaysia. However, to support marine application and national data infrastructure, it requires more comprehensive bathymetric data which is giving high in accuracy and reliability, further research needs to undertake to fulfil this support

In this presented paper, an effort to improve the accuracy of the bathymetric model derived from optical satellite imagery is discussed. According to the previous study, the accuracy approximately measures in 2 m for depth up to 10 m by means of the Global Bathymetric Inversion Methods. Therefore, the improvement is done based on the so-called Cluster-Based Method applied to the analytical and log-ratio methods. The Cluster-Based Method partitions the working area on the by classifying the errors between the known depths and the predicted ones. The data for the known and predicted depths are acquired from the in-situ survey and the Sentinel-2 imagery. Improvement by one-third to the accuracy of the resulting bathymetry is obtained.

Indonesia is located side by side with the Pacific Ocean and the Indian Ocean where there are often tropical cyclones in these two oceans. As was the case some time ago in the Indian Ocean a tropical cyclone of Cempaka and Dahlia occurred which had a significant impact on Indonesian areas. Another impact felt is the disruption of economic activity in the area of tourism, ports, and power plants. Numerical modeling is carried out to simulate the phenomena of Cempaka and Dahlia tropical cyclones to determine the impacts caused especially in Lampung to Lombok areas. Numerical modeling is done using SWAN version 41.20. SWAN was chosen because it has good modeling calculations in coastal areas and is very suitable for wave analysis in coastal areas. The results of the modeling are verified by the significant wave height correlation coefficient from altimetry satellites that cross the tropical cyclones of Cempaka and Dahlia. The results showed a significant increase in wave height in the study area with an increase of up to 1028.31% at the observation point in Pelabuhan Ratu, West Java Province.

Pangandaran Village is a tourist village located in Pangandaran Regency, West Java Province, Indonesia. The beautiful view of sand beaches and abundant marine resources make Pangandaran Village has great economic potential. However, in 2006, an earthquake with a magnitude of 7.7 Mw triggered a tsunami disaster in the Pangandaran area that caused more than 600 fatalities, injuries, and damage to buildings, especially in Pangandaran Village. Based on current research, there is potential for an 8.7 magnitude earthquake off the south coast of Java in the near future, triggering an enormous tsunami. The coastal community in Pangandaran Regency has been building a tsunami risk reduction strategy to anticipate the tsunami disaster. In Pangandaran Village, the local community is piloting the 12 tsunami ready indicators following the guideline from UNESCO-IOC. Therefore, this study aims to map 12 tsunami ready IOC-UNESCO indicators in Pangandaran Village to evaluate which indicators the government and community of Pangandaran Village. The method used in mapping 12 tsunami ready indicators in Pangandaran Village is to take data in the field by doing aerial photographs, conducting interviews with the village government and other related local stakeholders, mapping tsunami evacuation plan and infrastructure, and disseminating questionnaires to the community to find out the response to the tsunami disaster. Based on the IOC-UNESCO tsunami indicator mapping results, all indicators have been fulfilled. However, several other aspects of tsunami preparedness indicators still need to be improved to strengthen tsunami preparedness in Pangandaran.

Geospatial information is increasingly needed for the development of Indonesia’s Special Economic Zones (SEZ) concept. Pangandaran Raya is one of the areas that have been proposed as one of the SEZ locations, having nature and coastal tourism as its primary economic activities, and certainly in need of geospatial information for its land, coastal, and marine areas. However, land, coastal, and marine geospatial information in Pangandaran have been collected and processed separately by different institutions and have caused an absence in data continuity in terms of resolution, reference, and data format. This paper aims to integrate the topographic and bathymetric data of Pangandaran to generate seamless digital elevation model of Pangandaran coastal area. Verification was done by calculating the RMSE of the difference between elevation produced by the seamless digital elevation model and elevation that had been observed with RTK in the field. The results show that the RMSE of the seamless digital elevation model was 27 cm and there were 6 factors that had controlled the quality of seamless digital elevation model. The main factor that had controlled the quality of seamless digital elevation model was topographic data quality.

On September 28, 2018, Indonesia was devastated by a 7.5Mw earthquake that triggered a tsunami off of the coast of Palu Bay, Central Sulawesi. This incident was puzzling because strike-slip fault earthquakes rarely generates destructive tsunamis. Previous studies have shown that the 2018 Palu tsunami had not been generated solely by a tectonic source, but there had been other motions such as submarine landslide which could have potentially contributed to and intensified the main tectonic tsunami. Such hypothesis was concluded based on the significant difference between the result of numerical simulation and the tide gauge’s record. The purpose of this study is to further analyze the conclusion of this hypothesis by comparing the result of numerical simulation with the post-tsunami survey in several observed points. The observed points were located at two tide gauges, Pantoloan and Mamuju, as well as twenty-two other points located both within and outside of Palu Bay. The comparison of simulation results with observed data showed a 30-minute arrival delay of the tsunami in Mamuju. Maximum inundation in observed points also showed a difference of 0.2–6 meters compared with post-tsunami survey. The inundation areas were significantly different at a range of 1–7 km2, which indicated other motions that could have contributed to the Palu tsunami.

Indonesia is located in and surrounded by areas that have active plate movements, making its coastal and marine areas prone to tsunami, and creating negative impacts, such as damage to properties and increase in death rates. One of these areas is the coastal area in Pangandaran Regency, West Java. This study aimed to analyze the level of building vulnerability and impact of losses as a result of tsunami. The research method combined data of buildings that have been classified based on their type and uses with data of inundation caused by tsunami and coefficient of Damage Ratio. The study results showed that the type of buildings in the tourism area of Pangandaran Regency is dominated by 1-story permanent buildings (P1), in which 2,050 out of 3,103 buildings were identified as residences and businesses. In general, based on the coefficient of Damage Ratio in the tourism area of Pangandaran Regency, vulnerability level of buildings is within 51%–70%, which is considerably high and indicates that the buildings could suffer heavy damage if they are hit by tsunami. The tourism industry in the area lost 700 million rupiahs and fisheries industry lost 6.055 billion rupiahs due to the 2016 tsunami. Eight hotel/resort buildings have been recommended as temporary evacuation sites or shelter in the event of a tsunami.

With the on-going construction of deep water port in Patimban area, a more dense marine traffic is expected to occur in the coastal belt between the ports of Jakarta and Cirebon. Precise prediction of tide is inevitably becoming more important in order to maintain safe navigation. The purpose of this work is carrying out a dedicated tidal simulation for the area in question. The presented result contains primarily the selection of bathymetric data for the development of computational domain and sensitivity tests due to bottom roughness and the quantity of elevation points along the model’s open boundaries. For the purpose of constructing computational domain, we assess the suitability of global and national bathymetry data. Data from two water level stations in Sunda Kelapa and Cirebon ports are used to verify the model output, for example surface elevation due to tide. The simulation of tide is carried out using two-dimensional horizontal numerical model facilitated by Delft3D software. Sensitivity tests considering two bottom roughness values and three scenarios of boundary conditions are carried out. It is found that the short-term tidal simulation indicates reasonable agreement against tidal data from Sunda Kelapa and Cirebon stations. It seems that bottom roughness does not provide significant control to the resulting magnitude. We have learned that an optimum number of tidal elevation points along the boundary condition must be set. Despite of the demands in improving the tidal phase, our present results indicate promising milestones toward a precise tidal simulation for the domain in question.

To support continuity of life, information on the availability of natural resources is needed. Natural resources need in a region must not exceed their availability. Panggang Island is a small island with an area of 13.76 ha and a population density up to 4,388 people in 2019. The land use of the island is intended as a residential area. With a small area and dense population, the ability of the environment to support life in Panggang Island is concerning. This study aims to determine the carrying capacity of water and land in Panggang Island. Water carrying capacity analysis is carried out by comparing the amount of water resource availability with standard water needs. The Thornthwaite Mather method is applied to calculate the water resource availability. Land carrying capacity analysis is based on a comparison of the amount of actual residential land with minimum space requirements of each individual according to the Indonesian National Standard (SNI 03-1733-2004). The results showed that Panggang Island has a very low carrying capacity for water and land. The water and land carrying capacity index reaches 0.12 and 0.98 respectively. This shows that the demands of residential land and water in Panggang Island are higher than the resources.

Satellite-derived bathymetry (SDB) emerging as a cost-effective that provides high-resolution mapping over a wide area. This method can map shallow water environment, especially that are difficult to access by boat or airplane. SDB is not for replacing the conventional bathymetry method but to assist. The accuracy of SDB does not meet current International Hydrographic Organization (IHO) S-44 standards but still can use when planning hydrographic surveying, i.e., unsurvey areas or areas with old data. In this paper, the SDB method applies to produces bathymetric mapping at Pantai Tok Jembal, Terengganu, Malaysia. Derived from Landsat 8 images and for the bathymetry method use is an empirical-based method, Log-ratio Transform. To diversify the result, utilizing three atmospheric correction approaches: No. atmospheric correction, Dark Object Subtraction (DOS), and Fast Line-of-sight Atmospheric Analysis of Hypercubes (FLAASH). The SDB result then evaluates using Single Beam Echo Sounding (SBES) ground truth data. The result indicates that Log-ratio Transform with DOS atmospheric correction produces the best result based on the error analysis. The error mostly occurs when there is no data available in the particular area due to cloud cover and shallow water area, i.e., inaccessible boat or vessel area. The error also occurs as it goes deeper area where the light is limited. In conclusion, this study successfully produces bathymetric mapping at Pantai Tok Jembal, Terengganu, Malaysia, through the SDB technique. This method strengthens the SBES data by effectively filling the data gaps; however, further research needs to fulfill this support in giving high accuracy and reliability.

CityGML merupakan model data yang bersifat terbuka untuk memodelkan wilayah perkotaan maupun lanskap secara 3D. Dari lima tingkat perincian/ Level of Detail (LOD) pada CityGML, LOD1 dan LOD2 menjadi tingkat perincian yang penting karena dimilikinya informasi mengenai struktur atap bangunan yang merupakan syarat data dalam pelaksanaan aplikasi seperti perencanaan detail maupun penataan lingkungan dan bangunan. Dalam mendukung perencanaan dan pengembangan perkotaan dan lanskap yang berkelanjutan, pengetahuan mengenai efek aliran angin di sekitar bangunan menjadi hal yang penting dalam menyelesaikan permasalahan perkotaan yang berkaitan dengan aliran angin. Integrasi model 3D CityGML dengan perangkat lunak simulasi Computational Fluid Dynamics (CFD) OpenFOAM dapat memberikan visualisasi dan informasi mengenai aliran angin di perkotaan dengan lebih baik. Makalah ini mempunyai tujuan untuk membangun dan memvalidasi model 3D CityGML LOD1 lanskap dari data DSM, DTM, dan tutupan lahan serta menerapkan simulasi aliran angin pada model 3D CityGML LOD1 lanskap yang telah dibangun dengan menggunakan perangkat lunak OpenFOAM. Model 3D LOD1 direkonstruksi dari data Digital Surface Model dan peta vektor 2D Kampus ITB Jatinangor, sedangkan bentuk atap pada model 3D LOD2 dihasilkan dari pengamatan stereo fotogrametri. Hasil simulasi aliran angin menunjukkan pengaruh model 3D LOD1 terhadap aliran angin berupa perubahan arah dan kecepatan, serta geometri model 3D LOD1 bangunan dan pohon menyebabkan informasi aliran angin menjadi kurang akurat di sekitar atap bangunan dan di sekeliling pohon. Hal ini dapat diperbaiki dengan menambah tingkat perincian model yang digunakan menjadi LOD2.

The Southern Coast of West Java Province in the Java Islands is one of prone and exposed area to tsunami hazard. It has about 428 kilometers coastline length, covering 5 administrational regencies (i.e. Sukabumi, Cianjur, Garut, Tasikmalaya, and Pangandaran). It is a strategic area that support many economic activities including tourism, fisheries, electricity power plants, agricultures, markets as well as social factors such as coastal villages, schools and other public facilities. The existence of this strategic area is threatened by the potential for a tsunami disaster mainly from megathrust along the Southern Coast of Java Island. On 2006, a tsunami earthquake of M7.7 occurred off Pangandaran Regency with tsunami height of 5-8 meters and inundated about 500 meters along southern coast of West and Central Java Province. The tsunami caused more than 600 casualties and damage to buildings, public facilities and insfrastructure. Yet, the Indonesia National Earthquake Source and Hazard Map suggest a bigger threat of a plausible M8.7 – M9.2 megathrust earthquake off Java island. This research aims to analyze and map potential areas affected by the tsunami in the South Coast of West Java Province based on numerical modelling carried out with Cornell Multi-grid Coupled Tsunami Model (COMCOT) v1.7 based on the several megathrust earthquake scenarios in southern off West Java. The results of tsunami modelling show that the highest impact is generated in the Sunda Straits & West Java - Central Java Megathrust Scenarios with highest tsunami inundation and the fastest travel time occurred in Cianjur Regency with 26,7 meters height and estimated arrival time of tsunami wave approximately 10 minutes after the mainshock, while the farthest inundation distance is estimated in Sukabumi Regency about 5.8 kilometers from the coast due to existence of river.

Makalah ini membahas perilaku jangka pendek arus dan kekeruhan relatif. Pembahasan didasarkan pada analisis data dari pengamatan lapangan di satu titik pada kedalaman sekitar 30 m. Titik pengamatan terletak di kanal antar-terumbu sekitar 600 m timur laut Pulau Pramuka ke arah Pulau Panggang. Acoustic Doppler Current Profiler (ADCP) berfrekuensi 614,4 kHz digunakan dalam pengukuran selama 25 jam dan 50 menit, sekitar dua hari setelah pasang perbani. ADCP mengukur profil arus dan hamburan balik dengan interval 1 m. Analisis dilakukan dengan menghubungkan saat perubahan kecepatan arus dengan pasut. Selain itu, kekeruhan relatif dihitung dari hamburan balik menggunakan persamaan kalibrasi empiris. Dari analisis, diperoleh korelasi positif antara tunggang pasut dengan kecepatan arus. Kecepatan arus tertinggi (yaitu 0,42 meter per detik) berkorelasi dengan saat air tinggi yang lebih rendah ( lower high water ). Kecepatan arus terdistribusi secara merata di sepanjang kolom air. Dibandingkan dengan di lapisan bawah, kecepatan arus di lapisan atas meningkat lebih cepat. Kekeruhan relatif yang dihitung dari hamburan balik menunjukkan bahwa material padat tersuspensi lebih banyak terkumpul di lapisan bawah. Peningkatan kekeruhan relatif diidentifikasi terjadi saat air rendah setelah air pasang tinggi ( higher high water ). Arah gerak arus saling berkebalikan dengan jumlah kejadian yang dua kali lebih banyak dan kecepatan arus yang dua kali lebih kuat ke arah ke arah 33° dibandingkan dengan ke arah 226°.

Mangrove has an important role not only for ecosystem services such as erosion control and water purification but also for human life. For instance, mangrove has been satisfactorily saving people from the ocean such as storm surge or tsunami. However, mangrove population has fallen for about a fifth over these 25 years. Therefore, rehabilitation and restoration of mangrove are essential to be taken to overcome mangrove loss. Nonetheless, in several areas, while doing the rehabilitation mangrove, some species of mangroves failed to survive due to several parameters that were not suitable for them to grow. Hence, this research aimed to determine suitable sites for mangrove life in Indonesia globally. This research used several parameters which were: elevation, slope, air temperature, and precipitation, to measure the suitable sites. The result shows that 62% from the total area (99,773 ha) of coastline in Indonesia are suitable for mangrove to grow included 59% is suitable class (95,347 ha) and 3% is perfectly suitable class (4,427 ha), while the unsuitable class has 38% (61,616 ha) from the total area. Furthermore, in some areas, the decreasing number of suitable land for mangrove was related to the increasing number of mangrove deforestation.

Mentawai Island is adjacent with Indian Ocean that prone to high waves due to the wind in the Australia monsoon periods so that this island affected by coastal erosion. This coastal hazard causes significant risk like physical damage. Accordingly, disaster risk reduction program in coastal areas is indispensable in advance for the next destructive coastal hazard event. This need is answered by conducting disaster risk analysis as the first step in coastal erosion identification in the Mentawai Islands. The risk was obtained using a qualitative approach by combining the multidimensional aspects of hazard as well as vulnerability. Hazards aspect was derived from identification of physical variables to erosion and was represented by index value. Vulnerability aspects consist of physical aspect and social aspect. The physical aspect is the distribution of buildings and the social aspect is population density that obtained by modeling process. The result indicated that the eastern Mentawai coast has a wider area of erosion risk than the west coast due to the influence of the Australian monsoon.

Wilayah pesisir sebagai kawasan peralihan yang menghubungkan ekosistem darat dan ekosistem laut, sangat rentan terhadap kerusakan dan perubahan yang diakibatkan oleh berbagai aktifitas manusia di darat maupun di laut. Kabupaten Indramayu merupakan salah satu wilayah di Pesisir Utara Jawa Barat yang mengalami kerusakan paling parah diantara seluruh kabupaten di wilayah pesisir Utara Jawa Barat serta memiliki penggunaan lahan pesisir yang cukup lengkap mulai dari pemukiman, persawahan, tambak, dan industri (PLTU dan MIGAS)..Besarnya perubahan garis pantai yang meliputi abrasi dan sedimentasi diturunkan dari data citra satelit Landsat wilayah pesisir Kabupaten Indramayu tahun 1994-2009 dengan metode komposit RGB 4, 5, 7 dan Metode AGSO kemudian dilakukan proses digitasi.. Luas abrasi di 11 Kecamatan Pesisir Indramayu dari tahun 1994 – 2009 sebesar 3900,41 Ha dengan laju abrasi rata-rata sebesar 23,64 Ha/ tahun dan Luas sedimentasi sebesar 650,29 Ha dengan laju sedimentasi rata-rata sebesar 4,81 Ha/tahun. Hasil perhitungan regresi terhadap rasio lahan penduduk untuk tahun 2015 sebesar 0,07 Ha/ jiwa dan menurun pada tahun 2025 menjadi 0,05 Ha/jiwa .Rasio lahan petani untuk tahun 2015 sebesar 0,66 Ha/petani dan menurun menjadi 0,55 Ha/petani di tahun 2025. Kata Kunci : Pesisir indramayu, citra satelit, abrasi dan sedimentasi, Rasio lahan ABSTRACT Coastal areas as a transitional region connecting the land ecosystems and marine ecosystems, are vulnerable to damage and changes caused by various human activities on land and at sea. Indramayu regency is one of the areas in the North Coast of West Java is the most severely damaged among all districts in the northern coast of West Java and has a coastal land use complete enough from residential areas, wet rice fields, ponds, and industrial (power plant and Gas). The number of change in coastal line include erosion and sedimentation derived from Landsat satellite image data coastal areas of Indramayu district in 1994-2009 with the composite method RGB 4, 5, 7 and methods AGSO then do the digitization process. The extent of abrasion in 11 districts of the coastal Indramayu from 1994 - 2009 are 3900.41 hectares with average abrasion rate of 23.64 ha / year and sedimentation area of 650.29 hectares with an average sedimentation rate of 4.81 ha / year. Results of regression calculations to land ratio for the 2015 population of 0.07 ha / life and decreased in 2025 to 0.05 hectares /life .Rasio farmers' fields for 2015 of 0.66 ha / farmer and decreased to 0.55 Ha / farmers in 2025. Keywords : Coastal area of indramayu, satellite imagery, erosion and sedimentation, land Ratio

Wilayah dan potensi kelautan yang besar di Negara Kesatuan Republik Indonesia (NKRI) memerlukan pengelolaan yang sesuai agar dapat terjaga dan termanfaatkan dengan baik. Penyusunan dan pengesahan undang-undang nomor 32 tahun 2014 tentang kelautan adalah suatu bentuk usaha yang dilakukan negara dalam menata dan mengatur ruang lautnya secara terpadu. Undang-undang kelautan di dalamnya mempunyai sebelas asas dan delapan tujuan. Asas dan tujuan tersebut berisi mimpi-mimpi besar di bidang kelautan Indonesia dan harapannya dapat dicapai melalui undangundang ini. Akan tetapi kenyataanya masih banyak pekerjaan yang harus dilakukan untuk mengimplementasikannya sehingga mencapai kondisi ideal yang diharapkan. Penelitian ini bertujuan mengetahui sejauh mana undang-undang dapat diimplementasikan melalui uji prasyarat hukum undang-undang. Hasilnya undang-undang kelautan memenuhi syarat sah dan absah, sehingga dapat diimplementasikan dari aspek muatan hukum tersebut. Sedangkan, hasil analisis SWOT dan semantik bahasa menunjukkan bahwa implementasi dari undang-undang kelautan masih jauh dari harapan. Harapan kedepannya dengan dibuatnya aturan-aturan pendukung dan diperbaikinya kinerja pemerintahan, maka implementasinya akan berjalan lebih baik. Peranan bidang geodesi dan geomatika dalam bidang kelautan sudah sampai dalam tahapan membantu berbagai permasalahan di bidang kelautan.Kata kunci: undang-undang, kelautan, asas, tujuan, implementasiABSTRACTLarge marine regions and potential in the Republic of Indonesia require appropriate management and maintainance. Drafting and legitimating of maritme law no. 32 in 2014 are government effort in maintining and organizing of Indonesia sea n integrated manner. Maritime law has eleven principles and eight objectives contained within. The principles and objectives contain big dreams for Indonesian marine. These dreams hope can be achieved with the existence of this law. But in fact is still much work to be done in implementing such a big dream to reach the ideal situation. This research aims to determine in which extent legislation can be implemented and carried out to test the legal prerequisite legislation, and the result is marine legislation qualified from legitimate and legal test so that it can be implemented from the aspect of the legal aspect. While the SWOT and semantic analysis can be seen that the implementation of marine legislation is still far from expectations, expected in the future with the establishment of rules from the and improved performance of the government, the implementation will be better. For the geodesy and geomatics roles are already in the level helpin in the problems of marine field.Keywords: law, principle, objective, implementation

The Seribu Islands are located in the Java Sea about 50 km northwest of Jakarta, Indonesia. The islands and surrounding waters support tourism, fishing and mariculture, transportation, waste disposal, mining, energy production, and environmental protection. Mariculture has become an important fisheries component since its products are highly valued and command good prices on the export market. However, mariculture sites, mostly located close to the 14 inhabited Seribu Islands, may potentially conflict with tourism and have become an issue in the development of the area. A Decision Support System (DSS), based on optimization of physical, chemical, and socioeconomic parameters to determine suitable locations for mariculture, is presented in this article.

Sea level anomaly (SLA) is one of the oceanic parameters that play a crucial role in the ocean dynamics. In the Indonesian region, spatio-temporal characteristic of SLA is significantly affected by local topographic features of the region. In this research, we investigate long-term variation of SLA over the region based on Topex/Poseidon, Jason-1 and Jason-2 data, during the period of Sept 1992 to January 2017. After removing some geophysical effects, time series of SLA values at each point of the collinear tracks are analyzed. The result show the long term MSSH in Indonesia area have increase from western part of Indonesia to eastern part with range -40 m to 80 m. The long term SST in Indonesia have almost same trend with the deviation from geoid undulation full degree with short wavelength type, and this phenomena represent the local effect such as shallow bathymetry and close sea. And for long term SLA, Indonesia shows positive value that the anomaly increasing with variable from western part to eastern part of Indonesia from 2.5 mm/year until 7 mm/yr.

Mariculture (marine aquaculture) has been intensified and has created essential employment opportunities over the last two-decades in Indonesia, as well as many other countries in the world. This development has also augmented environmental concerns and questions about possible environmental impacts. Considerable amounts of nutrient waste in dissolved and particulate form were released by intensive fish faming into the environment through feed excess, soluble fish excretion and faeces production. One of the first steps to avoid the dangerous environmental impacts is careful site selection. Hence, before the implementation of fish farming mariculture activities, appropriate site conditions for culturing the species should be selected in order to minimize environmental impacts arising from the farming activities (sustainability) as well as to guarantee adequate conditions from the operational point of view (suitability). The paper focuses on the development of a Decision Support System (DSS) as a tool for the decision maker in coastal zone management and mariculture for the appropriate selection of mariculture site location. Extensive use of GIS as part of the Decision Support System was deployed in this study. The DSS is based on physical, chemical and sediment criteria as well as on data of conflicting coastal use. The GIS analysis results in a map indicating the suitable areas for the improved method of offshore cage mariculture. In this study, emphasis was placed on finfish species, however the methods and results may be employed for other species as well following some modifications. The DSS was applied for the western part of Java Sea, Indonesia. The data were acquired from direct field measurement, numerical modelling and existing information from particular agencies. Numerical modelling was used to obtain spatial and temporal distributions of hydrodynamic parameters (i.e. current velocities and water levels). The Delft3D modelling system (Delft Hydraulics, The Netherlands) was employed for this purpose. The DSS was developed under GIS application of ESRI® ArcGIS™ using weighted overlay method. Due to lack of data, some parameters were excluded from the analysis. The results showed the adequacy of the system for supporting governmental authorities in the implementation, environmental controlling, and estimation of overall carrying capacity for environmental sustainable marine fish farming.

Harbours are a focus of intensive and diverse activities and thus have a high potential to become centres of conflict between users. Reviewing the multiple uses associated with harbours provides important insights into maritime communities and the management of conflict. In this paper, seven international, multi-disciplinary groups provide their expert synthesis of individual harbours. After a detailed discussion experts from Sydney, Qingdao, Vigo, Auckland, Jakarta, Crete and Plymouth synthesised and shared their harbour’s characteristics, user conflicts and how such conflicts have been researched and managed. The paper addresses an omission of “conflict” in most of the research literature about harbours, and ports and scopes a research agenda that includes integration, risk appreciation and other approaches to these increasingly contentious maritime environments. This process provided an opportunity for global researchers to share the ways harbour conflicts are mitigated and the kinds of adaptations that are possible.