Spatial Multi Criteria Evaluation for Vulnerability Assessment Cees

Spatial Multi Criteria Evaluation for Vulnerability Assessment Cees van Westen United Nations University – ITC School for Disaster Geo-Information Management International Institute for Geo-Information Science and Earth Observation (ITC) Enschede, The Netherlands E-mail: westen@itc. nl Associated Institute of the ISL 2004

This week § Today: Presentations of hazard assessment exercises § Afternoon: SMCE § Wednesday: participatory GIS § Thursday: physical vulnerability assessment § Friday: quantitative risk assessment

Presentations § Erosion from Pyroclastic flow deposits: case study Pinatubo (Raphael Spiekermann) § Flood hazard assessment using 2 D flood propagation model outputs (Sandra Traper) § Bangladesh SPOT multi temporal flood mapping (Stefan Premm) § Modelling of Land Subsidence & Sea level rise in Semarang city, Indonesia (Tobias Grau) § Landslide susceptibility assessment using statistical method (Ekrem Canli) § Deterministic landslide hazard assessment (Bernd Loigge) § Seismic hazard assessment

Framework § Input data § Susceptibility § Initiation § Runout § Hazard assessment § Vulnerability § Risk assessment § Quantitative § Qualitative

Spatial Multi Criteria Evaluation

SMCE Spatial Multi Criteria Evaluation. You can combine all types of data § Define goal & subgoals § Select indicators § Make a decision tree § Standardize § Weighting § Combination § Classification ISL 2004

SMCE process § Identification of the main goal. § Identification of a hierarchy of sub goals. § Identification of criteria or effects, which measure the performance of the sub goals. § Creating and filling a criteria tree, which represents the hierarchy of the main goal, any sub goals, and the criteria. § Identification of alternatives to be evaluated. § Assignment of input maps to criteria for each alternative. § Determination of a standardization method per criterion. § Weighing of criteria in the criteria tree. § Calculation of the Composite Index maps and visualization. § Classifying or slicing the Composite Index maps and visualization. § Calculation of Shape Index and/or Connectivity Index. ISL 2004

Spatial Multi Criteria Evaluation § Composite multi- hazard risk index for Cuba at national scale. § Spatial indicators. § Hazard index § Vulnerability index

FACTOR INDICATOR B+ B+ CCC- 0. 48 0. 29 0. 11 0. 04 0. 07 Income level (0. 396) Families Below Food Threshold (% unit) Families Below Poverty Threshold Families Above Poverty Threshold B+ B+ C- 0. 61 0. 28 0. 11 Dependency ratio (0. 117) 1 2 4 5 CCB+ B+ 0. 06 0. 12 0. 26 0. 56 Family size (0. 07) Less than 5 residents (% of unit) 6 to 10 11 to 15 More than 15 CB+ B+ B+ 0. 06 0. 12 0. 26 0. 56 House type (0. 55) Reinforced Brick-Concrete (% of unit) Semi-Concrete Light materials class 1 Light materials class 2 Light Materials class 3 CCB+ B+ B+ 0. 03 0. 06 0. 13 0. 26 0. 53 Land ownership (0. 45) Owned (% of unit) Rented-tenancy Squatted, illegal occupation CB+ B+ 0. 06 0. 27 0. 67 Access to drinking water (0. 60) Private faucet (% of unit) Shared faucet Buy to Private Faucet Public faucet and Pump Public Pump CB+ B+ 0. 04 0. 09 0. 15 0. 30 0. 42 Sanitary facilities (0. 40) Water sealed unit (% of unit) Shared unit Open pit Public toilet Other CB+ B+ 0. 02 0. 17 0. 11 0. 12 0. 57 Waste disposal (0. 40) Number of garbage accumulation spots B+ 0. 40 stagnated waters (0. 60) Percentage of the unit perennially occupied by stagnated waters B+ 0. 60 Topographic elevation of facilities with economic importance (0. 67) Commercial activities Transport-related activities Mixed residential-small businesses Agriculture Topographic elevation of Road Network (0. 33) Main road Secondary road Pathways 0. 62 0. 30 0. 09 Health services Institutional services Educational services Religious services Areas for recreation 0. 41 0. 20 0. 10 0. 04 Facilities Community Capacities W Labourers (% of unit) Informal workers (% of unit) Formal workers Skilled & highly educated workers Transferences from outside areas Housing Economic opportunities CH Livelihood (0. 396) Socioeconomic status Environmental quality of surroundings CATEGORY Topographic elevation of Facilities with social importance for the community (0. 15) to or 1 (% of unit) 3 to 1 1 more to 1 0. 29 0. 21 0. 10 0. 05

Indicators 1. Generic social vulnerability indicators: § § § Percentage of Percentage of Literacy rate young children elderly people minority groups single parent households living below poverty level. 2. Hazard specific social vulnerability indicators § § people located in in flood risk zones, both a daytime and nighttime scenario landslide risk zones, both a daytime and nighttime scenario technological risk zones, both a daytime and nighttime scenario seismic risk zones, both a daytime and nighttime scenario 3. Hazard specific physical vulnerability indicators § § buildings located landslides buildings located to landslides buildings located periods in flood risk zones, with different return periods in landslide risk zones, with different degree of susceptibility to in technological risk zones, with different degree of susceptibility in seismic risk zones, with different intensities and return 4. Capacity indicators § § § Distance to Evacuation sites Distance to hospitals. Awareness ISL 2004

Input data § This exercise uses the results of the loss estimation exercises done earlier for landslides, floods, earthquakes and technological hazards. ISL 2004

Different levels of aggregation • Districts • Wards • Census tracts • Mapping units • • City blocks Basic units for risk • Building footprints • • Unemployment Literacy rate ISL 2004

Indicators 1. Generic social vulnerability indicators: § § § Percentage of Percentage of Literacy rate ISL 2004 young children elderly people minority groups single parent households living below poverty level.

Indicators 2. Hazard specific social vulnerability indicators § § people ISL 2004 located in in flood risk zones, both a daytime and nighttime scenario landslide risk zones, both a daytime and nighttime scenario technological risk zones, both a daytime and nighttime scenario seismic risk zones, both a daytime and nighttime scenario

Steps in the exercise § Step 1: Generation in SMCE of a criteria tree for Generic Social Vulnerability Indicators, with the groups of factors. § Step 2: Generation in SMCE of a criteria tree for Hazard specific social vulnerability indicators, with the groups of factors related to population affected by earthquakes, landslides, flooding and technological disasters in a daytime, and nighttime scenario. § Step 3: Generation in SMCE of a criteria tree for Hazard specific physical vulnerability indicators, with the groups of factors related to buildings affected by earthquakes, landslides, flooding and technological disaster scenarios. § Step 4: Generation in SMCE of a criteria tree for Capacity indicators, which in this case are the distance to emergency centers (e. g. hospitals or fire stations) and the level of awareness. § Step 5: Combination of the 4 sets of indicators into an overall vulnerability indicator. ISL 2004

SMCE process § Identification of the main goal. § Identification of a hierarchy of sub goals. § Identification of criteria or effects, which measure the performance of the sub goals. § Creating and filling a criteria tree, which represents the hierarchy of the main goal, any sub goals, and the criteria. § Identification of alternatives to be evaluated. § Assignment of input maps to criteria for each alternative. § Determination of a standardization method per criterion. § Weighing of criteria in the criteria tree. § Calculation of the Composite Index maps and visualization. § Classifying or slicing the Composite Index maps and visualization. § Calculation of Shape Index and/or Connectivity Index. ISL 2004

The criteria tree ISL 2004

The criteria tree ISL 2004

Spatial multi-criteria analysis A criteria tree contains all criteria Factors: a criterion that contributes to a certain degree to the output § Benefits § contributes positively to the output; the more you have (the higher the values), the better it is § Costs § contributes negatively to the output; the less you have (the lower the values), the better it is Constraints: criterion that determines in the calculation of the main goal. Mask out area ISL 2004

Criteria tree: Generic Social Vulnerability § Generate Criteria Tree: § Factors: Age related, Income Related, Ethnicity related, Social structure § Link with attributes in tables § Standardization § Weighting § Optional: constraint ISL 2004

Standardization of criteria § § § § Maximum: The input values are divided by the maximum value of the map Interval: Linear function with the maximum and minimum values of the map Goal: Linear function with a specified maximum and minimum values Piecewise linear: Linear function with two breaking points located between the extremes Convex: Convex function with one user defined value to re-shape the curve Concave: Concave function with one user defined value to re-shape the curve U-Shape: U-shape curve with one user defined value to stretch or shrink the curve. Gaussian. Bell-shape curve with one user defined value to stretch or shrink the curve ISL 2004

How to select weights? § Direct estimation by expert § The user has to specify weight values him/herself. These userdefined weights are automatically normalized § Pair-wise comparison § With a pairwise comparison matrix, each variable (or criterion) is compared to all others in pairs in order to evaluate whether they are equally significant, or whether one of them is somewhat more significant / better than the other for the goal concerned § Ranking method § the criteria and variables are simply ranked according to their importance as landslide controlling factors § Source: ILWIS Multi Criteria Evaluation ISL 2004

Criteria tree ISL 2004

Criteria tree: Physical Vulnerability & capacity ISL 2004

Final combination § The overall vulnerability indicator is made by combining the four indicator that we have calculated thus far: § A. Generic_Social_Vulnerability (exercise 8. 1) § B. Population_Vulnerability (exercise 8. 2) § C. Physical_Vulnerability (exercise 8. 3) § Capacity (exercise 8. 4) § Combine A, B, C with SMCE Final Vulnerability : = Vulnerability / Capacity ISL 2004