Judul: Karakteristik Habitat Preferensial Orangutan Pongo pygmaeus wurmbii di Taman Nasional Sebangau
Abstrak: The orangutan Pongo spp. was once widespread in Asia but is now found only on the islands of Borneo and Sumatra. In Central Kalimantan orangutan with the highest population number can be found in Sebangau National Park (SNP). Densities were found to be highest in the tall interior and mixed swamp forest sub-types and also concentrate in habitat + 4 km near from the river. Today, the probability of a direct observation for this animal is very low. The literature study shows that large animals have preferences in their habitat and therefore tend to distribute uniformly or clumped. In consequence, the management of orangutan population and habitat must consider their habitat preference. This study that was carried out in SNP from November to December 2010, were aimed to: (1) determining characteristic of habitat preference for orangutan, (2) identifying dominant habitat factor for orangutan. Tools used in the study consisted of; map of SNP, binoculars, GPS, digital camera, thermo-hydrometer, tally sheet, and measuring tape. Direct field observation and literature review were done to collect data. Based on multiple linear regressions analysis, the dominant habitat factors that determine habitat preference for orangutan were the species number of diet for tree level (X11) and species density of diet for tree level (x14). The equation formulated was Y = - 0.033 + 0.534 X11 - 0.516 X14, indicating that one unit increase of species number of diet for tree level presence by 0.534 points and a one point decrease in species density of the diet for tree level presence by 0.516 points. Using Neu’s method of preferential index’s analysis it was concluded that out of 5 locations studied, 2 locations (mix swamp forest and tall interior forest) had preferential indices greater than 1.
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Judul: Pemodelan Spasial Kesesuaian Habitat Orangutan Kalimantan (Pongo pygmaeus wurmbii Linneaus, 1760) di Suaka Margasatwa Sungai Lamandau, Kalimantan Tengah
Abstrak: Orangutan is categorized as a rare animal since it only exist in Indonesia and its populations tend to decrease, especially in Sungai Lamandau area. The population decreasing is caused by environmental degradation, land conversion, and also hunting. Orangutan population is grouped into critically endangered status according to IUCN Red Listand listed into APPENDIX 1 CITES also by government is protected by Government in Regulation Number 7 Year 1999. Sungai Lamandau Wildlife Reserve is one of the orangutan habitat in Kalimantan. Besides, this location has important value since it is a region which is used as wild conservation of orangutan from rehabilitation. Related to the fact, research of orangutan kalimantan habitat by applying Geographical Information System (GIS) needs to be developed to get spatial data of suitable habitat model for orangutan kalimantan in Sungai LamandauWildlife Reserve. Data collection is done in Sungai Lamandau Wildlife Reserve and in limited usage suggestion zone (Buffer zone). Orangutan kalimantan habitat suitability modeling is done by identifying orangutan kalimantan nest points in spatial to the habitat factors, which is distance by the river and Normalized Difference Vegetation Index(NDVI) value, and disturbance factors via distance with road and distance with the villages. Identification result is analyzed by using Principal Componen Anayisis (PCA) to get value each habitat components so that would be found suitability model with orangutan kalimantan habitat. Habitat suitability map is found by overlaying habitat components to model had built and validated with nest points found in field. Orangutan kalimantan habitat suitability model found is Y=(1,747 x distance with river factor)+(1,747 x NDVI value factor)+(1,215 x distance with road factor)+(1,215 x distance with village factor). Orangutan kalimantan habitat suitability map is divided by three, of suitability which is in low suitability class 6311,70 hectare or 7,88% from overall of research location width, mid suitability class 52378,70 hectare or 65,46% from overall of research location width and high suitability class 21328,60 hectare or 26,65% from overall research location. Validation for low suitability class 0%, mid-suitability class 60,87% and high suitability class 39,13%. Orangutan kalimantan suitability model can be accepted with 100% validation in mid and high suitability class.
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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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