Identification of Reservoir Thickness and Estimation of Hydrocarbon Reservation Used the Pre-Stack Depth Migration (PSDM) in Cikung Area

Information from the geological data shows that the Cikung field has the complex structure which is characterized by carbonate reef. Therefore, it is required in the domain depth migration (PSDM) using interval velocity model is sensitive to variations in vertical and horizontal velocity to identify the thickness of the reservoir and estimation of hydrocarbon reserves. Stages include making the depth structure maps, map making the thickness of the reservoir, and the calculation of hydrocarbon reserves. The results showed that the thickness of the reservoir in Cikung Field, estimated to range from 71 meters to 175 meters with the prospect reservoir is at a depth of 1216 meters to 1247 meters from the surface. Hydrocarbon deposits (oil) is estimated at 1,134 × 106 or 1,311 × 108 kilo litre by the porosity of 22.6% and 70.7% water saturation

The Tsunami Simulation Generated by ‘Anak Krakatau’ Volcano Flank Collapse using MIKE 21Hydrodynamics Flexible Mesh with Manning Number Variation

This study aims to calculate the tsunami investment and the estimated arrival time at several locations around the Sunda strait, caused by the December 2018 Krakatao's eruption. The propagation of the tsunami wave is simulated using MIKE 21 Hydrodynamics Flexible Mesh (HD FM). The spatial data consist of the bathymetry and topography of the Sunda Strait area and its surroundings, whilst assumptions are made on the tsunami source topology and its exact location. Several runs of the simulation are then conducted by varying the Manning Number, i.e. bed resistance values, at the tsunami source and throughout the simulation domain, which accordingly would influence the propagation speed, inundation, and arrival time. Smaller Manning's values, which correspond to increasing roughness, are applied at locations closer to the tsunami source. In this simulation, Manning's number ranges from 10 to 40 m1/3s-1. Surface elevation, still water depth, and u and v velocity components are generated from this simulation

Factors affecting land transfer function and its impact on farmers' income in Srigading Village, Sanden Sub-district, Bantul Regency

Coastal area is a specific area where the region can be used as a tourist area, settlements, and agriculture. Some forms of utilization in the field of agriculture, among others, is farming of paddy fields or fishery ponds. As is the case along the southern coast of the Special Territory of Yogyakarta. Coastal residents of Bantul and Kulon Progo districts utilize coastal land as dryland farming and fishery ponds. This study aims to determine the effect of land use change in the Srigading Village (especially for the conversion of shrimp ponds) to the farmers' income in the Village. This research uses the tools of remote sensing technology to identify land use change that happened in the research area and combine with interview result data to know earnings difference from a farmer. The result of the analysis shows that land use in the coastal area of Srigading Village, Sanden Sub-District, Bantul Regency, before being used as shrimp pond is dominated by agricultural land and garden/moor. There are also settlements, and bodies of water contained in the study area. Land in the form of gardens/moor and agricultural land is a land that has the potential to switch function to shrimp farms as long as get enough brackish water supply. The distance is quite close to the beach and the river makes the land is very potential to switch functions into ponds. The results of the analysis also showed that farmers' income before and after shrimp farming in Srigading village experienced an average increase of almost 50%.Kawasan pesisir merupakan wilayah yang berpotensi mengalami perubahan penggunaan lahan. Penduduk pesisir Kabupaten Bantul dan Kulon Progo memanfaatkan lahan pesisir sebagai pertanian lahan kering dan kolam perikanan. Penelitian ini bertujuan untuk mengetahui pengaruh perubahan penggunaan lahan di Desa Srigading (terutama untuk konversi tambak udang) terhadap pendapatan petani di desa. Penelitian ini menggunakan alat teknologi penginderaan jauh untuk mengidentifikasi perubahan penggunaan lahan yang terjadi di daerah penelitian dan digabungkan dengan data hasil wawancara untuk mengetahui perbedaan pendapatan dari petani. Hasil analisis menunjukkan bahwa penggunaan lahan di wilayah pesisir Desa Srigading, Kecamatan Sanden, Kabupaten Bantul, sebelum digunakan sebagai tambak udang didominasi oleh lahan pertanian dan kebun/tegalan. Ada juga pemukiman, dan area air yang terdapat di wilayah studi. Kebun/tegalan dan lahan pertanian adalah lahan yang berpotensi untuk beralih fungsi ke tambak udang selama mendapat pasokan air payau yang cukup. Jaraknya yang cukup dekat dengan pantai dan sungai menjadikan tanah sangat potensial untuk beralih fungsi menjadi kolam. Hasil analisis juga menunjukkan bahwa pendapatan petani sebelum dan sesudah budidaya udang di desa Srigading mengalami peningkatan rata-rata hampir 50%.DOI: http://dx.doi.org/10.17977/um017v24i12019p03

The Coherency and Correlation between Sea Surface Temperature and Wind Velocity in Malacca Strait: Cross Wavelet Transform and Wavelet Coherency Application

This study tried to observe the correlation and coherency between sea surface temperature (SST) and wind velocity in the Malacca Strait at the year of 2015. The SST and wind velocity data with 6 hours interval step have been used in this study. S-Transform, the Cross Wavelet Transform, and the Wavelet Coherency were applied to observe the influence of the variation of sea surface temperature to the wind velocity in Malacca Strait. These methods could produce the phase lag and the time of occurrence between them. S-Transform was used to show the spectrum energy of the sea surface temperature variation. The strongest correlation between them has the period of 32 days during July to August and October to November at each point with significance level of 95 %. The coherency of them has the range of 4 to 64 days at each point. The last result is the spectrum energy of SST variation that has the period of 5 to 50 days at each point. It was similar to the result of the correlation and coherence period between the wind velocity and the SST dat

Dinamika Pantai Praikalogu di Provinsi Nusa Tenggara Barat, Indonesia

Fenomena lautan terkait dengan bidang kajian oseanografi dimana tiap parameter mempengaruhi satu sama lain, misalnya angin dengan gelombang. Kajian data angin penting diolah untuk meramalkan gelombang yang terbentuk. Pengolahannya pun harus diekstrak menggunakan ODV, selanjutnya ditentukan berdasarkan perhitungan rumus terkait. Angin berperan sebagai pembangkit gelombang. Angin yang bergerak terus-menerus, dalam durasi lama, kecepatan konstan, wilayah yang luas dan bertiup pada arah yang tetap mampu membangkitkan gelombang dengan ketinggian yang besar. Perairan Samudera Hindia tergolong besar dan 50% ukuran fraksi sedimen sebesar 0.13 mm. Perambatan energi gelombang yang besar mampu membawa sedimen yang besar. Laju transport sedimen dapat digunakan untuk menentukan perubahan garis pantai akibat sedimentasi maupun erosi/abrasi

The Characteristics of Significant Wave Height and Sea Surface Temperature in the Sunda Strait

Sunda Strait has an important role in the water mass exchange from the Pacific Ocean and the Indian Ocean so that the oceanographic condition is strongly affected by seasonal factors. The purpose of this study is to observe the relationship and the characteristics of significant wave height (SWH) and sea surface temperature (SST) in the Sunda strait and its relationship with IOD. The method employed is spatial analysis, low-pass filter, and spectrum analysis by S-Transform, beside that the correlation between SST and SWH is analyzed by wavelet coherency. The period of SWH and SST is dominantly semiannual, at the time of winter monsoon (the Northeast Monsoon), the SWH was reaching up to 2,11 m, while at the summer monsoon, the SWH was reaching up to 3.62 m. Reversely, the SST increased during the winter monsoon. At the time of 2016 had been detecting by the negative IOD with the IOD index of -0.65 and it caused the SWH increased by 0.3 m than its average. Based on the wavelet coherence, the SWH and the SST have the coherence in the period of 8 to 16 days, especially in March to April, and June to August

Hydro-oceanographic condition (Tide, Sea Current, and Waves) of Nongsa Batam Sea

Tanjung Bemban is one of the seas found in the Nongsa sub-district, Batam city which is currently developed as a tourist attraction. This research aims to find out the hydro-oceanographic component, which consists of tide and the current and wave pattern in the sea of Tanjung Bemban Nongsa. To collect the data regarding tide, Tide Pole method, using measuring sign, is used, To collect data of sea current, Float Tracking (Lagrangian) method, by measuring distance and displacement of floating objects in the sea, is utilized,  To collect the data of the wave, Wave Pole method, by measuring wave height, is employed. Based on the result of the research, it is clear that the tide of the sea is categorized as the semi diurnal, since there are two tides in one day with identical height, which occur sequentially and regularly. The highest flow reaches 260 cm and the lowest ebb 19 cm in the 4 days of observation, with 15 minutes interval. The measuring of ocean current is carried out for every 30-second intervals. Current velocity in Nongsa sea ranges from 0.02 m/s to 0.26 m/s. The current moves from east to southwest and west, even though some move northwest and north. Wave height is quite low, between 18 cm and 23 cm. Hydro-oceanographically, the Tanjung Bemban Nongsa area can be developed into a strategic tourism are

KARAKTERISTIK SUHU PERMUKAAN LAUT DAN KECEPATAN ANGIN DI PERAIRAN BATAM HUBUNGANNYA DENGAN INDIAN OCEAN DIPOLE (IOD)

This study aimed to observe the characteristics of sea surface temperature (SST) and wind velocity and its relation with the Indian Ocean Dipole (IOD) in the waters of Batam. The data used in this study is the SPL and the wind speed in 2016 in the waters of Batam. The method used in this research is the visual analysis using the data ocean view (ODV) to look at the spatial and temporal distribution of the SPL and the wind speed in Batam waters at different seasons. The next method is a fast Fourier transform (FFT). Transitional season one that occurred in April seen the highest wind speed seen with the value of 3.9 m/s**-1 for components U. As for the V component has the highest value of -3.6 m/s**-1. Sea surface temperature (SST) Batam highs in April occurred on 19-04-2016 with a value of 304.2°C (31.05°C). West monsoon winds that occurred in January seen the highest wind speed with a value of 4.5 m/s**-1 for components U. As for the V component has the highest value of 5.2 MS m/s**-1 in the waters of Batam. . Sea surface temperature (SST) highest Batam in January occurred on 19-01-2016 with a value of 302.8°C (29.65°C). Based on the results of the FFT, wind speed and SPL in the waters of the island has a dominant 6-month period (semiannual)

A Simple Aerial Photogrammetric Mapping System Overview and Image Acquisition Using Unmanned Aerial Vehicles (UAVs)

Aerial photogrammetry is one of the Alternative technologies for more detailed data, real time, fast and cheaper. Nowadays, many photogrammetric mapping methods have used UAV / unmanned drones or drones to retrieve and record data from an object in the earth. The application of drones in the field of geospatial science today is in great demand because of its relatively easy operation and relatively affordable cost compared to satellite systems especially high - resolution satellite imagery.  This research aims to determine the stage or overview of data retrieval process with DJI Phantom 4 (multi - rotor quad - copter drone) with processing using third party software. This research also produces 2 - dimensional high resolution image data on the research area. Utilization of third party software (Agisoft PhotoScan) making it easier to acquire and process aerial photogrammetric data. The results of aerial photogrammetric recording with a flying altitude of 70 meters obtained high resolution images with a spatial resolution of 2 inches / pixels.&nbsp