Judul: Perubahan Tutupan Lahan dan Pengaruhnya Terhadap Serapan CO2-e Menggunakan Citra SPOT-7 di Kecamatan Tebet
Abstrak: Kepadatan penduduk yang tinggi di wilayah perkotaan memicu tingginya kegiatan alih fungsi lahan menjadi permukiman. Kecamatan Tebet merupakan wilayah dengan jumlah kepadatan penduduk tertinggi di Jakarta Selatan. Penelitian ini bertujuan untuk mengidentifikasi tutupan lahan beserta perubahannya dan pengaruh perubahan tersebut terhadap sekuestrasi karbon menggunakan citra SPOT-7 pada tahun 2018 dan 2022. Metode yang digunakan dalam penelitian ini adalah interpretasi visual dengan digitasi on screen. Nilai kappa accuracy dari hasil klasifikasi mencapai angka 0,95 dan overall accuracy sebesar 96%. Perubahan tutupan lahan terbesar di Kecamatan Tebet dari tahun 2018 hingga 2022 adalah bangunan permukiman kota dengan luas perubahan sebesar 10,04 ha. Nilai estimasi serapan CO2-e yang diperoleh pada tahun 2018 sebesar 88778,11 ton dan tahun 2022 sebesar 83173,72 ton. Nilai estimasi serapan CO2-e dari tahun 2018 sampai 2022 mengalami penurunan sebesar 1401,1 ton/tahun. Hasil analisis perubahan tutupan lahan yang terjadi mempengaruhi nilai serapan CO2-e pada tutupan lahan bervegetasi., High population density in urban areas drives the high rate of land conversion into residential areas. Tebet District is the area with the highest population density in South Jakarta. This study aims to identify land cover and its changes, as well as the impact of these changes on carbon sequestration, using SPOT-7 imagery in 2018 and 2022. The method used in this study is visual interpretation with on-screen digitization. The Kappa accuracy value from the classification results reached 0,95 and the overall accuracy was 96%. The largest land cover change in Tebet District from 2018 to 2022 was urban residential buildings, with a change area of 10.04 ha. The estimated CO2-e sequestration value obtained in 2018 was 88778,11 tons and in 2022 it was 83173,72 tons. The estimated CO2-e sequestration value from 2018 to 2022 decreased by 1401,1 tons/year. The results of the land cover change analysis indicate that the changes affect the CO2-e sequestration value of vegetated land cover.
Keyword: Akurasi, tutupan lahan, CO2-e

Judul: Land Using Sentinel-2 Imagery in Sukamakmur District, Bogor Regency from 2018-2023
Abstrak: Pertumbuhan penduduk yang pesat mengakibatkan tingkat kebutuhan masyarakat terhadap lahan semakin meningkat sehingga menyebabkan terjadinya perubahan tutupan lahan. Penelitian ini bertujuan untuk mengidentifikasi dan menganalisis perubahan tutupan lahan di Kecamatan Sukamakmur Kabupaten Bogor menggunakan Citra Sentinel-2 tahun 2018–2023. Terdapat 9 kelas tutupan lahan yaitu hutan, sawah, kebun campuran, pertanian lahan kering, pemukiman, lahan terbuka tanah, semak, sungai, dan danau. Kelas tutupan lahan yang mengalami peningkatan adalah tutupan lahan hutan (83,40 ha), pertanian lahan kering (48,94 ha), sawah (6,35 ha), dan permukiman (1,08 ha). Sedangkan kelas tutupan lahan yang mengalami penurunan adalah kelas tutupan lahan semak belukar (80,97 ha), lahan terbuka (40,01 ha), dan perkebunan campuran (18,79 ha). Perubahan tutupan lahan yang terjadi di Kecamatan Sukamakmur Kabupaten Bogor menunjukkan sebesar 73,86% mengalami perubahan ke arah positif dan 26,14% mengalami perubahan ke arah negatif. Perubahan ke arah positif yang lebih besar menunjukkan bahwa cadangan karbon di Kecamatan Sukamakmur semakin meningkat sehingga tanaman mampu menyerap CO2 dari atmosfer lebih banyak dan menyimpannya dalam bentuk biomassa tanaman., Rapid population growth results in the level of people's need for land increasing, causing changes in land cover. This research aims to identify and analyze changes in land cover in Sukamakmur District, Bogor Regency using Sentinel-2 Imagery in 2018–2023. There are 9 land cover classes, namely forest, rice fields, mixed gardens, dry land agriculture, settlements, open land, bushes, rivers, and lakes. The land cover classes that experienced an increase were forest land cover (83.40 ha), dry land agriculture (48.94 ha), rice fields (6.35 ha), and settlements (1.08 ha). Meanwhile, the land cover classes that experienced a decline were the land cover classes of shrubs (80.97 ha), open land (40.01 ha), and mixed plantations (18.79 ha). Land cover changes that occurred in Sukamakmur District, Bogor Regency showed that 73.86% experienced changes in a positive direction and 26.14% experienced changes in a negative direction. Changes in a greater positive direction indicate that carbon reserves in Sukamakmur District have increased so that plants are able to absorb more CO2 from the atmosphere and store it in the form of plant biomass.
Keyword: tutupan lahan, sentinel-2, Sukamakmur

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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