hydrograph

1. 1
DEPARTMENT OF CIVIL ENGINEERING
COLLEGE OF ENGINEERING
WATER RESOURCES CEWB 423
NAME : Vivien Lai Mei Yen
ID : CE093314
SECTION : 01
DATE OF PROJECTSUBMISSION 3/11/2015
LECTURER : PROF. IR. DR. LARIYAH BTE MOHD SIDEK

2. 2
Question: Find rainfall intensity and Q in Hometown. For both minor and major.
Details:
Hometown: Bukit Mertajam, Taman Sri Rambai
Nearest River to hometown : Sg Juru
Nearest station: Sg Simpang, Ampat Tangki
From Table 2.B2 (Low ARIs) From Table 2.B1 (High ARIs)
Λ= 59.3122 Λ= 62.089
Κ= 0.3394 Κ= 0.220
η = 0.8090 η = 0.785
θ= 0.3350 θ= 0.402

3. 3
Design Drawing
The area landuse is assumed as below:
Residential (Link and Terrace ) 19ha
Shop Lots (Commercial Area) 2ha
Roads 5ha
Residential Area (Sport field) 0.3ha
Sg Juru
Neareststation:SgSimpang
AmpatTanki
Hometown:BukitMertajam
CatchmentArea:26.3ha
B= 8m
Y= 10m

4. 4
Calculation
Low ARIs – Design for 12 months
Step 1 : time of concentration
Tc = td + to
= 1.82+15.13
= 16.95minutes
= 17 minutes
Td= nL/60R2/3 S1/2
= (0.015)(850)/ (60)(2.86)2/3 (0.003365)1/2
= 1.82minutes
n = 0.015 (Lined Drain, Concrete, Smooth Finish) – Table 2.3
L = 850m (assume)
R= A/P = 80/ 28 = 2.86
S= 2.86/ 850 = 0.003365
To = 107 n L1/3 /S1/5
= 107 (0.035) (100)1/3 / (2)1/5
= 15.13minutes
n = 0.035 (Poorly Grassed) – Table 2.2
L = 100m
S= 2%

5. 5
Step 2 : Rainfall Intensity
𝐼17𝑚𝑖𝑛
𝐴𝑅𝐼𝑠 =12𝑚𝑜𝑛𝑡ℎ𝑠
= λTK / (d+θ) η
= (59.3122)(12/12)0.3394 / ((17/60)+0.3350)0.8090
= 59.3122/0.6778
= 87.5069mm/hr
Step 3: Q
Q= CIA/ 360
= (0.9076)(87.5069)(26.3)/ 360
= 5.80 m3 / s
C = (0.9x19)+ (0.95x2) + (0.95x5) + (0.4x0.3) / 26.3 = 0.9076

6. 6
High ARIs – Design for 10 years
Step 1 : time of concentration
Tc = td + to
= 1.82+15.13
= 16.95minutes
= 17 minutes
Td= nL/60R2/3 S1/2
= (0.015)(850)/ (60)(2.86)2/3 (0.003365)1/2
= 1.82minutes
n = 0.015 (Lined Drain, Concrete, Smooth Finish) – Table 2.3
L = 850m (assume)
R= A/P = 80/ 28 = 2.86
S= 2.86/ 850 = 0.003365
To = 107 n L1/3 /S1/5
= 107 (0.035) (100)1/3 / (2)1/5
= 15.13minutes
n = 0.035 (Poorly Grassed) – Table 2.2
L = 100m
S= 2%

7. 7
Step 2 : Rainfall Intensity
𝐼17𝑚𝑖𝑛
𝐴𝑅𝐼𝑠 =10𝑦𝑟𝑠
= λTK / (d+θ) η
= (62.089)(10)0.220 / ((17/60)+0.402)0.785
= 160.4912 mm/hr
Step 3: Q
Q= CIA/ 360
= (0.9076)(160.4912)(26.3)/ 360
= 10.64 m3 / s
C = (0.9x19)+ (0.95x2) + (0.95x5) + (0.4x0.3) / 26.3 = 0.9076