lecture on flood damage assessment

FLOODRESILIENCE

FLOODRESILIENCEGROUP


FLOOD DAMAGE ANALYSIS

William Veerbeek, Flood Resilience Group, Unesco-IHE, Delft, Netherlands

URBAN FLOOD MANAGEMENT DORDRECHTHSRR02: FLOOD DAMAGE ASSESSMENT ROTTERDAM-RIJNMOND

FLOODRESILIENCE



UFM DORDRECHT: Knowledge development by DESIGN

WORK PACKAGES: -Risk and Vulnerability assessment-Resilient Planning and Building-Urban Design-Communication and Emergency Response-Policy and Governance

STAKEHOLDERS: -Governement (federal, regional, local)-Research Institutes-Water-board-Housing corporation-Developers, Building industry-Insurance Companies-Citizens

Flood modelling,Vulnerability assessment Flood proofi ng technologies

Vulnerability assessmentDamage assessment

GuidelinesCommunicationFLOOD RESILIENT DESIGN

FLOODRESILIENCE



UFM DORDRECHT: LEARNING by DOING, Iterative Process (Slow Prototyping)

Flood modelling,Vulnerability assessment

Flood proofi ng technologies

Vulnerability assessmentDamage assessment

GuidelinesCommunicationDESIGN PROTOTYPES

PRACTISE: TREMENDOUS AMOUNT OF INFORMATION EXCHANGE

FLOODRESILIENCE



INTERGRATED UFM: Incorporate fl ood impact reduction into the city

YET: CITIES ARE COMPLEX AND HIGHLY DIFFERENTIATEDNEED FOR A HIGHLY EXPRESSIVE VULNERABILITY/IMPACT MODEL

1. WHAT? Need for broad set of impact evaluation tools, climate scenarios2. WHERE? Need for detailled impact assessment3. WHEN? Need for incorporation of renewal strategies

FLOODRESILIENCE



FLOOD DAMAGE ASSESSMENT

TERMINOLOGY

Tangible damages• : expressed in money (direct, indirect)Intangible damages• : Cannot be expressed in money (culture, health, etc.)

Direct damages: • cleaning, repair, replacement, etc.Indirect damages: • business interruption, ‘ripple eff ects’, etc.

FLOODRESILIENCE



FLOOD DAMAGE ASSESSMENT

TERMINOLOGY

Cummulative frequency• : fi nd frequency of occurence of some value (e.g. dis-charge, water stage)-> from historical recordsReturn period• : period in which the event occursExceedance probability• = return period-1 -> Probability that a given value (e.g. discharge, water stage) is exceeded

COMMON MISCONCEPTIONS:

A 100 year fl ood doesn’t happen every 100 years• A 10000 year fl ood is based on fl ood records•

FLOODRESILIENCE



FLOOD RISK ASSESSMENT: Only from the ‘driver’ perspective

2D FLOOD SIMULATIONS: 4000-1 EPHigh resolution (max 10x10m grid), including sewerInundation, Velocity for a multitude of design fl oods events

limited inundation depth (<1m) limited fl ow velocities (<0.75m3/s)

FLOOD RISK FOCUSSED ON FLOOD EXTENT AND INUNDATION DEPTH-Little knowledge about impact assessment

FLOODRESILIENCE



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dam

ag

e [

€]

Cleaning Floors & Walls Doors Kitchen Installation

CALCULATING DAMAGE FOR INDIVIDUAL FEATURES

1. STAGE-DAMAGE FUNCTIONRelates inundation depth to damage level• Diff ers per feature type, region• Can be composed of diff erent damage contributors• Can be multi-modal (inundation depth, velocity, duration)•

Stage damage curve for detached housing

FLOODRESILIENCE




2. 2D OR 1D-2D FLOOD SIMULATIONGenerates maximum inundation depth per grid-cell• Apply diff erent fl ood scenarios (i.e. EPs associated to a water stage)•

Flood extent for diff erent EPs

FLOODRESILIENCE



0,3 0,6 0,9 1,2 1,5 1,8 2,1

water stage [m]

0,3 0,6 0,9 1,2 1,5 1,8 2,1

water stage [m]

0,3 0,6 0,9 1,2 1,5 1,8 2,1

water stage [m]

H1 H2 Hn

.... Classify feature

Attributes feature Fi (e.g. house)type• area• location• etc.•

Flood characteristics at location (Xi, Yi)depth• velocity• duration• etc.•


3. APPLICATION OF STAGE-DAMAGE FUNCTION AND 2D INUNDATION MAPClassifi cation of individual features•

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y = 4E-08x5.8845

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ect

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ag

e [

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]


4. RESULTING AGGREGATE DAMAGE LEVELSWater stage - Expected damage•

Return periods - Expected damage•

Current

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Current

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STAGE-DAMAGE CURVES: ATTRIBUTES

MEAN ANNUAL DAMAGE (MAD)Average contribution of each damage level per year•

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Exceedance probability-1 [-](Water stage [m +NAP])

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ag

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x m

ln €

]

2100 Total

MAD

i

I

i

iiP

P

pddpdpDMAD

1

1

2 )(

max

0

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SENSITIVITYMaximum value for the derative of the stage-damage curve.•

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ag

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SENSITIVITY

max11

11maxYSENSITIVIT dPPdd

ii

ii

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GRADUALITYIdentify discontinuities in the derivates of the stage-damage curve•

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ag

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ln €

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2100 Total

Strong infl ection point

N

p

ii DPGRADUALITY

1 21

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RESILIENT PLANNING AND BUILDING: Damage model (where?)

HIGH LEVEL OF DETAIL: High precision but low usability

Dordrecht outer marches: Damage Distribution

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WP3 RESILIENT PLANNING AND BUILDING: Damage model (where?)

Dordrecht outer marches: Damage Clustering

GEOGRAPHICAL DISTRIBUTION(CLUSTERING): High usability(where)

€17.545.537 (71%)

€147.886 (1%)

FLOODRESILIENCE




Example from Rotterdam-Rijnmond(where)

Rotterdm-Rijnmond: Damage Clustering EP = 10000-1

FLOODRESILIENCE



Roze

nbur

g

Maa

sslu

is

Vlaa

rdin

gen

Schi

edam

Spijk

enis

se

Kore

ndijk

Oud

-Bei

jerla

nd

Bare

ndre

cht

Cape

lle a

an d

en IJ

ssel

Krim

pen

aan

den

IJss

el

Ned

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k

Nie

uw-L

ekke

rland

Hen

drik

-Ido-

Am

bach

tA

lbla

sser

dam

Pape

ndre

cht

Berg

amba

cht

Lies

veld

Scho

onho

ven

Lopi

k

Slie

drec

ht

Har

dinx

veld

-Gie

ssen

dam

Gor

inch

em

Wou

dric

hem

Zaltb

omm

el

Dor

drec

ht

Wer

kend

am

Drim

mel

en

Moe

rdijk

Zwijn

drec

ht

Strij

en

Moe

rdijk

Goe

dere

ede

Hel

levo

etsl

uis

Bern

isse

Mid

delh

arni

s

Dirk

slan

d

Brie

lle

Cro

mst

rijen

Oos

tflak

kee

Gee

rtru

iden

berg

Ling

ewaa

l

Rott

erda

m


ADMINISTRATIVE DISTRIBUTION: Damage per Municipality

FLOODRESILIENCE



€ 0.0

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Exceedance probability-1 [-]

Dam

ag

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x m

ln €

]

1e Merwedehaven en omgeving

2e Merwedehaven en omgeving

3e Merwedehaven

Achterhakkers en omgeving

Beekmanstraat en omgeving

Bleijenhoek

Boogjes en omgeving

Groenmarkt en omgeving

Grote Markt en omgeving

Handelskade en 's-Gravendeelsedijk

Julianahaven

Kalkhaven

Krabbegors

Lijnbaan

Maasstraat en omgeving

Merwelanden

Krabbepolder

Nieuwe Haven en omgeving

Noorderkwartier

Plein 1940-1945 en omgeving

Wantijpark en omgeving

Weeskinderendijk en Dokweg

Wijnstraat en omgeving

Wilhelminahaven

Dordrecht outer marches: Damage distribution per neighborhood


ADMINISTRATIVE DISTRIBUTION: Damage per Neighborhood1. DIFFERENTIATED2. ‘CEILINGS’3. HIERARCHY (4 Nhoods account for about 40% total expected damage)

FLOODRESILIENCE



WP3 RESILIENT PLANNING AND BUILDING: Damage model (when?)

TEMPORAL DISTRIBUTION: Lifecycle management1. PROACTIVE RETROFITTING (up to 32.3% damages to historical buildings)2. REACTIVE RETROFITTING (end of lifecycle)3. RENEWAL SCHEMES (up to 67.8% damages on post-war buildings)

CHANCES FOR INTEGRATED UFM

0

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till 1904

1905-1

909

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1915-1

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1920-1

924

1925-1

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1930-1

934

1935-1

939

1940-1

944

1945-1

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1950-1

954

1955-1

959

1960-1

964

1965-1

969

1970-1

974

1975-1

979

1980-1

984

1985-1

989

1990-1

994

1995-1

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2000-2

004

Year of construction[y]

Dam

ag

e [

x m

illi

on

€]

1/4000 1/2000 1/1000 1/500 1/250 1/100 1/50 1/25 1/10Dordrecht outer marches: Damage distribution age housing stock

FLOODRESILIENCE



WP3 RESILIENT PLANNING AND BUILDING: Damage model (what?)

FUNCTIONAL DISTRIBUTION:-Features (e.g. businesses, housing, infrastructure, public space)-Typologies (e.g. row houses, appartments, detached houses)-Components (e.g. cleaning costs, structural damage, interior damage)

DAMAGE TO INFRASTRUCTUREDamage over Typology

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Row House

Semi-Detached

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DAMAGE OVER BUILDING TYPOLOGY0.053 0.039

0.023

0.049

0.087

0.750

Cleaning Floors & Walls Doors Kitchen Installations interior

DAMAGE COMPONENTS

-Especially for higher EPs, damage to infrastructure is major damage component-Interior damage contributes 75% to total damages to housing-Majority of inundated houses are row houses

FLOODRESILIENCE



Aggregate Flood Damage for scenarios

RESILIENT PLANNING AND BUILDING: Damage model

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Current 2050 G+ 2100 Veerman 2050 Lockable/Open 2100 Lockable/Open

INFLUENCE OF CLIMATE CHANGE (what?)-Impacts of climate change are substatial, yet relatively gradual in progression-Levels?-Trend shift?

FLOODRESILIENCE



WP3: From Damage model to Decision Support

REDUCING FLOOD IMPACTS ACROSS SCALES:-Assessment of damage diff erentiation provides foundation for mixed-strategy-Bottom-up: Implementation of various dry-proof, wet-proof solutions-Top-down: Implementation of levee systems, combined with elevated infrastructure

Hamburg, Germany Dura Vermeer, (2004), Gouden Kust, Maasbommel, Netherlands. DuraVermeer, (2005), Drijvende Kas, Naaldwijk, Netherlands

Dura Vermeer, (2004), Impression Flood Resilient Neighborhood

spill-over eff ects

spill-over eff ects

Housing-level

Urban-level

Catchment-level

FLOODRESILIENCE



WP3: From Damage model to Decision Support

WHAT ABOUT THE IMPACT OF NON-STRUCTURAL MEASURES:-Compensation measures-Flood insurance

MOTIVATION:-Diff erentiated ‘Risk Landscape’ (spatial, temporal, functional)-Overall impact relatively low-Yet, higher impact levels excpected in future-Stadwerven pilot

Artist Impression Pilot Flood Proof Building

lecture on flood damage assessment

Education

flood impact reduction

year flood doesnt

flood resilience group

d flood simulations

detailled impact assessment

floodresilience ufm

indirect damages

water stage