General assessment and dangers characteristics
The result is a manifestation of the dangers of accidents, accident, disaster, accompanied by deaths, lower life expectancy, injury, damage to natural or man-made environment, disorganizing influence on society and livelihoods of individuals.
Important characteristics danger (a measure of possible danger) - the frequency with which it can be shown, or risk.
Risk (R) - the ratio of the number of events with undesirable consequences (c) to their maximum possible quantity (N) for a certain period of time:
R = n/N
The formula allows you to calculate the amount of total and group risk. In assessing the total risk value of N determines the maximum number of all events, and in assessing the risk group - the maximum number of events in a particular group, selected from the total number of a certain feature. In particular, the group may include people who belong to the same profession, age and sex; Groups can also make vehicles of the same type; one class of business entities and more.
As for risk classification (Table. 2.1) - first can be done depending on the main reason of hazards: natural risks - risks associated with the manifestation of the elemental forces of nature: earthquakes, floods, flooding, storms, etc.; technogenic risks - risks associated with the hazards being realized from industrial facilities; social risks - risks associated with the hazards that occur in the social environment, the most dangerous day of its kind that takes a global nature - terrorism; ecological risks - risks associated with environmental pollution and so on.
Classification and description of types of risk
The main quantitative indicators of the risk of death are:
- Individual risk - the probability of death of a person who is in the region from possible hazards of high danger for the year taking into account the probability of staying in the affected area;
- Political risk - the probability of death within one year of a man who is on a particular space of possible hazards of high risk;
- Social risk probability of loss of life over a certain amount (or the expected number of deaths) in the region during the year from potential sources of danger (the MHI), with the probability of their stay in the affected area
Methods for determining risk:
o engineering - it is based on calculations of the frequency display of the dangers probabilistic safety assessment and to build a "tree" dangers;
o statistical - based on statistical data;
o model - based on building models of the impact of hazards both on an individual and on the social and professional groups;
o Expert - followed by the probability of different events determined by experienced professionals-experts;
o Sociology (Sociometric rating) - based on a survey of the public and employees;
o combined - based on the use of several methods.
Each method of assessing the level of risk has its advantages and disadvantages, hence the conditions and possibilities of its application in practice.