Landslide Risk Management

General Public Quiz

Introduction

This module is directed towards members of the general public of Australia, with particular relevance to those interested in the potential impact of landslide events upon themselves, or upon their property.

This module is particularly to provide a broad introduction to the philosophy and concepts embedded within the broad topic of risk management as it applies to landslides within Australia.

This module is applicable to you if you:

  • Are involved with a building development within a local government area that is prone to landslide events (of one form or another) and are required to have a landslide risk assessment conducted prior to gaining building approval; or
  • Are adjacent to (beside, above or below) a proposed development which requires a landslide risk assessment prior to its approval, and you are therefore an interested party; or
  • You are aware of landslide hazards within public property; or
  • You are interested in the topic in general terms;

The format of this module is a series of questions to step you through the concepts involved in Landslide Risk management (LRM) and to familiarise you with the terminology and jargon that you may encounter.

Question 3 of 10

3. What is RISK? How is risk defined?

  • RISK is a measure of the probability and severity of an adverse effect to life, health, property or the environment ? ie a measure of likelihood and the consequences of the event.
  • RISKY is defined as something that is likely to occur.
  • RISK is very difficult to define as there are many variables to consider that cannot be determined.
  • I live in an environment that is without RISK, and expect that this will always be the case.

Landslide Risk Management uses an engineering definition for “Risk”

3. What is RISK? How is risk defined?

RISK is a measure of likelihood and the consequence of an event should it occur.

The definition adopted for landslide risk assessment is a measure of the probability and severity of an adverse effect to life, health, property, or the environment.

Australian Geoguide LR7, “Landslide risk”

In its simplest form, the definition of “risk” adopted for landslide risk assessments is the engineering definition:

RISK = Likelihood x Consequence

This definition should be clearly separated from, and should not be confused with colloquial usage, such as “That’s risky”.

This is because such a colloquial usage frequently has an implied consequence of a fatality – such as “risky to cross that road” that really means a high probability (or likelihood) of being killed (consequence) in the event of an event occurring (being hit by a vehicle in heavy traffic whilst crossing the road).

It is important that the question be asked “Do we live in a risk-free environment?” and for us all to be aware of the risk environment that we as humans occupy and accept in our daily lives.

It is a readily demonstrated situation that we, collectively, live in a world that has various risk levels, and that many of these are accepted as reasonable as we go about our daily lives. There is a definable level of risk — see “Risk to life” section of Australian Geoguide LR7, “Landslide risk” (above).

Yes, we can define risk simply as

RISK = PROBABILITY x CONSEQUENCES

The steps and terminology used are shown in the following flowchart

This chart can be simplified to show the basic steps and components as follows:

It is important to realize that the likelihood or probability of a landslide event is only part of RISK. The consequences of the event must also be taken into account.

Whilst it may seem appropriate to choose a concept of risk to suit a particular project, this approach is not preferred in AGS 2007c. This approach has been used in the past, but it leads to misunderstandings/confusion and may not be directly comparable to the Acceptance Criteria. Practitioners need to use a clearly defined approach and terminology which is common to all.

Formal definitions of the terms are given in AGS 2007c Appendix A: