DONG DONG-A UNIVERSITY Historical Flood in in

2 DONG-A UNIVERSITY Online Collaboration Web Platform Web Platform was used as part of the communication media and storage of documentation. Web Platform was used as part of the communication media and storage of documentation. MSN and Adobe Connect. MSN and Adobe Connect. Remote Desktop for available technical software. Remote Desktop for available technical software.

3 DONG-A UNIVERSITY About Incheon Located in the mid- west Korea peninsula near Yellow Sea Located in the mid- west Korea peninsula near Yellow Sea 37° 29 N, 126° 38 E 3 rd biggest city in Korea 3 rd biggest city in Korea Area: km2 Gateway of North East Asia Gateway of North East Asia Facilitated with both international airport and port.

4 DONG-A UNIVERSITY Project Overview 1. Incheon Gyo Total area: 34 ㎞ 2 Total area: 34 ㎞ 2 Elevation: 0 ~ 201m(EL+) Elevation: 0 ~ 201m(EL+) Average of slope: 0.01% Average of slope: 0.01% Reclamation land. Reclamation land. Tidal difference of Yellow sea which is linked with Incheon Gyo watershed is 9m. Tidal difference of Yellow sea which is linked with Incheon Gyo watershed is 9m. Concentration of rainfall is usually in August. Concentration of rainfall is usually in August. Study area Gaja WWTP City Hall Gansuk station Juan station Pump Station

5 DONG-A UNIVERSITY Project Overview 2. Flooding Occurrence Occurred at coastal area located at the downstream of drainage system. despite the heavy rainfall return period of 2-3 years. Occurred at coastal area located at the downstream of drainage system. despite the heavy rainfall return period of 2-3 years. Max. rainfall (1997-present) Max. rainfall (1997-present) In 1997: 260.8mm/day 3. Impact Direct: buildings and houses destroyed quality of life decrease profit losses costly repair and management. Indirect: country’s economy and security.

6 DONG-A UNIVERSITY Hydrology Geography Rainfall intensity Duration Time interval Storm return period Catchments Building Manholes Road DHIISIS 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 Process Retry Suggestion

7 DONG-A UNIVERSITY Hydrology Analysis Precipitation data Precipitation data – Design Precipitation – Observed Real Precipitation Runoff Coefficient Runoff Coefficient – Total Runoff Coefficient – Sub-catchments Runoff Coefficient

8 DONG-A UNIVERSITY Precipitation Data Design Precipitation Suggested probability rainfall intensity formula in Incheon mm/hr

9 DONG-A UNIVERSITY Precipitation Data Design Precipitation Intensity-Duration-Frequency curves for Incheon-Gyo area

10 DONG-A UNIVERSITY Precipitation Data Design Precipitation Design precipitation hyetographs from IDF relationships

11 DONG-A UNIVERSITY Precipitation Data Real Precipitation

12 DONG-A UNIVERSITY Runoff Coefficient Incheon Gyo as a Whole

13 DONG-A UNIVERSITY Runoff Coefficient Segmentation of Catchment

14 DONG-A UNIVERSITY ArcGIS GIS files: GIS files: – Catchment – Manholes – Building – Road – Contour GIS files were used to create TIN, DEM, and also others, being converted to ASCII files to produce necessary input for MIKE (Simulation) GIS files were used to create TIN, DEM, and also others, being converted to ASCII files to produce necessary input for MIKE (Simulation) + Simulation Simulation(MIKE)

15 DONG-A UNIVERSITY DHI MIKE Introduction To analyze the flooding problem we try to obtain a real approach of rain impact on Incheon Gyo catchment. To analyze the flooding problem we try to obtain a real approach of rain impact on Incheon Gyo catchment. We have simulated the general Incheon Gyo characteristic with the MIKE software. We have simulated the general Incheon Gyo characteristic with the MIKE software. It is easy and efficient to report the realistic aspect of the flooding reality with DHI software It is easy and efficient to report the realistic aspect of the flooding reality with DHI software

16 DONG-A UNIVERSITY DHI MIKE Introduction There are several processes to simulate the flood. There are several processes to simulate the flood. To simulate the flood imputation of the sewer network (Mouse) and the DEM (MIKE 21) must be connected to observe the catchment behavior. To simulate the flood imputation of the sewer network (Mouse) and the DEM (MIKE 21) must be connected to observe the catchment behavior. It is necessary to couple with MIKE21 It is necessary to couple with MIKE21 MIKE FLOOD MIKE FLOOD

17 DONG-A UNIVERSITY DHI MIKE Process Flowchart MIKE ZERO Bathymetry MIKE 21 Simulating the surface flowSimulating the sewer network flow MOUSE MIKE FLOOD Coupling MOUSE with MIKE21

18 DONG-A UNIVERSITY Bathymetry Bathymetry file from MIKE Zero to MIKE 21 Bathymetry file from MIKE Zero to MIKE 21

19 DONG-A UNIVERSITY DHI MIKE Process Flowchart Bathymetry Boundaries conditions Simulation period MIKE 21 Simulating the surface flow

20 DONG-A UNIVERSITY Removed the bad node to obtain good result from the simulation (conflict between bad node and building altitude) Removed the bad node to obtain good result from the simulation (conflict between bad node and building altitude) Rainfall Data & Water Level Sewer Network Boundaries Conditions Simulation Period Mouse Simulating the surface flow DHI MIKE Part Concept

21 DONG-A UNIVERSITY DHI MIKE Part Process We can calculate the water level and flooding and the real reaction of the sewer network. We can calculate the water level and flooding and the real 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 = 1997/08/04 Reference rainfall intensity = 1997/08/04 Time = 24 hours H= 207,6 mm

22 DONG-A UNIVERSITY Flooding Simulation Produced by MOUSE

23 DONG-A UNIVERSITY With these stock basin we can observe some result:

24 DONG-A UNIVERSITY After the first simulation containing the 6 extremes rainfall value of 1997 : Research of the principal nodes of junction where there are some flood problems. Research of the principal nodes of junction where there are some flood problems. Creation of under reservoirs in these nodes junction to reduce the rain impact on the sewer network (330 m3 each under reservoir) Creation of under reservoirs in these nodes junction to reduce the rain impact on the sewer network (330 m3 each under reservoir) DHI MIKE Part Process

25 DONG-A UNIVERSITY Proposed Solution Buried Retention System Inlet discharge Bottom Outlet discharge Storage water 330 m 3 1.1m Integrated reservoir to get the water out. Integrated reservoir to get the water out.

26 DONG-A UNIVERSITY Retention System Without Storage Basin Discharge: / / With Storage Basin Discharge: / /

27 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 Software Halcrow ISIS

28 DONG-A UNIVERSITY Thank you for your attention!