Contribution of multi-criteria decision aid methods for natural risk analysis and

management studies

Myriam M. MERAD1,3, Thierry VERDEL2, Romuald SALMON3, Bernard ROY1

1 Laboratory for Analysing and Modelling Decision-Aid Systems (LAMSADE)- Université Paris-Dauphine. Place du Maréchal de Lattre de Tassigny. 75775 Paris Cedex 16 (France).

2 LAboratory of Environnement, GeOmechanic and Structures (LAEGO). Ecole des Mines de Nancy. Parc de Saurupt. 54042 Nancy Cedex (France).

3 National Institut of Environnement and Industrial Risk (INERIS). Parc Technologique Alata. 60555 Verneuil-en-Halatte (France).

Introduction

Risk = Hazard Vulnerability (sensitivity) of the element at risk

Fig.1. Rooms and pillars exploitation

Fig. 2. Underground Instabilities: Subsidence

Fig. 3. Consequences of mining subsidence on constructions

The concept of «Risk Study»Risk management consists on :

Contextual analysis. Risk analysis.

Risk control.

The “Risk Study” : is a « decisional problem » ; is a multi-criteria problem ; can be handled using “collective expertise”.

Each step represents a “project” that we decide to

call “Risk Study”

Role of the « analyst » :

To contribute to the collective expertise. To propose an approach for modeling « Risk studies ».

Analyst

Subsidence

due to

underground activities

Risk Study

Collective expertise

MCDAM Project management

Organisation science

Methods and tools

Stakeholders (Actors) 1

Decision objects 2

Criteria 4

Problematics 3

Aggregation Procedures5

« Risk Study » is a « project » carried out within a « organization » ...

Multi-Criteria Decision Aid Method (MCDAM)

« Risk Study » is a decisional problem ...

The level of the decisional problem 1

The level of available information and knowledge

2

The Importance of the internal and external constraints

3

The dominant culture 4

The criticity of the context 5

1 2 3 4 5

1

2

3

4

5

A help for risk

management

The aim of this approach

To be able to practice a « Contextual analysis »A four Groups « Risk Study » typology

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Operational Tactical Strategical

Level of decisional problem

Knowledge and

information

Type B

Forecast

Type D

Negotiate

Type C

Explore

Type A

Communicate

A description of the “type C”

Identifying and understanding the risk are the finalities of this type of « Risk Study ». The « actors » involved are of the « analytical » type ; they tend towards determinism even if their preferences are not set a priori. In this type of study the actor ’s needs and expectations are a help to structure the decision making problem.

Observations :

- No a priori preferences.

- Often a single actor (routine and analytical operations).

- Mixed information.

- Mainly technical.

- Tendency to determinism.

Requirements :

- Structuring the decision making problem.

To be able to practice a « Risk hierarchization »Proposition of some PMCAs for each « Risk Study » typology

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Operational Tactical Strategical

Level of decisional problem

Knowledge and

information

Type BType D

Type C

Type AELECTRE (I, II, III, IV, TRI)NAIADE

PROMETHEE I /IIFuzzy

conjunctive/Disjunctive methodMELCHIOR

ORESTE ; REGIMEMartel et Zaras

Methods like ELECTRE (I, II, III, IV, TRI)

NAIADE

Fuzzy maximinFuzzy weighted

sum TOPSISMAVTUTA

SMARTMAUT

AHP ; EVAMIX

Fuzzy conjunctive/Disjunctive method

Martel et Zaras Method

Some suggestions concerning Aggregation procedures (MCDAPs):

- Preference structures (S, R) seem of interest. For “Type C”, the “incomparability” relation R lets the different actors ask themselves about the pertinence of the the “Risk Study” problem structure.

- PMCAs that use both quantitative and qualitative information.

[G1]. Are the stakeholders numerous or not? [G2]. Which cognitive procedure (Comparison, etc.) do the decision makers use ? [G3]. What is the decision reference problematic (ranking, choice, etc.)? [G4]. What information (quantity and quality) do we have? [G5]. What level of compensation the decision maker wish to obtain? [G6]. What are the basic assumptions of the MCAD one has ? [G7]. Is there a software that can handle with the principles of the PMCA to choose?

General questions : Hwang et Yoon (1981), Teghem et al. (1989), Orzony (1992), Laaribi et al. (1996), Guitouni et Martel (1998)

Some recommendations for Risk studies of the type C :

To be able to identify a change in the decisional context in the case of a long-term Project

Three levels of concern in decision are identified :

The level of the decisional problem 1

The level of available information and knowledge

2

The Importance of the internal and external constraints

3

The dominant culture 4

The criticity of the context 5

Importance of technical dimension

Decision impact

Information

Global

Very importa

nt

Weak Precise

Local

National

TacticalStrategical

Operational

A Case study : Risk of subsidence induced by

underground works in the North-East of France (Lorraine region)

Beginning of the Study: 1997. Extention: 120 km 30 km. Zones under building or infrastructures. Imperfect knowledge. « Making of » of Mining Risk Prevention Plan (MRPP).

A description of the study

The expected results

Land use proposal.

A Hazard zoning according to (3) urbanization constraints.

Risk zoning in four risk classes.

Multi-Criteria Decision Aid Method (MCDAM)

INERIS : Research and expertise activities. GEODERIS : Expertise group. GISOS : Scientific group. Local Expert committee. Ministries Associations of defense. Mayors.

1. Stakeholders (Actors)

1. The level of the decisional problem

Importance oftechnical

dimension

Decisionimpact

Information

Tactical

Operational

The study in1997

Crisis group management

The study in 2003

Planning and analysis group

The direct and/or indirect actors implied in the risk analysis study have changed : the socio-political dimension is less important that in 1997.

Type 2

Type 3

Type 1

Type 2

Type 3

Type 1

Homogenious zones which consists of many pillars and many galeries (431 zones).

2. Decision objects :

3. Problematics :

To sort the zones to one of the 4 risk classes.

Class 2

Class 3

Class 1

Class 4

zi

To sort the zones to one of the 3 urbanization constraints classes.zi

Shape of the zone to hierarchized

Presence of fault

(bar).τ1-

H0,25k

0 : Large pillars.

10 : Small pillars or tentering.

20 : Small irregular pillars .

ScoreQuali .Sensitivity to waterC1.5ScoreQuali .Size, shape of pillarsC1.4

ScoreQuali .Pillars superpositionC1.3

ScoreQuali .Presence of faultC1.2barQuant.Stress on pillarC1.1

Direction ofrisk

increasing

UnitTypeCriteriaN°

hectareQuant.Zone ExtentC2.4

cm/mQuant.Deformation (Am /H)C2.3

cmQuant.MaximumsubsidenceC2.2

mQuant.DepthC2.1

ScoreQuali .Networksvulnerability

C2.5.5

ScoreQuali .Constructionworksvulnerability

C2.5.4

ScoreQuali .Railwaysvulnerability

C2.5.3

ScoreQuali .Roadsvulnerability

C2.5.2

ScoreQuali .Constructionvulnerability

C2.5.1

4. Criteria

Size and shape of pillars « C1.4 »

Stress on pillar « C1.1 »

Which MCDAPs to choose for the Lorraine case?

Problematics: sorting P and ranking P. Experts commitee. Finalities: Installing monitoring devices ;

urbanization constraints.

Some specificities of the study …R

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Operational Tactical Strategical

Level ofdecisionalproblem

Knowledgeand

information

Type BType D

Type C

Type AELECTRE (I, II, III, IV, TRI)NAIADE

PROMETHEE I /IIFuzzy

conjunctive/Disjunctivemethod

MELCHIORORESTE ; REGIME

Martel et Zaras

Methods like ELECTRE (I, II, III, IV, TRI)

NAIADE

Fuzzy maximinFuzzy weighted

sumTOPSISMAVTUTA

SMARTMAUT

AHP ; EVAMIX

Fuzzy conjunctive/Disjunctive method

Martel et Zaras Method

ELECTRE (I, II, III, IV, TRI)

NAIADE

PROMETHEE I /II

Fuzzy conjunctive/Disjunctive

method

MELCHIOR

ORESTE

REGIME

Martel et Zaras

Choice of the ELECTRE method

Type C

Some other observations ...3. Constraints More hardware. Geographical Information Systems (GIS). A relaxation of time constraints.

4. Dominant culture

Geotechnics.

5. Criticity of the decisional context

Crisis (1997) to Post-crisis (2003).

This makes it possible to be conscious of the group dynamics:

consensual or directed conclusions ;

a rupture of the dynamics of the innovation.

Conclusions and remarks

What are the contributions of the MCDAM?

Reintroduces the « analyst and the experts » in the modeling process.

Considers the various aspects of risk: (transdisciplinarity).

Show that « risk studies » aims action. Proves that complex problems are « decidables ».

Specifies the limits between « expertise » and « decision ».

MCDAMRisk Study

Helps to formulate the decision problem: organization and formalization.

Manages the interface « Analyst/Expertise (Decision aid)/Decision maker »:

SatisfactionSatisfaction Needs: To formulate the decision

problem ; to communicate; etc.

Modeling and conclusions.