Judul: Kaji Ulang Neraca  Air pada Daerah Irigasi Sempor Kabupaten Kebumen
Abstrak: Daerah Irigasi Sempor terletak di Kecamatan Sempor, Kabupaten Kebumen, Provinsi Jawa Tengah. Daerah Irigasi Sempor memiliki luas sebesar 6.478 ha. Daerah Tangkapan Air (DTA) Waduk Sempor memiliki luas 4.231 ha. Perubahan tata guna lahan dari lahan hijau menjadi lahan permukiman yang terjadi di DTA Waduk Sempor dapat mengakibatkan terjadinya erosi. Erosi yang terjadi akan menyebabkan sedimen di dasar waduk dan mengakibatkan berkurangnya kapasitas tampungan waduk. Penelitian ini bertujuan untuk melakukan kaji ulang besaran kebutuhan, ketersediaan, dan neraca air yang ada di Daerah Irigasi Sempor. Ketersediaan air DTA Waduk Sempor dihitung menggunakan metode F.J. Mock. Ketersediaan air tertinggi terjadi pada bulan Januari periode I sebesar 5,20 Juta m3 dan terkecil terjadi pada bulan Oktober periode I sebesar 0,01 Juta m3. Sedangkan kebutuhan air Daerah Irigasi Sempor terbesar terjadi pada bulan Mei periode I sebesar 6,97 Juta m3 dan yang terkecil pada bulan September periode II sebesar 0,70 Juta m3. Secara keseluruhan, neraca air DI Sempor mengalami defisit sebesar 38 Juta m3. Ketersediaan air DTA Waduk Sempor hanya dapat memenuhi 60% dari kebutuhan air Daerah Irigasi Sempor., The Sempor Irrigation Area is located in Sempor District, Kebumen Regency, Central Java Province. The Sempor Irrigation Area has an area of 6,478 ha. The Sempor Reservoir Water Catchment Area (DTA) has an area of 4,231 ha. The change in land use from green land to residential land that occurs in the Sempor Reservoir catchment can result in erosion. The erosion that occurs will cause sediment at the bottom of the reservoir and result in a reduction in the reservoir's storage capacity. This research aims to review the amount of demand, availability and balance of water in the Sempor Irrigation Area. The water availability of the Sempor Reservoir DTA was calculated using the F.J. Mock. The highest water availability occurred in January period I is 5.20 million m3 and the smallest occurred in October period I is 0.01 million m3. Meanwhile, the largest water demand for the Sempor Irrigation Area occurred in May period I is 6.97 million m3 and the smallest in September period II is 0.70 million m3. Overall, DI Sempor's water balance experienced a deficit of 38 million m3. Water availability in the Sempor Reservoir DTA can only meet 60% of the water needs of the Sempor Irrigation Area.
Keyword: F.J. Mock, Water Requirement, Water Availability, Water Balance

Judul: Perancangan Penggunaan Air Sungai Ciapus untuk Menyuplai Air Irigasi di Persemaian Permanen Dramaga Bogor
Abstrak: Air dan sistem penyiraman sangat berdampak dalam produksi bibit berkualitas di persemaian permanen. Persemaian Permanen Dramaga menggunakan dua sumur resapan yang diisi oleh air hujan, saat musim kemarau terjadi kekurangan air. Air sungai Ciapus dapat dimanfaatkan dengan menggunakan pompa hidram. Oleh karena itu, perlu dirancang bak penampung yang dapat menyimpan sementara air dari pompa dan menyuplai air secara kontinu. Penelitian ini bertujuan menentukan kebutuhan air irigasi, serta menentukan kapasitas dan menghasilkan rancangan bak penampung air di lokasi penelitian. Kebutuhan air diperoleh berdasarkan nilai defisit pada neraca air antara laju evapotranspirasi dengan laju curah hujan. Defisit air rata-rata pada periode kemarau tahun 2015 merupakan nilai yang tertinggi selama tahun 2003-2020, yakni sebesar 2,63 mm/hari. Berdasarkan nilai tersebut diperoleh kebutuhan air irigasi sebesar 15,78 m3/hari untuk lahan seluas 0,60 ha. Debit pemompaan berpotensi mengisi bak penampung selama waktu penyiraman. Kapasitas bak penampung didesain setengah dari kebutuhan air harian, yakni 7,89 m3, dan dibulatkan menjadi 8 m3. Bak penampung direncanakan menggunakan bahan panel fiberglass. Ukuran panjang, lebar dan tinggi bak penampung masing-masing sebesar 2 m., Water and irrigation systems have a major impact on the production of quality seedlings in permanent nurseries. The Dramaga Permanent Nursery uses two infiltration wells filled by rainwater, during dry season there is a shortage of water. Ciapus river water can be utilized by using a hydraulic ram pump. Therefore, it is necessary to design a reservoir to temporarily store water from the pump and to supply water continuously. The research aimed to determine the need for irrigation water, determine the capacity and produce a water reservoir design at the research site.Water requirement was obtained based on the deficit value in the water balance between evapotranspiration rate and rainfall rate. The average water deficit in the dry season in 2015 was the highest value during 2003-2020, which was 2,63 mm/day. Based on this value, the irrigation water requirement was 15,78 m3/day for an area of 0,60 ha. The pumping discharge had the potential to fill the reservoir during watering time. The designed reservoir capacity was half of the daily water requirement, which was 7,89 m3, and fulfilled to 8 m3. The reservoir was planned to use fiberglass panel material. The length, width, and height of the reservoir were 2 m each.
Keyword: evapotranspiration, fiberglass reservoir, irrigation, rainfall

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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