ANALISA BENDUNG

PERHITUNGAN STABILITAS BENDUNG

1 Rembesan dan Tekanan Air

CL = LV + 1/3 LH

H

Dimana :

CL = Angka rembesan lane

LV = Jumlah panjang vertikal ( m )

LH = Jumlah panjang horizontal ( m )

H = Beda tinggi muka air ( m )

Px = Hx - H = Hx - lx x HW/L

2 Stabilitas Terhadap Erosi Bawah Tanah

3 Stabilitas Bendung Saat Q Normal

Muka air Hulu adalah + 25,52 ( Elevasi Mercu ) dan muka air hilir merupakan

elevasi embang kolam olak

Gaya - gaya yang bekerja pada Bendung adalah :

- Tekanan air

- Tekanan tanah

- Tekanan sendiri bendung

Akibat dari pembendungan, maka muka air di Hulu akan naik. Sehingga terjadi

perbedaan muka air dengan Hilir bendung, hal ini akan mengakibatkan rembesan

(seepage) di bawah konstruksi bendung yang dapat mengakibatkan piping. Untuk

mengatasi gejala ini dapat dilakukan dengan cara membuat lantai muka. untuk

mengetahui panjang aliran di bawah pondasi dihitung dengan Methode Lane, yaitu

:

Untuk menentukan tekanan air, panjang jalur rembesan harus diambil sampai

elevasi ambang hilir kolam olak, dimana harga CL diambila harga aman.

Tekanan air tanah ( Px ) dihitungan dengan rumus :

Untuk mencegah terjadinya bahaya piping pada ujung hilir Bendung akibat

tekanan air dari bawah Bendung ( Uplift ), maka pada muka Bendung perlu

dibuat lantai muka. Panjang lantai muka terencana sampai dibuat harga CL

yang aman

Gaya - gaya tersebut dapat dilihat pada gambar :

TABEL

PERHITUNGAN GARIS REMBESAN SAAT DEBIT NORMAL

NO GARISPANJANG REMBESAN H

VER HOR 1/3 HOR Iw H

0

0 - 1 1.50

1

1 - 2 0.50 0.17

2

2 - 3 0.50

3

3 - 4 3.00 1.00

4

4 - 5 0.50

5

5 - 6 0.50 0.17

6

6 - 7 0.50

7

7 - 8 3.00 1.00

8

8 - 9 0.50

9

9 - 10 0.50 0.17

10

10 - 11 0.50

11

11 - 12 3.00 1.00

12

12 - 13 0.50

13

13 - 14 0.50 0.17

14

14 - 15 0.50

15

15 - A 2.50 0.83

A

A - B

B

B - C

C

C - D

D

D - E

E

E - F

F

F - G

G

G - H

H

H - I

I

I - J

J

J - K

K

K - L

L

L - M

M

M - N

N

TABEL

PERHITUNGAN GARIS REMBESAN SAAT DEBIT NORMAL

A HORIZONTAL

NOTASI

W1 X X X

W2

1.00

0.99

0.98

0.97

0.96

0.95

0.94

0.93

0.92

0.91

0.90

0.89

0.88

0.87

0.86

0.85

0.84

0.83

0.82

0.81

1.5 1 2 3

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

1.0 2.0 3.0

4 5 6 7 8 9 10

Catatan : Sahih jika P/H1 ≥ 1.5

3.0 5.04.0 6.0 7.0 8.0 9.0 10.0

Perhitungan Debit Banjir dengan Metode Rasional Jepang

Dalam menganalisa debit banjir rencana digunakan data - data sebagai berikut :

a Luas Cachment Area (A) = 150.00 Km

b Panjang Sungai ( L ) = 35.00 Km

c Kemiringan Sungai (i) = 0.00419 M

Langkah perhitungan Metode Rasional Jepang

1 Harga koefisien pengaliran diambil (f) = 0.75

2 Kecepatan rambat banjir :

V = 72 x ( i ) 0.6

= 72 x 0.00419 0.6

= 72 x 0.0374

= 2.6956 Km/Jam

3 Lamanya perambatan banjir :

t = L

V

t = 35.00 = 12.984 Km/Jam

2.6956

4 Intensitas curah hujan :

r = Xt x 24 0.6667

24 t

r = Xt x 24 0.6667

24 12.984

r = Xt x 1.5061541

24

r = 0.0628 Xt

5 Debit banjir :

Qt = f x r x A x Xt

3.6

Qt = 0.75 x 0.0628 x 150.00 x Xt

3.6

Qt = 1.9611 Xt

Tabel

Debit Banjir Rational dengan Metode Gumbel

T Xt r f A Qt

(Tahun) (mm) (mm/jam)

2 873.74025 54.83281 0.75 150.00 1713.5253

5 912.34492 57.255502 0.75 150.00 1789.2344

10 937.90085 58.8593 0.75 150.00 1839.3531

25 970.20085 60.886332 0.75 150.00 1902.6979

50 1008.2431 63.273725 0.75 150.00 1977.3039

100 1017.9407 63.882313 0.75 150.00 1996.3223

Tabel

Debit Banjir Rational dengan Metode Log Person Type III

T Xt r f A Qt


2 1.7120365 0.1074413 0.75 150.00 3.3575401

5 1.9315078 0.1212145 0.75 150.00 3.7879536

10 2.0351916 0.1277213 0.75 150.00 3.9912918

25 2.1386169 0.1342119 0.75 150.00 4.1941232

(Km2) m3/det

(Km2) m3/det

50 2.2019093 0.1381839 0.75 150.00 4.3182483

100 2.2566493 0.1416192 0.75 150.00 4.4256011

Tabel

Debit Banjir Rational dengan Metode Hasper

T Xt r f A Qt


2 49.075123 3.079779 0.75 150.00 96.243094

5 88.392267 5.5471823 0.75 150.00 173.34945

10 116.73719 7.3260079 0.75 150.00 228.93775

25 155.13998 9.7360297 0.75 150.00 304.25093

50 184.85643 11.600928 0.75 150.00 362.52898

100 215.9444 13.551898 0.75 150.00 423.4968

808.08156

(Km2) m3/det

1 Menghitung besarnya koefisien aliran

α = 1 + 0.012 A 0.70

1 + 0.075 A 0.70

= 1 + 0.012 150.00 0.70

1 + 0.075 150.00 0.70

= 1 + 0.012 33.36

1 + 0.075 33.36

= 1.4003549

3.502218

α = 0.40

2 Menghitung waktu konsentrasi

t = 0.10 L 0.80 i -0.30

= 0.10 35.00 0.80 0.00419 ###

= 0.10 17.1892 5.1682

t = 8.88

3

1 = 1 + t + ( 3.7 10 ### x A 0.75

β t 2 + 15 12

= 1 + 8.8836252 + ( 3.7 x 0.0002796 ) x 42.8616

78.91879713179 + 15 12.0000

= 1 + 8.8847 x 3.5718005

93.919

= 1 + 0.0946 x 3.5718005

= 1.3379

β = 0.75

4 Menghitung Distribusi Hujan

Untuk t antara 2 sampai 19 jam

Rt = t x Rt

t + 1

Rt = 8.8836 x Rt = 0.90 Rt

8.8836 + 1

5 Menghitung Hujan Maksimum (q)

q = 0.8988 x Rt = 0.03 Rt

8.8836 x 3.60

Menghitung harga koefisien reduksi (β)

t )

6 Menghitung Debit Maksimum (Qt)

Qt = α β q A

Qt = 0.40 x 0.75 x 0.03 Rt x 150

Qt = 1.2599 Rt

TABEL

DEBIT BANJIR HASPER - GUMBEL

T Xt α βq A Qt

(Thn) (mm) m3/det/km (Km2) m3/det

2 873.74 0.40 0.75 24.56 150.00 1100.85

5 912.34 0.40 0.75 25.64 150.00 1149.49

10 937.90 0.40 0.75 26.36 150.00 1181.69

25 970.20 0.40 0.75 27.27 150.00 1222.39

50 1008.24 0.40 0.75 28.34 150.00 1270.32

100 1017.94 0.40 0.75 28.61 150.00 1282.54

TABEL

DEBIT BANJIR HASPER - LOG PERSON TYPE III

T Xt α βq A Qt


2 1.71 0.40 0.75 0.05 150.00 2.16

5 1.93 0.40 0.75 0.05 150.00 2.43

10 2.04 0.40 0.75 0.06 150.00 2.56

25 2.14 0.40 0.75 0.06 150.00 2.69

50 2.20 0.40 0.75 0.06 150.00 2.77

100 2.26 0.40 0.75 0.06 150.00 2.84

TABEL

DEBIT BANJIR HASPER - HASPER

T Xt α βq A Qt


2 49.08 0.40 0.75 1.38 150.00 61.83

5 88.39 0.40 0.75 2.48 150.00 111.37

10 116.74 0.40 0.75 3.28 150.00 147.08

25 155.14 0.40 0.75 4.36 150.00 195.47

50 184.86 0.40 0.75 5.20 150.00 232.91

100 215.94 0.40 0.75 6.07 150.00 272.08

1 Menentukan Koefisien Pengaliran, sesuai dengan daerah pengaliran

Daftar koefisien pengaliran (f) dari Metode Rasional Jepang

Kondisi daerah pengaliran dan sungai

Koefisien

Pengaliran

( f )

Daerah pegunungan yang curam 0.75 - 0.90

Daerah pegunungan tertier 1.75 - 1.90

Tanah bergelombang dan hutan 2.75 - 2.90

Persawahan yang diairi 3.75 - 3.90

Tanah dataran yang ditanami 4.75 - 4.90

Sungai di daerah pegunungan 5.75 - 5.90

Sungai kecil di dataran 6.75 - 6.907.75 - 7.90

Dari peta situasi/topografi dan hasil survei lapangan, maka diketahui bahwa daerah

Pengaliran Sungai Oko - Oko termasuk koefisien = 0.75

Kecepatan rambat banjir (V) dengan rumus :

V = 72 x ( i ) 0.6

0.6666667

Sungai besar yang lebih dari setengah daerah pengalirannya dataran

54.83281 103.01859 98.7564

24.69

22.43

2000

0.0012556

11.6489

0.0002805

42.8616

12.0000

52.53

66.184209

1 Buat elips pada gambar catcment area dengan ketentuan :

a < 0.67 x b

dimana :

a = Sumbu pendek elips

b = Sumbu panjang elips

Luas Elips (nA) = 0.25 x 3.14 x a x b

Dengan ketentuan :

0.60 < A < 0.90

nA

Dari peta situasi/topografi dan hasil survei lapangan, maka diketahui bahwa daerah

2 Kemiringan rata - rata sungai :

i = ΔH

Lt

Dimana ;

i = Kemiringan rata - rata sungaiΔH =

Lt = Panjang teorotis sungai ( 0.9 x L ) (m)

L = Panjang Sungai (m)


Beda tinggi antara tempat rencana bendung dan tempat mulainya teoritis panjang sungai

c Kemiringan Sungai (i) = 0.00419


1

Perhitungan Debit Banjir dengan Metode GumbelDalam menganalisa debit banjir rencana digunakan data - data sebagai berikut :

a Luas Cachment Area (A) = 150.00 Kmb Panjang Sungai ( L ) = 35.00 Km

No T X i (Xi - X)(tahun) (mm)

1 2 873.74025 -79.654853916 6344.895752352 5 912.34492 -41.050176307 1685.116974843 10 937.90085 -15.494247588 240.0717083294 25 970.20085 16.8057486851 282.4331888675 50 1008.2431 54.847956781 3008.298363056 100 1017.9407 64.5455723452 4166.13090937

∑ 5720.3706 -1.1368684E-13 15726.9468968

X =∑Xi

=5720.3706

= 953.3951 mmn 6

S =n - 1

S = 15726.94689685

0.99= 56.0838

Y = - Ln ln ( 100 - 1 )100

= - Ln 0.0100503

= 4.600149

Untuk Periode Ulang 100 tahun

Yn = 0.5600

Sn = 1.2065

X100 = X + Y - Yn x SSn

(Xi - X)2

∑ (Xi - X)2

X100 = 953.3951 + 4.6001492 - 0.5600 x 56.08381.2065

X100 = 953.3951 + 3.3486525 x 56.0838

X100 = 1141.2


α = 1 + 0.012 A 0.701 + 0.075 A 0.70

= 1 + 0.012 150.00 0.701 + 0.075 150.00 0.70

= 1 + 0.012 33.361 + 0.075 33.36

= 1.40035493.502218

α = 0.40

2 Menghitung waktu konsentrasit = 0.10 L 0.80 i -0.30

= 0.10 35.00 0.80 0.00419 ###

= 0.10 17.1892 5.1682

t = 8.88

31 = 1 + t + ( 3.7 10 ### x A 0.75β t 2 + 15 12

= 1 + 8.8836252 + ( 3.7 x 0.0002796 ) x 42.861678.9187971318 + 15 12.0000

= 1 + 8.8847 x 3.571800593.919

= 1 + 0.0946 x 3.5718005

= 1.3379

β = 0.75

4 Menghitung Distribusi Hujan Untuk t antara 2 sampai 19 jam

Rt = t x Rtt + 1

Rt = 8.8836 x Rt = 0.90 Rt8.8836 + 1


q = 0.8988 x Rt = 0.03 Rt8.8836 x 3.60

6 Menghitung Debit Maksimum (Qt) Qt = α β q A

Qt = 0.40 x 0.75 x 0.03 Rt x 150

Menghitung harga koefisien reduksi (β)t )

Qt = 1.2599 Rt

TABELDEBIT BANJIR HASPER - GUMBEL

T Xt α βq A Qt

(Thn) (mm) m3/det/km (Km2) m3/det2 873.74 0.40 0.75 24.56 150.00 1100.855 912.34 0.40 0.75 25.64 150.00 1149.49

10 937.90 0.40 0.75 26.36 150.00 1181.6925 970.20 0.40 0.75 27.27 150.00 1222.3950 1008.24 0.40 0.75 28.34 150.00 1270.32

100 1017.94 0.40 0.75 28.61 150.00 1282.54

TABELDEBIT BANJIR HASPER - LOG PERSON TYPE III

T Xt α βq A Qt


10 2.04 0.40 0.75 0.06 150.00 2.5625 2.14 0.40 0.75 0.06 150.00 2.6950 2.20 0.40 0.75 0.06 150.00 2.77

100 2.26 0.40 0.75 0.06 150.00 2.84

TABELDEBIT BANJIR HASPER - HASPER

T Xt α βq A Qt


10 116.74 0.40 0.75 3.28 150.00 147.0825 155.14 0.40 0.75 4.36 150.00 195.4750 184.86 0.40 0.75 5.20 150.00 232.91

100 215.94 0.40 0.75 6.07 150.00 272.08

1017.9407 605.8934 367106.8516215.9444 -196.1028 38456.3242

2.2566 -409.7906 167928.32901236.1417 573491.5048

412.0472

X =∑Xi

=1236.14

= 412.0472 mmn 3

S =n - 1

S = 573491.50482

0.99= 535.4865

Y = - Ln ln ( 100 - 1 )100

= - Ln 0.0100503

= 4.600149

Untuk Periode Ulang 100 tahun

Yn = 0.5600

Sn = 1.2065

X100 = X + Y - Yn x SSn

∑ (Xi - X)2

X100 = 412.04724 + 4.6001492 - 0.5600 x 535.48651.2065

X100 = 412.04724 + 3.3486525 x 535.4865

X100 = 2205.205

11.6489

0.0002805

52.53

66.184209

c Panjang Sungai Teoritis ( 0.9 x L ) = 31.50 Kmd Elevasi Sungai Pada Hulu = 24.69 Me Elevasi sungai pada Hilir = 22.43 M

f Kemiringan Sungai (i) = 0.00419

g Curah Hujan Maksimum = R50 = 1008.2431 mm

R100 = 1017.9407 mm

Langkah perhitungan Metode Mecior1 Buat elips pada gambar catcment area dengan ketentuan :

a < 0.67 x bdimana :

a = Sumbu pendek elipsb = Sumbu panjang elips

Luas Elips (nA) = 0.25 x 3.14 x a x b

Dengan ketentuan :

0.60 < A < 0.90nA


i = ΔHLt

Dimana ;i = Kemiringan rata - rata sungai

ΔH =Lt = Panjang teorotis sungai ( 0.9 x L ) (m)L = Panjang Sungai (m)



Y Yn x SSn

A. Stasiun Mowewe

Tabel 5.1 Perhitungan Curah Hujan Stasiun Mowewe dengan Metode Gumbel

NO TAHUN X i

1 1992 152.00 9124.91

2 1993 135.50 6244.85

3 1994 62.00 30.52

4 1995 51.00 29.98

5 1996 24.00 1054.67

6 1997 32.31 583.98

7 1998 66.00 90.71

8 1999 91.00 1191.93

9 2000 43.30 173.60

10 2001 25.00 990.71

11 2002 49.00 55.88

12 2003 15.00 1720.23

13 2004 42.00 209.54

14 2005 65.00 72.66

15 2006 35.50 439.98

16 2007 15.00 1720.23

∑ 903.61 23734.387

X = ∑ X = 903.61 = 56.476 mm

n 16

S = = 23734.39 = 39.778 mm

n - 1 15

n = 16 tahun Yn = 0.5157 (Tabel Lampiran

Sn = 1.0316 (Tabel

(X I - X)2

∑ (Xi - X)2

Tabel

Periode Ulang Yt Yn Sn

T = 2 0.3665 0.5157 1.0316

T = 5 1.4999 0.5157 1.0316

T = 10 2.2502 0.5157 1.0316

T = 25 3.1985 0.5157 1.0316

T = 50 3.9019 0.5157 1.0316

T = 100 4.6001 0.5157 1.0316

Xt = X + K . Sx

K = Yt - Yn

Sn

Sehingga

Xt = X + Yt - Yn Sx

Sn

X2 = 903.61 + 0.3665 - 0.5157 x 39.778

1.0316

X2 = 903.61 + -0.1446297 x 39.778

X2 = 897.8569 mm

X5 = 903.61 + 1.4999 - 0.5157 x 39.778

1.0316

X5 = 903.61 + 0.95405196 x 39.778

X5 = 941.5603 mm

X10 = 903.61 + 2.2502 - 0.5157 x 39.778

1.0316

X10 = 903.61 + 1.68136875 x 39.778

X10 = 970.4916 mm

X25 = 903.61 + 3.1985 - 0.5157 x 39.778

X25 = 903.61 +

1.0316

x 39.778

X25 = 903.61 + 2.6006204 x 39.778

X25 = 1007.0576 mm

X50 = 903.61 + 3.9019 - 0.5157 x 39.778

1.0316

X50 = 903.61 + 3.28247383 x 39.778

X50 = 1034.1804 mm

X100 = 903.61 + 4.6001 - 0.5157 x 39.778

1.0316

X100 = 903.61 + 3.95928655 x 39.778

X100 = 1061.1027 mm

Perhitungan Curah Hujan Stasiun Mowewe dengan Metode Hasper

Rumus

Rt = X + Sx x Ux

Sx = 1 R1 - X + R2 - X

2 U1 U2

Dengan

Curah Hujan Maksimum 1 R1 = 152.00 mm


Hujan Rata - Rata Maksium X = 56.48 mm

Lama Pengamatan n = 16 Thn

Tabel

Hujan Maksimum

Periode Ulang

T = n + 1

m

152.00 1 17 1.740

135.50 2 8.5 1.115

Urutan Terbesar

Standar Variabel U

Menentukan Standar Deviasi

Sx = 1 152.00 - 56.48+

135.50 - 56.48

2 1.740 1.115

Sx = 0.595.52

+79.02

1.740 1.115

Sx = 0.5 54.899 + 70.874

Sx = 62.886

Dengan menggunakan rumus

Rt = X + Sx x Ux

Tabel Perhitungan curah hujan rencana dengan metode Hasper

No Tahun X (mm) Ux Sx Rt = X + Sx x Ux

1 2 56.48 -0.22 62.886 42.641

2 5 56.48 0.64 62.886 96.723

3 10 56.48 1.26 62.886 135.713

4 25 56.48 2.10 62.886 188.537

5 50 56.48 2.75 62.886 229.413

6 100 56.48 3.43 62.886 272.176

Tabel Perhitungan curah hujan rencana dengan Metode Log Person Type III

NO TAHUN X i Log Xi Log (Xi - X)

1 1992 152.00 2.18184 0.52278 0.27330 0.14287

2 1993 135.50 2.13194 0.47287 0.22361 0.10574

3 1994 62.00 1.79239 0.13332 0.01778 0.00237

4 1995 51.00 1.70757 0.04850 0.00235 0.00011

5 1996 24.00 1.38021 -0.27886 0.07776 -0.02168

6 1997 32.31 1.50934 -0.14973 0.02242 -0.00336

7 1998 66.00 1.81954 0.16048 0.02575 0.00413

8 1999 91.00 1.95904 0.29997 0.08998 0.02699

9 2000 43.30 1.63649 -0.02258 0.00051 -0.00001

10 2001 25.00 1.39794 -0.26113 0.06819 -0.01781

11 2002 49.00 1.69020 0.03113 0.00097 0.00003

12 2003 15.00 1.17609 -0.48298 0.23327 -0.11266

13 2004 42.00 1.62325 -0.03582 0.00128 -0.00005

Log (Xi - X)2 Log (Xi - X)3

14 2005 65.00 1.81291 0.15385 0.02367 0.00364

15 2006 35.50 1.55023 -0.10884 0.01185 -0.00129

16 2007 15.00 1.17609 -0.48298 0.23327 -0.11266

∑ 26.55 26.55 1.30594 0.01637

1 Nilai Rata - Rata Sampel

Log X = ∑ Log Xi

n

Log X = 26.55 = 1.6591

16

2 Standar Deviasi

S Log X = = 1.3059 = 0.295 mm

n - 1 15

3 Nilai Koefisien Kemencengan

CS = = 0.2620 = 0.049 mm

5.3947

Sehingga Persamaan dapat ditulis

Log X = Log X + k (S Log X)

Koefisen Kemencengan CS = 0.049

Log Xt = 1.6591 + 0.049 (Tabel Lampiran

Log X2 = 1.6591 + 0.000 x 0.295

= 1.6591

Log X5 = 1.6591 + 0.842 x 0.295

= 1.9075

Log X10 = 1.6591 + 1.282 x 0.295

= 2.0373

Log X25 = 1.6591 + 1.751 x 0.295

= 2.1757

Log X50 = 1.6591 + 2.054 x 0.295

= 2.2651

Log X100 = 1.6591 + 2.326 x 0.295

= 2.3454

∑ (LogXi - LogX)2

n∑ (LogXi - LogX)3

(n - 1) (n - 2) (S Log X)3

Stasiun Toari

NO TAHUX (mm)

1 1995 85

2 1996 43

3 1997 58

4 1998 12.25

5 1999 96.5

6 2000 94

7 2001 56

8 2002 21

9 2003 60

10 2004 133

11 2005 58

12 2006 105 12.5

13 2007 55

Data Sebelum Direngking Data Setelah Direngking

NO TAHUNBesar (mm) NO TAHUNBesar (mm)

1 1992 50.67 1 1992 50.67 152.00

2 1993 45.17 2 1993 58.33 135.50

3 1994 20.67 3 1994 45.77 62.00

4 1995 45.33 4 1995 46.67 136.00

5 1996 22.33 5 1996 45.17 67.00

6 1997 30.10 6 1997 62.50 90.31

7 1998 26.08 7 1998 20.67 78.25

8 1999 62.50 8 1999 56.00 187.50

9 2000 45.77 9 2000 55.95 137.30

10 2001 #REF! 10 2001 49.50 #REF!

11 2002 23.33 11 2002 47.00 70.00

12 2003 25.00 12 2003 40.00 75.00

13 2004 58.33 13 2004 39.27 175.00

14 2005 41.00 14 2005 37.00 123.00

15 2006 46.67 15 2006 32.00 140.01

16 2007 23.33 16 2007 28.00 70.00

#REF!

Data Sebelum Direngking

NO TAHUNBesar (mm)

1 1992 50.67 6.01 ###

2 1993 58.33 ### ###

3 1994 45.77 1.11 1.234

4 1995 46.67 2.01 4.058

5 1996 45.17 0.51 0.261

6 1997 62.50 ### ###

7 1998 20.67 ### ###

8 1999 56.00 ### ###

9 2000 55.95 ### ###

10 2001 49.50 4.84 ###

11 2002 47.00 2.34 5.496

12 2003 40.00 -4.66 ###

13 2004 39.27 -5.39 ###

14 2005 37.00 -7.66 ###

15 2006 32.00 ### ###

16 2007 28.00 ### ###

### ###

16

44.66

S 11.42

Lampiran Hubungan antara T dan U

Tabel

T U T U T U

1.00 -1.86 15.00 1.63 70.00 3.08

1.01 -1.35 16.00 1.69 72.00 3.11

1.02 -1.28 17.00 1.74 74.00 3.13

1.03 -1.23 18.00 1.80 76.00 3.16

1.04 -1.19 20.00 1.89 78.00 3.18

1.05 -1.15 21.00 1.94 80.00 3.21

1.08 -1.07 22.00 1.98 82.00 3.23

1.10 -1.02 23.00 2.02 84.00 3.26

1.20 -0.85 24.00 2.06 86.00 3.28

1.30 -0.73 25.00 2.10 88.00 3.30

1.40 -0.63 26.00 2.13 90.00 3.33

1.50 -0.54 27.00 2.17 92.00 3.35

1.60 -0.46 28.00 2.19 94.00 3.37

1.70 -0.40 30.00 2.27 96.00 3.39

1.80 -0.33 31.00 2.30 98.00 3.41

1.90 -0.28 32.00 2.33 100.00 3.43

2.00 -0.22 33.00 2.36 120.00 3.62

2.20 -0.13 34.00 2.39 130.00 3.70

2.40 -0.04 35.00 2.41 140.00 3.77

2.60 0.04 36.00 2.44 150.00 3.84

2.80 0.11 37.00 2.47 160.00 3.91

3.00 0.17 38.00 2.49 170.00 3.97

3.20 0.24 39.00 2.51 80.00 4.03

3.40 0.29 40.00 2.54 200.00 4.14

3.60 0.34 42.00 2.59 220.00 4.24

3.80 0.39 43.00 2.61 240.00 4.33

4.00 0.44 44.00 2.63 260.00 4.42

4.50 0.55 45.00 2.65 280.00 4.50

5.00 0.64 46.00 2.67 300.00 4.57

5.50 0.73 47.00 2.68 350.00 4.77

6.00 0.81 48.00 2.71 400.00 4.88

6.50 0.88 49.00 2.73 450.00 5.01

7.00 0.95 50.00 2.75 500.00 5.13

7.50 1.01 52.00 2.79 600.00 5.33

8.00 1.06 54.00 2.83 700.00 5.51

8.50 1.12 56.00 2.86 800.00 5.56

9.00 1.17 58.00 2.90 900.00 5.80

10.00 1.26 60.00 2.93 1000.00 5.92

11.00 1.35 62.00 2.96 5000.00 7.90

12.00 1.43 64.00 2.99 10000.00 8.83

13.00 1.50 66.00 3.00 50000.00 11.08

14.00 1.57 68.00 3.05 500000.00 13.74

Lampiran

Tabel Nilai K Distribusi Person Type III & Log Person dengan Koef. Kemencengan (Cs)

Cs

Periode Ulang (Tahun)

2 5 10 25 50 100 200 1000

Peluang ( % )

50 20 10 4 2 1 0.5 0.1

3 -0.360 0.420 1.180 2.278 3.152 4.051 4.970 7.250

2.5 -0.360 0.518 1.250 2.262 3.048 3.845 4.625 6.600

2.2 -0.330 0.574 1.284 2.240 2.970 3.705 4.444 6.200

2 -0.307 0.609 1.302 2.219 2.912 3.605 4.298 5.910

1.8 -0.282 0.643 1.318 2.193 2.848 3.499 4.147 5.660

1.6 -0.254 0.675 1.329 2.163 2.780 3.388 3.990 5.390

1.4 -0.225 0.705 1.337 2.128 2.706 3.271 3.828 5.110

1.2 -0.195 0.732 1.340 2.087 2.626 3.149 3.661 4.820

1 -0.164 0.758 1.340 2.043 2.542 3.022 3.489 4.540

0.9 -0.148 0.769 1.339 2.018 2.498 2.957 3.401 4.395

0.8 -0.132 0.780 1.336 1.998 2.453 2.891 3.312 4.250

0.7 -0.116 0.790 1.333 1.967 2.407 2.824 3.223 4.105

0.6 -0.099 0.800 1.328 1.939 2.359 2.755 3.132 3.960

0.5 -0.083 0.808 1.323 1.910 2.311 2.686 3.041 3.815

0.4 -0.066 0.816 1.317 1.880 2.261 2.615 2.949 3.670

0.3 -0.050 0.824 1.309 1.849 2.211 2.544 2.856 3.525

0.2 -0.033 0.830 1.301 1.818 2.159 2.472 2.763 3.380

0.1 -0.017 0.836 1.292 1.785 2.107 2.400 2.670 3.235

0 0.000 0.842 1.282 1.751 2.054 2.326 2.576 3.090

-0.1 0.017 0.836 1.270 1.761 2.000 2.252 2.482 3.950

-0.2 0.033 0.850 1.258 1.680 1.945 2.178 2.388 2.810

-0.3 0.050 0.853 1.245 1.643 1.890 2.104 2.294 2.675

-0.4 0.066 0.855 1.231 1.606 1.934 2.029 2.201 2.540

-0.5 0.083 0.856 1.216 1.567 1.777 1.955 2.108 2.400

-0.6 0.099 0.857 1.200 1.528 1.720 1.880 2.016 2.275

-0.7 0.116 0.857 1.183 1.488 1.663 1.806 1.926 2.150

-0.8 0.132 0.856 1.166 1.448 1.606 1.733 1.837 2.035

-0.9 0.148 0.854 1.147 1.407 1.549 1.660 1.749 1.910

-1 0.164 0.852 1.128 1.366 1.492 1.588 1.664 1.800

-1.2 0.195 0.844 1.086 1.382 1.379 1.449 1.501 1.625

-1.4 0.225 0.832 1.041 1.198 1.270 1.318 1.351 1.465

-1.6 0.254 0.817 0.994 1.166 1.166 1.197 1.216 1.280

-1.8 0.282 0.799 0.945 1.035 1.069 1.087 1.097 1.130

-2 0.307 0.777 0.895 0.959 0.980 0.990 1.995 1.000

-2.2 0.330 0.752 0.844 0.888 0.900 0.905 0.907 0.910

-2.5 0.360 0.711 0.771 0.793 0.798 0.799 0.800 0.802

-3 0.396 0.636 0.66 0.666 0.666 0.667 0.667 0.668

]

A. Stasiun Toari

Tabel 5.1 Perhitungan Curah Hujan Stasiun Toari dengan Metode Gumbel

NO TAHUN X i

1 1995 85.00 309.60

2 1996 43.00 595.59

3 1997 58.00 88.45

4 1998 12.25 3042.03

5 1999 96.50 846.54

6 2000 94.00 707.31

7 2001 56.00 130.07

8 2002 21.00 2153.39

9 2003 60.00 54.83

10 2004 133.00 4302.75

11 2005 58.00 88.45

12 2006 104.51 1376.81

13 2007 55.00 153.87

∑ 876.26 13849.684

X = ∑ X = 876.26 = 67.405 mm

n 13

S = = 13849.68 = 33.973 mm

n - 1 12


Sn = 0.9971 (Tabel


T = 2 0.3665 0.507 0.9971

T = 5 1.4999 0.507 0.9971

T = 10 2.2502 0.507 0.9971

T = 25 3.1985 0.507 0.9971

T = 50 3.9019 0.507 0.9971

(Xi - X)2

∑ (Xi - X)2

T = 100 4.6001 0.507 0.9971

Xt = X + K . Sx

K = Yt - Yn

SnSehingga

Xt = X + Yt - Yn Sx

Sn

X2 = 876.26 + 0.3665 - 0.507 x 33.973

0.9971

X2 = 876.26 + -0.14090864 x 33.973

X2 = 871.4730 mm

X5 = 876.26 + 1.4999 - 0.507 x 33.9730.9971

X5 = 876.26 + 0.99578778 x 33.973

X5 = 910.0895 mm

X10 = 876.26 + 2.2502 - 0.507 x 33.973

0.9971

X10 = 876.26 + 1.74826998 x 33.973

X10 = 935.6533 mm

X25 = 876.26 + 3.1985 - 0.507 x 33.973

X25 = 876.26 +

0.9971

x 33.973

X25 = 876.26 + 2.69932805 x 33.973

X25 = 967.9633 mm

X50 = 876.26 + 3.9019 - 0.507 x 33.973

0.9971

X50 = 876.26 + 3.40477384 x 33.973

X50 = 991.9292 mm

X100 = 876.26 + 4.6001 - 0.507 x 33.973

0.9971

X100 = 876.26 + 4.10500451 x 33.973

X100 = 1015.7178 mm

Perhitungan Curah Hujan Stasiun Toari dengan Metode Hasper

Rumus

Rt = X + Sx x Ux

Sx = 1 R1 - X + R2 - X

2 U1 U2

Dengan





Tabel

Periode Ulang

T = n + 1

m

133.00 1 14 1.57

104.51 2 7 0.95


Sx = 1 133.00 - 67.40 + 104.51 - 67.40

2 1.570 0.95

Sx = 0.5 65.60 + 37.11

1.570 0.950

Sx = 0.5 41.780 + 39.058

Sx = 40.419


Rt = X + Sx x Ux



1 2 67.40 -0.22 40.419 58.512

2 5 67.40 0.64 40.419 93.273

3 10 67.40 1.26 40.419 118.333

4 25 67.40 2.10 40.419 152.285

5 50 67.40 2.75 40.419 178.558

Hujan Maksimum

Urutan Terbesar

Standar Variabel U

6 100 67.40 3.43 40.419 206.043



1 1992 85.00 1.92942 0.17038 0.02903 0.00495

2 1993 43.00 1.63347 -0.12557 0.01577 -0.00198

3 1994 58.00 1.76343 0.00439 0.00002 0.00000

4 1995 12.25 1.08814 -0.67090 0.45011 -0.30198

5 1996 96.50 1.98453 0.22549 0.05085 0.01147

6 1997 94.00 1.97313 0.21409 0.04584 0.00981

7 1998 56.00 1.74819 -0.01085 0.00012 0.00000

8 1999 21.00 1.32222 -0.43682 0.19081 -0.08335

9 2000 60.00 1.77815 0.01912 0.00037 0.00001

10 2001 133.00 2.12385 0.36482 0.13309 0.04855

11 2002 58.00 1.76343 0.00439 0.00002 0.00000

12 2003 104.51 2.01916 0.26012 0.06766 0.01760

13 2004 55.00 1.74036 -0.01867 0.00035 -0.00001

∑ 876.26 22.86747 0.98402 -0.29493


Log X = ∑ Log Xi

n

Log X = 22.87 = 1.7590

13

2 Standar Deviasi


S Log X = = 0.9840 = 0.286 mm

n - 1 12


CS = = -3.8340 = -1.237 mm

3.0996



Koefisen Kemencengan CS = -1.237

Log Xt = 1.7590 + -1.237 (Tabel Lampiran

Log X2 = 1.7590 + 0.195 x 0.286

= 1.8149

Log X5 = 1.7590 + 0.844 x 0.286

= 2.0007

Log X10 = 1.7590 + 1.086 x 0.286

= 2.0700

Log X25 = 1.7590 + 1.282 x 0.286

= 2.1261

Log X50 = 1.7590 + 1.379 x 0.286

= 2.1539

LogX100 = 1.7590 + 1.449 x 0.286

= 2.1740

∑ (LogXi - LogX)2


(n - 1) (n - 2) (S Log X)3

Tabel Hujan Rencana Ketiga Stasiun dengan Tiga Metode Gumbel

Gumbel (mm) Hasper (mm)

R2 #VALUE!

R5

R10

R25

R50

R100

Curah Hujan (Periode Ulang)

Log Person Type III

13



1 1992 79.00 1 1992 79.00 237.00

2 1993 59.50 2 1993 76.67 178.50

3 1994 40.00 3 1994 65.77 120.00

4 1995 49.42 4 1995 #REF! 148.25

5 1996 54.50 5 1996 59.50 163.50

6 1997 61.44 6 1997 69.50 184.31

7 1998 44.75 7 1998 40.00 134.25

8 1999 69.50 8 1999 56.00 208.50

9 2000 65.77 9 2000 55.95 197.30

10 2001 71.33 10 2001 49.50 214.00

11 2002 42.67 11 2002 47.00 128.00

12 2003 59.84 12 2003 40.00 179.51

13 2004 76.67 13 2004 39.27 230.00

14 2005 #REF! 14 2005 37.00 #REF!

15 2006 #REF! 15 2006 32.00 #REF!

16 2007 #REF! 16 2007 28.00 #REF!

#REF!


NO TAHUNBesar (mm)

1 1992 79.00 #REF! #REF!

2 1993 76.67 #REF! #REF!

3 1994 65.77 #REF! #REF!

4 1995 #REF! #REF! #REF!

5 1996 59.50 #REF! #REF!

6 1997 69.50 #REF! #REF!

7 1998 40.00 #REF! #REF!

8 1999 56.00 #REF! #REF!

9 2000 55.95 #REF! #REF!

10 2001 49.50 #REF! #REF!

11 2002 47.00 #REF! #REF!

12 2003 40.00 #REF! #REF!

13 2004 39.27 #REF! #REF!

14 2005 37.00 #REF! #REF!

15 2006 32.00 #REF! #REF!

16 2007 28.00 #REF! #REF!

#REF! #REF!

16

#REF!

S #REF!

Stasiun Toari

NO TAHUNX (mm)

1 1995 85

2 1996 43

3 1997 58

4 1998 12.25

5 1999 96.5

6 2000 94

7 2001 56

8 2002 21

9 2003 60

10 2004 133

11 2005 58

12 2006 104.5

13 2007 55

Yt - Yn

SxSn

R1 - X + R2 -

1.570 U1 U2

0.95

85

43

58

12.25

96.5

94

56

21

60

133

58

104.5

55

Tabel

0.0000

Stasiun Mowewe

NO TAHUNX (mm)

1 1992 152

2 1993 135.5

3 1994 62

4 1995 51

5 1996 24

6 1997 32.31

7 1998 66

8 1999 91

9 2000 43.3

10 2001 25

11 2002 49

12 2003 15

13 2004 42

14 2005 65

16 2007 15

X

U2

C. Stasiun Baladente

Tabel 5.1 Perhitungan Curah Hujan Stasiun Baladente dengan Metode Gumbel

NO TAHUN X i

1 1992 85.00 991.07

2 1993 73.00 379.52

3 1994 115.00 3779.94

4 1995 32.00 463.06

5 1996 17.00 1333.62

6 1997 27.50 676.98

7 1998 89.60 1301.86

8 1999 18.00 1261.58

9 2000 79.70 685.46

10 2001 30.00 553.13

11 2002 71.00 305.59

12 2003 21.00 1057.47

13 2004 50.00 12.38

14 2005 25.50 785.05

15 2006 72.00 341.56

16 2007 50.00 12.38

∑ 856.30 13940.644

X = ∑ X = 856.30 = 53.519 mm

n 16

S = = 13940.64 = 30.486 mm

n - 1 15


(X I - X)2

∑ (Xi - X)2

Sn = 1.0316 (Tabel


T = 2 0.3665 0.5157 1.0316

T = 5 1.4999 0.5157 1.0316

T = 10 2.2502 0.5157 1.0316

T = 25 3.1985 0.5157 1.0316

T = 50 3.9019 0.5157 1.0316

T = 100 4.6001 0.5157 1.0316

Xt = X + K . Sx

K = Yt - Yn

Sn

Sehingga

Xt = X + Yt - Yn Sx

Sn

X2 = 856.30 + 0.3665 - 0.5157 x 30.486

1.0316

X2 = 856.30 + -0.1446297 x 30.486

X2 = 851.8909 mm

X5 = 856.30 + 1.4999 - 0.5157 x 30.486

1.0316

X5 = 856.30 + 0.95405196 x 30.486

X5 = 885.3849 mm

X10 = 856.30 + 2.2502 - 0.5157 x 30.486

1.0316

X10 = 856.30 + 1.68136875 x 30.486

X10 = 907.5577 mm

X25 = 856.30 + 3.1985 - 0.5157 x 30.486

1.0316

X25 = 856.30 + 2.6006204 x 30.486

X25 = 935.5817 mm

X50 = 856.30 + 3.9019 - 0.5157 x 30.486

1.0316

X50 = 856.30 + 3.28247383 x 30.486

X50 = 956.3684 mm

X100 = 856.30 + 4.6001 - 0.5157 x 30.486

1.0316

X100 = 856.30 + 3.95928655 x 30.486

X100 = 977.0015 mm

Perhitungan Curah Hujan Stasiun Baladente dengan Metode Hasper

Rumus

Rt = X + Sx x Ux

Sx = 1 R1 - X + R2 - X

2 U1 U2

Dengan Curah Hujan Maksimum 1 R1 = 115.00 mm




Tabel

Periode Ulang

T = n + 1

m

115.00 1 17 1.740

89.60 2 8.5 1.115


Sx = 1 115.00 - 53.52 + 89.60 - 53.52

2 1.740 1.115

Sx = 0.5 61.48 + 36.08

1.740 1.115

Sx = 0.5 35.334 + 32.360

Sx = 33.847


Rt = X + Sx x Ux



1 2 53.52 -0.22 33.847 46.072

2 5 53.52 0.64 33.847 75.181

Hujan Maksimum

Urutan Terbesar

Standar Variabel U

3 10 53.52 1.26 33.847 96.166

4 25 53.52 2.10 33.847 124.597

5 50 53.52 2.75 33.847 146.598

6 100 53.52 3.43 33.847 169.614



1 1992 85.00 1.92942 0.27631 0.07634 0.02109

2 1993 73.00 1.86332 0.21021 0.04419 0.00929

3 1994 115.00 2.06070 0.40758 0.16612 0.06771

4 1995 32.00 1.50515 -0.14796 0.02189 -0.00324

5 1996 17.00 1.23045 -0.42266 0.17865 -0.07551

6 1997 27.50 1.43933 -0.21378 0.04570 -0.00977

7 1998 89.60 1.95231 0.29919 0.08952 0.02678

8 1999 18.00 1.25527 -0.39784 0.15828 -0.06297

9 2000 79.70 1.90146 0.24834 0.06167 0.01532

10 2001 30.00 1.47712 -0.17599 0.03097 -0.00545

11 2002 71.00 1.85126 0.19814 0.03926 0.00778

12 2003 21.00 1.32222 -0.33089 0.10949 -0.03623

13 2004 50.00 1.69897 0.04586 0.00210 0.00010

14 2005 25.50 1.40654 -0.24657 0.06080 -0.01499

15 2006 72.00 1.85733 0.20422 0.04171 0.00852

16 2007 50.00 1.69897 0.04586 0.00210 0.00010

∑ 856.30 26.45 1.12880 -0.05148


Log X = ∑ Log Xi

n


Log X = 26.45 = 1.6531

16

2 Standar Deviasi

S Log X = = 1.1288 = 0.274 mm

n - 1 15


CS = = -0.8236 = -0.190 mm

4.3352



Koefisen Kemencengan CS = -0.190

Log Xt = 1.6531 + 0.033 (Tabel Lampiran

Log X2 = 1.6531 + 0.033 x 0.274

= 1.6622

Log X5 = 1.6531 + 0.850 x 0.274

= 1.8863

Log X10 = 1.6531 + 1.258 x 0.274

= 1.9982

Log X25 = 1.6531 + 1.680 x 0.274

= 2.1140

Log X50 = 1.6531 + 1.945 x 0.274

∑ (LogXi - LogX)2


(n - 1) (n - 2) (S Log X)3

= 2.1867

LogX100 = 1.6531 + 2.178 x 0.274

= 2.2506

Stasiun Mowewe

NO TAHUNX (mm)

1 1992 152

2 1993 135.5

3 1994 62

4 1995 51

5 1996 24

6 1997 32.31

7 1998 66

8 1999 91

9 2000 43.3

10 2001 25

11 2002 49

12 2003 15

13 2004 42

14 2005 65

15 2006 35.5

16 2007 15

Stasiun Toari

NO TAHUNX (mm)

1 1995 85

2 1996 43

3 1997 58

4 1998 12.25

5 1999 96.5

6 2000 94

7 2001 56

8 2002 21

9 2003 60

10 2004 133

11 2005 58

12 2006 104.51 12.5

13 2007 55



1 1992 79.0 1 1992 79.0 237.00

2 1993 69.5 2 1993 75.0 208.50

3 1994 59.0 3 1994 72.3 177.00

4 1995 56.0 4 1995 70.7 168.00

5 1996 28.0 5 1996 69.5 84.00

6 1997 39.3 6 1997 68.5 117.81

7 1998 55.9 7 1998 59.0 167.85

8 1999 68.5 8 1999 56.0 205.50

9 2000 72.3 9 2000 56.0 217.00

10 2001 37.0 10 2001 49.5 111.00

11 2002 47.0 11 2002 47.0 141.00

12 2003 32.0 12 2003 40.0 96.00

13 2004 75.0 13 2004 39.3 225.00

14 2005 49.5 14 2005 37.0 148.50

15 2006 70.7 15 2006 32.0 212.01

16 2007 40.0 16 2007 28.0 120.00

878.7


NO TAHUNBesar (mm) rata

1 1992 79.00 24.08 579.836

2 1993 75.00 20.08 403.198

3 1994 72.33 17.41 303.217

4 1995 70.67 15.75 248.056

5 1996 69.50 14.58 212.570

6 1997 68.50 13.58 184.411

7 1998 59.00 4.08 16.645

8 1999 56.00 1.08 1.166

9 2000 55.95 1.03 1.060

10 2001 49.50 -5.42 29.379

11 2002 47.00 -7.92 62.730

12 2003 40.00 -14.92 222.613

13 2004 39.27 -15.65 244.929

14 2005 37.00 -17.92 321.134

15 2006 32.00 -22.92 525.336

16 2007 28.00 -26.92 724.698

878.72 ###

16

54.92

S 16.494

85.00

152.00 237.00

85.00 79

152.00

85.00 79.00

107.33

31.48125

991.0691016

68003.34

78.34

783.4

6631.784

736.864889

27.1452554

1.740

R1 - X + R2 - X

1.929418926

Stasiun Baladente Stasiun Mowewe Stasiun ToariNO TAHUN X i NO TAHUN X (mm) NO TAHUN X (mm)1 1992 85.00 1 1992 152.00 1 1995 85.002 1993 73.00 2 1993 135.50 2 1996 43.003 1994 115.00 3 1994 62.00 3 1997 58.004 1995 32.00 4 1995 51.00 4 1998 12.255 1996 17.00 5 1996 24.00 5 1999 96.506 1997 27.50 6 1997 32.31 6 2000 94.007 1998 89.60 7 1998 66.00 7 2001 56.008 1999 18.00 8 1999 91.00 8 2002 21.009 2000 79.70 9 2000 43.30 9 2003 60.00

10 2001 30.00 10 2001 25.00 10 2004 133.0011 2002 71.00 11 2002 49.00 11 2005 58.0012 2003 21.00 12 2003 15.00 12 2006 104.5113 2004 50.00 13 2004 42.00 13 2007 55.0014 2005 25.50 14 2005 65.00 ∑ 876.2615 2006 72.00 15 2006 35.5016 2007 50.00 16 2007 15.00

∑ 856.3 ∑ 903.61

Data Sebelum Direngking Data Setelah Direngking NO TAHUN Besar (mm) NO TAHUN Besar (mm)1 1992 79.00 1 1992 79.00 237.002 1993 69.50 2 1993 75.00 208.503 1994 59.00 3 1994 72.33 177.004 1995 56.00 4 1995 70.67 168.005 1996 28.00 5 1996 69.50 84.006 1997 39.27 6 1997 68.50 117.817 1998 55.95 7 1998 59.00 167.858 1999 68.50 8 1999 56.00 205.509 2000 72.33 9 2000 55.95 217.00

10 2001 37.00 10 2001 49.50 111.0011 2002 47.00 11 2002 47.00 141.0012 2003 32.00 12 2003 40.00 96.0013 2004 75.00 13 2004 39.27 225.0014 2005 49.50 14 2005 37.00 148.5015 2006 70.67 15 2006 32.00 212.0116 2007 40.00 16 2007 28.00 120.00

878.72

Data Sebelum Direngking NO TAHUN Besar (mm)1 1992 79.00 24.08 579.8362 1993 75.00 20.08 403.1983 1994 72.33 17.41 303.2174 1995 70.67 15.75 248.0565 1996 69.50 14.58 212.5706 1997 68.50 13.58 184.4117 1998 59.00 4.08 16.6458 1999 56.00 1.08 1.1669 2000 55.95 1.03 1.060

10 2001 49.50 -5.42 29.37911 2002 47.00 -7.92 62.73012 2003 40.00 -14.92 222.61313 2004 39.27 -15.65 244.92914 2005 37.00 -17.92 321.13415 2006 32.00 -22.92 525.33616 2007 28.00 -26.92 724.698

878.72 4080.97716

54.9202083S 16.4943968

NILAI RATA - RATA 3 Stasiun dengan METODE GUMBEL

X2 = 851.89 + 897.86 + 871.47

3

X2 = 873.74

X5 = 885.38 + 941.56 + 910.09

3

X5 = 912.345

X10 = 907.56 + 970.5 + 935.65

3

X10 = 937.901

X25 = 935.6 + 1007.1 + 967.96

3

X25 = 970.201

X50 = 956.4 + 1034.2 + 1034.2

3

X50 = 1008.24

X100 = 977.0 + 1061.1 + 1015.7

3

X100 = 1017.94

NILAI RATA - RATA 3 Stasiun dengan METODE HASPER

X2 = 46.07 + 42.64 + 58.512

3

X2 = 49.0751

X5 = 75.18 + 96.72 + 93.273

3

X5 = 88.3923

X10 = 96.17 + 135.7 + 118.33

3

X10 = 116.737

X25 = 124.6 + 188.5 + 152.29

3

X25 = 155.14

X50 = 146.6 + 229.4 + 178.56

3

X50 = 184.856

X100 = 169.6 + 272.2 + 206.04

3

X100 = 215.944

NILAI RATA - RATA 3 Stasiun dengan METODE LOG PERSON TYPE III

X2 = 1.66 + 1.66 + 1.8149

3

X2 = 1.71204

X5 = 1.89 + 1.91 + 2.0007

3

X5 = 1.93151

X10 = 2.00 + 2.0 + 2.07

3

X10 = 2.03519

X25 = 2.1 + 2.2 + 2.1261

3

X25 = 2.13862

X50 = 2.2 + 2.3 + 2.1539

3

X50 = 2.20191

X100 = 2.3 + 2.3 + 2.174

3

X100 = 2.25665

Perhitungan Debit Banjir dengan Metode Hasper

Dalam menganalisa debit banjir rencana digunakan data - data sebagai berikut :

a Luas Cachment Area (A) = 150.00 Km

b Panjang Sungai ( L ) = 35.00 Km

c Elevasi Sungai Pada Hulu = 24.69 M

d Elevasi sungai pada Hilir = 22.43 M

e Kemiringan Sungai (i) = 0.00419 M

f Curah Hujan Maksimum = R50 = 1008.2431 mm

= R100 = 1017.9407 mm


α = 1 + 0.012 A 0.70

1 + 0.075 A 0.70

= 1 + 0.012 150.00 0.70

1 + 0.075 150.00 0.70

= 1 + 0.012 33.36

1 + 0.075 33.36

= 1.4003549

3.502218

α = 0.40

2 Menghitung waktu konsentrasi

t = 0.10 L 0.80 i -0.30

= 0.10 35.00 0.80 0.00419 ###

= 0.10 17.1892 5.1682

t = 8.88

3

1 = 1 + t + ( 3.7 10 ### x A 0.75

β t 2 + 15 12

= 1 + 8.8836252 + ( 3.7 x 0.0002796 ) x 42.8616

Menghitung harga koefisien reduksi (β)

t )

= 1 +

78.92 + 15

x

12.0000

= 1 + 8.8847 x 3.5718005

93.919

= 1 + 0.0946 x 3.5718005

= 1.3379

β = 0.75

4 Menghitung Distribusi Hujan

Untuk t antara 2 sampai 19 jam

Rt = t x Rt

t + 1

Rt = 8.8836 x Rt = 0.90 Rt

8.8836 + 1


q = 0.8988 x Rt = 0.03 Rt

8.8836 x 3.60

6 Menghitung Debit Maksimum (Qt)

Qt = α β q A

Qt = 0.40 x 0.75 x 0.03 Rt x 150

Qt = 1.2599 Rt

TABEL

DEBIT BANJIR HASPER - GUMBEL

T Xt α βq A Qt


2 873.74 0.40 0.75 24.56 150.00 1100.85

5 912.34 0.40 0.75 25.64 150.00 1149.49

10 937.90 0.40 0.75 26.36 150.00 1181.69

25 970.20 0.40 0.75 27.27 150.00 1222.39

50 1008.24 0.40 0.75 28.34 150.00 1270.32

100 1017.94 0.40 0.75 28.61 150.00 1282.54

TABEL

DEBIT BANJIR HASPER - LOG PERSON TYPE III

T Xt α βq A Qt


2 1.71 0.40 0.75 0.05 150.00 2.16

5 1.93 0.40 0.75 0.05 150.00 2.43

10 2.04 0.40 0.75 0.06 150.00 2.56

25 2.14 0.40 0.75 0.06 150.00 2.69

50 2.20 0.40 0.75 0.06 150.00 2.77

100 2.26 0.40 0.75 0.06 150.00 2.84

TABEL

DEBIT BANJIR HASPER - HASPER

T Xt α βq A Qt


2 49.08 0.40 0.75 1.38 150.00 61.83

5 88.39 0.40 0.75 2.48 150.00 111.37

10 116.74 0.40 0.75 3.28 150.00 147.08

25 155.14 0.40 0.75 4.36 150.00 195.47

50 184.86 0.40 0.75 5.20 150.00 232.91

100 215.94 0.40 0.75 6.07 150.00 272.08

519.15

R100 = 1017.9407 mm

e Kemiringan Sungai (i) = 0.00419

f Curah Hujan Maksimum = R50 = 1008.2431 mm

11.6489

0.0002805

#REF!

#REF!

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