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: 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: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology