**Section 2**

156 Risk Management for the Future – Theory and Cases

Yates, J. F. (2001). "Outsider:" Impressions of Naturalistic Decision making. In E. Salas & G.

Lawrence Erlbaum Associates.

Klein (Eds.), *Linking Expertise and Naturalistic Decision Making*. Mahwah, NJ:

**Engineering** 

**8** 

*France* 

**Uncertainties and Risk Analysis Related to** 

*LAEGO – Laboratoire Environnement Géomécanique et Ouvrages, Université de Lorraine,* 

Geohazards correspond to hazards that involve geological or geotechnical phenomena like earthquake, landslide, subsidence… Such hazards are generally classed into natural hazards even if their origin is not always natural, as for mining subsidences that are the consequence of industrial underground excavations. Geohazards are mostly investigated for the purpose of risk analysis. Studies first concern hazard (HAZUS®MH MR4, Romeo et al. 2000, Wahlström and Grünthal 2000) and vulnerability assessment (Zhai *et al.* 2005, McGuire 2004, Hazus 1999, Spence *et al.* 2005, Ronald *et al.* 2008), and secondly risk assessment and management (Karmakar *et al.* 2010, Merad *et al*. 2004). However, risk management must deal with many uncertainties that concern different aspects of risk assessment. This chapter aims to clarify the interactions between risk management and uncertainties within the context of geohazards.

Uncertainties may first be semantic when applied to the definition of the vocabulary used in risk analysis related to geohazards. Risk is generally synthesised as the conjunction of hazard and vulnerability (Karimi and Hüllermeier 2007), but many definitions are available for both terms. Moreover, themselves use terms that are mostly discussed in the literature, such as resilience (Klein *et al.* 2003). As a consequence, a precise definition of risk is necessary, in a given context, to avoid many misunderstandings amongst public authorities, scientists and citizens that may arise from semantic problems. Such a precise definition should not be interpreted as better than others but as a consensual definition adapted to the

The third section addresses the question of the relationship between risk and uncertainties and the identification or classification of the different possible uncertainties. While many authors consider aleatoric and semantic uncertainties (Bogardi 2004, Adger 2006, Ezell 2007) as the two main groups, this part focuses on other classifications and highlights definitions

Finally, this chapter focuses on two specific aspects of the uncertainties and risk analysis related to geohazards: risk prioritisation and vulnerability assessment. These two aspects are illustrated with recent trends developed in the field of risk management within the

context of mining subsidence hazards. Some final remarks are offered in Section 4.

specific context of each study. This goal is addressed in Section 2 of this chapter.

**1. Introduction** 

of uncertainties.

**Geohazards: From Practical Applications** 

*Ecole des Mines de Nancy – Parc de Saurupt – F 54042 – Nancy Cedex -* 

**to Research Trends** 

Olivier Deck and Thierry Verdel
