DAFTAR ISI. Halaman Judul... Lembar Pengesahan... Berita Acara Tugas Akhir... Lembar Persembahan... Kata Pengantar... Daftar Isi

DAFTAR ISI

Halaman Judul...........................................................................................

i

Lembar Pengesahan ..................................................................................

ii

Berita Acara Tugas Akhir .........................................................................

iii

Lembar Persembahan ................................................................................

iv

Kata Pengantar ..........................................................................................

vi

Daftar Isi....................................................................................................

viii

Daftar Gambar ...........................................................................................

xi

Daftar Tabel ..............................................................................................

xii

Abstrak ......................................................................................................

xiii

BAB I PENDAHULUAN .........................................................................

1

1.1 1.2 1.3 1.4 1.5

Latar Belakang ..................................................................... Maksud dan Tujuan ............................................................. Ruang Lingkup Penelitian ................................................... Lokasi Penelitan ................................................................... Sistematika Penulisan ..........................................................

1 2 2 3 3

BAB II TINJAUAN PUSTAKA...............................................................

5

2.1 Kolam Retensi...................................................................... 2.1.1 Pengertian Kolam Retensi .......................................... 2.1.2 Fungsi Kolam Retensi ................................................ 2.2 Analisa Hidrologi ................................................................. 2.2.1 Curah Hujan Wilayah ................................................. 2.2.2 Siklus Hidrologi ......................................................... 2.3 Analisa Frekuensi Curah Hujan ........................................... 2.3.1 Distribusi Gumbel ...................................................... 2.3.2 Distiribusi Log Pearson Type III ................................ 2.3.3 Uji Kesesuaian Pemilihan Distibusi ........................... 2.4 Intensitas Curah Hujan......................................................... 2.5 Waktu Konsentrasi ............................................................... 2.6 Debit Air Kotor .................................................................... 2.6.1 Debit Limpasan .......................................................... 2.6.2 Debit Air Buangan...................................................... vii

5 5 6 6 7 10 11 13 16 19 22 23 25 25 27

2.7 Analisa Hidrolika ................................................................. 2.7.1 Analisa Saluran........................................................... 2.7.2 Dimensi Saluran ......................................................... 2.8 Dimensi Kolam Retensi ....................................................... 2.9 Drainase ............................................................................... 2.9.1 Analisa Saluran........................................................... 2.9.2 Dimensi Saluran ......................................................... 2.10 Pompa .................................................................................. 2.10.1 Tipe-tipe Pompa ....................................................... 2.10.2 Kapasitas Pompa ......................................................

29 29 33 36 36 31 35 37 37 39

BAB III METODE PENELITIAN............................................................

40

3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9

Pengertian Umum ................................................................ Tipe Penelitian ..................................................................... Metode Pengumpulan Data .................................................. Tahap Persiapan ................................................................... Metode Analisis Data........................................................... Metode Pengolahan Data ..................................................... Batasan Masalah .................................................................. Pemecahan Masalah ............................................................. Flowchart Metodologi Kajian ..............................................

40 40 40 41 42 43 44 46 45

BAB IV ANALISA DAN PEMBAHASAN ............................................

49

4.1 Tinjaun Umum ..................................................................... 4.2 Analisa Hidrologi ................................................................ 4.2.1 Penentuan Daerah Aliran Sungai ............................... 4.2.2 Analisa Curah Hujan .................................................. 4.2.3 Perhitungan Debit Banjir Rencana Dengan Metode Rasional ...................................................................... 4.3 Analisa Debit Tampungan Air Dalam Kolam Retensi ........ 4.3.1 Dimensi Saluran Kolam Retensi ................................ 4.3.2 Perhitungan kapasitas kolam Retensi ........................ 4.4 Simulasi Tampungan dan Pemompaan ................................ 4.4.1 Routing Berdasarkan Waktu Pengurasan ................... 4.4.2 Routing Berdasarkan Hidrograf .................................

47 47 47 48

viii

63 67 67 69 75 75 79

BAB V KESIMPULAN ............................................................................

103

5.1 Kesimpulan .......................................................................... 5.2 Saran .................................................................................... 5.3 Daftar Pustaka ......................................................................

103 104 105

LAMPIRAN-LAMPIRAN

ix

DAFTAR GAMBAR No

JUDUL GAMBAR

Halaman

1.1

Peta Administrasi Kecamatan Jati Kab. Kudus.......................................

3

2.1

Metode Thiessen .....................................................................................

8

2.2

Metode Isohyet ....................................................................................... 10

2.3

Siklus Hidrologi ..................................................................................... 11

2.4

Penampang Persegi Panjang .................................................................. 31

2.5

Penampang Segi Tiga .............................................................................. 32

2.6

Pompa archemedian screw ..................................................................... 37

2.7

Pompa centrifugal ................................................................................... 38

2.8

Pompa axial ............................................................................................. 38

2.9

Pompa aliran campuran ........................................................................... 39

2.10

Kurva Head-Kapasitas Pompa ................................................................ 39

3.1.

Bagan Alur Penelitian ............................................................................ 46

4.1

Catchment area ....................................................................................... 48

4.2

Lokasi Stasiun Kudus, Jekulolor dan Karanganyar ................................ 51

4.3

Skema Debit Rencana ............................................................................. 66

4.4

Penampang Melintang Ruas 1 ................................................................. 67

4.5

Penampang melintang Ruas 2 ................................................................. 68

4.6

Penampang melintang Ruas 3 ................................................................. 68

4.7

Lay Out Long Storage ............................................................................. 69

4.8

Debit banjir maksimum DAS Kali kencing ............................................ 91

4.9

Kurva Elevai Muka Air ........................................................................... 100

4.10

penampang melintang Storage tambahan................................................ 101

4.11

Lay Out Long Storage Tambahan ........................................................... 101

4.12

Skema Long Storage ............................................................................... 102

xi

DAFTAR TABEL No.

JUDUL TABEL

Halaman

2.1

Reduced Mean (Yn) ................................................................................ 14

2.2

Reduced Standard Deviation (σn) ........................................................... 14

2.3

Reduced Variate (Yt) .............................................................................. 15

2.4

Harga K untuk Metode Sebaran Log- person Type ................................. 18

2.5

Harga Kritis Chi-Kritis ........................................................................... 20

2.6

Nilai Kritis (DO) dari Smirnov - Kolmogorof ........................................ 21

2.7

Koefisien Hambatan ................................................................................ 24

2.8

Nilai Koefisien Kekasaran Lahan ........................................................... 25

2.9

Koefisien Pengaliran C ........................................................................... 27

2.10

Pendekatan Jumlah Aliran Buangan Untuk bebrepa tipe Bangunan ...... 28

2.11

Desain Saluran Berdasarkan Kecepatan izin........................................... 34

2.12

Hubungan Kemiringan Berdasarkan Jenis material ................................ 34

2.13

Hubungan debit dengan kemiringan Saluran .......................................... 35

2.14

Hubungan Kemiringan Saluran Dengan Kecepatan raTa-rata Aliran..... 35

4.1

Data Curah Hujan Bulanan Maksimum (mm) St.Kudus, Kudus ........... 49

4.2

Data Curah Hujan Bulanan Maksimum(mm) St.Jekulolor, Kudus ........ 50

4.3

Data Curah Hujan Bulanan Maksimum(mm) St.Karang Anyar, Demak 50

4.4

Curah Hujan Harian Maksimum Bulanan .............................................. 51

4.5

Curah Hujan Rata-Rata Bulanan pada DAS .......................................... 52

4.6

Distribusi Gumbel .................................................................................. 54

4.7

Perhitungan Curah Hujan Rancangan Metode Gumbel ......................... 55

4.8

Distribusi Log Pearson Tipe III .............................................................. 56

4.9

Perhitungan Curah Hujan Rancangan Metode Log Pearson Tipe III .... 56

4.10

Hubungan Antara Cs dengan Kala Ulang (T) atau dengan Perchent Change (P%) .......................................................................................... 50

4.11

Rekapitulasi Hujan Rancangan Sta. Kudus, Sta. Jekulolor, Sta. Karangayar .............................................................................................. 57

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4.12

Besar Peluang dan Batas Nilai Kelas Distribusi Gumbel ...................... 58

4.13

Perhitungan Uji Chi-Square Distribusi Gumbel .................................... 59

4.14

Besar Peluang dan Batas Nilai Kelas Distribusi Log Pearson Tipe III .. 60

4.15

Perhitungan Uji Chi-Square Distribusi Log Pearson Tipe III ................ 60

4.16

Perhitungan Uji Smirnov Kolmogorof Distribusi Gumbel ..................... 61

4.17

Perhitungan Uji Smirnov Kolmogorof Distribusi Log Pearson Tipe III.

4.18

Hasil Uji Chi-Square dan Uji Smirnov Kolmogorof .............................. 62

4.19

Luas DAS Tiap Saluran ......................................................................... 64

4.20

Perhitungan Debit Banjir Rencana Q25 .................................................. 65

4.21

Perhitungan Kapasitas Long Storage ..................................................... 70

4.22

Hasil Perhitungan HSS Nakayasu Kala Ulang 2 tahun .......................... 84

4.23

Hasil Perhitungan HSS Nakayasu Kala Ulang 5 tahun .......................... 85

4.24

Hasil Perhitungan HSS Nakayasu Kala Ulang 10 tahun ........................ 86

4.25

Hasil Perhitungan HSS Nakayasu Kala Ulang 20ahun .......................... 87

4.26

Hasil Perhitungan HSS Nakayasu Kala Ulang 25 tahun ........................ 88

4.27

Hasil Perhitungan HSS Nakayasu Kala Ulang 50 tahun ........................ 89

4.28

Hasil Perhitungan HSS Nakayasu Kala Ulang 100 tahun ...................... 90

4.29

Routing Dengan Kapasitas Pompa 1,2 m3/dt dan dengan Volume awal

62

Long Storage .......................................................................................... 94 4.30

Routing Dengan Kapasitas Pompa 1,2 m3/dt dan dengan Volume Long Storage diperbesar ................................................................................... 96

4.31

Routing Dengan Kapasitas Pompa 4,5 m3/dt dan dengan Volume Long Storage diperbesar ................................................................................... 98

xiii