Water Resources Researchesearch Center YEUNGNAM University, , KOREA

INTEGRATEDINTEGRATED FLOODFLOOD RISKRISK MANAGEMENTMANAGEMENT

Soontak LEE, Ph.D., D.Sc., Hon.D.Eng.Sc. Distinguished Professor

School of Civil and Environmental Engineering Yeungnam University Kyongsan, Daegu 712-749 Republic of Korea Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

‹‹ FLOODFLOOD CHARACTERISTICSCHARACTERISTICS

‹‹ FLOODFLOOD RISKRISK FACTORSFACTORS

‹‹ INTEGRATEDINTEGRATED FLOODFLOOD RISKRISK MANAGEMENTMANAGEMENT METHODOLOGIESMETHODOLOGIES

‹‹ INTEGRATEDINTEGRATED FLOODFLOOD RISKRISK MANAGEMENTMANAGEMENT MEASURESMEASURES

‹‹ BASINWIDEBASINWIDE INTEGRATEDINTEGRATED FLOODFLOOD MANAGEMENTMANAGEMENT PLANPLAN Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FLOODFLOOD CHARACTERISTICSCHARACTERISTICS Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

¾¾ KoreanKorean RiverRiver BasinBasin CharacteristicsCharacteristics CharacteristicsCharacteristics ofof thethe RiversRivers inin Korea(1/2)Korea(1/2)

□ The river reaches are relatively short and channel slopes are relatively steep.

- The river reaches are short and drainage areas are small in Korea compared with other major continental rivers.

- The channel slopes are relatively steep upstream because of steep mountains and deep valleys in the uplands.

□ Floods occur quickly and peak flood discharges are enormous.

- Due to the topographical conditions and torrential rainfalls, the hydrographs of rivers in Korea are very sharp and peak flood discharges are enormous compared with other comparable rivers in the continent. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

CharacteristicsCharacteristics ofof thethe RiversRivers inin Korea(2/2)Korea(2/2)

□ Flow variations are high.

- The coefficients of the river regime, expressed by maximum discharge over minimum discharge for rivers in Korea usually range from 100 up to 700.

- This large variation in the flow discharge causes serious problems in river management concerning flood control and water use. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FFiiveve MMaajjoror RRiveriver BBaassinsins inin KKoorreeaa

Geum River Basin Han River Basin

Seomjin River Basin

Nakdong Yongsan River Basin River Basin Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

¾¾ KoreanKorean RiverRiver BasinBasin CharacteristicsCharacteristics MetMeteeorologiorologiccalal BBackground(1/3)ackground(1/3)

□ The main season, which affects Korea, normally runs between June and September. Korea is normally hit directly by 1 to 3 heavy typhoon storms per year with most events occurring in August.

Monthly Variation of Korean Month Number of Events(1950-2002) Percentage of Total June 5 7.5% July 24 35.8% August 26 38.8% September 10 14.9% October 2 3.0% Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

MetMeteeorolorologicalogical Background(2/3)Background(2/3)

Over Annual Average Air Temperature 2.0 ) ) ℃ ℃ 1.5

1.0

0.5

0.0 ion of Temperature( ion of Temperature(

-0.5 Deviat Deviat -1.0

-1.5 1954 1964 1974 1984 1994

Since late 1980’s air temperature has risen significantly, higher than global average. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

MetMeteeorolorologicalogical Background(3/3)Background(3/3)

Number of Daily Rainfall Events

1992-2001 1971-1980 120 107 100 83 80 57 60 52 49 44 37 40 26 28 25 26 20 13

0 100.1~110 110.1~120 120.1~130 130.1~140 140.1~150 More than 150.1

Unit : mm

Rainfall Intensity has been increased significantly, especially for higher intensity events. Water Resources Researchesearch Center TyphoonTyphoon Rusa(Rusa(11//33)) YEUNGNAM University, Daegu, KOREA

□ Track and Characteristics

- Typhoon Rusa formed in the west Pacific Ocean on 22 August 2002 and strengthened into a typhoon on 24 August while tracking northwest.

- The cyclone tracked northwest toward Okinawa for approximately 8 days before turning toward the Korean Peninsula and subsequently made landfall at approximately 0630Z 31 August near the city of Goheung, Korea, with maximum sustained winds of 65 knots, gusting to 80 knots.

- Rusa reached a peak intensity of 115 knots on 26 August 2002 near the Bonin Islands and maintained this intensity for 24 hours before beginning a slow weakening trend until landfall in Korea.

- During the Rusa, maintained at 950hPa and Rusa poured 1.7 times of maximum heavy storms across Korean peninsula.

- Typhoon Rusa caused the death of around 246 people and generated more than USD 5,000 million damage losses with more than 60,000 people Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

TyphoonTyphoon Rusa(Rusa(22//33))

Path of Typhoon Rusa Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

TyphoonTyphoon Rusa(Rusa(33//33))

Maximum Rainfall for Given Durations

Maximum Second Storm Period Station Rainfall(mm) Station Rainfall(mm) Duration 6hr Yangyang-kun 403.0 Kangleung 274.5 08/31 20~ Duration 12hr Samcheok City Kangleung 576.0 529.0 08/31 12~ Miro-myeon Duration 24hr Kangleung 880.0 Daekwanryung 739.0 08/31 01~ Duration 48hr Kangleung 897.5 Daekwanryung 758.8 08/30 05~ Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon RusaRusa (1/5)(1/5)

Flooded Urban Area(Hallim-myeon, Gimhae-si, Gyeongsangnam-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon RusaRusa (2/5)(2/5)

Town and View of Farmland (Hallim-myeon, Kimhae-si, Kyeongsangnam-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon RusaRusa (3/5)(3/5)

Broken Levee in Nam River (Beobsu-myeon, Haman-gun, Kyeongsangnam-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon RusaRusa (4/5)(4/5)

Destroyed Spillway (Gangneung-si, Gangwon-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon RusaRusa (5/5)(5/5)

Broken Gamcheon Railway Bridge (Gimcheon-si, Kyeongsangbuk-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

SuperSuper TyphoonTyphoon MMaaemiemi((1/1/3)3)

□ Track and Characteristics of Super Typhoon Maemi

- Super Typhoon Maemi formed as a tropical depression near , east of the on 5 September and as it approached the southern Japanese islands of Okinawa, it developed into a super typhoon(Saffir-Simpson scale 5).

- It struck the southern coast of Korea during the night of September 12 with wind gusts reaching 216 kph and rainfall of up to 450 mm.

- According to the Korea’s official weather service, Maemi was the most powerful typhoon to strike the country since records began in 1904 (KMA, 2003).

- Super Typhoon Maemi caused the death of around 120 people and generated more than USD 500 million in insurance-related losses. The typhoon also left more than 25,000 people homeless. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

SuperSuper TyphoonTyphoon MMaaemiemi((2/2/3)3)

Path of Super Typhoon Maemi Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

SuperSuper TyphoonTyphoon MMaaemiemi((3/3/3)3) History of Maximum Wind Velocity(unit : m/s) Maemi 60.0 2003. 9. 12 Bukjeju Prapiroon 58.3 2000. 8. 31 Heuksando Ted 51.0 1992. 9. 25 Ullungdo Vera 49.0 1986. 8. 28 Uljin Sara 46.9 1959. 9. 17 Jeju Faye 46.6 1995. 7. 23 Tongyeong Emma 45.7 1956. 9. 10 Yeosu Louise 44.3 1955. 9. 30 Ullungdo Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon MMaaemiemi((1/4)1/4)

Broken Micheonje Levee (Uiseong-gun, Gyeongsangbuk-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon MMaaemiemi((2/4)2/4)

Flooded Inland Punping Station in Lowland (Uiseong-gun, Gyeongsangbuk-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon MMaaemiemi((3/4)3/4)

Broken Hoecheonje Levee (Goryeong-gun Gyeongsangbuk-do) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FlFloodood DDamamageage PictPicturesures bbyy TyphoonTyphoon MMaaemiemi((4/4)4/4)

Broken Crane ( Metropolitan City) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FLOODFLOOD RISKRISK FACTORSFACTORS Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

RiskRisk Factors(1/5)Factors(1/5)

□□ AbnormalAbnormal weatherweather eventsevents duedue toto globalglobal warmingwarming

□□ RapidRapid urbanizationurbanization andand industrializationindustrialization

□□ InsufficientInsufficient infrastructureinfrastructure forfor floodflood defensedefense

□□ LackLack ofof socialsocial systems,systems, cooperationcooperation betweenbetween sectorssectors andand publicpublic participationparticipation Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

RiskRisk Factors(2/5)Factors(2/5)

Annual Average Air Temperature Air temperature has risen significantly, higher than global average

Abnormal weather Number of Daily Rainfall Events events due to global Rainfall Intensity has been increased warming significantly, especially for higher intensity events Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

RiskRisk Factors(3/5)Factors(3/5)

Social System Indices

Index Population GDP Urban Average Area(km2) Year (thousand) (trill. Won) Ratio(%) Life(year) 1960 98,222 24,990 0.2 39.1 52.4 1970 98,222 31,470 2.8 50.1 63.2 1980 98,992 37,440 37.8 68.7 65.8 1990 99,274 43,410 178.8 81.9 70.2 1999 99,800 47,360 483.8 87.6 74.4

For the last four decades, population increase two times; GDP increased 2,500 times; and urban ratio increaincreasedsed more than two times.

Rapid urbanization and industrialization Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

RiskRisk Factors(4/5)Factors(4/5)

□ Change of Land Cover in Han River Basin

Seoul Rapid Urbanization

1975 1980 1985 Water Urban Barren Land Wetland Grass Land Forest Paddy 1990 1995 2000 Field Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

RiskRisk Factors(5/5)Factors(5/5)

Insufficient infrastructure for flood defense

□ Lack of fund for flood control

□ Difficulty in securing investment funds for middle and small-sized streams

□ Insufficient flood control facilities in urban areas

□ Deficient improvement of stream management system

□ Deterioration of stream functions Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

INTEGRATEDINTEGRATED FLOODFLOOD RISKRISK MANAGEMENTMANAGEMENT METHODOLOGIESMETHODOLOGIES Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA IntegratedIntegrated FloodFlood RiskRisk ManagementManagement Methodologies(1/2)Methodologies(1/2) Flood Forecasting and Warning

□ Concept of Flood Forecasting and Warning

- Storm monitoring and forecasting

- Flood information monitoring and transmitting Regional Administr ative Detention Office reservoir MOCT Regional Bureau

Ministry of Construction and Regional Flood Transportation Control Office Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA FloodFlood RiskRisk ManagementManagement Methodologies(2/2)Methodologies(2/2) Flood Forecasting and Warning

Minister of Ministry of Request of approval Construction & Transportation for releasing water Report of results from dam Administrator of Dam Flood Control Office Telemetering Observation Station · To make plans for releasing · To estimate possible outflow by water from dam divided basin areas · Monitoring Stations for water · To start releasing water · Flood forecast level and rainfall · Announcement and cancellation · Water level of dam and volume of flood forecast of release Approval for releasing Notification of results water from dam dam Central Disaster Prevention and Safety Countermeasures Headquarters Notification of Notification of plans flood-forecasting for releasing water announcement from dam Announcement to the Public (through broadcast or newspaper)

Related Agencies

Regional Disaster Prevention and Safety Countermeasures Headquarters in Cities or Provinces

Residents in the regions Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(1/3)Methodologies(1/3)

Flood Control Flood Control Effect of Multipurpose Dam in System (at Jindong) (Flood Period : 2002. 8. 30 ~ 9. 2)

Expected Maximum Water Level : 15.77m (20,970 cms)

Flood Control Effect of four dams : 4.73m (10,280 cms) ) ) Maximum Water Level : 11.04m (10,690 cms) Danger Water Level : 10.5m

Warning Water Level : 8.5m er Level(EL. m er Level(EL. m Water Level (Jindong) Wat Wat Without Andong, Imha, Hapcheon and Namgang dam Without Namgang dam

Month, Day Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(2/3)Methodologies(2/3)

Flood Control - Han River Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(3/3)Methodologies(3/3)

Flood Control - Nakdong River Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(1/4)Methodologies(1/4) Flood Hazard Map

□ Flood Hazard Map : A map that provides with geographical information that is essential for local residents to conduct “safe & smooth evacuation”

□ The purposes of producing Flood Hazard Map

- For local residents: To promote proper and prompt evacuation actions by providing them with prior information of flood risk and evacuation

- For local municipalities: to promptly and smoothly accomplish evacuation of residents using Flood Hazard Map to reduce human losses Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(2/4)Methodologies(2/4) Flood Hazard Map

□ Effectiveness of Flood Hazard Map - Quicker evacuation - Higher evacuation ratio - Correct direction to evacuate □ Guidance to Flood Hazard Map

- Flooding mechanism - Topographic features and flooding types - Real danger of flood, Predicted extent of damage - Meteorological information - Past flood records (rainfall, inundation, and damage) - Rules to follow in cases of flood - Explanation and direction to use Flood Hazard Map - Preparedness against flood Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(3/4)Methodologies(3/4) Flood Hazard Map Hydrologic Surveying Analysis

Preprocess &

Field Data DEM

Inundation Mapping Analysis Postprocess Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Methodologies(4/4)Methodologies(4/4) Flood Hazard Map

Ansungchun Flood Hazard Map (100 yr Return Period) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

INTEGRATEDINTEGRATED FLOODFLOOD RISKRISK MANAGEMENTMANAGEMENT MEASURESMEASURES Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Measures(1/6)Measures(1/6)

□□ NewNew planningplanning ofof comprehensivecomprehensive andand integratedintegrated floodflood disasterdisaster preventionprevention andand managementmanagement onon thethe basisbasis ofof basinwidebasinwide □□ EarlyEarly eliminationelimination ofof uncertainuncertain factorsfactors □□ ImprovingImproving thethe managementmanagement andand operationoperation ofof damsdams andand riverriver structuresstructures □□ UpdatingUpdating thethe guidelinesguidelines forfor riverriver worksworks andand implementationimplementation ofof themthem □□ NewNew legislationlegislation forfor thethe effectiveeffective floodflood damagedamage mitigationmitigation □□ AdoptingAdopting moremore nonnon--structuralstructural measuresmeasures andand improvingimproving thethe recoveryrecovery systemsystem □□ DrawingDrawing moremore publicpublic awarenessawareness andand participationparticipation FloodFlood RiskRisk ManagementManagement Water Resources Researchesearch Center Measures(2/6)Measures(2/6) Satellite YEUNGNAM University, Daegu, KOREA BasinwideBasinwide IntegratedIntegrated FloodFlood ManagementManagement PlansPlans Rainfall Rader Rainfall Gauge Water Level Station Gauge Station Forest Erosion Management Control Project Multipurpose Dam Dam

Landslide Dam Control Flood Control Prevention Office Flood Control Office Office Agricultural Land Project Bank & Unused Land Stormwater Reservoir Of Seepage Water Pumping Station Driving Channel Playground Parking (storage) (storage) Wetland (Flood Control & Water Purification) Bank

Break water Super Bank Seewall Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Measures(3/6)Measures(3/6) BasinwideBasinwide IntegratedIntegrated FloodFlood ManagementManagement PlansPlans ObjectivesObjectives By 2007, completing the Basinwide Integrated Flood Management Plans for the 13 river basins in the nation to defend the flood from the extreme rainfall; - Upgrade the flood management paradigm for the abnormal climate change - Overcome the deficiency of flood control capacities due to the limitation of dam construction and river flood protection facilities - Raise the storage capacities of flood in the basin - Establish the measures for the urban population and properties in the flood prone areas - Establish the integrated optimal operation system of dams and flood control facilities in each basin Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Measures(4/6)Measures(4/6) BasinwideBasinwide IntegratedIntegrated FloodFlood ManagementManagement PlansPlans

MainMain contentscontents (Basic(Basic direction)direction) (1/2)(1/2)

- Distributing flood control functions into both river channel and basin for the present and future flood flow by changing the flood control policy.

- Increasing the flood storage capacities in upstream areas by the construction of riverside detention reservoirs or by using floodplain areas, and accordingly, increasing the safety level of flood management in whole river basin and decreasing the flood control volume in downstream channel reach.

- Spatial and master planning for the flood control including storages, rainwater capture systems, levees, pumping stations and landuse plan for their construction and share of flood flow. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Measures(5/6)Measures(5/6) BasinwideBasinwide IntegratedIntegrated FloodFlood ManagementManagement PlansPlans

MainMain contentscontents (Basic(Basic directiondirection )) (2/2)(2/2)

- Planning, development and maintenance of optimal integrated operation system for the flood control

- Building flood control plans of both structural and nonstructural measures appropriate to the regional characteristics

- Examining the links with higher level or other related plans as well as the links of the facilities with other infrastructures such as railways, roads and bridges Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

FloodFlood RiskRisk ManagementManagement Measures(6/6)Measures(6/6) BasinwideBasinwide IntegratedIntegrated FloodFlood ManagementManagement PlansPlans

Classification by the variation of flood discharge and the scope of plan

Abnormal flood Nonstructural Basinwide measures Integrated (scope of disaster Flood Management prevention) Plan

Structural measures Future increment Channel max. Structural measures (scope of disaster (channel+basin max.) +basin share (scope of disaster prevention)

Design flood River Scope of flood Channel share Improvement control projects Basic Plan 0 Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA StructuralStructural andand NonstructuralNonstructural MeasuresMeasures

Remark Scope of Plan Plan Measures

Channel Improvement, River Improvement Design Flood Levees, Drainage Basic Plan Channel Facilities Reach Above Design Flood Structural Channel Acceptable Retarding Reservoir, Measures Maximum Value Riverside Detention Reservoir, Temporary Future Urban Storage in Agricultural River Increment Basinwide Land, Bypass, Flood Basin Excess of Channel Integrated Control Reservoir Share Flood Management Abnormal Storm Plan Flood Forecasting and Excess of Basin Nonstructural Warning System, Flood Share Measures Hazard Map, Flood Emergencies due to Insurance System Levee Break etc.

Others System Improvement, Roof Storage, School Ground Storage, Basin Measures Underground Storage of Roads, Parking Lot and Park etc. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

BASINWIDEBASINWIDE INTERGRATEDINTERGRATED FLOODFLOOD MANAGEMENTMANAGEMENT PLANPLAN

-- NAKDONGNAKDONG RIVERRIVER BASINBASIN -- Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

Flood Flow Distribution Plan

‰ Increased flood flow by recent abnormal climate change (19,400cms to 22,000cms)

‰ Basinwide Integrated Management Plan established.

- River improvement works by 2011

- Reinforcement of existing flood protection facilities by 2016

- In channel reach, additional share of flood flow of 300~1,000cms by enlargement of estuary barrage, improvement of low-flow channel and narrow channel.

- In basin share, establishing the flood protection plan for the excess of channel share by further construction of storage facilities such as flood control reservoir, riverside detention reservoirs and short-cut channel.. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA Assessment Procedure

Prediction of River Flood Flow Review Basin Condition’s Change

Estimation of Flood Flow Change

Determination of Channel Share of Flood Flow

Development of Flood Protection Alternatives (Channel and Basin Alternatives)

Assumption of Flood Flow Share on each Flood Protection Alternatives

Hydraulic and Hydrologic Assessment on Flood Flow Share

Optimality of Alternatives NO

YES Determination of Optimal Flood Protection Alternatives Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

Proposed Plans (Alternatives) (1/2)

River Channel + New Dams + Redeveloped Existing Dams+ Riverside Detention Reservoir + Flood Control Reservoir + Short-Cut Channel

z Channel shares another 900cms by enlargement of estuary barrage and Plan -Ⅰ sedimentation removal out of increased flood flow of 2,600cms.

z Basin shares 1,700cms by 4 new dams, redevelopment of 4 existing dams, 20 riverside detention reservoirs, 1 flood control reservoir and 1 short-cut channel. River Channel + Levee Heightening + New Dams + Redeveloped Existing Dams + Riverside Detention Reservoirs + Flood Control Reservoirs

z In case of no short-cut channel, basin shares 700cms and channel shares Plan - Ⅱ 1,900cms by 4 new dams, redevelopment of 4 existing dams, 75 riverside detention reservoirs, 2 flood control reservoirs and levee heightening. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

Proposed Plans (Alternatives) (2/2)

New Dams + Redeveloped Existing Dams + Riverside Detention Reservoirs + Flood Control Reservoir + Short-Cut Channel

z This plan maintains the legally designated present design flood 19,400cms in the Ⅲ Plan - channel but the excessive flood flow 2,600cms is managed by 4 new dams, redevelopment of 4 existing dams, 75 riverside detention reservoirs, 1 flood control reservoir and 1 short-cut channel.

River Channel + Diversion Channel + New Dams + Redeveloped Existing Dams + Riverside Detention Reservoirs + Flood Control Reservoir

z Using the diversion channel and existing river channel, flood flow is managed at the Plan – Ⅳ estuary.

River Channel + New Dams + Redeveloped Existing Dams + Levee Heightening

Plan - Ⅴ z The excessive flood flow 2,600cms is shared and managed by the river channel with the levee heightening. Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

Flood Management Plans (Alternatives) - Summary and Comparison -

Plans Plan - Ⅰ Plan - Ⅱ Plan - Ⅲ Plan - Ⅳ Plan - Ⅴ

Plan ¾ Channel + Basin ¾ Channel + Basin ¾ Basin share ¾ Channel share ¾ Channel Share Outline Share Share Only Only Only

Share ¾ Channel : 900cms ¾ Channel : 1,900cms ¾Basin:2,600cms ¾ Channel: 2,600cms ¾ Channel:2,600cms Plan ¾ Basin : 1,700cms ¾ Basin : 700cms

¾ Channel Project ¾ Channel Project ¾ Channel Project ¾ Channel Project ( 900cms) (1,900cms) (2,600cms) (2,600cms) - Sedimentation - Sedimentation - Sedimentation - Sedimentation removal & removal & removal & removal & River channel River Channel River channel River channel improvement improvement improvement improvement - Enlargement of - Enlargement of - Enlargement of - Enlargement of estuary barrage estuary barrage estuary barrage estuary barrage - Levee heightening - Diversion channel - Levee heightening : L=64km Project

Details ¾ Basin Project ¾ Basin Project ¾Basin Project ¾ Basin Project ¾ Basin Project (1,700cms) ( 700cms) (2,600cms) -4 New dams -4 New dams -4 New dams -4 New dams -4 New dams - 4 Existing dams - 4 Existing dams - 4 Existing dams - 4 Existing dams - 4 Existing dams redevelopment redevelopment redevelopment redevelopment redevelopment -20 Riverside - 20 Riverside - 75 Riverside - 75 Riverside detention reservoirs detention reservoirs detention reservoirs detention reservoirs - 1 Flood control - 1 Flood control - 2 Flood control - 2 Flood control reservoir reservoir reservoirs reservoirs - 1 Short-cut channel - 1 Short-cut channel : L=35 km : L=35 km Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

Hydrograph at Nakdong River Estuary

25000

Established Present Design Flood Flow : 20000 19,400cms

Peak Flood Flow

15000 Plan - Ⅰ: 20,300cms Plan - Ⅱ: 21,300cms /s)

㎥ Plan - Ⅲ: 19,400cms (

ow Plan - Ⅳ: 22,000cms Fl Plan - Ⅴ: 22,000cms 10000

Plan - Ⅰ Plan - Ⅱ Plan - Ⅲ 5000 Plan - Ⅳ Plan - Ⅴ Established Present Design Flood Flow

0 0 24 48 72 96 120 144 168 192 Time(hr) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

Means of Analysis

Flood홍수관리계획 홍수관리계획Management Plan

Finding Project-Concerned Dete대상rmi지역설정ne & Eval및 uate 이해관계자파악및 역할모색 PhasePhase 11 People & Their Role 지역Targ평가실et Area시 (생태학자Ecol,ogi수문학자st, Hydr,지역전문가ologist,주, 민등 ) Local Specialist, Residents

사업의Project타당성 Feas평가ibility Study PhasePhas e3, 24 Establish the Standard of Flood Management Plan Evaluation Detailed Flood Evaluate Opinion of Managem구체적인 e치수대nt Pla안n Project-C이해관계자의oncern의사평ed 가People

PhPhasease 53 R시나리오별ating of Plan순위s (Scen매기기arios) Water Resources Researchesearch Center YEUNGNAM University, Daegu, KOREA

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