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Risk Sensitive Land Use Planning 1
Establishing Basic Parameters:
Risk Assessment
Session 2World Bank Institute
2
Risk Assessment: Concepts and Definitions
Risk Probability/likelihood of loss due to one or more hazard
eventsin pre-defined geographical area
Depends on severity of hazard, vulnerability of exposed assetsand the capacity to cope with risk
Includes time dimension or frequency of occurrence of hazards
Risk Assessment Analysis of both the severity of hazard and vulnerability of
assetsin a particular location
Could include a time-dependent dimension Can be undertaken at various levels of precision Provides input to planning strategies
Risk Sensitive Land Use Planning
3
Process to determine severity and spatial distribution of risk Analytical tool for disaster risk reduction Basis for land use planning interventions
Risk Assessment: The Process
Risk Assessment
Risk Assessment
Vulnerability Assessment
Vulnerability Assessment
Hazard Assessment
Hazard Assessment
Assets at Risk
Assets at Risk
Capacity AssessmentCapacity
Assessment
Risk Sensitive Land Use Planning
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Precision of data Relatively rough information sufficient for public information and
commitment building Greater levels of precision required to justify differential treatment
of land Increasing precision increases the cost of assessment
Time-related factors Recurrence interval of extreme events Current land use practices or future risks associated with
alternative land use scenarios
Depth of assessment Hazard analysis defines the spatial scale of the hazard and also
generates commitment to public policy initiatives Vulnerability analysis helps to understand the consequences of
alternativeland use configurations
Probabilistic risk analysis captures the full range of potential casualty anddamage experiences for a rational comprehensive approach
Risk Assessment: Initial Decisions
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Analysis of: Hazards that may occur in a given area The history of the hazard occurrence The hazard intensity and impact Change in exposure with respect to time Areas that would be most affected
within the city Population groups impacted the most
Quantifies severity of hazard at a given site As a point estimate, or As a time-dependent probabilistic statement
Results can be mapped to increase understanding and usage
Geographic Information Systems can be useful
Step 1: Hazard Identification and Analysis
Risk Sensitive Land Use Planning
Risk Sensitive Land Use Planning 6
Quantifies the degree of susceptibility of people and assets to sustain damage under various levels of hazard
Physical vulnerability varies across a city and depends on the existingbuilding stock and site conditions
Socio-economic vulnerability depends on population distribution,socio-economic status, gender, race/ethnicity, age, nature of economy etc.
Indicates elements at risk that need land use planning interventions
Integrates capacity analysis to estimate protective and coping capabilities
Step 2: Vulnerability Analysis
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Combines parameters of hazard and vulnerability to quantify losses
Losses may include casualty, direct material losses and indirect material losses
May or may not be time-dependent
Time dependent risk assessment provides basis to determine acceptable level of risk
Can be used to determine benefit-cost for land use planning interventions
Level of precision/approximation of risk assessment depends on purpose of its use
Step 3: Risk Analysis
8
Risk Assessment
Quantitative Qualitative Expert-driven Community-driven Participatory in nature
Incorporate variations in perception and acceptability of risk of stakeholders
Community-based hazard and risk mapping
Vulnerability and capacity assessments
Performed by experts
Requires high level of technical expertise
Relies on quantitative methods
Risk Assessment: Methods & Approaches
Use analytical tools
Provides technical and financial parameters for land use planning
Suitable for subjective data
that is difficult to quantify
Do not require high level of technical expertise
Can be performed by various stakeholders
Risk Sensitive Land Use Planning
Risk Sensitive Land Use Planning 9
Determines hazards that may occur in area Includes description of area and its environment
Identifies and characterizes susceptible elements to the hazard Includes vulnerability and capacity of population,
institutions and critical facilities
Uses mapping tools to facilitate the process of stakeholders’ consultation and provide input to landuse planning
Risk Assessment Techniques: Risk Identification
Risk Sensitive Land Use Planning 10
Best for a specific project, event or area
Best for parameters that are difficult to quantify
Helps planners follow systematic procedure for land use decisions
Risk Assessment Techniques: Risk Checklist
Risk Sensitive Land Use Planning 11
Charts parameters of frequency versus severity of hazards Uses two-dimensional chart
Can be both quantitative and qualitative Interpretation must be
consistent
Used by planners to prioritize types of risks
Risk Assessment Techniques: Risk Matrix
12
Location 1
Location 2
Location 3
Location 4
Severity of Hazard 3 5 4 2
Frequency of Hazard 5 3 3 1
Human Loss Potential 3 5 4 3
Economic Loss Potential 3 5 4 4
Response Capacity 3 3 3 3
Cumulative 17 21 18 13
Ris
k In
dex t
o C
om
mu
nit
y
Risk Assessment Techniques: Risk Matrix
Ranking of multiple locations on basis of a risk index (Location 2 has highest risk)
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Ranking of multiple hazards
FREQ
UEN
CY
SEVERITY (LOSS)
Very High
High
Medium
Low
Very Low
Very Low
Low Medium HighVery High
Epidemics
Forest Fires
Floods
Technological
Droughts
Earthquakes
Risk Assessment Techniques: Risk Matrix
Risk Sensitive Land Use Planning
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Calculates potential losses from a hypothetical event Provides understanding of the spatial distribution of losses
to the built environment Develops internal institutional knowledge regarding
vulnerabilitiesof infrastructure and population
Serves as effective communication tool between variousstakeholders
Steps involve: Creating an inventory of built environment, human exposure,
and economic value Analysis of potential hazards Analysis of potential damage Translation into social and economic loss
Risk Assessment Methods: Scenario Analysis
Risk Sensitive Land Use Planning
Risk Sensitive Land Use Planning 15
Estimates disaster loss from multiple events and the probability of occurrence of each event in time
Analytically most sophisticated Important for planners to understand the concepts of
probabilistic assessment Forms basis for: building code regulation, micro-
zoning,benefit/cost analysis of risk reduction options
Used to establish a threshold for acceptable risk Provides spatial distribution of severity of various
hazardsat a high level of resolution
Risk Assessment Methods: Time – based Probabilistic Assessment
Risk Sensitive Land Use Planning 16
Using the Results: Establishment of Basic Planning Parameters
Based on participatory approach to: Establish level of acceptable risk Establish priorities Set planning strategies and interventions
Look at options to reduce risk: Transfer or share Eliminate or avoid Accept, or retain and manage Mitigate
Continuously monitor status of risk and interaction with land use
Factor into risk assessment and land use planning process the changes in risk
Check the effectiveness of land use planning measures in reducing risk by:
Using monitoring and evaluation forms Scheduling regular monitoring activities Assigning responsible parties Submitting progress reports Using indicators and benchmarks
Monitoring Implementation
Risk Sensitive Land Use Planning 17
Risk Sensitive Land Use Planning 18
Multiple hazards to which people are simultaneously exposed
Difficulty in aggregating vulnerability across sectors
Wide range of assets to be accounted for in measuring vulnerability and capacity
Large number of stakeholders with roles to play in shaping risk
Unequal access to technology, Inequality in the distribution of human resources, as well as hardware and inability to buy in data from private sources
Focus on built assets at risk and less on people
Difficulty of measuring human vulnerability
Rapid changes in slums and low-income settlements
Inability to include highly vulnerable populations in assessments
Difference in expert risk assessments and public perceptions of risk
Challenges to Risk Assessment