Disaster Readiness and Risk Reduction

1. CHARACTERISTICS OF HAZARD

2. In a sports event like basketball, heights
considered as might. Players of a team
are classified according to height so that
they take suitable roles. Height is not the
only measure of strength for a basketball
player. Speed is critical, if not more
important in many basketball games.
CHARACTERISTICS OF HAZARD

4. KEY HAZARD PARAMETERS

5. KEY HAZARD PARAMETERS
Most hazard quantification methods consider the
magnitude and intensity in determining the level of harm
that a hazard event might bring. The magnitude of the
event is a measure of its strength and is an indication of
how destructive it can be. Most hazard events are measured
on some kind of scale to give them quantifiable outcome.

6. KEY HAZARD PARAMETERS
SPEED OF ONSET – is among the most important aspects of hazards. How
predictable a hazard and how much lead time is allowed by it, is critical in
determining how damaging it will be. The more predictable an event is, the lesser
lesser the chance of incurring casualties and damages. Earthquakes, landslides,
and flashfloods usually occur without warning. Tsunamis typically can have long
warning periods of minutes to hours as long as warning systems are in place. The
The same applies to volcanoes which can provide signs of impending eruption
weeks or months in advance.

7. KEY HAZARDS PARAMETERS
Once the onset of the hazard event is known, the duration
also becomes a concern as the chance of experiencing
severe damage will depend on how long the hazard affects
an area. In the same manner, the larger the aerial extent or
scope of an event is, the greater the potential for damage
will be. The areas affected by landslides and fires are more
limited compared with those tsunamis and typhoon.

8. HAZARD IDENTIFICATION and
ASSESSMENT
If you are living in an area exposed to multiple hazards, you should try to gather
information about hazards and the threats they pose. Individuals, disaster-related
agencies, and planners do this sort of information gathering and analysis as part of
their hazard assessment (Hazard Evaluation and Hazard Analysis), which is required to
come up with risk assessment.
Hazard Assessment and Risk Assessment are two different concepts. Risk Assessment
involves both the assessment from a scientific point of view and the socioeconomic
impacts of a hazardous event. Thus, without hazard assessment, no risk assessment can
be complete. Scientists employ various methods to assess natural hazards. These
includes the following:

9. “Hazard Assessment is the process of estimating, for
defined areas, the probabilities of the occurrence of
potentially damaging phenomenon of given
magnitude within a specific period of time”.
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-UNDRO

10. QUANTITATIVE APPROACH
Mathematical functions or equations relating the
hazard variables used are formulated or adopted to
quantify the hazards. Data fro3m the past historical
records and from those derived from basic science
principles are used to come up with the relationship
between the variables considered.

11. QUALITATIVE APPROACH
Instead of representing with numbers, this method
uses expert opinion in ranking in relative terms (e.g.,
high, moderate, and low or 1, 2, 3…. and so on) the
intensity or probability of occurrence of a hazard
event. This method is preferred not possible to
express numerically one or more variables.

12. PROBABILISTIC APPROACH
It provides an objective estimate of the probability of each hazard
affecting an area or region by considering past record of events.
Probability of occurrence of rainfall of a given intensity can be
estimated, for example, by ranking past rainfalls and applying the
appropriate statistical method of analysis. For earthquakes,
probabilistic ground motion maps combine the likely ground shaking
caused by earthquakes from all nearby earthquake generators over a
specified time period.

13. DETERMINISTIC APPROACH
This is a more subjective approach of estimating probability. A past event of a
given intensity or magnitude is selected and the consequences at certain
intensities are described. The use of deterministic hazard assessment avoids the
under-estimation of hazard at a site. For instance, a seismically quiescent
earthquake generator (seismic gap) has more potential to cause a large-
magnitude earthquake than a feature that constantly releases energy in the
form of small earthquake events. The phenomenon would be ignored in a
probabilistic approach of estimating earthquake hazard and the resulting hazard
estimate will not reflect reality.