Ejemplos de evaluación de riesgo RISK ASSESSMENT

Ejemplos de evaluación de riesgo
UNESCO RAPCA
RISK ASSESSMENT
RISK = HAZARD * VULNERABILITY * AMOUNT
Hazard= PROBABILITY of event with a
Vulnerability
certain magnitude
= Degree of damage. Function of:
• magnitude of event, and
• type of elements at risk
Amount = Quantification of the elements at risk e.g.
• Replacement costs of buildings, infrastructure etc.
• Loss of function or economic activities
• Number of people
UNESCO RAPCA
1
Firework explosion
Enschede
• 13 May 2000
• 177 tons
• Explosive
Size of the disaster area
Number of inhabitants in most affected zone
Number of completely destroyed houses
Number of completely damaged business and industrial buildings
Number of houses declared “inhabitable”
Number of damaged houses outside mostly affected zone
Number of persons killed
Number of persons injure d
Number of homeless persons
Number of persons that had to be evacuated
Total mate rial damage
40 ha
4163
205
± 50
293
ca. 1500
22
947
1250
± 10.000
1 billion guilders
Pre-disaster airphoto 1998
UNESCO RAPCA
Outer-ring
Inner-ring
Firework storage
UNESCO RAPCA
2
Grolsch brewery
S.E.F.
UNESCO RAPCA
RISK ASSESSMENT
RISK = HAZARD * VULNERABILITY * AMOUNT
Hazard= PROBABILITY of event with a
Vulnerability
certain magnitude
= Degree of damage. Function of:
• magnitude of event, and
• type of elements at risk
Amount = Quantification of the elements at risk e.g.
• Replacement costs of buildings, infrastructure etc.
• Loss of function or economic activities
• Number of people
UNESCO RAPCA
3
Vulnerability
• Degree of loss to a given type of elements
at risk resulting from the occurrence of a
damaging phenomena. Normally
expressed on a scale between 0 (no
damage) and 1 (complete damage)
• Determined:
– Using existing damage reports
– Using analytical methods
• What do we normally use:
– Data from literature
– Educated guesses
UNESCO RAPCA
Foreign damage
datasets: handle with
care!
UNESCO RAPCA
4
UNESCO RAPCA
UNESCO RAPCA
5
UNESCO RAPCA
UNESCO RAPCA
6
POPULATION VULNERABILITY
DENSITY CHANGES
•
•
•
At home
– 20:30 – 08:30
– 14:30 - 17:30
At work
– 9:00 – 14:00
– 17:00 – 20:00
Commuting
– 8:30 – 9:00
– 14:00 – 14:30
– 16:30 – 17:00
– 20:00 – 20:30
(average ITC staff)
• At home
– 18:00 - 8:30 am
• At work
– 9:00 - 17:30
• Commuting
– 8:30 - 9:00
– 17:30 - 18:00
UNESCO RAPCA
Distribution of People in Census Tract
Basic Group
2:00 a.m.
2:00 p.m.
5:00 p.m.
Residential
0.99(NRES)
0.80(DRES)
0.95(DRES)
Commercial
0.02(COMW)
0.50(COMW)
Industrial
0.10(INDW)
0.98(COMW) +
0.15(DRES) +
0.80(AGE_16)
0.80(INDW)
Commuting
0.01(POP)
0.05(POP)
0.05(DRES) +
1.0(COMM)
0.50(INDW)
•
•
•
•
where:
POP is the census tract population taken from census data
DRES is the daytime residential population inferred from census data
NRES
is the nighttime residential population inferred from census
data
• COMM is the number of people commuting inferred from census data
• COMW is the number of people employed in the commercial sector
• INDW
is the number of people employed in the industrial sector.
UNESCO
RAPCA is the number of people 16 years of age and under inferred from
• AGE_16
7
POPULATION VULNERABILITY
POPULATION DISTRIBUTION
INVENTORY
VULNERABILITY
Table 13.2
CASUALTY
CASUALTY
Table 13.4
Table 13.6
Table 13.7
Table 13.3
Table 13.5
Damage State 1
B ldg. Type 1
Residential Population
z
Commuting Population
Level 1
Level 2
Level 2
Level 3
Level 3
Level 4
Damage State 3
Damage State 4
Commercial Popula tion
Industrial Population
Damage State 2
Level 1
No Collapse
With Collapse
z
Bldg. Type 36
Level 4
CASUALTY
Level 1
Level 2
Level 3
Bridge 1
Damage State 4
CASUALTY
Level 4
z
Level 1
z
Level 2
Bridge 4
Damage State 4
Level 3
Level 4
UNESCO RAPCA
Cost estimation
UNESCO RAPCA
8
Which costs?
• Real-estate agencies
– Market price – “real”
• Cadastres in most developing countries
– Ratable price – “fictitious”
• Engineering societies
– Construction price – “replacement”
Price m2
• Depreciation factor
• Inflation
With renovation/good maintenance
w ithout renovation/good maintenance
Age
UNESCO RAPCA
Source: NYCEM
UNESCO RAPCA
9
Source: NYCEM
UNESCO RAPCA
Deterministic (Fixed Location)
5.0M
6.0M
7.0M
Casualties – 2pm earthquake
Casualties 4 (Instant Death)
# of People
CAS 4 or CAS 3
2
8
16
At least
24
District Key
1
2
3
4
5
6
7
8
9
10
11
12
CAS 4
Instant
Death
2pm
-
All
-
District
#
District
#
CAS 4
Instant Death
1
2
3
4
5
6
7
8
9
10
11
12
2pm
9.265
1.981
2.019
0.986
3.252
1.598
0.237
0.150
0.047
0.131
0.467
0.147
%
46%
10%
10%
5%
16%
8%
1%
1%
< 1%
1%
2%
1%
All
21
100%
District
#
CAS 4
Instant Death
1
2
3
4
5
6
7
8
9
10
11
12
2pm
89.322
14.285
17.551
10.397
70.507
32.512
5.838
5.752
3.219
6.121
9.610
5.589
%
33%
5%
6%
4%
26%
12%
2%
2%
1%
2%
4%
2%
All
271
100%
UNESCO RAPCA
10
Deterministic (Fixed Location)
5.0M
6.0M
7.0M
Essential Facilities – Medical
Casualties 2 (Hospitalization Required) + Casualties 3 (Immediate Medical Attention)
distance to nearest maj or
medical facility (meters)
300
medical facility
functionality people in need of
hospitalization
at day 0 (%)
1,200
0-10
10-20
20- 30
30-40
each dot is
5 five
people
40-50
2,400
50-60
60-70
70-100
Average
Functionality
Average
Functionality
63%
96%
Above
4,000
Need
Hospital
District
#
1
2
3
4
5
6
7
8
9
10
11
12
2pm
-
beds
av ailable
2pm
101.915
21.791
22.209
10.846
35.772
17.578
2.607
1.650
0.517
1.441
5.137
1.617
%
46%
10%
10%
5%
16%
8%
1%
1%
< 1%
1%
2%
1%
All
-
6,130
1
2
3
4
5
6
7
8
9
10
11
12
All
223. 08
100%
District
#
District Key
beds
av ailable
9,387
Average
Functionality
26%
Need Hospital
District
#
Need Hospital
beds
av ailable
1
2
3
4
5
6
7
8
9
10
11
12
2pm
982.542
157.135
193.061
114.367
775.577
357.632
64.218
63.272
35.409
67.331
105.710
61.479
%
33%
5%
6%
4%
26%
12%
2%
2%
1%
2%
4%
2%
2,627
All
2977.73
100%
UNESCO RAPCA
Source: NYCEM
UNESCO RAPCA
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Source: NYCEM
UNESCO RAPCA
Source: NYCEM
UNESCO RAPCA
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UNESCO RAPCA
UNESCO RAPCA
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UNESCO RAPCA
UNESCO RAPCA
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Case study Kathmandu
UNESCO RAPCA
Building Damage Ratio in 1934
UNESCO RAPCA
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Actual Damage in 1934
From ‘Images of Century’
UNESCO RAPCA
Building Damage in 1934
UNESCO RAPCA
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Death Toll in 1934
UNESCO RAPCA
Comparison of Results
Damaged Houses
Casualties
(Death)
Actual
Calculated
Actual
Calculated
38,055
35,592
4,296
3,814
UNESCO RAPCA
17
Building Damage (Number)
1934 EQ (in present)
1934 EQ (actual)
UNESCO RAPCA
Death Toll
1934 EQ (in present)
1934 EQ (actual)
UNESCO RAPCA
18
Comparison of Results
Damaged Houses
Casualties
(Death)
Actual in
1934
Calculated in
present
Actual in
1934
Calculated in
present
38,055
136,474
4,296
19,523
Vulnerability increased !
UNESCO RAPCA
Basic Unit for Analysis
UNESCO RAPCA
19
Seismic Intensity Map
I. Mid Nepal Earthquake
UNESCO RAPCA
Seismic Intensity Map
II.North Bagmati Earthquake
UNESCO RAPCA
20
Seismic Intensity Map
III. KV Local Earthquake
UNESCO RAPCA
Liquefaction Potential
I. Mid Nepal Earthquake
UNESCO RAPCA
21
Fragility Curve for this Study
100
D am age(%)
90
80
70
60
A ++
B
B ++
K5
K3
50
40
30
20
A++: ST, AD
10
0
B++: BMW, BC
B: BM
0
100
200
300
PG A
400
500
600
～Intensity
K5: (RC5)
K3: (RC3)
Damage is different at each building type!!
UNESCO RAPCA
Building Damage Ratio
I. Mid Nepal Earthquake
UNESCO RAPCA
22
Case study Tegucigalpa
UNESCO RAPCA
Digital Elevation Models
UNESCO RAPCA
23
Digital Elevation Models
LIght Detection And Ranging
Position of the aircraft
+
Attitude of the aircraft
+
Distance between the
aircraft and the
‘ground’
+
Angle under which
the distance has been
measured
UNESCO RAPCA
Digital Elevation Models
UNESCO RAPCA
24
Lidar can be used to measure
building height
UNESCO RAPCA
Lidar and Geometric corrections
UNESCO RAPCA
25
UNESCO RAPCA
UNESCO RAPCA
View 3-D using analgyph image
Mapping buildings
26
UNESCO RAPCA
Mapping damage
UNESCO RAPCA
27
Case study Turrialba
• Within: UNESCO programme on Capacity Building for Natural
Disaster Reduction , regional action programme Central
America.
• Test site in Turrialba, Costa Rica
• Objective: provide municipality information on expected losses
due to natural disaster, as a basis for risk mitigation
• Relatively small municipality with limited resources
– Solution: use of low cost, easy to use system
• No digital urban data available
– Solution: use of orthophoto and extensive field campaign using
graduate students
• No detailed hazard information available
– Solution: use of historical information on events and intensities,
through questionnaires
UNESCO RAPCA
Data Input
Point map
Seismic
events
Orthophoto
with segments
of parcels
Field Survey
and polygon
conversion
create table with vulnerability
data per building type"
Attenuation relation
relation between
distance from
epicentrum,magnitude
and PGA value
soil map
scarps
map
Soil
amplification
factors
Topographic
amplification factors
Flowchart
Seismic risk
Assessment
PGA values for return period
25,50,100 and 200 years
Cadastral
data
join table
Link to table with
information on
each parcel using
field observations
PGA map with soil and
topographic
amplification
Cadastral map
Convert to mmi raster maps
Add information on
construction cost
for different
building types
Calculate population
densityboth during
daytime and nighttime
Add information
on: minor injuries
majo rinjuriesand
casualties
join table
estimation of
market price
Apply age
depretion
factor
calculate replacement cost by
multipliying building area *
constructuion cost * damage ratel
cross map, produce
table: mmicomplete
(every return period)
Esitmation off:
* Damage rate
* Minor injuriesl
* Major injuries
* Casualtiesl
Specific risk
UNESCO RAPCA
Legend
28
Stored data
Field
questionnaires
on flood depth
Cadastral
map
Geomorphological map
table with
building cost
informationt
interpolate
Link with
vulnerability
table
Flood depth maps
for 25, 50 and 75
years return period
Vulnerability map
for each return
period
Survey on
contents costs
for buildings
recognize
residential
content value
maximum
flood map
Segment
map of main
river
rasterize
distance
map
content
cost map
Building
cost
maximum
flood damage
map
Assign classes
with probability
Flowchart
Flood risk
Assessment
Lateral
damage
map
damage maps
25,50,75
return period
annual
exceedance
probability
legend
Risk analysis
* 25,50,75 return period
* lateral erosion
* maximum flood
input data
UNESCO
RAPCA
Process
Elements at risk database
UNESCO RAPCA
29
Flood vulnerability assessment
Flood vulnerability maps
for different return periods
Map of elements at risk:
attribute landuse
Degree of loss
Flood depth map = flood scenarios
of different return periods
Vulnerability
functions
for each
landuse
Floodwater depths
(m)
UNESCO RAPCA
Cost calculation
• Cost for contents
of buildings
–
–
–
–
Size of building
Landuse class
Social class
Number of floors
• Cost for structure
of buildings
– material type
– Size
– Percentage built-up area
per plot
UNESCO RAPCA
30
Cost maps
UNESCO RAPCA
Risk assessment:
Probability*vulnerability*cost
•
•
•
•
Risk = probability * vulnerability * cost
Generation of risk curves for each hazard type
Combine risk curves
Information can be derived for:
–
–
–
–
entire city
Building block
landuse types
Public or private losses
UNESCO RAPCA
31
Case study: San Sebastian,
Retalhuleu, Guatemala
UNESCO RAPCA
UNESCO RAPCA
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Growth of San Sebastian
UNESCO RAPCA
City block mapping
UNESCO RAPCA
33
Data collection
UNESCO RAPCA
Damage assessment
UNESCO RAPCA
34
Stage damage curves
UNESCO RAPCA
Vulnerability map
UNESCO RAPCA
35
Risk map
UNESCO RAPCA
Vulnerability assessment
Event
damages(
million
Ris
k (Annual
loss Ininmillion
US$)
US$
)
Loss-Probability Curve
Annual Risk Analysis Curve
35.00
2.00
30.00
1.80
1.60
25.00
Landuse
landuse
Infrastructure
Infra
structure
1.40
1.20
20.00
15.00
1.00
Total
Total
0.80
10.00
0.60
5.00
0.40
0.00
0.20
0.00
0.01
0.01
0.02
0.04
0.1
0.2
0.02Exceedence
0.04
0.1
0.2
Probability
1
1
Exceedence Probability
UNESCO RAPCA
36
Case study: flood risk assessment
objectives
• Assessing the risk of different flood
scenarios for a polder area in the Netherlands
due to slow rising due to rainfall or snowmelt
(not flash floods).
• Comparison of the expected losses regarding
the land use type and flood magnitude
– Death by drowning
– Direct property losses (crops, buildings,
main roads/railroads)
• Determination of the overall annual risk
UNESCO RAPCA
STUDY
AREA:
• Area subject to
riverine floods (not
coastal floods).
• Population of
approximately 106,000
Amsterdam
• Population density of
296 /km2.
GERMANY
• Grassland: 60%,
orchards 9%, forest
4%, agriculture 8%,
urban areas 5% of the
area.
BELGIUM
0
10 0 k m
UNESCO RAPCA
37
AVAILABLE SPATIAL DATA
• Digital Elevation Model (DEM), based on
the Topographic Map 1:10.000 updated
using terrestrial measurements
• Land-use, based on a classification of a
Landsat-TM image (1992) and updated for
urban land-use
• Municipality boundaries and population
data
UNESCO RAPCA
METHODOLOGY
•
Based on
– flood depth maps (several scenarios),
– vulnerability functions,
– a landuse map,
the losses per scenario will be developed
•
Each scenario will be transformed into annual losses (through probability data) in
order to produce a final map depicting the total annual losses due to the flood
hazard.
•
Annual losses per hazard allow to compare all the hazards and decide which one
should be given priority.
UNESCO RAPCA
38
OVERVIEW OF METHODOLOGY
Flood Extent
EHx
Neighbourhood
Funtion
Flood level
ZHx
consists
of
Landuse
Subtraction
Flood Depth
DHx
Landuse
Classes
Ly
Vulnerability
functions
FLy(D)
Calculation
Hazards
Hx
(x=returnperiod)
Vulnerability
V Hx
DEM
Exceed.
probability
PHx
Multiplication
Total Loss
LHx
Annual
Risk
RHx
Loss
LHx
RHx
=
Additional
Data
Value of
Elements at
Risk
A
Multiplication
PHx
*
V Hx
*
A
UNESCO RAPCA
FLOOD SCENARIOS
A
RETUR PROBABILITY
MAX.
N
DEPTH
(cm) PERIOD
5
175
0.2
B
195
10
0.1
C
210
20
0.05
D
230
50
0.02
E
260
100
0.01
F
300
250
0.004
G
325
500
0.002
G
A
F
B
E
C
D
UNESCO RAPCA
39
VULNERABILITY FUNCTIONS
Scale between 0 (no destruction) and 1(complete destruction)
according to the depth of the water.
Vulnerability
Other flood characteristics, such as duration of the flood, its
velocity and sediment load of the water are not considered in
this study.
1
0.8
0.6
0.4
Houses
Source: Standard M ethod
(Vrisou van Eck et. al. 1999)
0.2
0
0
1
2
3
4
5
Water depth (m)
6
UNESCO RAPCA
AGRICULTURE AND
RECREATION
• Steeply rising up to 50 cms, with max. at
around 4ms.
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
5
Water depth (m)
UNESCO RAPCA
IFF (D<350 MIN (D/100 0 24*D/100 0 4
40
BEETS AND POTATOES
• Reaches 1 at water depth of 40cm. At
20cm, half of the crop is destroyed.
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
5
Water depth (m )
UNESCO RAPCA
GREENHOUSES
• Damage increases constantly up to complete
destruction at aprox. 1.8m
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
Water depth (m)
UNESCO RAPCA
41
FOREST
• Low waters do not have a strong impact
on trees. Maximum damage is reached at
3m
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
Water depth (m)
UNESCO RAPCA
ROADS
• Relatively steep gradient up to 1m, with
maximum damage at 5m
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
Water depth (m)
UNESCO RAPCA
42
HOUSES
• Little damage until 2 meters, steep raise until
around 5 m.
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
5
6
Water depth (m)
UNESCO RAPCA
HOUSEHOLD GOODS
• High damage at low depths. Little extra damage
between 1 and 2 m there is hardly any increase in
vulnerability. From 2 mts onwards, increase in
damage.
1
Vulnerability
0.8
0.6
0.4
0.2
0
0
1
2
3
4
Water depth (m)
UNESCO RAPCA
43
DEATH BY DROWNING
• Moderate damage up to 1m, high damage
from 2 to 6.5m
1
Drown factor
0.8
0.6
0.4
0.2
0
0
1
2
3
4
5
6
7
Water depth (m)
UNESCO RAPCA
COMBINING VULNERABILTY MAPS
landuse map
landuse class
function
•
In two steps:
– VulXXXL2 = IFF ((landvul)="va", vulagric(fldXXX),
IFF ((landvul)="vg", vulglass(fldXXX),
IFF ((landvul)="vf", vulfor(fldXXX),
IFF ((landvul)="vr", vulroads(fldXXX), 0))))
•
Where:
– XXX refers to the flood level of a flooding scenario.
–
•
flood depth map
–
The map „landvul“ (based on the land use map) indicates which vulnerability function
has to be applied on a land use class.
„vulagric“, „vulglass“ and „vulfor“ are abbreviations for the vulnerability functions.
–
„fldXXX“ is the flood depth layer in each flood scenario.
The command finds out for every raster cell in the map „landvul“ the appropriate function to
use, applies this function on the flood depth map and the writes the calculated value into the
output file VulXXXL2. Values range from 0 to 1.
UNESCO RAPCA
44
COSTS OF ELEMENTS AT RISK
• The cost data has to be converted from
values per hectare to values (pixel of
936,4m 2).
• Roads: 500,000 Nlg per kilometer. This
value is divided by the length of the
pixel cell (30.6) leading to 15,300 per cell
• It will be assumed that the villages are
100% residential.
UNESCO RAPCA
OVERALL ANNUAL RISK
•All the annual loss
scenarios are added
together to obtain the
overall annual risk
for flooding
1.800
Event damgages (Mio. NLG)
•The resulting maps
are divided by the
return period to
create the annual
losses per scenario.
1.600
Total damage
1.400
Urban damage
1.200
Road damage
1.000
Agricultural damage
800
600
400
200
0
0
0,05 0,1
0,15
0,2
Exceedence probability [1/r]
UNESCO RAPCA
45