Judul: Studi Pemanfaatan Citra Landsat 8 untuk Pendugaan Potensi di Hutan Rakyat Kabupaten Kulon Progo Daerah Istimewa Yogyakarta
Abstrak: Potensi akan kayu dan tegakan yang berasal dari hutan rakyat meningkat pesat seiring dengan timbulnya ketertarikan masyarakat untuk membangun hutan rakyat. Hal ini disebabkan oleh manfaat dari pembangunan hutan rakyat mulai dirasakan oleh masyarakat. Untuk mempermudah dalam pengelolaannya, diperlukan suatu kegiatan yang dapat menghitung dengan cepat potensi yang ada pada hutan rakyat tersebut. Metode yang dapat digunakan yaitu metode penginderaan jauh dengan memanfaatkan teknologi citra Landsat 8. Tujuan penelitian ini adalah merumuskan model pendugaan potensi tegakan dan membuat peta sebaran potensi hutan rakyat Kabupaten Kulon Progo dari persamaan model terbaik menggunakan citra Landsat 8. Tahapan penelitian ini terdiri dari: pengumpulan data, pra-pengolahan citra, pengambilan data lapang, dan pengolahan data. Hasil pengolahan data menunjukkan bahwa model regresi terbaik, yaitu model eksponensial V = 0.274*e(8.107*NDVI) dengan nilai R2 sebesar 83.3%. Uji akurasi pemetaan potensi memiliki nilai overall accuracy sebesar 91.8% dan kappa accuracy sebesar 87.23%. Luas hutan rakyat di Kabupaten Kulon Progo sebesar 50 921.86 Ha dengan potensi hutan rakyat terbesar terdapat pada Kecamatan Samigaluh dengan luas hutan rakyat sebesar 6729.92 Ha dan total potensinya sebesar 823 565.20 m
Keyword: Landsat 8, private forest, potential, regression model

Judul: Analisis perubahan penggunaan lahan dan potensi terjadinya lahan kritis di Kabupaten Kulon Progo Daerah Istimewa Yogyakarta
Abstrak: Population growth and development activities have been affecting change of land use. The change of land use, in many case has caused land degradation that lead to formation of critical land. This study aims to (1) analyzed the spatial patterns of land use in Kulon Progo District during 1996 until 2009, (2) analyzed the formation of critical land, (3) analyzed change of land use that affect for critical land. The method used in the study include land use interpretation using landsat image, analyze change of land use by utilizing remote sensing technology. Determining critical land using criteria from forestry according to SK Dirjen RLPS No: SK.167/V-SET/2004. The result of study showed that land use in Kulon Progo District during period 1996-2009 have two type of change: decrease and increase. Land use that decrease include bush: 148 ha, forest: 981 ha, mixed garden: 406 ha, and paddy field: 168 ha. Land use type that increase include residential: 1,101 ha, rain fed field: 74 ha, farmstead: 390 ha, and waduk (water reservoir): 144 ha. During 1996-2009, the land in Kulon Progo District show that area of critical land increase 657 ha from 3,274 ha to 3,931 ha, rather critical land increase 227 ha from 4,025 ha to 4,252 ha. Meanwhile, the area of potential critical land decrease 746 ha from 16,127 ha to 15,381 ha, and un-critical land decrease 138 ha from 34,601 ha to 34,463 ha. The change of land use that cause critical land especially in conservation area is conversion land use of forest to land use non-forest include rain fed field, and farmstead. Rehabilitation of critical land have to consider level of critical land, and the function area so that can be effective and efficient.
Keyword: 

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.
Keyword: