Judul: Analisis cadangan karbon pohon pada lanskap hutan kota di DKI Jakarta
Abstrak: In order to reduce enviromental problem, such as air polutions and increasing of air temperature in DKI Jakarta caused the presence of urban forest is very neccessary. Tree has an inportant role becouse its function as store carbon and most efficient carbon sinks in urban areas. Urban forest in DKI Jakarta has problems in development, beside technical aspects are also affected by the goverment policy. The objectives of research were (1) to analyze tree carbon stock, CO2 sequestration and tree species that have potential of carbon, and (2) to analyze policies that support the development of urban forest. The study was conducted at DKI Jakarta, which was focused on tree urban forests, i.e. University Indonesia (Jakarta Selatan), Srengseng (Jakarta Barat) and PT JIEP (Jakarta Timur). The research location was determined by using purposive sampling method, which is based on the representation of the main functions of the urban forest landscape services. Data was collected through survey method. The selection of respondents was conducted by purposive sampling. Sampling plots determination was done by purposive sampling method. Square plot with a size of 20 m x 20 m is used in this research. Determination of tree biomass is done by non-destructive sampling method and tree carbon stocks by using biomass content formula. CO2 uptake values was determined by using the comparative of relative molecular mass CO2 : 3.67 x carbon stocks. Wood density obtained from the database of wood density of trees world agroforestry. Carbon stock analysis was calculated by using allometric equation and urban policy analysis was executed by Analytical Hierarchy Process (AHP) approach. The largest tree carbon stocks were found on UI urban forest was 178.82 ton/ha, Srengseng was 24.04 ton/ha and PT JIEP was 23.64 ton/ha. The largest CO2 uptake generated from UI urban forest was 634.40 ton/ha, Srengseng was 88.15 ton/ha and PT JIEP was 86.76 ton/ha. Factors that affecting the enhancement of carbon stocks, i.e. stem diameter, tree density and the age of the trees. CO2 uptake value resulting from the biggest urban forest UI was 634.40 ton/ha, followed by Srengseng 88.15 ton/ha and PT JIEP 86.76 ton/ha. This information illustrates that in addition for conservation of biodiversity, water uptake and aesthetics landscape, urban forest also has the potential in reducing CO2. Tree of fabaceae family, i.e. Acacia crassicarpa A.Cunn.Ex.Benth, Acacia mangium Willd, Paraserianthes falcataria L, Leucaena leucocephala L, Bauhinia purpurea L, Delonix regia Boj Ex.Hook, Pterocarpus indicus Willd, Erythrina crista-galli L and Abrus precarorius are found that they have biggest contribution for tree carbon stocks in study sites. Policy priorities the supporting the development of urban forest in level factor are increasing of urban forests quality, level actor are government and level alternative are rules evaluation and urban forest expantion.
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Judul: Evaluasi Jenis Pohon bagi Konservasi Keragaman Tanaman Hutan Kota di DKI Jakarta
Abstrak: Urban forest in Indonesia can only be declared if it has been approved by the competent authorities in accordance with Goverment Regulation PP No. 63/2002. Therefore, it is necessary to evaluate the diversity of plant species in the urban forest. The purpose of this study is to analyze the plant diversity in the urban forest, and to analyze the physical condition of the urban forest’s trees. This study was conducted in three selected urban forest in DKI Jakarta, i.e. Indonesian University (UI), Srengseng and PT. JIEP. Vegetation Analysis and Shannon Wiener Index were used as a method for analyzing the plant diversity. In this study, the physical condition of the trees also were observed by scoring the physical criterias of the existing tree condition. Result for this analysis were used as input to urban forest management recommendations using SWOT analysis. The result showed that the diversity of tree species in three selected urban forest is moderate (1 < H’ < 3). Indigenous species in UI and PT. JIEP predominant were found than in Srengseng urban forest. While the physical condition of trees in PT. JIEP urban forest have the highest levels of damage compared to the other two urban forest. Suitability of ecological functions of trees examined by urban forest type, shows that PT. JIEP Urban Forest as a buffer for industry region has only 30% of trees that have either category as absorbing gaseous pollutants. While the UI Urban Forest and the Srengseng Urban Forest, ecological functions of trees based on the type of urban forest have been appropriate for the city to provide comfort for visitors. Recommendations of Urban forest management are produced from SWOT analysis. It is resulted 10 recommendations for trees biodiversity conservation in urban forest based on internal factor and external factor of the three selected urban forest in DKI Jakarta.
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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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