Judul: Efektivitas Sumur Resapan di Pemukiman Dalam Pengendalian Limpasan (Studi Kasus : Desa Claket, Kecamatan Pacet, Kabupaten Mojokerto, Jawa Timur)
Abstrak: Dampak perubahan iklim terhadap kenaikan temperatur permukaan bumi telah menyebabkan terjadinya peningkatan cuaca ekstrim seperti banjir dan kekeringan. Sumur resapan, yang dibuat sebagai adaptasi terhadap perubahan iklim, merupakan salah satu alternatif pengendalian limpasan yang dapat diterapkan baik di daerah pedesaan maupun perkotaan, terutama pada kawasan pemukiman. Manfaat sumur resapan diantaranya yaitu sebagai pengendali limpasan, pengisian air tanah, serta meningkatkan kapasitas infiltrasi tanah. Selama tahun 2012–2013, dari pendugaan limpasan menggunakan metode SCS– CN pada pemukiman seluas 200 m2 menghasilkan limpasan sebesar 177 m3 dengan hari hujan yang menghasilkan limpasan sebanyak 123 hari. Hasil pendugaan infiltrasi dengan model infiltrasi Horton menunjukkan bahwa pembangunan sumur resapan di Desa Claket, Mojokerto, dengan ukuran 2 x 2 x 2 m mampu meningkatkan kapasitas infiltrasi tanah dari 28.5 mm jam-1 menjadi 78 mm jam-1. Parameter infiltrasi Horton fo, fc dan k yaitu 0.56, 0.125 dan –0.01. Adanya sumur resapan juga menurunkan volume limpasan hingga sebesar 154 m3 atau 87 % dari total limpasan.
Keyword: perubahan iklim, infiltrasi, limpasan, Mojokerto, sumur resapan

Judul: Efektivitas Pembangunan Sumur Resapan dalam Pengendalian Limpasan di Kelurahan Pinang Ranti dan Bendungan Hilir Jakarta
Abstrak: Jakarta City development has caused in the decline of open green space quantity. It impacts to decreasing soil infiltration capacity, increasing surface runoff and flood potential. The construction of Sumur Resapan aims to reduce flood potential and improve ground water reserves in Jakarta. RunOff estimation method using SCS-CN obtained value of 1,68 m3 in 77m2 of water catchment area in Pinang Ranti and 2,08m3 in 95m2 of water catchment area in Bendungan Hilir. The average rate of infiltration are 41,34 cm/jam and capable to infiltrate water by 3,33 m3 in Pinang Ranti. The average rate of infiltration are 10,34 cm/jam and capable to infiltrate water by 1,61 m3 in Bendungan Hilir. By the infiltration rate, it can be concluded that Sumur Resapan will not be full or overflowing.The constructon of sumur resapan can reduce runoff and increase soil water reserves so it is able to meet water needs of society, particularly in society who doesn’t affordable yet by PDAM.
Keyword: recharging well, infiltration

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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