DAFTAR ISI
HALAMAN JUDUL .......................................................................................... I HALAMAN PERSETUJUAN .......................................................................... II HALAMAN PERSEMBAHAN ...................................................................... III PERNYATAAN ............................................................................................... IV KATA PENGANTAR ....................................................................................... V DAFTAR ISI .................................................................................................. VII DAFTAR GAMBAR ......................................................................................... X DAFTAR TABEL ......................................................................................... XIV DAFTAR LAMPIRAN ................................................................................. XVI DAFTAR NOTASI...................................................................................... XVII INTISARI ................................................................................................... XVIII ABSTRACT.................................................................................................... XIX BAB I PENDAHULUAN .................................................................................. 1 1.1
Latar Belakang ......................................................................................... 1
1.2
Tujuan Penelitian ...................................................................................... 4
1.3
Ruang Lingkup Penelitian ........................................................................ 4
BAB II TINJAUAN PUSTAKA ....................................................................... 8 2.1
Penelitian Terdahulu ................................................................................. 8
2.2
Waduk Wonogiri .................................................................................... 11
2.2.1 Daerah Tangkapan Air Waduk Wonogiri ................................................ 11 2.2.2 Data Teknis Waduk Wonogiri ................................................................ 13 2.2.3 Data Teknis Waduk Wonogiri Setelah Pembangunan Closure Dike ........ 16 2.2.4 Pola Operasi Waduk Wonogiri pada Periode Banjir ................................ 19 2.2.5 Manual Operasi Pintu Spillway Waduk Wonogiri ................................... 20
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2.2.6 Pedoman Baru Operasi Pintu Spillway Waduk Wonogiri ........................ 23 2.3
Daerah Aliran Sungai Bengawan Solo Hulu Ruas Waduk Wonogiri – Bendung Colo......................................................................................... 24
2.4
Daerah Aliran Sungai Bengawan Solo Hulu Ruas Bendung Colo – Pos AWLR Jurug .......................................................................................... 25
2.5
Hujan DAS ............................................................................................. 27
2.6
Hujan Efektif .......................................................................................... 27
2.7
Hidrograf Satuan .................................................................................... 28
2.8
Aliran Dasar ........................................................................................... 28
2.9
Pengalihragaman Hujan menjadi Aliran .................................................. 29
2.10
Hidrograf Debit ...................................................................................... 29
2.11
Penelusuran Aliran ................................................................................. 30
2.12
Pelimpah Tipe Ogee ............................................................................... 31
2.13
Pelimpah Tipe Ambang Lebar ................................................................ 33
2.14
Bahasa Pemrograman VB .NET.............................................................. 33
2.15
Microsoft Visual Studio 2012 Express Edition ........................................ 33
2.16
Microsoft Access .................................................................................... 34
BAB III LANDASAN TEORI ........................................................................ 35 3.1
Hujan Efektif .......................................................................................... 35
3.2
Hidrograf Satuan .................................................................................... 35
3.3
Aliran Dasar ........................................................................................... 36
3.4
Hidrograf Debit ...................................................................................... 36
3.5
Keseimbangan Air di Waduk .................................................................. 37
3.6
Penelusuran Banjir di Waduk ................................................................. 37
3.7
Debit Melalui Spillway ........................................................................... 38
3.8
Debit Melalui Overflow Dike dan Closure Dike ...................................... 43
3.9
Penelusuran Banjir di Sungai .................................................................. 48
3.10
Konsep Pengembangan Model................................................................ 49
BAB IV METODE PENELITIAN ................................................................. 52 4.1
Prosedur Penelitian ................................................................................. 52 viii
4.2
Pengumpulan dan Review Data ............................................................... 53
4.3
Penyusunan Database Perangkat Lunak ................................................. 53
4.3.1 Stasiun Hidrologi.................................................................................... 54 4.3.2 Koefisien Thiessen ................................................................................. 56 4.3.3 Curve Number ........................................................................................ 61 4.3.4 Rating Curve .......................................................................................... 63 4.3.5 Hidrograf Satuan .................................................................................... 64 4.3.6 Parameter Muskingum ............................................................................ 65 4.4
Penyusunan Struktur Perangkat Lunak.................................................... 67
4.5
Pengujian Perangkat Lunak .................................................................... 71
BAB V HASIL DAN PEMBAHASAN ........................................................... 72 5.1
Hasil Pengembangan Perangkat Lunak ................................................... 72
5.1.1 Input Data............................................................................................... 74 5.1.2 Flood Forecasting .................................................................................. 77 5.1.3 Reservoir Flood Routing......................................................................... 81 5.1.4 Hydrologic Channel Routing .................................................................. 83 5.1.5 Hasil Akhir Simulasi .............................................................................. 85 5.2
Contoh Penerapan Perangkat Lunak ....................................................... 88
5.3
Evaluasi Kinerja Perangkat Lunak .......................................................... 97
BAB VI KESIMPULAN DAN SARAN......................................................... 102 6.1
Kesimpulan .......................................................................................... 102
6.2
Saran .................................................................................................... 102
DAFTAR PUSTAKA ..................................................................................... 104 LAMPIRAN ................................................................................................... 106 Lampiran 1. Hidrograf Satuan DAS ................................................................. 107 Lampiran 2. Parameter DAS ............................................................................ 111 Lampiran 3. Hasil Simulasi Hujan 25 Januari 2014 .......................................... 112 Lampiran 4. Hasil Pengamatan Real Time 25 - 27 Januari 2014 ....................... 132
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DAFTAR GAMBAR
Gambar 1.1
Daerah Aliran Sungai Bengawan Solo. .......................................... 1
Gambar 1.2
Peta Lingkup Penelitian. ................................................................ 5
Gambar 1.3
Skema Sistem DAS dari DTA Waduk Wonogiri Sampai Pos AWLR Jurug. ................................................................................ 6
Gambar 2.1
Daerah Tangkapan Air Waduk Wonogiri. .................................... 12
Gambar 2.2
Foto Waduk Wonogiri. ................................................................ 14
Gambar 2.3
Foto Spillway Waduk Wonogiri................................................... 14
Gambar 2.4
Skema Zona Tampungan Waduk Wonogiri. ................................ 15
Gambar 2.5
Kurva Karakteristik Tampungan Waduk Wonogiri. ..................... 15
Gambar 2.6
Skema Tampungan Waduk Wonogiri Setelah Pembangunan Closure Dike. .............................................................................. 16
Gambar 2.7
Skema Tata Letak Closure Dike dan Spillway Baru. .................... 17
Gambar 2.8
Kurva Karakteristik Tampungan Waduk Wonogiri Setelah Pembangunan Closure Dike. ....................................................... 19
Gambar 2.9
Wilayah DAS Bengawan Solo Hulu Ruas Waduk Wonogiri – Bendung Colo. ............................................................................ 24
Gambar 2.10 Wilayah DAS Bengawan Solo Ruas Bendung Colo – Pos AWLR Jurug. .......................................................................................... 26 Gambar 2.11 Poligon Thiessen. ........................................................................ 27 Gambar 2.12 Skema Hujan, Sistem DAS, dan Aliran. ...................................... 29 Gambar 2.13 Komponen Hidrograf Banjir. ....................................................... 30 Gambar 2.14 Pelimpah Tipe Ogee. ................................................................... 32 Gambar 2.15 Pelimpah Tipe Ogee dengan Pintu Radial. ................................... 32 Gambar 2.16 Pelimpah Tipe Ambang Lebar. .................................................... 33 Gambar 3.1
Aliran Debit Melalui Spillway Tipe Ogee Tanpa Pintu Pengendali. .................................................................................................... 39
Gambar 3.2
Grafik Hubungan Cs/Ci dan (Hd+d)/H. ........................................ 40
Gambar 3.3
Grafik Hubungan Ci/Coi dan H/H0. .............................................. 41
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Gambar 3.4
Aliran Debit Melalui Spillway Tipe Ogee dengan Pintu Pengendali. .................................................................................................... 42
Gambar 3.5
Hubungan Antara C dan a/H1. ..................................................... 42
Gambar 3.6
Sketsa Overflow dan Closure Dike Tampak Depan. ..................... 43
Gambar 3.7
Faktor Pengurangan Debit Pelimpah Dalam Kondisi Submerged. 44
Gambar 3.8
Bagan Konsep Pengembangan Model. ......................................... 50
Gambar 4.1
Diagram Alir Penelitian. .............................................................. 52
Gambar 4.2
Lokasi Stasiun ARR dan AWLR di DAS Bengawan Solo Hulu. .. 55
Gambar 4.3
Poligon Thiessen DAS di DTA Waduk Wonogiri. ....................... 56
Gambar 4.4
Poligon Thiessen di DAS Bengawan Solo Hulu Ruas Waduk Wonogiri – Bendung Colo. .......................................................... 58
Gambar 4.5
Poligon Thiessen di DAS Bengawan Solo Hulu Ruas Bendung Colo – Pos AWLR Jurug. ............................................................ 59
Gambar 4.6
Skema Pembagian Ruas Sungai antara Waduk Wonogiri – Bendung Colo. ............................................................................ 65
Gambar 4.7
Skema Pembagian Ruas Sungai antara Bendung Colo – Pos AWLR Jurug. .......................................................................................... 66
Gambar 4.8
Bagan Struktur Utama Perangkat Lunak. ..................................... 68
Gambar 4.9
Bagan Alir Simulasi Flood Forecasting. ..................................... 69
Gambar 4.10 Bagan Alir Simulasi Reservoir Flood Routing. ............................ 70 Gambar 4.11 Bagan Alir Simulasi Hydrologic Channel Routing....................... 71 Gambar 5.1
Tampilan Awal Perangkat Lunak. ............................................... 72
Gambar 5.2
Tampilan Map pada Menu Map and Watershed Scheme. ............. 73
Gambar 5.3
Tampilan About Application pada Menu Help. ............................ 73
Gambar 5.4
Tampilan Tab Time pada Menu Input Data. ................................ 75
Gambar 5.5
Tampilan Tab Realtime Monitoring pada Menu Input Data. ........ 75
Gambar 5.6
Tampilan Tab Thiessen Coefficient pada Menu Input Data. ......... 76
Gambar 5.7
Tampilan Tab Loss Parameter pada Menu Input Data................. 77
Gambar 5.8
Tampilan Tab Unit Hydrograph pada Menu Flood Forecasting. . 78
Gambar 5.9
Tampilan Perhitungan Hujan Efektif DAS pada Simulasi Flood Forecasting. ................................................................................ 79
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Gambar 5.10 Tampilan Perhitungan Initial Flow pada Simulasi Flood Forecasting. ................................................................................ 79 Gambar 5.11 Tampilan Hasil Perhitungan Flood Forecasting........................... 80 Gambar 5.12 Tampilan Hidrograf Inflow Waduk. ............................................. 80 Gambar 5.13 Tampilan Tab Total Inflow Hydrograph. ..................................... 81 Gambar 5.14 Tampilan Tab Initial Condition of Reservoir pada Menu Reservoir Flood Routing. ............................................................................ 82 Gambar 5.15 Tampilan Hidrograf Inflow – Outflow SSR. ................................. 83 Gambar 5.16 Tampilan Tab Initial Flow pada Menu Hydrologic Channel Routing. ...................................................................................... 85 Gambar 5.17 Tampilan Hidrograf Banjir Hasil Simulasi Hydrologic Channel Routing. ...................................................................................... 85 Gambar 5.18 Tampilan Hidrograf Inflow-Outflow pada Tab Result................... 86 Gambar 5.19 Tampilan Operasi Pintu Spillway pada Tab Result. ...................... 87 Gambar 5.20 Tampilan Debit dan TMA di Bendung Colo pada Tab Result. ..... 87 Gambar 5.22 Hasil Simulasi Flood Forecasting. .............................................. 90 Gambar 5.23 Hidrograf Banjir dan Hujan Efektif DAS Wiroko. ....................... 90 Gambar 5.24 Kategori Banjir dan Petunjuk Operasi Pintu Spillway. ................. 91 Gambar 5.25 Hidrograf Outflow Waduk Hasil Simulasi Reservoir Flood Routing. .................................................................................................... 92 Gambar 5.26 Hidrograf Outflow SSR Hasil Simulasi Reservoir Flood Routing. 92 Gambar 5.27 Kondisi Aliran di Bendung Colo Hasil Simulasi Hydrologic Channel Routing. ........................................................................ 93 Gambar 5.28 Hidrograf Lateral Inflow DAS Walikan Hasil Simulasi Hydrologic Channel Routing. ........................................................................ 94 Gambar 5.29 Hidrograf Banjir di Setiap Junction pada Ruas Waduk Wonogiri – Bendung Colo. ............................................................................ 95 Gambar 5.30 Kondisi Aliran di Pos AWLR Jurug Hasil Simulasi Hydrologic Channel Routing. ........................................................................ 96 Gambar 5.31 Hidrograf Banjir di Setiap Junction pada Ruas Bendung Colo – Pos AWLR Jurug. .............................................................................. 97
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Gambar 5.32 Perbandingan Outflow Waduk Hasil Simulasi dan Hasil Pengamatan. ................................................................................ 98 Gambar 5.33 Perbandingan Elevasi Muka Air Hasil Simulasi dan Hasil Pengamatan di Bendung Colo...................................................... 99 Gambar 5.34 Perbandingan Tinggi Muka Air Hasil Simulasi dan Hasil Pengamatan di Pos AWLR Jurug............................................... 100
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DAFTAR TABEL
Tabel 2.1.
Luas DAS pada DTA Waduk Wonogiri ......................................... 12
Tabel 2.2.
Manual Operasi Pintu Spillway Waduk Wonogiri .......................... 22
Tabel 2.3.
Pedoman Baru Operasi Pintu Spillway Waduk Wonogiri ............... 24
Tabel 2.4.
Luas DAS Bengawan Solo Hulu Ruas Waduk Wonogiri – Bendung Colo .............................................................................................. 25
Tabel 2.4.
Luas DAS Bengawan Solo Ruas Bendung Colo – Pos AWLR Jurug ...................................................................................................... 26
Tabel 3.1.
Persamaan Debit Melalui Overflow dan Closure Dike ................... 45
Tabel 3.1.
Persamaan Debit Melalui Overflow dan Closure Dike (lanjutan) ... 46
Tabel 3.1.
Persamaan Debit Melalui Overflow dan Closure Dike (lanjutan) ... 47
Tabel 4.1.
Data Penelitian .............................................................................. 53
Tabel 4.2.
Data Input dan Output Perhitungan ................................................ 54
Tabel 4.3.
ARR di DAS Bengawan Solo Hulu ............................................... 55
Tabel 4.4.
AWLR di DAS Bengawan Solo Hulu ............................................ 56
Tabel 4.5.
Nilai Koefisien Thiessen DAS di DTA Waduk Wonogiri............... 57
Tabel 4.6.
Nilai Koefisien Thiessen di DAS Bengawan Solo Hulu Ruas Waduk Wonogiri – Bendung Colo ............................................................. 58
Tabel 4.6.
Nilai Koefisien Thiessen di DAS Bengawan Solo Hulu Ruas Waduk Wonogiri – Bendung Colo (lanjutan) ............................................. 59
Tabel 4.7.
Nilai Koefisien Thiessen di DAS Bengawan Solo Hulu Ruas Bendung Colo – Pos AWLR Jurug ................................................ 60
Tabel 4.7.
Nilai Koefisien Thiessen di DAS Bengawan Solo Hulu Ruas Bendung Colo – Pos AWLR Jurug (lanjutan) ................................ 61
Tabel 4.8.
CN komposit dan CN (AMC III) di DTA Waduk Wonogiri ............ 62
Tabel 4.9.
CN komposit dan CN (AMC III) di DAS Bengawan Solo Hulu Ruas Bendung Colo – Pos AWLR Jurug ................................................ 62
Tabel 4.10. Persamaan Rating Curve di tiap AWLR......................................... 63 Tabel 4.11. Penetapan DAS Acuan di DTA Waduk Wonogiri .......................... 64
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Tabel 4.12. Nilai Parameter Muskingum Ruas Sungai antara Waduk Wonogiri – Bendung Colo ............................................................................... 66 Tabel 4.13. Nilai Parameter Muskingum Ruas Sungai antara Bendung Colo – Pos AWLR Jurug .......................................................................... 67 Tabel 5.1.
Data Hujan Realtime pada 25 Januari 2014 .................................... 89
Tabel 5.2.
Data Kedalaman Muka Air Hipotetik pada Stasiun AWLR ............ 89
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DAFTAR LAMPIRAN
Lampiran 1. Hidrograf Satuan DAS ................................................................. 107 Lampiran 2. Parameter DAS ............................................................................ 111 Lampiran 3. Hasil Simulasi Hujan 25 Januari 2014 .......................................... 112 Lampiran 4. Hasil Pengamatan Real Time 25 - 27 Januari 2014 ....................... 132
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