DONGDONG DONG-A UNIVERSITY

Historical Historical FloodFlood

inin

Historical Historical FloodFlood

inin

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DONG-A UNIVERSITY

Online Online CollaborationCollaborationWeb PlatformWeb Platform

• Web Platform was used Web Platform was used as part of the as part of the communication media and communication media and storage of documentation.storage of documentation.

•MSN and Adobe Connect.MSN and Adobe Connect.

•Remote Desktop for Remote Desktop for available technical available technical software.software.

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DONG-A UNIVERSITY

About IncheonAbout Incheon• Located in the mid- west Located in the mid- west Korea peninsula near Korea peninsula near Yellow Yellow Sea Sea

37° 29 N, 126° 38 E37° 29 N, 126° 38 E

• 33rdrd biggest city in Korea biggest city in KoreaArea: 1002.7 km2Area: 1002.7 km2

• Gateway of North East AsiaGateway of North East AsiaFacilitated with both Facilitated with both international airport and international airport and port.port.

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DONG-A UNIVERSITY

Project Project OverviewOverview1. Incheon Gyo1. Incheon Gyo

• Total area: 34Total area: 34 ㎞㎞ 22

• Elevation: 0 ~ 201m(EL+)Elevation: 0 ~ 201m(EL+)

• Average of slope: Average of slope: 0.01%0.01%

•Reclamation land.Reclamation land.

•Tidal difference of Yellow sea Tidal difference of Yellow sea which is linked with Incheon which is linked with Incheon Gyo watershed is 9m. Gyo watershed is 9m.

•Concentration of rainfall is Concentration of rainfall is usually in August.usually in August.

Study area

Gaja WWTP

City HallGansuk station

Juan station

Pump Station

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DONG-A UNIVERSITY

Project Project OverviewOverview

2. Flooding Occurrence2. Flooding Occurrence

• Occurred at coastal area Occurred at coastal area located at the downstream located at the downstream of drainage system. despite of drainage system. despite the heavy rainfall return the heavy rainfall return period of 2-3 years.period of 2-3 years.

• Max. rainfall (1997-present)Max. rainfall (1997-present)In 1997: 260.8mm/dayIn 1997: 260.8mm/day

3. Impact3. Impact

Direct: • buildings and houses destroyed• quality of life decrease• profit losses• costly repair and management.

Indirect: country’s economy and security.

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Hydrology Geography

•Rainfall intensity

•Duration •Time interval •Storm return

period

•Catchments•Building•Manholes•Road

DHI ISIS Sobek

Mike Flood

Mike 21

Mouse

Mike Zero

Results format: video; figure; table…Analysis: Physical meaning & comparing with observed data

Preparation (input)

Preparation (input)

Tools

(software)Tools

(software)Solution analysis

(output)

Solution analysis(output)

Simulation ProcessSimulation Process

RetryRetry

SuggestionSuggestion

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DONG-A UNIVERSITY

Hydrology AnalysisHydrology Analysis

• Precipitation dataPrecipitation data– Design Precipitation Design Precipitation – Observed Real PrecipitationObserved Real Precipitation

• Runoff CoefficientRunoff Coefficient– Total Runoff CoefficientTotal Runoff Coefficient– Sub-catchments Runoff CoefficientSub-catchments Runoff Coefficient

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DONG-A UNIVERSITY

Precipitation DataPrecipitation DataDesign PrecipitationDesign Precipitation

Suggested probability rainfall intensity formula in Incheon

min60t

2989.3

t 0.7105 15.2389.1 mm/hr

368.10182.21

7.43207413.0

t

mm/hr

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DONG-A UNIVERSITY

Precipitation DataPrecipitation DataDesign PrecipitationDesign Precipitation

Intensity-Duration-Frequency curves for Incheon-Gyo area

0 50 100 150 200 250 300 350D uration (m in)

0

50

100

150

200

250

Rain

fall

inte

nsi

ty (m

m/h

r)

Suggested P robability R ain fa ll in tensity Form ula

100-year frequency50-year frequency

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DONG-A UNIVERSITY

Precipitation DataPrecipitation DataDesign PrecipitationDesign Precipitation

Design precipitation hyetographs from IDF relationships

0 10 20 30 40 50 60 70 80 90 100 110 120

T im e (m in)

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Pre

cipi

tatio

n (

mm

)

Peak: 14.33m m

A 100-year 2-hour designhyetograph using the a lterm ating b lock m ethod

0 10 20 30 40 50 60 70 80 90 100 110 120

T ime (m in)

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Pre

cipita

tion (m

m)

Peak: 13.65m m

A 50-year 2-hour designhyetograp using the a lternating b lock m ethod

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DONG-A UNIVERSITY

Precipitation DataPrecipitation DataReal PrecipitationReal Precipitation

0

10

20

30

40

50

60

70

80

Precipitation (mm)

1hr 3hr 5hr 7hr 9hr 11hr 13hr 15hr 17hr 19hr 21hr 23hr

Time duration

Real precipitation in Aug. 4 1997

Duration Precipitation(mm)

1hr 02hr 17.53hr 84hr 0.85hr 26hr 07hr 08hr 15.49hr 1910hr 53.111hr 72.512hr 47.613hr 5.914hr 6.315hr 5.416hr 4.617hr 2.218hr 0.519hr 020hr 021hr 022hr 023hr 024hr 0

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DONG-A UNIVERSITY

Runoff CoefficientRunoff CoefficientIncheon Gyo as a WholeIncheon Gyo as a Whole

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DONG-A UNIVERSITY

Runoff CoefficientRunoff CoefficientSegmentation of CatchmentSegmentation of Catchment

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DONG-A UNIVERSITY

ArcGISArcGIS

• GIS files:GIS files:– CatchmentCatchment– ManholesManholes– BuildingBuilding– RoadRoad– ContourContour

• GIS files were used to create TIN, DEM, and also others, being converted GIS files were used to create TIN, DEM, and also others, being converted to ASCII files to produce necessary input for MIKE (Simulation)to ASCII files to produce necessary input for MIKE (Simulation)

++

SimulationSimulation(MIKE)(MIKE)

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DONG-A UNIVERSITY

DHI MIKEDHI MIKEIntroductionIntroduction

• To analyze the flooding problem we try to obtain To analyze the flooding problem we try to obtain a real approach of rain impact on Incheon Gyo a real approach of rain impact on Incheon Gyo catchment.catchment.

• We have simulated the general Incheon Gyo We have simulated the general Incheon Gyo characteristic with the MIKE software. characteristic with the MIKE software.

• It is easy and efficient to report the realistic It is easy and efficient to report the realistic aspect of the flooding reality with DHI software aspect of the flooding reality with DHI software

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DONG-A UNIVERSITY

DHI MIKEDHI MIKEIntroductionIntroduction

• There are several processes to simulate the flood.There are several processes to simulate the flood.

• To simulate the flood imputation of the sewer To simulate the flood imputation of the sewer network (Mouse) and the DEM (MIKE 21) must network (Mouse) and the DEM (MIKE 21) must be connected to observe the catchment behavior.be connected to observe the catchment behavior.

• It is necessary to couple with MIKE21It is necessary to couple with MIKE21 MIKE FLOODMIKE FLOOD

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DONG-A UNIVERSITY

DHI MIKEDHI MIKEProcess FlowchartProcess Flowchart

MIKE ZEROMIKE ZERO

BathymetryBathymetry

MIKE 21MIKE 21

Simulating the surface flowSimulating the surface flow Simulating the sewer network flowSimulating the sewer network flow

MOUSEMOUSE

MIKE FLOODMIKE FLOOD

Coupling MOUSE with MIKE21Coupling MOUSE with MIKE21

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BathymetryBathymetry

• Bathymetry file from MIKE Zero to MIKE 21Bathymetry file from MIKE Zero to MIKE 21

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DONG-A UNIVERSITY

DHI MIKEDHI MIKEProcess FlowchartProcess Flowchart

BathymetryBathymetry Boundaries conditionsBoundaries conditions

Simulation periodSimulation period

MIKE 21

Simulating the surface flow

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DONG-A UNIVERSITY

• Removed the bad node to obtain good result from the simulation (conflict Removed the bad node to obtain good result from the simulation (conflict between bad node and building altitude)between bad node and building altitude)

Rainfall Data &

Water Level

Rainfall Data &

Water Level

Sewer NetworkSewer

Network Boundaries Conditions

Boundaries Conditions

Simulation Period

Simulation Period

Mouse

Simulating the surface flow

DHI MIKEDHI MIKEPart ConceptPart Concept

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DONG-A UNIVERSITY

DHI MIKEDHI MIKEPart ProcessPart Process

• We can calculate the water level and flooding and the real We can calculate the water level and flooding and the real reaction of the sewer network.reaction of the sewer network.

• With retention pond,With retention pond,

• Downstream water level : 4,64 m,Downstream water level : 4,64 m,

• Reference rainfall intensity = 1997/08/04Reference rainfall intensity = 1997/08/04Time = 24 hoursTime = 24 hoursH= 207,6 mmH= 207,6 mm

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Flooding SimulationFlooding SimulationProduced by MOUSEProduced by MOUSE

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With these stock basin we can observe some result: With these stock basin we can observe some result:

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DONG-A UNIVERSITY

After the first simulation containing the 6 extremes rainfall value After the first simulation containing the 6 extremes rainfall value of 1997 :of 1997 :

• Research of the principal nodes of junction where there Research of the principal nodes of junction where there are some flood problems.are some flood problems.

• Creation of under reservoirs in these nodes junction to Creation of under reservoirs in these nodes junction to reduce the rain impact on the sewer network (330 m3 reduce the rain impact on the sewer network (330 m3 each under reservoir)each under reservoir)

DHI MIKEDHI MIKEPart ProcessPart Process

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DONG-A UNIVERSITY

Proposed SolutionProposed SolutionBuried Retention SystemBuried Retention System

Inlet discharge

Bottom

Outlet dischargeStorage

water 330 m3

1.1m

• Integrated reservoir to get the water out.Integrated reservoir to get the water out.

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DONG-A UNIVERSITY

Retention SystemRetention SystemWithout Storage BasinWithout Storage BasinDischarge: Discharge: 25.503/ 24.795/ 26.08225.503/ 24.795/ 26.082

With Storage BasinWith Storage BasinDischarge: Discharge:

26.748/ 25.888/ 26.94426.748/ 25.888/ 26.944

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DONG-A UNIVERSITY

• Initial idea of using another software for validation of simulation.Initial idea of using another software for validation of simulation.• However, due to time constraint focus was given to 1 software (MOUSE)However, due to time constraint focus was given to 1 software (MOUSE)

Attempt on Other SoftwareAttempt on Other SoftwareHalcrow ISISHalcrow ISIS

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DONG-A UNIVERSITY

Thank you for your attention!Thank you for your attention!