DAFTAR ISILEMBAR PENGESAHAN......................................................................................................................... i KATA PENGANTAR ............................................................................................................................... ii DAFTAR ISI .......................................................................................................................................... iii DAFTAR TABEL ..................................................................................................................................... v DAFTAR GAMBAR ............................................................................................................................... vi DAFTAR GRAFIK ................................................................................................................................. vii

BAB I

PENDAHULUAN ......................................................................................................................1 1.1 Latar Belakang ................................................................................................................1 1.2 Tujuan .............................................................................................................................1 1.3 Ruang Lingkup.................................................................................................................2 1.4 Metodologi Penulisan .....................................................................................................2 1.5 Sistematika Penyusunan Laporan ...................................................................................3

BAB II DASAR TEORI ..........................................................................................................................4 2.1 Teori Hidrologi ................................................................................................................4 2.1.1 Teori Perhitungan Ketersediaan Air .....................................................................5 2.2 Teori Irigasi .....................................................................................................................6 2.2.1 Jenis-Jenis Sistem Irigasi .......................................................................................6 2.2.2 Pendukung Sistem Irigasi .....................................................................................8 2.2.3 Teori Perhitungan Kebutuhan Air.......................................................................12 2.3 Teori Bangunan Air .......................................................................................................15

BAB III DATA DAN KAJIAN WILAYAH IRIGASI ...................................................................................20 3.1 Lokasi dan Topografi Wilayah .......................................................................................20 3.2 Data Curah Hujan dan Klimatologi ...............................................................................21 3.2.1 Data Curah Hujan ...............................................................................................21 3.2.2 Data Klimatologi .................................................................................................23

BAB IV PERHITUNGAN DAN ANALISIS ..............................................................................................26 4.1 Pengisian Data Curah Hujan yang Hilang......................................................................26 4.2 Curah Hujan Regional ...................................................................................................27 iii

4.3 Debit Andalan dan Awal Musim Tanam .......................................................................28 4.3.1 Curah Hujan Andalam.........................................................................................28 4.3.2 Debit Andalan .....................................................................................................29 4.4 Curah Hujan Efektif .......................................................................................................30 4.5 Evapotranspirasi ...........................................................................................................31 4.6 Koefisien Tanam dan Pola Tanam.................................................................................35 4.7 Kebutuhan Air Lahan ....................................................................................................36 4.8 Luas Lahan yang Dapat Diairi ........................................................................................42 4.9 Dimensi Saluran ............................................................................................................45 4.10 Tinggi Muka Air Saluran ................................................................................................49

BAB V KESIMPULAN DAN SARAN ....................................................................................................51 5.1 Kesimpulan ...................................................................................................................51 5.2 Saran .............................................................................................................................52

DAFTAR PUSTAKA

LAMPIRAN

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DAFTAR TABELTabel 2.1 Pola Tanam dalam Satu Tahun ........................................................................................ 13 Tabel 2.2 Koefisien Padi Berdasarkan Varietas ............................................................................... 13 Tabel 3.1 Data Curah Hujan Hilang Stasiun Arjasari ........................................................................ 22 Tabel 3.2 Data Curah Hujan Hilang Stasiun Pacet1 ......................................................................... 22 Tabel 3.3 Data Curah Hujan Hilang Stasiun Majalaya ..................................................................... 22 Tabel 3.4 Data Temperatur ............................................................................................................. 23 Tabel 3.5 Penyinaran Matahari ....................................................................................................... 24 Tabel 3.6 Kecepatan Angin .............................................................................................................. 24 Tabel 3.7 Kelembapan Udara .......................................................................................................... 25 Tabel 4.1 Data Curah Hujan Stasiun Arjasari ................................................................................... 26 Tabel 4.2 Data Curah Hujan Stasiun Pacet1 .................................................................................... 27 Tabel 4.3 Data Curah Hujan Stasiun Majalaya ................................................................................ 27 Tabel 4.4 Curah Hujan Rata-Rata Regional DAS Cirasea ................................................................. 28 Tabel 4.5 Hasil Perhitungan R80 dan R50 dengan Metode Weibull Plotting ..................................... 29 Tabel 4.6 Debit Andalan ................................................................................................................... 30 Tabel 4.7 Hasil Perhitungan Curah Hujan Efektif Stasiun Arjasari ................................................... 31 Tabel 4.8 Hubungan Suhu dengan Nilai ea, W, (1-W), dan f(t) ....................................................... 31 Tabel 4.9 Hubungan Nilai Anggota (Ra) dengan Letak Lintang di Indonesia ................................... 33 Tabel 4.10 Hasil Perhitungan Evapotranspirasi Keseluruhan .......................................................... 35 Tabel 4.11 Koefisien Tanam ............................................................................................................. 35 Tabel 4.12 Pola Tanam dan Koefisien Tanaman Golongan A ........................................................... 36 Tabel 4.13 Pola Tanam dan Koefisien Tanaman Golongan B........................................................... 36 Tabel 4.14 Pola Tanam dan Koefisien Tanaman Golongan C........................................................... 36 Tabel 4.15 Nilai IR saat LP setiap Bulan ........................................................................................... 38 Tabel 4.16 Kebutuhan Air Golngan A ............................................................................................... 39 Tabel 4.17 Kebutuhan Air Golongan B ............................................................................................. 40 Tabel 4.18 Kebutuhan Air Golongan C ............................................................................................. 41 Tabel 4.19 Alternatif Kebutuhan Air dan Nilai Maksimumnya ........................................................ 42 Tabel 4.20 Luas Areal Maksimum yang Dapat Diairi untuk Setiap Alternatif .................................. 43 Tabel 4.21 Tata Nama Petak Daerah Irigasi Cirasea dan Besar Debit per Petaknya........................ 44 Tabel 4.22 Hasil Perhitungan Dimensi Saluran ................................................................................ 48 Tabel 4.23 Hasil Perhitungan Tinggi Muka Air di Udik dan Hilir ...................................................... 50 v

DAFTAR GAMBARGambar 1.1 Sistem Irigasi ...................................................................................................................1 Gambar 2.1 Siklus Hidrologi ...............................................................................................................4 Gambar 2.2 Contoh Penamaan Petak Tersier ..................................................................................12 Gambar 2.3 Bendung ........................................................................................................................15 Gambar 2.4 Tata Letak Bangunan Bagi Sadap Bentuk Menyamping ...............................................16 Gambar 2.5 Pintu Air ........................................................................................................................17 Gambar 2.6 Gorong-Gorong .............................................................................................................18 Gambar 3.1 Lokasi Sungai Cirasea ....................................................................................................20 Gambar 3.2 Daerah Aliran Sungai Cirasea ........................................................................................21

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DAFTAR GRAFIKGrafik 4.1 Hubungan antara Bulan dan R80 .......................................................................................29

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