topic 6 cc606
TRANSCRIPT
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Topic 6
BASIC CONCEPTS OF URBAN DRAINAGE
DESIGN OF URBAN CHANNEL
(Urban Stormwater Management Manual For Malaysia)
MASMA
Types Of Urban
Drainage
System
Intensity-duration-
frequency Relations
(IDF Curves)
Estimates Time Of
Concentration
Determine The Peak
Discharge
Calculate Open Channel
Size And Storm SewerDesign Detention Storage
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STORMWATER MANAGEMENT IN MALAYSIA:
INTRODUCTION
Shaari Haron, CPESCJPSKelantan.
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Hydrological Cycle
Al-Mu`minuun:018
Dan Kami turunkan air dari langit menurutsuatu ukuran; lalu Kami jadikan air itumenetap di bumi, dan sesungguhnya Kamibenar-benar berkuasa menghilangkannya.
29%
6%
30%
35%
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Concept Of Convensional
Drainage System :
Fast Flow
Local
One FunctionQuantity
Conveyance Oriented Approach- Open Drain
Planning and Design Procedures No. 1:Urban Drainage Design Standards andProcedures for Peninsular Malaysia 1975
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ISSUE:Flash Flood
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COSTtransfer, accident (life), property >RM 1b/year
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StatesFlood Prone Area
Total Area (km2) People Affected (no.)
PERLIS 19 13,000
KEDAH 209 124,000
PULAU PINANG 232 510,000
PERAK 535 244,000
SELANGOR 1,652 726,000
W.P. KUALA LUMPUR 3 13,000
NEGERI SEMBILAN 130 42,000MELAKA 81 31,000
JOHOR 2,367 297,000
PAHANG 6,274 615,000
TERENGGANU 2,223 457,000
KELANTAN 1,640 714,000SABAH 3,241 635,000
SARAWAK 11,114 494,000
P. MALAYSIA 15,365 3,786,000
SABAH & SARAWAK 14,355 1,129,000
JUMLAH 29,720 4,915,000
Flood Prone Area by States
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ISSUE:Blocked
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http://3.bp.blogspot.com/_CYjOFYx7d9s/SQ-7ylGbvoI/AAAAAAAAAIY/KvwBLwzq5qI/s1600-h/Image(187).jpghttp://3.bp.blogspot.com/_sDHQWqABwwE/TBgVvqXCwmI/AAAAAAAADQk/v8zVLpUIFIA/s1600/terbakar+tmn+wira,ziarah+dan+longkang+tersumbat+056.jpg -
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Blocked Artery Blocked Drainage
VS
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ISSUE:Quality
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Kajian DOE, 2000
52 river basin tercemar oleh Pepejal Terampai
pembangunan tak terkawal
18 river basin tercemar oleh Dissolved Oxigen
effluen industri
33 river basin tercemar oleh amonical nitrogen
animal farming & domestic waste
http://3.bp.blogspot.com/_sDHQWqABwwE/TBgVwG7ApvI/AAAAAAAADQs/wC0yD13md4I/s1600/terbakar+tmn+wira,ziarah+dan+longkang+tersumbat+058.jpghttp://4.bp.blogspot.com/_sDHQWqABwwE/TBgU6hTD6ZI/AAAAAAAADQU/A6kQ5jUZkKc/s1600/terbakar+tmn+wira,ziarah+dan+longkang+tersumbat+057.jpg -
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ISSUE: Development (Uncontrolled)
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After Rain
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Natural Environment
Development
20cm top soil area 1000 ha = 0.51juta m3
water
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Decrease infiltration rateKadar pembangunan 040%:
Kuantiti air larian meningkat sehingga 190%
halaju air meningkat 50% masa tumpuan turun
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ISSUE:Requirement Cost
Widening, deepening anddiversion of rivers
Rubbish Traps and dumpsites Floodwalls
RMK 9 Tebatan Banjir RM 4b
Pemeliharaan Sungai RM 510m
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Need changes
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PENDEKATAN BARU
Perubahan Dalam Pengurusan Sumber
Air Negara
Kaedah baru menggunakan
pendekatan pengurusan air ribut
Urban Stormwater Management
Manual (MSMA, 2001)
Lebih Mesra Alam
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aliran cepat ke hilir
KAEDAH LAMA
kawalan di punca
PENDEKATAN BARU
Parit Konkrit
Alur Berumput
Takungan Setempat
K Ut
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Kawalan Kualiti
Kawalan Hakisan &
Mendapan
Komponen Utama
Kawalan Kuantiti
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KAWALAN KUANTITI
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Storage Classification
1. On-site storage
3. Regional storage
2. Community storage
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Storage Classification
small storage
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Storage Classification
constructed in public open area
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Storage Classification
large community storageconstructed at the lower
end of catchment
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Penuaian air hujan(Rainwater Harvesting)
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kolam takungan
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KAWALAN KUALITI
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Vegetated Filter Strip
Biofiltration swale
Composite swale
Source control
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Source Control
Sand Filtration
Oil Separator
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Gross Pollutant Trap(GPT)
to retain litter, debris& coarse sediment
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Kawalan semulajadi
dalam merawat/membersih
air larian & tebatan banjir
Wetland (Tanah bencah)
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Rain Garden
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landscape
approach
Rain Garden
Pervious Pavement
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Pervious Pavement
Inlet/outlet protection
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Inlet/outlet protection
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Dramatically enhance the development
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increase property value &
quality of life
Dramatically enhance the development
Dan Allah menurunkan hujan dari langit, lalu Ia menghidupkan
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dengan air hujan itu akan bumi sesudah matinya; sesungguhnyapada yang demikian itu terdapat satu tanda kekuasanNya bagi
kaum yang mendengar
An-Nahl: 65
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The Main Objectives Of Proper Stormwater
Management In Malaysia Are To:
Provide Safety For The Public,
Minimise And Control Nuisance Flooding And Provide For The
Safe Passage Of Less Frequent Flood Events,
Stabilise The Landform And Control Erosion,
Protect Property,
Enhance The Landscape,
Optimise The Land Available For Development, And
Minimise The Environmental Impact Of Runoff On Water
Quality
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Types Of Urban Drainage System
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Types Of Urban Drainage System
Covered drainOpen drain - dry
Outlet
Sump
Open - wet
Inlet
Stormwater Management Policy
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Runoff Quantity Control (14)
Runoff Quality Control (9)
During Construction (ESCP)
Post Construction
Aesthetical (2)
Operation and Maintenance (2)
g y(Urban Drainage Planning and Desig n Standard Requirement)
Stormwater Management Policy
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
Minor and major system shall be plannedbothgenerally confirm to natural drainage pattern anddischarge to natural drainage system withincatchment as possible.
1.
Stormwater Management Policy
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
Runoff at development site within catchment orsub-catchment shall be maintained dischargedat the existing natural drainage outlet/s and thecontrols discharges shall be less or equal to theexisting capacityof the existing natural drainage
(Urban Drainage Planning and Desig n Standard Requirement)
2.
Stormwater Management Policy
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Stormwater management system must bedesigned so that post development peakdischarge rate (2 yr, 10yr, 50 yr and 100yr ARI)less than the pre-development 2 yr.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
3.
(Urban Drainage Planning and Desig n Standard Requirement)
Stormwater Management Policy
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There will be no new stormwater conveyancesystem outfall may discharge the runoffdirectly into the existing receiving waterwithout any control.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
4.
Stormwater Management Policy
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All new urban development shall be providedwith a minordrainage system with capacity notmore than the 10 yr ARI.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
5.
Stormwater Management Policy
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
The minor drainagesystem may comprise anycombination of pipe, swale, open drain orengineered waterway, to be served for thecatchment less than 20 ha.
(Urban Drainage Planning and Desig n Standard Requirement)
6.
Stormwater Management Policy
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Conveyance system for the drainage area from20 to 40 hashould be designed with storm of ARI50 years.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
7.
Stormwater Management Policy(U b D i Pl i d D i S d d R i )
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Themajor drainagesystem shall be provided forthe development area and the catchment of thedevelopment area equal to or larger than 40 ha.the stormwater design ARI shall be 100 years.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
8.
Stormwater Management Policy(U b D i Pl i d D i St d d R i t)
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(Urban Drainage Planning and Desig n Standard Requirement)
CONVEYANCEDESIGN:
1. MINORArea: Less than 20 haARI: Not more than 10 Year
2. INTERMMEDIATEArea: 20 40 haARI: 50 Year
3. MAJORArea: More than 40 ha
ARI: 100 Year
On-site
Regional
Community
summary
Stormwater Management Policy(U b D i Pl i d D i St d d R i t)
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The platform (or lowest floor level) in all newurban development and re-development shall beprotected for regional flooding up to 100 yearsARI with 0.3m freeboard.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
9.
Stormwater Management Policy(U b D i Pl i d D i St d d R i t)
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Diversion of runoff to or from other catchment orsub-catchment isprohibited (not permitted).
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
10.
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Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
13.Adequate storage shall be provided for thedetention pond to store the post-developmentdesign flows of 1 in 100 years ARI from thecatchment without overflowthe secondaryoutlet (spillway).
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
14.Primary outlets for the detention pond shall bedesigned to reduce post-development peakflows from the pond must not exceedthe pre-development peaks flows of 2 year (minorprimary outlet).
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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No land clearingshall be allowed for theconstruction site before the installation ofsediment control facilities onsite.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
1.
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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The erosion and sedimentation controls shall be
provided on all land development and buildingproject to prevent up to the maximum extentpossible, the transport of the sediment from theproject site resulting from clearing and gradingor others land disturbing activities.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(Urban Drainage Planning and Desig n Standard Requirement)
2.
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Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
Sediment pond / trap / basin should retain a
minimum 70% of coarse of sediment > 0.02 mmfor storm up to or including 3 months ARI (ie. 40mm rainfall) for construction period < 2 yearsand 6 months ARI (ie. 50 mm rainfall) forconstruction > 2 yearsto be completed.
(Urban Drainage Planning and Desig n Standard Requirement)
4.
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Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Erosion and sedimentation control must beimplementedduring construction and duringany land disturbance activities (earthworksphase).
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
(U ba a age a g a d es g Sta da d equ e e t)
6.
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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No new stormwater conveyance outfall maydischarge the untreated runoff directly to anyreceiving water of the area.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
( g g g q )
1.
KELODAK DI PANTAI BARAT
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Any stormwater (runoff) discharges to
Environmental Sensitive Area (ESA) must utilizecertain BMPs approved for that area.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
( g g g q )
2.
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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The use of infiltration practices without pre-treatmentis prohibited
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
( g g g q )
3.
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Stormwater management system shall bedesigned with appropriate aestheticvalueto enhance the appearance of the areawith proper landscaping.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
1.
Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
The proper landscapingis required for any
proposed engineered waterway,watercourse management and proposeddetention pond.
2.
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Stormwater Management Policy(Urban Drainage Planning and Desig n Standard Requirement)
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All stormwater management system must
have the O&M plan and scheduleto ensurethe system function as per design.
Runoff Quantity Control
Runoff Quality Control
During Construction (ESCP)
Post Construction
Aesthetical
Operation and Maintenance
2.
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Runoff Estimation
(Rational Method)
ESTIMATION METHOD
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ESTIMATION METHOD
RATIONAL HYDROGRAPH
TimeArea
Kinematic Wave
Non-linear Reservoir
Simplified method
Conveyance design discharge
Up to 80 haAssumptions:
Qpoccurs by flow contribution of entire catchment
Uniform intensity over entire catchmentUniform intensity over tc
n ARI of intensity n ARI peak flow
RATIONAL FORMULA
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Qy= C x
y
Itx A360
Eqn. 14.7
Qy = y year ARI peak flow (m3/s)
C = runoff coefficient
y
It = y year ARI intensity over time ofconcentration (mm/hr)
A = drainage area (ha)
General Procedure for Estimating Peak Flow for a
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g
Single Sub-Catchment using Rational Method
Select design ARI
Discretise sub- catchment
Estimate time of concentration
Determine average rainfall intensity,
ylt
Estimate runoff coefficients
Calculate average runoff coefficient
Calculate peak flow rate for the sub-
catchment
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Rational Method CalculationWorked Example
Catchment
Area 10 ha
Main Drain
River
To determine the design peak for flow generated from a
minor drainage of medium density residential area of 10
hectares in Kuala Lumpur. Assume 80 m of overland
flow followed by 400 m of flow in an open drain.
Catchment area average slope = 0.5%.
1) Select design ARI Select design ARI for both minor &major drainage systems
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major drainage systems
Table 4.1 : Design Storm ARIs for Urban Stormwater Systems
Type of Development Average Recurrence Interval (ARI) of
Design Storm (year)
(See Note 1) Quantity Quality
Minor
System
Major System
(see Note 2 and 3)
Open Space, Parks and Agricultural
Land in urban areas
1 up to 100 3 month ARI(for all types of
development)
Residential:
Low density
Medium density High density
2
5
10
up to 100
up to 100
up to 100
Commercial, Business and Industrial
Other than CBD5 up to 100
Commercial, Business, Industrial in
Central Business District (CBD) areas of
Large Cities
10 up to 100
2) Discretise sub-
t h t
Devide sub-catchment
i t t f
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catchment into segments of
homogeneous land use
or surface slope
Catchment area average slope = 0.5%.
3) Estimate time of concentrationEstimate overland flow time
Estimate flow times for all other flow
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) Estimate flow times for all other flowcomponents within the sub-catchment
such as kerb gutters, pipe and
channels, etc.
4) Determine average Calculate ylt for design ARI of yyears & duration equal to the
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rainfall intensity, yltyears & duration equal to the
time of concentration, from IDF
data for area of interest
Table 13.2 Coefficients of the Fitted IDF Equation for Kuala Lumpur
(data period 1953-1983); Validity: 30
t
1000 minutes
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5) Estimate runoff coefficientsDevide sub-catchment
i t t f
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5) Estimate runoff coefficients into segments of
homogeneous land use
or surface slope
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6) Calculate average runoff
coefficient
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Design Chart 14.3 : Runoff Coefficients for Urban Catchments1.0
RunoffCoefficient,
C
Rainfall Intensity, I (mm/hr)
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
190 200
2
1
7
6
5
4
3
8
Impervious Roofs, Concrete
City Areas Full and Solidly Built Up
Urban Residential Fully Built Up with Limited Gardens
Surface Clay, Poor Paving, Sandstone Rock
Commercial & City Areas Closely Built Up
Semi Detached Houses on Bare Earth
Bare Earth, Earth with Sandstone Outcrops
Bare Loam, Suburban Residential with Gardens
Widely Detached Houses on Ordinary Loam
Suburban Fully Buil t Upon Sand Strata
Park Lawns and Meadows
Cultivated Fields with Good Growth
Sand Strata8
7
6
5
4
3
2
1
7) Calculate peak flow rate for
the sub-catchmentCalculate peak flow rate
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Qy = C.ylt. A
360
Exercise 6a
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Exercise 6a
Based on the information below,determine the peak flow of residential area
in Malacca by using Urban Stormwater
Management Manual For Malaysia
(MSMA).Housing area = 20 hectares
Residential density = high density
Drainage type = major drainageLength of overland flow = 80 m
Length of the drain = 400 m
Slope average = 1%
Exercise 6b
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Exercise 6b
Determine the design peak for flowgenerate from minor drainage of high
density residential area of 20 hectares in
Kuala Lumpur. Assume 100 m of
overland flow followed by 300 m of flow in
a open drain. The catchment area
average slope is 0.2 %