dam-break flood risk management : nakdong river case studies · dam-break flood risk management :...

DamDam--Break Flood Risk Management : Break Flood Risk Management : Nakdong River Case StudiesNakdong River Case Studies

Soontak LEE

Professor of civil and Hydrosystems EngineeringDean, Graduate School of Industrial Sc. & Tech.

Yeungnam UniversityDaegu 712-749, Korea

Dam, like “all structures, will be broken in the end —

just as all people will die in the future. It is the purpose

of the medicine and engineering to postpone these

occurrence for a decent interval”.

(J. F. Gordon)

Water Resources Research Center YEUNGNAM University, Daegu, KOREA

Modern dam safety regulationsModern dam safety regulations

! Risk assessment at downstream floodplains

! Consideration of potential damages due to dam-break

— to increase the safety level along the river basin against

abnormal floods caused by dam accidents

! Following items should be considered by dam managers or exploitants :

— dam risk classification

— design flood selection criteria

— inundation maps and zoning

— basin vulnerability to floods



Main objectivesMain objectives

! To improve the engineering capability for dam-break flow analysis and prediction on real complex situations

! To develop methodologies and guidelines for dam-break flood risk management in Nakdong River, Korea, as a first step toward a new integrated flood safety system based on structural and non-structural measures

! To create a new concept for operational crisis control and integrated dam safety management


Integrated dam safety conceptIntegrated dam safety concept

! Technical - operational

— dam design, construction and exploitation

— minimize the failure probability

! Monitoring

— opportunity to observe and control the dam behavior

! Emergency and risk management

— planning and organization along the basin and all emergency

procedures in order to anticipate and mitigate the

downstream dangers from a dam accident

"""" To develop new methodologies for this third aspect

– supported by three pillars :

Downstream risk level Downstream risk level -- a new concepta new concept


DRLDRLDRLDRL

DAM OWNERSDAM OWNERSDAM OWNERSDAM OWNERS

PUBLICPUBLICPUBLICPUBLICAUTHORITIESAUTHORITIESAUTHORITIESAUTHORITIES

PUBLIC PARTICIPATION AND MEDIAPUBLIC PARTICIPATION AND MEDIAPUBLIC PARTICIPATION AND MEDIAPUBLIC PARTICIPATION AND MEDIA

SOCIETY BENEFITSSOCIETY BENEFITSSOCIETY BENEFITSSOCIETY BENEFITSBETTER PROTECTIONBETTER PROTECTIONBETTER PROTECTIONBETTER PROTECTION

PUBLIC PARTICIPATIO

N AND M

EDIA

PUBLIC PARTICIPATIO

N AND M

EDIA

PUBLIC PARTICIPATIO

N AND M

EDIA

PUBLIC PARTICIPATIO

N AND M

EDIA

INFORMATIO

N

INFORMATIO

N

INFORMATIO

N

INFORMATIO

N

LOCAL BENEFITS

LOCAL BENEFITS

LOCAL BENEFITS

LOCAL BENEFITS

CONS

TRAINT

S A

ND R

EGUL

ATIO

NS

CONS

TRAINT

S A

ND R

EGUL

ATIO

NS

CONS

TRAINT

S A

ND R

EGUL

ATIO

NS

CONS

TRAINT

S A

ND R

EGUL

ATIO

NS

SAFE

DES

IGN A

ND

SAFE

DES

IGN A

ND

SAFE

DES

IGN A

ND

SAFE

DES

IGN A

ND

OPE

RATION

OPE

RATION

OPE

RATION

OPE

RATION


Social sciences contributions to dams and Social sciences contributions to dams and safety management at downstream basinssafety management at downstream basins

To know in order to define and support interventionTo know in order to define and support interventionTo know in order to define and support interventionTo know in order to define and support intervention

Specific features of communities in floodable areasSpecific features of communities in floodable areasSpecific features of communities in floodable areasSpecific features of communities in floodable areas

UNDERSTANDUNDERSTANDUNDERSTANDUNDERSTAND…

Who is at risk ?Who is at risk ?Who is at risk ?Who is at risk ?

Sociological, demographicSociological, demographicSociological, demographicSociological, demographic

and housing knowledgeand housing knowledgeand housing knowledgeand housing knowledge

Dam break risk public perceptionDam break risk public perceptionDam break risk public perceptionDam break risk public perception

People beliefs, attitudes, judgments andPeople beliefs, attitudes, judgments andPeople beliefs, attitudes, judgments andPeople beliefs, attitudes, judgments and

feelings towards damfeelings towards damfeelings towards damfeelings towards dam’s risks, benefits and safetys risks, benefits and safetys risks, benefits and safetys risks, benefits and safety

SocioSocioSocioSocio----geographicalgeographicalgeographicalgeographical

SocioSocioSocioSocio----structuralstructuralstructuralstructural

Diagnoses of vulnerabilities SDiagnoses of vulnerabilities SDiagnoses of vulnerabilities SDiagnoses of vulnerabilities Socioocioocioocio----demographicdemographicdemographicdemographic

SocioSocioSocioSocio----cognitivecognitivecognitivecognitive

Risk informingRisk informingRisk informingRisk informing

communication without alarmingcommunication without alarmingcommunication without alarmingcommunication without alarming

People living inPeople living inPeople living inPeople living inLocal authoritiesLocal authoritiesLocal authoritiesLocal authorities

disaster support institutionsdisaster support institutionsdisaster support institutionsdisaster support institutions

Promote acceptability and viabilityPromote acceptability and viabilityPromote acceptability and viabilityPromote acceptability and viability

of warning systems against spillwaysof warning systems against spillwaysof warning systems against spillwaysof warning systems against spillways

And dam break riskAnd dam break riskAnd dam break riskAnd dam break risk

Guarantee the efficiency of emergency plansGuarantee the efficiency of emergency plansGuarantee the efficiency of emergency plansGuarantee the efficiency of emergency plans

in case of dam breakin case of dam breakin case of dam breakin case of dam break

AIMSAIMSAIMSAIMS…

EstuaryEstuaryEstuaryEstuary

Imha DamImha DamImha DamImha Dam

Youngcheon DamYoungcheon DamYoungcheon DamYoungcheon Dam

Andong DamAndong DamAndong DamAndong Dam

Unmun DamUnmun DamUnmun DamUnmun Dam

Milryang DamMilryang DamMilryang DamMilryang DamHapcheon DamHapcheon DamHapcheon DamHapcheon Dam

Namgang DamNamgang DamNamgang DamNamgang Dam

AndongAndongAndongAndong

DaljiDaljiDaljiDalji

SabeolSabeolSabeolSabeol

NakdongNakdongNakdongNakdong

GumiGumiGumiGumi

GoryeunggyoGoryeunggyoGoryeunggyoGoryeunggyo

JeokpogyoJeokpogyoJeokpogyoJeokpogyo

JindongJindongJindongJindong SamrangjinSamrangjinSamrangjinSamrangjin

GupoGupoGupoGupo

Estuary barrageEstuary barrageEstuary barrageEstuary barrage

Nakdong river basin channel system with damsNakdong river basin channel system with dams


Nakdong River system with

a catchment area of 23,393.7km2

and a river length of 509.7km

– largest river system in river

length and 2nd in catchment area

– 7 large multi-purpose dams in

operation

Dams in Nakdong river basinDams in Nakdong river basin


138.0160.0230.0135.075.0200.0200.0Dam foundation width(m)

0.200.200.300.25-0.250.18Core mean slope (1V:zH)

1.82.01.41.50.81.81.7Dam down slope(1V:zH)

2.22.71.41.50.12.22.0Dam upper slope(1V:H)

10.010.010.07.510.010.08.0Dam crest width(m)

407.0300.0535.01,126.5472.0515.0612.0Dam crest length(m)

7.87.22.553.030.331.060.0Reservoir area in HWL(km2)

7,594.02,959.03,054.014,892.08,984.09,362.09,913.0PMF peak inflow (m3/s)

135.396.473.6309.2790.0595.01,248.0Total storage capacity(106m3)

55.042.089.034.096.073.083.0Dam height(m)

ECRDECRDCFRDCFRDCGECRDECRDDam type

UnmunYeungcheonMilryangNamgangHapcheonImhaAndongDam

Index


DAMDAM--BREAK FLOOD SIMULATIONBREAK FLOOD SIMULATION


Choice of the breach model

! To simulate a more accurate outflow for flood mapping and for a risk assessment analysis ;

! To support crisis management (including a potential evacuation action) during a dam incident with a threat of dam overtopping or piping ;

! To reproduce a dam incident with failure and opening of a breach

Model depend on the objectives :


Dam-break flood simulation model

! Parametric model (DAMBRK model)

! Physical - parametric model (BREACH model)

Models used :


! Breach formation (breach width, time and shape) assumed or estimated

! Different flood hydrograph types and flood peak values (including PMF) as well as reservoir water level before dam-break considered

! Dam-break flood peak values and outflow hydrographs estimated and compared with results by empirical estimation

Dam - break mechanism and outflow hydrograph


Dam Dam -- break flood peak discharges by break flood peak discharges by different modelsdifferent models

39,12925,808(1.0hr)45,512

(1.0hr)46,589-113,929226,7013.0

53,23133,580(0.2hr)184,169

(0.2hr)47,660

(0.2hr)276,699135,274254,3712.0

72,55143,528(0.1hr)263,248

(0.1hr)48,907

(0.1hr)280,616166,193283,9171.0

3Hd

110.084.0178.068.0183.0146.0166.0Bb(m)T(hr)Bavr

37,14524,027(1.0hr)43,494

(1.0hr)35,343-106,580187,8393.0

47,11629,173(0.2hr)163,388

(0.2hr)35,653

(0.2hr)146,321125,153204,3092.0

58,55635,133(0.1hr)217,403

(0.1hr)35,690

(0.1hr)148,682145,400221,8181.0

2Hd

73.356.0118.734.0122.097.7110.7Bb(m)T(hr)Bavr

32,01720,094(1.0hr)40,345

(1.0hr)24,063-90,088137,5683.0

37,29122,717(0.2hr)129,723

(0.2hr)23,716

(0.2hr)94,20698,959145,6452.0

42,59625,717(0.1hr)159,000

(0.1hr)23,667

(0.1hr)94,686108,423154,1591.0

1Hd

36.728.059.317.061.048.355.3Bb(m)T(hr)Bavr

DAMBRK

38,77826,609---79,143105,598BREACH + DAMBRK

51,32720,522---78,74992,964BREACH

UnmunYeungcheonMilryangNamgangHapcheonImhaAndongDamModel

Unit : m3/s


Uncertainty analysis of dam Uncertainty analysis of dam -- break flood break flood peak dischargespeak discharges

1, 000

10, 000

100, 000

1, 000, 000

1. E+06 1. E+07 1. E+08 1. E+09 1. E+10 1. E+11 1. E+12

To ta l Re s e rv o ir S to ra g e ( S ) *Da m he ig ht( Hd) ( m4)

Pea

k O

utfl

ow(m

3/s

)

Hagen(1982, Envelope Eq. based on S*Hd)MacDonald and Langridge- Monopolis(1984, based on S*Hd)Costa(1985, based on S*Hd)BREACHBREACH+DAMBRKDAMBRK(BREACH + 1Hd)DAMBRK(BREACH + 2Hd)DAMBRK(2Hd, 1hr)DAMBRK(2Hd, 2hr)Froehlich(1995a)

Dam Dam -- breach shape (Andong dam)breach shape (Andong dam)


EL. 166.0m

L = 612.0m

Bt = 332.0m

83.0m

Bb = 166.0m

EL. 151.0m1:11:11:11:1

Dam Dam -- breach shape (Imha dam)breach shape (Imha dam)


EL. 168.0m

L = 515.0m

Bt = 292.0m

73.0m

Bb = 146.0m

EL. 151.0m1:1 1:11:11:11:1

Dam Dam -- breach shape (Hapcheon dam)breach shape (Hapcheon dam)


L = 472.0m

96.0m

Bb = 183.0 m

EL. 181.0m

EL.166.0m

Bt = 183.0 m

Dam Dam -- break flood outflow hydrographbreak flood outflow hydrograph


0

5 0 , 0 0 0

1 0 0 , 0 0 0

1 5 0 , 0 0 0

2 0 0 , 0 0 0

2 5 0 , 0 0 0

3 0 0 , 0 0 0

0 . 0 0 1 . 0 0 2 . 0 0 3 . 0 0 4 . 0 0 5 . 0 0 6 . 0 0 7 . 0 0 8 . 0 0 9 . 0 0 1 0 . 0 0Time (hr)

Dis

char

ge(m

3 /s

ec)

Ando ng dam Qp = 283,917c ms

Imha dam Qp = 166,193c ms

Hapc he o n dam Qp = 148,682c ms


DAM DAM -- BREAK FLOOD WAVE ANALYSISBREAK FLOOD WAVE ANALYSISAND AND

INUNDATION MAPPINGINUNDATION MAPPING


Flood wave simulation model

! HEC-RAS Version 3.1.1

! DAMBRK model

— compared in solution of governing equations,

use of GIS and input of channel cross section data

— found HEC-RAS ⅤⅤⅤⅤⅤⅤⅤⅤ.3.1.1 more efficient in GIS application.3.1.1 more efficient in GIS application

and geographic data inputand geographic data input

Models used :


Geographical - spatial simulation by GIS

! Terrain model (Arc View)

! HEC - GeoRAS

— Numerical maps syntheses

— Convert to shape file

— TIN composition (3-D surface model)

— Stream section abstraction

— HEC-RAS import

— Formulated dam downstream section, dam-break flood

simulation and inundation mapping

Models used :


Numerical maps synthesesNumerical maps syntheses

Shape file in Arc ViewShape file in Arc View


Elevation layer shape fileElevation layer shape file


TIN compositionTIN composition


Stream section abstractionStream section abstraction


HECHEC--RAS import in GIS formatRAS import in GIS format


Formulated stream sectionFormulated stream section


Flood wave mappingFlood wave mapping



Dam-break scenarios

! Sc-A : Single dam-break

! Sc-B : Two dam-break (Andong + Imha)

! Sc-C : Three dam-break (Andong + Imha + Hapcheon)

The following three scenarios were assumed :

River channel system and damsRiver channel system and dams



Imha damImha damImha damImha dam

Youngcheon damYoungcheon damYoungcheon damYoungcheon dam

Andong damAndong damAndong damAndong dam

Unmun damUnmun damUnmun damUnmun dam

Milryang damMilryang damMilryang damMilryang damHapcheon damHapcheon damHapcheon damHapcheon dam

Namgang damNamgang damNamgang damNamgang dam


DaljiDaljiDaljiDalji


NakdongNakdongNakdongNakdong

GumiGumiGumiGumi

GoryeunggyoGoryeunggyoGoryeunggyoGoryeunggyo


JindongJindongJindongJindong SamrangjinSamrangjinSamrangjinSamrangjin

GupoGupoGupoGupo


River channel cross sections applied in River channel cross sections applied in simulationsimulation


River channel longitudinal profileRiver channel longitudinal profile

Hwang river

Nakdong river

Hapcheon damAndong dam

Imha dam


Single dam-break simulation

18.987.7533.9845,711Goryenggyo

51.0223.3510.3130,441Estuary barrage

50.6023.2610.4033,324Gupo

42.3022.1512.9435,313Samrangjin

33.2014.3017.6735,590Jindong

28.2712.2324.3436,702Jeokpogyo

13.105.6338.3152,721Waegan

11.825.3240.4559,081Gumi

8.424.3845.0064,890Ilseongyo

5.472.6368.3169,408Sabeol

1.050.25116.19175,584Andong

0.000.00141.16283,917Andong dam

Max. flood W.L.arrival time(hr)

Flood wavearrival time(hr)

Max.flood W.L.(EL.m)

PeakDischarge(m3/sec)

Stations

! Andong dam-break results by extreme flood(PMF)

0

5 0 ,0 0 0

1 0 0 ,0 0 0

1 5 0 ,0 0 0

2 0 0 ,0 0 0

2 5 0 ,0 0 0

3 0 0 ,0 0 0

2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0

S imula tio n Time (hr)

Dis

char

ge

( m

3 /sec

)


Downstream flood hydrographby Andong dam-break




GoryenggyoGoryenggyoGoryenggyoGoryenggyo


JindongJindongJindongJindong

SamrangjinSamrangjinSamrangjinSamrangjin



Downstream longitudinal flood profileby Andong dam-break



GoryenggyoGoryenggyoGoryenggyoGoryenggyoJeokpogyoJeokpogyoJeokpogyoJeokpogyo




by Andong dam-breakDownstream flood inundation map (1/2)


by Andong dam-breakDownstream flood inundation map (2/2)

Hyenpung 1:5,000


Two dam-break(Andong + Imha) simulation

! Andong + Imha dam-break results by extreme flood (PMF)

42.2221.5313.6041,104Samrangjin

51.2224.4810.6738,487Gupo

51.6325.7210.5734,706Estuary barrage

32.3314.3818.8442,605Jindong

27.8012.5825.9943,816Jeokpogyo

18.977.9336.3459,529Goryenggyo

11.856.1740.7869,958Waegan

10.605.0543.0081,029Gumi

7.474.1547.9693,646Ilseongyo

4.752.7571.59105,328Sabeol

1.030.72122.38278,190Andong

0.000.00136.76166,193Imha dam

0.000.00142.59283,917Andong dam

Max. flood W.L.arrival time(hr)



PeakDischarge(m3/sec)

Stations


by Andong + Imha dam-breakDownstream flood hydrograph

0

5 0 , 0 0 0

1 0 0 , 0 0 0

1 5 0 , 0 0 0

2 0 0 , 0 0 0

2 5 0 , 0 0 0

3 0 0 , 0 0 0

3 5 0 , 0 0 0

2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0

S imula tio n Time ( hr)

Dis

cha

rge

(m

3 /sec

)

Andong damAndong damAndong damAndong damAndongAndongAndongAndong

SabeolSabeolSabeolSabeol GoryenggyoGoryenggyoGoryenggyoGoryenggyoJeokpogyoJeokpogyoJeokpogyoJeokpogyo

JindongJindongJindongJindongSamrangjinSamrangjinSamrangjinSamrangjin




by Andong + Imha dam-breakDownstream longitudinal flood profile



GoryenggyoGoryenggyoGoryenggyoGoryenggyoJeokpogyoJeokpogyoJeokpogyoJeokpogyo





by Andong + Imha dam-breakDownstream flood inundation map (1/2)


by Andong + Imha dam-breakDownstream flood inundation map (2/2)

Gumi 1:5,000


Three dam-break(Andong + Imha + Hapcheon) simulation

! Andong + Imha + Hapcheon dam-break results by extreme flood (PMF)Max. flood W.L.arrival time(hr)



PeakDischarge(m3/sec)Stations

31.8320.9015.3266,266Samrangjin

41.4722.4311.6750,692Gupo

41.8523.3311.5249,552Estuary barrage

23.9018.1721.1452,062Jindong

19.1510.5031.1191,259Jeokpogyo

18.977.9335.9359,529Goryenggyo

11.856.1740.7869,958Waegan

10.605.0543.0081,029Gumi

7.474.1547.9693,646Ilseongyo

4.752.7571.59105,328Sabeol

1.030.72122.38278,190Andong

0.000.00124.15148,682Hapcheon dam

0.000.00136.76166,193Imha dam

0.000.00142.59283,917Andong dam


by Andong + Imha + Hapcheon dam-break

Downstream flood hydrograph

0

50, 000

100, 000

150, 000

200, 000

250, 000

300, 000

20 40 60 80 100 120 140S imula tio n Time ( hr)

Dis

char

ge (

m

3 /sec

)

Andong damAndong damAndong damAndong damAndongAndongAndongAndong



JeokpogyoJeokpogyoJeokpogyoJeokpogyoJindongJindongJindongJindong

SamrangjinSamrangjinSamrangjinSamrangjinEstuary barrageEstuary barrageEstuary barrageEstuary barrage


Hapcheon damHapcheon damHapcheon damHapcheon dam


by Andong + Imha + Hapcheon dam-breakDownstream longitudinal flood profile










by Andong + Imha + Hapcheon dam-break (time-1)Downstream longitudinal flood profile










by Andong + Imha + Hapcheon dam-breakConvert HEC-RAS simulation bitmaps to an AVIfile

0

5 0 , 0 0 0

1 0 0 , 0 0 0

1 5 0 , 0 0 0

2 0 0 , 0 0 0

2 5 0 , 0 0 0

3 0 0 , 0 0 0

0 . 0 0 1 . 0 0 2 . 0 0 3 . 0 0 4 . 0 0 5 . 0 0 6 . 0 0 7 . 0 0 8 . 0 0 9 . 0 0 1 0 . 0 0Time (hr)

Dis

ch

arg

e(m

3

/s

ec

)

Andong dam Qp = 283,917cms2010/7/21 23:16

Imha dam Qp = 166,193cms2010/7/21 23:00

Hapcheon dam Qp = 148,682cms2010/7/22 14:20



Downstream flood inundation map (1/2)



Downstream flood inundation map (2/2)

Jindong 1:5,000

EEMERGENCYMERGENCYAACTIONCTIONPPLANSLANS


— For dam-break flood risk management

Internal and External EAPInternal and External EAP


IEAP EEAPDam’s owner Civil Protection

Main action for EAPMain action for EAP


! Detection

! Decision making - - - - - - - - - - IEAP

! Alert

! Warning

! Evacuation } - - - - - - - - - - EEAP

Interaction between IEAP and EEAPInteraction between IEAP and EEAP


! Definition of alert levels

! Alert and warning systems

Alert levels Alert levels (1/4)(1/4)


- Authority(MOCT, KOWACO)

- Dam owner




- Dam owner

- Civil Protection




- Dam owner- Civil Protection

Warning system Warning system (1/2)(1/2)



0. 00

5. 00

10. 00

15. 00

20. 00

25. 00

30. 00

0 50 100 150 200 250 300 350 400

Dis tanc e (km)

Tra

vel

Tim

e(h

r)

Imha Dam

Ando ng Dam

Ando ng + Imha Dam

Ando ng + Imha + Hapc he o n Dam

And

ong

Sabe

ol

Gum

i

Wae

gan

Gor

eung

gyo

Jeok

pogy

o

Jind

ong

Sam

rang

jin Gup

oEs

tuar

y ba

rrag

e

Imha

Flood arrival time to downstream areas of the dam

Warning system Warning system (2/2)(2/2)

Key points for EAPKey points for EAP


! Inundation maps - Dam owners or managers— dam-break flood simulation — flash floods, abrupt waves

!! Risk zoning criteriaRisk zoning criteria—— water levelswater levels—— velocitiesvelocities—— times of flood arrivaltimes of flood arrival

!! Basin vulnerability criteriaBasin vulnerability criteria—— land useland use—— social andsocial and—— economical characterizationseconomical characterizations

Basin vulnerabilityBasin vulnerability


— Downstream zoning criteria

! Vulnerability

— defined as a measure of the level of exposure and of damage

susceptibility toward the dam-break flood

— physical vulnerability and socioeconomic vulnerability

should be included for each sub-zone downstream of the dam


! maximum depth (water levels) (D)

! maximum flow power (V*D)

! maximum depth gradient

Physical vulnerability

— should include a quantification of the dam - break flood

impact as a function of variables like the following :


Socioeconomic vulnerability— be a weighted function of several characteristics factors :

! Social— families (number of members)— individual (age, education)

! Property— buildings— economic activities

! Strategic infrastructures— power and water networks— hospitals

! Warning and emergency system! Civil protection response (including training)! Psycho-social (public perception)

External EAPExternal EAP


! Means and resources allocation— for each vulnerability zone

! Actions of entities involved in crises management— Water organization or authority (Ministries, Institutes)— Civil protection national service— Dam owner or manager

! Action of entities involved in emergency— Civil protection national service

(National disaster prevention organization)— Civil protection agents— Municipalities

! Type of evacuation— by own people means— help of civil protection agents

Information systemInformation system


DAM INFO

EAP

Dam-break flood simulation

Flood wave analysis

Inundation

EAP in Nakdong River BasinEAP in Nakdong River Basin


! EAP for dam-break flood risk management in Nakdong river is being developed

!! All dams will dispose of emergency action plans, with All dams will dispose of emergency action plans, with proper alert and warning systems, in compliance with the proper alert and warning systems, in compliance with the legistrationlegistration

DamDam--Break Flood Risk Management :Break Flood Risk Management :

Some Dam Break AccidentsSome Dam Break Accidents


Teton dam failureTeton dam failure

! Location :— Teton river, Madison county, Southeast Idaho, U.S.A.

! Dam type :— 305-foot high earthfill dam

! Failure time :— 11:57 AM, 5 June , 1976

! Damage :— Loss of 14 lives— Cost estimated to be nearly $1 billion


Teton dam failure Teton dam failure (1)(1)


St. francis dam failureSt. francis dam failure

! Location :— Santa clarita, California, U.S.A.

! Dam type :— 185 feet high curved concrete gravity dam

! Failure time :— 12 March , 1928

! Damage :— Lost 450 people— Destroyed 1,200 homes and 10 bridges


St. francis dam failure St. francis dam failure (1)(1)


St. francis dam failure St. francis dam failure (2)(2)


Sheffield dam failure Sheffield dam failure

! Location :— Base of the Santa ynez mountains,

northern end of Santa barbara, California, U.S.A.

! Dam type :— 720 feet long, 25 feet high concrete gravity dam

! Failure time :— 1925

! Failure cause :— Earthquake


Sheffield dam failureSheffield dam failure


Other damOther dam--break examples break examples (1/2)(1/2)

Other damOther dam--break examples break examples (2/2)(2/2)

WWaterater RResourcesesources RResearch esearch CCenter enter YEUNGNAM Univ., DAEGU, KOREAYEUNGNAM Univ., DAEGU, KOREA

THANK YOUTHANK YOUFORFOR

YOUR ATTENTIONYOUR ATTENTION

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