Hazard Analysis-Poland, Maine


This study encompasses the research, knowledge, and opinions of county, local, and private sources. It was prepared in accordance with Title 37-B, Chapter 14, Subchapter II, Sections 781 and 783 of the Maine Revised Statutes Annotated. Its development was coordinated with support assistance from the Androscoggin Unified Emergency Management Agency and the Maine Emergency Management Agency.

Analysis of each hazard was based on four criteria:

History

The number of occurrences of disasters in the past is important in hazard analysis. If a certain kind of disaster occurred, a sufficient number of hazardous conditions were present to cause the catastrophe. Unless these conditions have been eliminated or substantially reduced, a similar disaster may recur.

History must be used with caution. If there is no record of a specific incident having occurred in an area, it does not necessarily mean that there is no hazard or disaster potential. Also, the technical and social framework of society changes rapidly. New hazards may be created without these changes being recorded in the relevant history of a community. Conversely, a high history may not indicate a high probability if mitigation procedures have been implemented.

 

Vulnerability

Vulnerability allows for the measurement of the percentage of the population that might be killed, injured or displaced and all property that might be damaged or destroyed due to a particular hazard. To describe vulnerability, the number of people and the amount of property in jeopardy is determined, thus providing information that is useful in establishing what is and what is not vulnerable.

Each area has its own special "mix of factors" that must be analyzed for vulnerability. History may be helpful in making this determination.

 

Maximum Threat

Maximum threat is the rating for the "worst case" scenario of a hazard. To determine maximum threat, the worst event possible and the greatest impact of a hazard will be considered. Knowledge of the impact of a hazard's maximum threat upon the area raises awareness of the extreme preparedness needs for the protection of life and property. Maximum threat impact is expressed in terms of human casualties and property loss. In addition, secondary consequences are estimated whenever possible.

 

Probability

Probability is the likelihood that an event will occur. It can be expressed as the number of chances per year that an event of a specific intensity, or greater, will occur.

It is acknowledged that there are similarities when considering the history and probability criteria. However, because of the recent development of a number of hazards (such as nuclear reactor incidents and hazardous materials accidents) and the amount of historical information about them, two distinct criteria are used in this hazard analysis approach. The rationale behind this distinction is that the probability rating for newly developing hazards would be decreased by combining probability and history criteria since there is a lack of historical occurrence. In the same way, this methodology recognizes the importance of the historical criteria for those disaster level hazards that have been confronted and have occurred with a relatively high degree of frequency.

 

Scoring System

The following scoring system permits the ranking of hazards. It provides a way for identifying those hazards that should be addressed in emergency management plans.

In the scoring system, each of the four criteria is assigned a severity rating. The three ratings and their respective numerical scores are:

LOW 1 point

MEDIUM 5 points

HIGH 10 points

Since some criteria are judged to be more important than others, a weighting factor is established to "balance out" the total scoring. The following weights are used:

History 2

Vulnerability 5

Maximum Threat 10

Probability 7

A composite score for each hazard is arrived at by multiplying the score value assigned to each criterion by its weight and then adding the four totals. For example:

 

Hazard "X"

History

HIGH

10 points

x

2 weighting factor

=20 points

Vulnerability

MEDIUM

5 points

x

5 weighting factor

=25 points

Maximum Threat

HIGH

10 points

x

10 weighting factor

=100 points

Probability

MEDIUM

5 points

x

7 weighting factor

=35 points

HAZARD X

TOTAL SCORE

=180 points

For planning purposes, a threshold score of 100 points distinguishes the significant hazards (100 + points) from lower priority hazards (less than 100 points).

Ratings of vulnerability and maximum threat are based on total population and property damage in the town. By combining the estimate of the number of people severely affected as well as the amounts of property damaged, the towns total scores were determined.

Significant Threats

Severe Winter Storms

Hazardous Materials Incident

Disease Epidemic

Severe Thunderstorms

 

Other Threats

Air Pollution

Major Structure Fire

Aviation Accident

Non-Structure Fire

Blight

Soil & Water Pollution

Civil Disorder

Dam Breaching

Power Failure

Drought

Railroad Accident

Earthquake

Explosion

Structural or Bridge Collapse

Heat Wave

Tornado

Hurricane

Transportation Accident

Flooding

Nuclear Attack

Copyright 1997-2002, Wayne Cotterly

Revised: 10/17/2002