Judul: Kajian intrusi air asin pada sistem akuifer Jakarta
Abstrak: Saltwater intrusion in the aquifer system of Jakarta area, is a study of ground-water in conjunction with hydrostatic equilibrium between freshwater and saltwater flows in aquifer system at border of coastal. There are two main objectives of this study, namely: (i). To analyze the rate of saltwater instrusion in Jakarta aquifer system and (ii) To analyze the impact of recharge of rainwater to control the rate of saltwater intrusion in Jakarta aquifer system. To achieve that objectives, research methodology and material use are as follows: (i). Method use are descriptive, analysis and modelling; (ii) System and technique of data required use secondary and primary data which are grouped in three area of transected zones. (iii). Material use are: Salinity data (EC, Cl- and TDS) were collected over period of 1995 - 2010 with inverval per 3 km at zone transected, hydrogeology, water consumption and recharge; and (iv) Mathematic model use is SHARP model with block-centered finite-difference grid at scale 3 km x 3 km area. Conclusion of this study are: (1). The average rate of saltwater instrusion during period of 1982 – 2010 at transection zone I was 0,1 km/year, at transection zone II was 0,06 km/year and at transection zone III was 0,11km/year. (2). Based on prediction in 2025 ground water consumption amount of 8,02 m3/second will impacted saltwater intrusion at transection zone I at distance of 9 km, at transection zone II at distance of 9 km and at transection zone III at distance of 13,5 km from coastal border. (3). Based on prediction for 2025, increase of ground-water recharge with amount of 3,95 m3/second by applied 100% artificial-recharge based on requirement government regulations, will decrease the saltwater instrusion at all transection zones which are transection zone I will decrease with amount of 1,5 km, transection zone II will decrease with amount of 3 km and at transection zone III will decrease with amount of 4,5 km compare with without artificial recharge, or decrease of saltwater intrusion as of conclusion item (2) above and (4). Based on prediction for 2025, increase of ground water recharge with amount of 0,99 m3/second by applied 25% artificial recharge based on requirement of government regulations, will decrease the saltwater instrusion at 2 transection zones which are transection zone II will decrease with amount of 1,5 km and at transection zone III will decrease with amount of 1,5 km compare with without artificial recharge, or decrease of saltwater intrusion as of conclusion item (2) above.
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Judul: Pengaruh eksploitasi air tanah terhadap sistem keseimbangan tata air di wilayah Jakarta
Abstrak: Tujuan penelitian ini adalah untuk mengetahui pengarunpengaruh, ataupun dampak yang disebabkan oleh pengambilan/penyedotan air tanah di wilayah DKI Jaya dan sekitarnya. Pengamatan cl i l akukan terhadap sumur-sumur pantau, sumur penduduk, uji pemompaan ( pumping test ), pengukuran daya hantar listrik (DHL atau electric conductivity ), serta menganalisis data reKaman sumursumur yang terpantau dengan balk dari tahun ke tahun. Atas dasar basil penelitian ini, maka aKan dihasil kan beberapa saran dan rekomendasi penanganan, agar tidak terjadi gangguan keseimbangan lingkungan yang parah. Daerah penelitian meliputi luas sekitar 650 km2 yang mencakup seluruh kawasan DKI Jaya dan sekitarnya r.Jii mana sistem cekungan akuifer (lapisan pembawa air) Jakarta berada. Mengingat sistem cekungan air tanah Jakarta mempunyai Kaitan erat dengan lingkungan di luarnya, maka dalam penelitian ini dibahas pula pengaruh DAS (daerah aliran sungai) Ciliwung dan Cisadane sebagai input (masukan) air tanah bagi wilayah DKI Jaya. ...
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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