Judul: Utilization of Geographic Information System for Mapping Flood  Prone Areas in Hulu Sungai Utara Regency, South Kalimantan
Abstrak: Bencana banjir dapat terjadi karena dipengaruhi oleh faktor alam dan faktor nonalam. Kabupaten Hulu Sungai Utara termasuk wilayah dengan potensi banjir yang cukup tinggi karena berada di dataran rendah. Tujuan penelitian ini adalah memetakan daerah rawan banjir dan mengidentifikasi daerah rawan serta risiko banjir di Kabupaten Hulu Sungai Utara. Metode yang digunakan dalam analisis kerawanan banjir adalah metode skoring dan pembobotan dengan bantuan sistem informasi geografis (SIG). Parameter kerawanan banjir yang digunakan yaitu curah hujan, kemiringan lereng, ketinggian lahan, penggunaan lahan, jenis tanah dan buffer sungai. Hasil penelitian menunjukkan wilayah Kabupaten Hulu Sungai Utara didominasi kelas kerawanan banjir kategori rendah seluas 41.310,67 ha (46,28%). Kelas kerawanan kategori tinggi dan sangat tinggi banyak terdapat di Kecamatan Babirik seluas 4.238,00 ha dan Kecamatan Paminggir seluas 651,34 ha. Tingkat risiko banjir di Kabupaten Hulu Sungai Utara sebagian besar masuk kategori sangat rendah seluas 53.363,24 ha (59,78%) yang didominasi Kecamatan Danau Panggang, Kecamatan Amuntai Selatan dan Kecamatan Paminggir., Flood disasters can occur because they are influenced by natural and nonnatural factors. Hulu Sungai Utara Regency is an area with a fairly high potential for flooding because it is located in the lowlands. The purpose of this study were to map flood-prone areas and identify flood-prone areas and risks in Hulu Sungai Utara Regency. The method used in the analysis of flood vulnerability is the method of scoring and weighting with the help of a geographic information system (GIS). The flood susceptibility parameters used are rainfall, slope, land height, land use, soil type and river buffer. The results showed that the area of North Hulu Sungai Regency was dominated by the low category of flood susceptibility class with an area of 41.310,67 ha (46,28%). The high and very high vulnerability classes are mostly found in Babirik District covering an area of 4.238,00 ha and Paminggir District covering an area of 651,34 ha. The flood risk level in Hulu Sungai Utara Regency is mostly in the very low category, covering an area of 53.363,24 ha (59,78%) which is dominated by Danau Panggang District, South Amuntai District and Paminggir District.
Keyword: flood, mapping, prone, risk

Judul: Flood Susceptibility Area Mapping in East Belitung  Regency based on Geographic Information System
Abstrak: Banjir merupakan salah satu permasalahan di Kabupaten Belitung Timur, namun belum dipetakan kerawanan banjir untuk wilayah kabupaten. Peta rawan banjir termasuk langkah untuk mengurangi dampak bencana banjir yang dapat diidentifikasi dengan cepat menggunakan sistem informasi geografis dan pengindraan jauh. Tujuan penelitian ini adalah membuat peta daerah rawan banjir di Kabupaten Belitung Timur dan memvalidasinya. Identifikasi daerah rawan banjir dilakukan dengan metode skoring dan pembobotan. Validasi dilakukan terhadap gambar dampak lokasi dan data pengindraan jauh Sentinel-1. Parameter yang mempengaruhi kerawanan banjir di Kabupaten Belitung Timur adalah curah hujan, kemiringan lereng, ketinggian lahan, tutupan lahan, jenis tanah, dan buffer sungai. Hasil penelitian menyatakan Kabupaten Belitung Timur memiliki tingkat kerawanan banjir sedang yang terluas. Tingkat kerawanan rendah dan sedang terluas terdapat di Kecamatan Kelapa Kampit, sedangkan tingkat kerawanan banjir tinggi dan sangat tinggi terluas terdapat di Kecamatan Gantung. Sebanyak 12 titik dari 18 titik kejadian banjir terletak di wilayah kerawanan tinggi. Genangan banjir menurut citra Sentinel-1 teramati di lima kecamatan dengan luas terbesar di kerawanan banjir tinggi sebesar 28,97 km2., Flood is one of problems in East Belitung Regency, but the flood susceptibility has not been mapped for the region. A Flood susceptibility map helps reduce the impact of flood disasters. The map can be quickly generated using geographic information systems and remote sensing. This research aims to create a flood susceptibility map in East Belitung Regency and validate it. Flood-susceptible areas are identified using a weighted scoring method. Validation is based on impact images of flooding and remote sensing data. Parameters affecting flood susceptibility in East Belitung Regency include rainfall intensity, land slope, land elevation, land cover, soil type, and buffer distance from a river. The results indicate that East Belitung Regency has the largest area of moderate flood susceptibility. Low and moderate susceptibility has the greatest area in Kelapa Kampit District, while high and very high susceptibility has the greatest coverage in Gantung District. Twelve of eighteen identified flood points are in high susceptibility areas. According to Sentinel-1 imagery, flooding is observed in five districts, covering an area of about 28.97 km2, primarily within high susceptibility areas.
Keyword: flood susceptibility, flood susceptibility map, Sentinel-1, validation

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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