1. FLOODRESILIENCE
FLOOD DAMAGE ANALYSIS
William Veerbeek, Flood Resilience Group, Unesco-IHE, Delft, Netherlands
URBAN FLOOD MANAGEMENT DORDRECHT
HSRR02: FLOOD DAMAGE ASSESSMENT ROTTERDAM-RIJNMOND
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 1

2. FLOODRESILIENCE
UFM DORDRECHT: Knowledge development by DESIGN
WORK PACKAGES: STAKEHOLDERS:
-Risk and Vulnerability assessment -Governement (federal, regional, local)
-Resilient Planning and Building -Research Institutes
-Urban Design -Water-board
-Communication and Emergency Response -Housing corporation
-Policy and Governance -Developers, Building industry
-Insurance Companies
-Citizens
Vulnerability assessment
Damage assessment
Flood modelling,
Vulnerability assessment Flood proofing technologies
FLOODRESILIENCEGROUP
Guidelines
FLOOD RESILIENT DESIGN Communication FLOODRESILIENCEGROUP
Page 2

3. FLOODRESILIENCE
UFM DORDRECHT: LEARNING by DOING, Iterative Process (Slow Prototyping)
PRACTISE: TREMENDOUS AMOUNT OF INFORMATION EXCHANGE
Vulnerability assessment
Damage assessment
Flood modelling,
Vulnerability assessment
Flood proofing technologies
DESIGN PROTOTYPES Communication
Guidelines
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 3

4. FLOODRESILIENCE
INTERGRATED UFM: Incorporate flood impact reduction into the city
YET: CITIES ARE COMPLEX AND HIGHLY DIFFERENTIATED
NEED FOR A HIGHLY EXPRESSIVE VULNERABILITY/IMPACT MODEL
1. WHAT? Need for broad set of impact evaluation tools, climate scenarios
2. WHERE? Need for detailled impact assessment
3. WHEN? Need for incorporation of renewal strategies
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 4

5. 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 effects’, etc.
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 5

6. FLOODRESILIENCE
FLOOD DAMAGE ASSESSMENT
TERMINOLOGY
• Cummulative frequency: find frequency of occurence of some value (e.g. dis-
charge, water stage)-> from historical records
• Return period: period in which the event occurs
• Exceedance probability = return period-1 -> Probability that a given value
(e.g. discharge, water stage) is exceeded
COMMON MISCONCEPTIONS:
• A 100 year flood doesn’t happen every 100 years
• A 10000 year flood is based on flood records
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 6

7. FLOODRESILIENCE
FLOOD RISK ASSESSMENT: Only from the ‘driver’ perspective
2D FLOOD SIMULATIONS: 4000-1 EP
High resolution (max 10x10m grid), including sewer
Inundation, Velocity for a multitude of design floods events
limited inundation depth (<1m) limited flow velocities (<0.75m3/s)
FLOOD RISK FOCUSSED ON FLOOD EXTENT AND INUNDATION DEPTH
-Little knowledge about impact assessment FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 7

8. FLOODRESILIENCE
CALCULATING DAMAGE FOR INDIVIDUAL FEATURES
1. STAGE-DAMAGE FUNCTION
• Relates inundation depth to damage level
• Differs per feature type, region
• Can be composed of different damage contributors
• Can be multi-modal (inundation depth, velocity, duration)
40000
35000
30000
25000
damage [€]
20000
15000
10000
5000
0
0 0,3 0,6 0,9 1,2 1,5 1,8 2,1 2,4 2,9
water stage [m]
Cleaning Floors & Walls Doors Kitchen Installation
FLOODRESILIENCEGROUP
Stage damage curve for detached housing
FLOODRESILIENCEGROUP
Page 8

9. FLOODRESILIENCE
CALCULATING DAMAGE FOR INDIVIDUAL FEATURES
2. 2D OR 1D-2D FLOOD SIMULATION
• Generates maximum inundation depth per grid-cell
• Apply different flood scenarios (i.e. EPs associated to a water stage)
FLOODRESILIENCEGROUP
Flood extent for different EPs
FLOODRESILIENCEGROUP
Page 9

10. FLOODRESILIENCE
CALCULATING DAMAGE FOR INDIVIDUAL FEATURES
3. APPLICATION OF STAGE-DAMAGE FUNCTION AND 2D INUNDATION MAP
• Classification of individual features
.... Classify feature
0,3 0,6 0,9 1,2 1,5 1,8 2,1 0,3 0,6 0,9 1,2 1,5 1,8 2,1 0,3 0,6 0,9 1,2 1,5 1,8 2,1
water stage [m] water stage [m] water stage [m]
H1 H2 Hn
Attributes feature Fi (e.g. house)
• type
• area
• location
• etc.
Flood characteristics at location (Xi, Yi)
• depth
• velocity
• duration
• etc.
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 10

11. FLOODRESILIENCE
CALCULATING DAMAGE FOR INDIVIDUAL FEATURES
4. RESULTING AGGREGATE DAMAGE LEVELS
• Water stage - Expected damage
180
160
5.8845
y = 4E-08x
140
expected Damage [m€]
120
100
80
60
40
20
0
225 250 275 300 325 350 375 400 425 450
water stage [cm +NAP]
• Return periods - Expected damage
Current
40
35
30
expected Damage [m€]
25
20
15
10
5
0
10 100 1000 10000
FLOODRESILIENCEGROUP
return period [Y]
Current
FLOODRESILIENCEGROUP
Page 11

12. FLOODRESILIENCE
STAGE-DAMAGE CURVES: ATTRIBUTES
MEAN ANNUAL DAMAGE (MAD)
• Average contribution of each damage level per year
d i 1  d i
Pmax I
MAD   D( p)d p  
P0 i 1 2
 pi
160
150
140
130
120
110
100
Damage [x mln € ]
90
80
70
MAD
60
50
40
30
20
10
0
20000
10000
4000
2000
1000
500
250
100
50
25
10
Exceedance probability -1 [-](Water stage [m +NAP])
2100 Total
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 12

13. FLOODRESILIENCE
STAGE-DAMAGE CURVES: ATTRIBUTES
SENSITIVITY
• Maximum value for the derative of the stage-damage curve.
d d 
SENSITIVITY  max i 1 i 1   d max
 P P 
 i 1 i 1 
160
150 SENSITIVITY
140
130
120
110
100
Damage [x mln € ]
90
80
70
60
50
40
30
20
10
0
20000
10000
4000
2000
1000
500
250
100
50
25
10
Exceedance probability -1 [-](Water stage [m +NAP])
2100 Total
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 13

14. FLOODRESILIENCE
STAGE-DAMAGE CURVES: ATTRIBUTES
GRADUALITY
• Identify discontinuities in the derivates of the stage-damage curve
 
N Pi  Di
GRADUALITY  1  
p 1 2
160
150
140
130
120
110
100
Damage [x mln € ]
90
80
70 Strong inflection point
60
50
40
30
20
10
0
20000
10000
4000
2000
1000
500
250
100
50
25
10
Exceedance probability -1 [-](Water stage [m +NAP])
2100 Total
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 14

15. FLOODRESILIENCE
RESILIENT PLANNING AND BUILDING: Damage model (where?)
HIGH LEVEL OF DETAIL: High precision but low usability
FLOODRESILIENCEGROUP
Dordrecht outer marches: Damage Distribution
FLOODRESILIENCEGROUP
Page 15

16. FLOODRESILIENCE
WP3 RESILIENT PLANNING AND BUILDING: Damage model (where?)
GEOGRAPHICAL DISTRIBUTION(CLUSTERING): High usability
(where)
€17.545.537 (71%)
€147.886 (1%)
FLOODRESILIENCEGROUP
Dordrecht outer marches: Damage Clustering
FLOODRESILIENCEGROUP
Page 16

17. FLOODRESILIENCE
WP3 RESILIENT PLANNING AND BUILDING: Damage model (where?)
Example from Rotterdam-Rijnmond(where)
FLOODRESILIENCEGROUP
Rotterdm-Rijnmond: Damage Clustering EP = 10000-1
FLOODRESILIENCEGROUP
Page 17

18. Goedereede
Hellevoetsluis
Dirksland
Brielle
Middelharnis
Rozenburg
Maassluis
Bernisse
Korendijk
Vlaardingen
Rotterdam
Oostflakkee
Schiedam
Spijkenisse
Oud-Beijerland
Cromstrijen
Moerdijk
Barendrecht
Strijen
Capelle aan den IJssel
Krimpen aan den IJssel
Moerdijk
Nederlek
Zwijndrecht
Nieuw-Lekkerland
Hendrik-Ido-Ambacht
Alblasserdam
Dordrecht
Papendrecht
Werkendam
Bergambacht
Sliedrecht
Liesveld
Drimmelen
Geertruidenberg
Schoonhoven
Hardinxveld-Giessendam
ADMINISTRATIVE DISTRIBUTION: Damage per Municipality
Lopik
Gorinchem
Woudrichem
WP3 RESILIENT PLANNING AND BUILDING: Damage model (where?)
Zaltbommel
Lingewaal
Page 18
FLOODRESILIENCE
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP

19. FLOODRESILIENCE
WP3 RESILIENT PLANNING AND BUILDING: Damage model (where?)
ADMINISTRATIVE DISTRIBUTION: Damage per Neighborhood
1. DIFFERENTIATED
2. ‘CEILINGS’
3. HIERARCHY (4 Nhoods account for about 40% total expected damage)
€ 8.0
€ 7.5
1e Merwedehaven en omgeving
€ 7.0 2e Merwedehaven en omgeving
3e Merwedehaven
€ 6.5 Achterhakkers en omgeving
Beekmanstraat en omgeving
€ 6.0
Bleijenhoek
€ 5.5 Boogjes en omgeving
Groenmarkt en omgeving
€ 5.0 Grote Markt en omgeving
Damage [x mln € ]
Handelskade en 's-Gravendeelsedijk
€ 4.5
Julianahaven
€ 4.0 Kalkhaven
Krabbegors
€ 3.5
Lijnbaan
€ 3.0 Maasstraat en omgeving
Merwelanden
€ 2.5 Krabbepolder
Nieuwe Haven en omgeving
€ 2.0
Noorderkwartier
€ 1.5 Plein 1940-1945 en omgeving
Wantijpark en omgeving
€ 1.0 Weeskinderendijk en Dokweg
Wijnstraat en omgeving
€ 0.5
Wilhelminahaven
€ 0.0
20000
10000
4000
2000
1000
500
250
100
50
25
10
Exceedance probability-1 [-] FLOODRESILIENCEGROUP
Dordrecht outer marches: Damage distribution per neighborhood
FLOODRESILIENCEGROUP
Page 19

20. FLOODRESILIENCE
WP3 RESILIENT PLANNING AND BUILDING: Damage model (when?)
TEMPORAL DISTRIBUTION: Lifecycle management
1. 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
8
7
Damage [x million €]
6
5
4
3
2
1
0
till 1904
1905-1909
1910-1914
1915-1919
1920-1924
1925-1929
1930-1934
1935-1939
1940-1944
1945-1949
1950-1954
1955-1959
1960-1964
1965-1969
1970-1974
1975-1979
1980-1984
1985-1989
1990-1994
1995-1999
2000-2004
Year of construction[y]
1/4000 1/2000 1/1000 1/500 1/250 1/100 1/50 1/25 1/10 FLOODRESILIENCEGROUP
Dordrecht outer marches: Damage distribution age housing stock
FLOODRESILIENCEGROUP
Page 20

21. 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 INFRASTRUCTURE DAMAGE OVER BUILDING TYPOLOGY DAMAGE COMPONENTS
Damage over Typology
0.053
0.039
300 0.023
0.049
250
0.087
200
Duplex
# Damaged
Appartment
150 Row House
Semi-Detached
Detached
100
0.750
50
0
4000
2000
1250
500
250
100
50
25
10
1
0.1
Frequency Cleaning Floors & Walls Doors Kitchen Installations interior
-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
FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 21

22. FLOODRESILIENCE
RESILIENT PLANNING AND BUILDING: Damage model
INFLUENCE OF CLIMATE CHANGE (what?)
-Impacts of climate change are substatial, yet relatively gradual in progression
-Levels?
-Trend shift?
175
150
125
expected Damage [m€]
100
75
50
25
0
10 100 1000 10000
return period [Y]
Current 2050 G+ 2100 Veerman 2050 Lockable/Open 2100 Lockable/Open
Aggregate Flood Damage for scenarios FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 22

23. FLOODRESILIENCE
WP3: From Damage model to Decision Support
REDUCING FLOOD IMPACTS ACROSS SCALES:
-Assessment of damage differentiation 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
Housing-level
Hamburg, Germany Dura Vermeer, (2004), Gouden Kust, Maasbommel, Netherlands. DuraVermeer, (2005), Drijvende Kas, Naaldwijk, Netherlands
spill-over effects
Urban-level
Dura Vermeer, (2004), Impression Flood Resilient Neighborhood
spill-over effects
Catchment-level FLOODRESILIENCEGROUP
FLOODRESILIENCEGROUP
Page 23

24. FLOODRESILIENCE
WP3: From Damage model to Decision Support
WHAT ABOUT THE IMPACT OF NON-STRUCTURAL MEASURES:
-Compensation measures
-Flood insurance
MOTIVATION:
-Differentiated ‘Risk Landscape’ (spatial, temporal, functional)
-Overall impact relatively low
-Yet, higher impact levels excpected in future
-Stadwerven pilot
FLOODRESILIENCEGROUP
Artist Impression Pilot Flood Proof Building
FLOODRESILIENCEGROUP
Page 24