Judul: Kajian dampak reklamasi lahan tambang batubara terhadap komponen fungsi hidrologis dan ekologis DAS serta manfaat bagi masyarakat
Abstrak: This research was conducted at the PT Adaro Indonesia coal mining area in Negara watershed, sub-watershed of Barito, South Kalimantan Province. The aims of the study were: 1) to identify of the methods used for coal mined land reclamation; 2) to analyze the impacts of the reclamation on the hydrological and ecological functions of the watershed; and 3) to analyze the impact of the land reclamation activities on the involvements of and benefits for the communities. This study was carried out using survey method and field measurements in identifying the methods of reclamation. Analyzis of watershed hydrological function showed that reclamation activities significantly increased soil infiltration rate from 0.27 cm/hr to 1.01 cm/hr, decreased runoff coefficient from 49.04% to 13.97% and decreased erosion rate from 130.28 ton/ha to 7.64 ton/ha. Biodiversity analysis showed that there was no significant impact of reclamation activities on biodiversity at the early stage of reclamation trees up to 6 years of its development. However, after the reclamation trees were at the age of 15 years, the biodiversity indexes increased significantly; shurb index increased up to 1,10, seedlings 0.76, saplings 0.85, poles 0.53, and trees 0.23. Carbon sequestration analysis showed that the reclamation activities increased carbon sequestration significantly. At the area where the reclamation trees were at 15 years old the carbon stock reached 103.57 ton/ha, which consist of 95.94 ton/ha at trees, 4.12 ton/ha at undergrowth, and 3.51 ton/ha at the litter. Analysis of the impact of reclamation on social-economic of the local communities showed that the income of labor increased substantially up to Rp 36,000,000 per year, the income that have been greater than the income that can support life worthed living standard (Rp 24,000,000/year). This income was also already greather than income of South Kalimantan GDP (195%) and national GDP (117%). Multiple benefits gained by the local communities during the reclamation activities among others were the opportunities for supplier of food and housing, compost and plant seeds; the post-mining benefits from timber and non timber product of reclamation; as well as benefits from infrastructure/roads and recreation facilities.
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Judul: Analysis of Development of Post-Coal Mining Land Reclamation Research in Indonesia
Abstrak: Pertambangan merupakan salah satu sektor yang dapat menyumbangkan devisa besar bagi negara. Komoditas pertambangan di Indonesia diklasifikasikan menjadi mineral, batu bara, serta minyak dan gas. Batu bara di Indonesia umumnya diekstrak dengan sistem penambangan terbuka yang menghilangkan ekosistem hutan beserta fungsinya. Kegiatan tersebut menyebabkan terbentuknya lahan terdegradasi sehingga dibutuhkan penerapan kegiatan revegetasi. Penelitian ini bertujuan untuk mengetahui perkembangan penelitian untuk mendukung keberhasilan reklamasi tambang batu bara di Indonesia serta mengetahui kategori penelitian yang kurang mendapat perhatian dan perlu pengembangan lebih lanjut. Penelitian dilakukan dengan mengumpulkan semua informasi yang tersedia secara online berasal dari jurnal, repository, buku dan sumber yang terkait dengan kegiatan reklamasi lahan bekas tambang batu bara. Berdasarkan hasil penelitian, kategori yang paling banyak diteliti adalah kategori kualitas tanah dan kategori pemilihan jenis tanaman dengan masing-masing 23 judul penelitian, sedangkan kategori persemaian yang paling sedikit diteliti, yaitu hanya 2 (dua) judul penelitian. Kata kunci: batu bara, jenis tanaman, reklamasi, tanah tambang, Mining is one of the sectors that can contribute large foreign exchange for the country. Mining commodities in Indonesia are classified into minerals, coal, and oil and gas. Coal in Indonesia is generally extracted by an open-pit mining system which eliminates forest ecosystems and their functions. These activities lead to the formation of degraded land so that the implementation of revegetation activities is needed. This study aims to determine the development of research to support the success of coal mine reclamation in Indonesia and to find out aspects of research that have received less attention and need further development. The research was conducted by collecting all the information available online from journals, repositories, books and sources related to land reclamation activities of former coal mines. Based on the results of the research, the most studied categories were the soil quality category and the plant species selection category with 23 research titles each, while the nursery aspect was the least studied, namely only 2 (two) research titles. Keywords: coal, mining land, reclamation, types of plants
Keyword: batu bara, jenis tanaman, reklamasi, tanah tambang, coal, mining land, reclamation, types of plants

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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