Judul: Perencanaan Sumur Resapan di Kawasan Pemukiman Perkotaan
Abstrak: Pertumbuhan penduduk yang pesat di Kota Bogor menyebabkan tata guna lahan banyak yang berubah menjadi lahan terbangun, sehingga meningkatkan limpasan dan mengurangi pengisian air tanah. Penelitian ini bertujuan merencanakan sumur resapan berbasis daya dukung sumber daya air di kawasan pemukiman daerah perkotaan. Telah dapat dilakukan penapisan lokasi prioritas sumur resapan berdasarkan kriteria topografi, tutupan lahan, dan aliran sungai. Lokasi prioritas tersebut yaitu di Kecamatan Bogor Selatan dengan DTA Cikaret, Cipakancilan, Cipinang Gading, dan Cisadane. Status DDL-air keempat DTA termasuk kategori “terlampaui” (overshoot). Hasil analisis neraca air menunjukkan surplus neraca air sebesar 1.272,3 mm/tahun dengan persentase limpasan yang relatif besar yaitu 75,7%-95%. Debit limpasan maksimum berkisar antara 31,3 m3/detik s/d 163,7 m3/detik. Telah dapat didesain sumur resapan individu dengan tiga tipe menurut luas atapnya, dengan kedalaman yang seragam 3 m, dan jari - jari 0,4 m-0,6 m. Dengan menggunakan skenario luas atap per pemukiman 10%-40% efektivitas sumur resapan individu diperkirakan berkisar antara 5,4%-39,9%. Total sumur yang diperlukan untuk empat DTA sejumlah 1.450 unit-43.073 unit. Sumur resapan komunal direncanakan terintegrasi dengan saluran drainase jalan lokal, kolektor, dan arteri. Perlu dilakukan penelitian lebih lanjut untuk mengkaji kelayakan dan akseptabilitas masyarakat terhadap pembangunan sumur resapan., The rapid growth in Bogor City has caused a lot of land use to be turned into built-up land, thereby increasing runoff and reducing groundwater recharge. This study aims to plan infiltration wells based on the carrying capacity of water resources (DDL-water) in urban residential areas. It have been done to filter the priority location of infiltration wells based on topography, land cover, and river flow criteria. The priority location are in South Bogor District with Cikaret, Cipakancilan, Cipinang Gading, and Cisadane catchment areas. The DDL-water status of the four catchment areas is in the “overshoot” category. Water balance analysis show an air balance surplus of 1.272,3 mm/year with a relatively large proportion of runoff, which is 75,7%-95%. The maximum runoff discharge ranges from 31,3 m3/s to 163,7 m3/s. It have been done to design individual infiltration wells with three types according to the roof area, with a uniform depth of 3 m, and a radius of 0,4 m-0,6 m. By using the scenario of roof area per settlement 10%-40%, the effectiveness of individual infiltration wells ranges from 5,4%-39,9%. The total wells required for the four catchment areas are 1.450 units-43.073 units. Communal infiltration wells are planned to be integrated with local, collectors, and arteries street drainage channels. Further study is needed to asses the feasibility and acceptability from society of the infiltration well development.
Keyword: DTA, limpasan, sumur resapan, Catchment areas, infiltration well, runoff

Judul: Perencanaan Bangunan Resapan Berbasis Daya Dukung Sumber Daya Air pada Kawasan Pemukiman di Daerah Perkotaan (Studi Kasus : Kecamatan Pamulang, Kota Tangerang Selatan)
Abstrak: Perubahan tutupan lahan akibat pertambahan penduduk di daerah perkotaan menimbulkan masalah daya dukung lingkungan sumber daya air (DDL-air), diantaranya adalah menurunnya tingkat resapan air hujan yang mengakibatkan meningkatnya limpasan. Penelitian ini bertujuan menganalisis status DDL-air dan neraca air untuk digunakan sebagai dasar pertimbangan rekomendasi yang tepat dalam upaya konservasi air dan pengelolaan limpasan berupa perencanaan bangunan resapan. Hasil penapisan menunjukkan Kecamatan Pamulang sebagai lokasi prioritas untuk penempatan bangunan resapan di Kota Tangerang Selatan. Status DDL-air termasuk kategori terlampaui (overshoot) dengan ratio supply/demand sebesar 0,054. Hasil analisis neraca air menunjukkan defisit sebesar 264,5 mm/tahun dan surplus sebesar 480,8 mm/tahun. Surplus neraca air menghasilkan limpasan sebesar 426,6 mm/tahun dan pengisian air tanah sebesar 54,2 mm/tahun. Debit limpasan maksimum berkisar antara 59,54 m3/detik-114,2 m3/detik. Bangunan resapan diharapkan mampu menampung CH maksimum sebesar 134,2mm. Sumur resapan direncanakan memiliki jari-jari 0,7m - 1,0m, dan kedalaman 5m - 6m. Dengan skenario luas atap rumah 10%-40% luas pemukiman, efektivitas sumur diperkirakan sebesar 6,1%-30,8%. Lubang resapan biopori direncanakan memiliki diameter 0,3m dan kedalaman 1,5m. Dengan skenario luas atap rumah 5% dan 10% luas pemukiman, efektivitas lubang diperkirakan sebesar 3,1%-7,7%. Identifikasi lokasi kolam retensi dipilih pada area hulu badan air di tiap DTA dengan elevasi yang relatif rendah., Changes in land cover due to population growth in urban area have caused problems with the environmental carrying capacity of water resources, including a decrease in the level of rainwater infiltration resulting runoff. This research aims to analyze the DDL-water status and water balance for recommendations in water conservation efforts and runoff management in the form of infiltration building planning. The screening results show Pamulang District as a priority location for the placement of infiltration buildings in South Tangerang. The DDL-air status is in the overshoot category with a ratio of 0.054. The water balance show a deficit of 264.5mm/year and surplus of 480.8mm/year. The runoff discharge ranges 59.54 m3 /sec-114.2 m3 /sec. Infiltration well are planned to have radius 0.7m-1.0m, and depth 5m-6m. With the house roof scenario 10%-40% of the residential area, the effectiveness is estimated 6.1%-30.8%. Biopore infiltration hole are planned to have diameter 0.3m and depth 1.5m. With a house roof scenario 5%-10% of residential area, the effectiveness is estimated 3.1%-7.7%. Identification of retention pond locations selected in the upstream area of the river in each catchment with a relatively low elevation.
Keyword: runoff, Catchment area, infiltration building, runoff

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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