Tariff assessment for rare and catastrophic risks - Insurance underwriting

Tariff assessment for rare and catastrophic risks

Rare and catastrophic in its consequences, risks can be conditionally divided into groups.

1. Natural disasters (earthquakes, floods, volcanic eruptions, avalanches, massive forest fires, etc.), which are known to have occurred in a given locality, can happen again, but it is not known when and with what level of damage. About these risks, there is usually statistical information, and, in fact, they are an integral part of the natural and climatic factors of the region.

2. Man-made and man-made disasters (dams, explosions and fires on dangerous objects, the fall of aircraft, harmful and poisonous substances entering the atmosphere, water, soil, etc.), which are known where they can happen, but it is not known when . Such risks may not have statistical information, but it is possible to predict their consequences on the basis of scenarios (mathematical modeling) of accidents.

3. Extremely rare dangerous events, for example, the fall of meteorites, a massive emergency power outage. Such risks are known that, in principle, they can occur (and have occurred!), And the approximate level of their consequences is known, but there is no statistical information.

Insurance of risks of natural disasters is carried out within the framework of federal programs (insurance against earthquakes in Japan, floods in the United States, etc.), as well as commercial insurers. In order to take into account natural risks, the net-tariff structure usually includes, in agreement with insurance supervision, a catastrophic surcharge that is calculated on the basis of statistics or evaluated by experts. This takes into account the cyclicity characteristic of some hazardous natural phenomena, such as floods.

Foreign Experience

The national flood insurance program (NFIP - National Flood Insurance Program ) operates in the United States.

NFIP is a federal program designed to protect the interests of property owners through insurance. This program is designed to provide the option of insurance assistance

In floods of any type, including during accidents of hydraulic structures (GTS), to recover damages from damage to property caused by flooding. Until recently, such insurance was generally not available to the private sector. Participation in the NFIP is based on an agreement between local settlements (communities) and the US government, which states that if the owner of the property (in particular the family as an economic entity) takes measures to reduce future flood losses, the US government will make flood insurance more accessible.

The US Congress established the NFIP with the adoption of the National Flood Insurance Act of 1968 NFIP was expanded and amended with the adoption of the Flood Protection Act of 1973 and other legislative measures. NFIP is managed by the Federal Insurance Administration (FIA), the offices of the Federal Agency for Accident Management (FEMA), as an independent agency.

As determined by the US Congress, the NFIP is subject to the rules and conditions of the Federal Insurance Administration. The FIA ​​has selected insurance companies with appropriate licenses as agents and brokers who sell insurance protection against floods to consumers. The administration regulates the activities of insurance companies and brokers responsible for providing NFIP customers with the same standard level of service that the state requires for other types of insurance.

Almost every type of building under the roof, which is located mainly above the ground and not completely above the water, can be provided with insurance protection if this building is owned by the family. In most cases, the insured property includes parts attached to permanent bases, but do not include vans. The contents inside the insured building can also be provided with a separate insurance cover. Buildings above water or underground gas and liquid tanks, animals, birds, fish, aircraft, piers, partitions, crops, land, livestock, roads, machinery or equipment in the open space and motor vehicles can not be insured.

The flood protection act of 1973 determines the acquisition of flood insurance as a condition for obtaining federal or regional financial assistance for the construction of real estate for any family.

Accommodation of a single family in their own home is provided with insurance cover from 35 to 185 thousand dollars. For other types of living quarters - from 100 to 250 thousand dollars. If the premises are not connected with permanent residence, then - from 100 to 200 thousand. Small business - from 100 to 300 thousand dollars

The flood insurance rate card shows the areas within the flood boundary that can happen in a given area, on average, once per hundred years (with a probability level of 0.01, or 1% per year). Such areas are called "special flood hazard areas (SFHAs). These areas can be further subdivided into zones of different insurance risk, taking into account additional hazards (wind storm water, etc.) and the depth of flooding. Borders are also established for rarer and stronger floods that occur once in 500 years. The areas between the 100-year and 500-year-old flood boundaries are called "moderate flood hazard areas". The remaining areas, above the 500-year boundary of the flood, are called the "minimum flood hazard" areas. Historically, about 1/3 of the insurance claims paid by NFIP were accounted for in the areas of moderate and minimal hazards (risks).

US law obliges property owners to register it with special Federal insurance agencies, which allows, in the presence of maps, to identify potential damages for risk zones. In the case of a very high risk associated with the catastrophic consequences of a GTS accident, special engineering centers ensure the calculation of possible damage based on developed and approved software.

A similar approach applies in Canada.

Insurance of risks of man-caused and man-made disasters is usually made in the form of liability insurance for organizations operating hazardous objects. If the statistics are known, albeit incomplete, the calculation of the tariff is made by the methods described above, with the exception of the risk premium, which, as a rule, is estimated on the basis of the real law of distribution of total losses, or, if statistics are insufficient, then qualitatively.

The tariff rate is also affected by the technical condition of a particular dangerous object.

Historical excursion

Until the end of the XVIII century. In the world there has been no systematic record of dams dams and dams, so more or less accurate data on their number and consequences are not available. From 1800 to 1983, serious accidents at 60 large dams led to the death of 16,000 people. Below are examples of the largest catastrophes of the 20th century.

In 1959, in France, as a result of rock subsidence, the Malpassa Dam collapsed under the foundation, blocking the Rairan River near the city of Frejus. Two and a half million cubic meters of water that fell into the valley, destroyed the city. More than 400 people died. In 1963, as a result of tremors in the vicinity of the Vayont reservoir, which regulated the Piave River (Italy), a landslide with a volume of more than 240 million cubic meters of soil occurred on the left bank during its filling. The cause of the landslide was an increase in seismic activity in the reservoir area caused by its filling. The landslide invaded the basin, and the wave formed by it, overflowing the crest of the dam, washed away the cities of Longarone, Villanova and others. 3 thousand people died.

In 1976 the Volan dam of 134 m high, built in 1960 in Pakistan, was destroyed, as a result 21 km2 of the territory was flooded. The height of the flood wave reached 15 m. There were no human casualties, but the material damage was huge, as the destruction of the Volan dam led to the destruction of 10 more dams located downstream. From the flood, 30 thousand people were affected to some extent.

The tragic consequences took place in connection with the destruction of the Rachkh dam in India. In 1979 the stone-earth dam was washed away by flood waters. As a result, 200 people died.

In 1962, a dam on the Piraeus River in central Greece was destroyed by torrential rains, which did not have sufficient reserves of strength and stability.

In the spring of 1972, in the upper reaches of the Buffalo Creek (Long County, West Virginia, USA), a dead dam over 100 m in height was demolished. The base of the dam was soaked with water, it settled, the water went over the edge. Unable to withstand the onslaught of a huge mass of water, the dam fell apart. Water poured down, destroying everything in its path. Entire villages were demolished. For three hours the current passed 24 km. 124 people were killed, 1 thousand people were injured, 551 houses were destroyed, 936 houses were damaged.

Over the past 70 years, out of one thousand accidents on large GTS, about 80% occurred in the United States. In general, the number of victims in developing countries is higher than in the US and European countries. So, in the years 1964-1984. 60 people died in the United States, 70 people in European countries, 500 people in the third world, without taking into account the victims of Rachkh.

Based on the analysis of the causes of the destruction of 300 dams, the following conclusions were drawn: 35% of accidents were due to low capacity of catchment facilities; 25% - as a result of suffusion, filtration, tectonic movements, subsidence, shifts, - the main causes leading to the destruction of the base of dams; 10% - due to the use of poor-quality materials during construction of dams or violation of the rules of construction works. The remaining 30% are caused by unsatisfactory operation of hydraulic structures, earthquakes, military actions and other established and unidentified factors.

It should be noted that damages and human casualties associated with the destruction of dams and dams are not as great as from floods caused by natural causes. Thus, annually in the world, when tropical cyclones pass, floods and hurricanes on the coasts of the seas and oceans and in river valleys kill 250,000 people. This is almost 14 times more than the number of deaths in 200 years during dam failures.

Approximate average statistical values ​​of the insurance net tariff for gas transportation systems, the level of safety of which basically corresponds to the requirements of regulatory documents, with insurance periods of one year (no more), are given in Table. 4.3.

Table 4.3. Estimated values ​​of insurance rates for GTS

GTS Security Class





Insurance tariff (gross rate), %





The expected amount of losses in an accident is calculated on the basis of calculations using accident scenarios.

Practice questions

Consider the scenarios of possible damage to the dam (the example of the Volga HPP).

In the case of a hydrodynamic accident, 2100 km2 of the Samara area, including 800 thousand hectares of agricultural land, are subjected to catastrophic flooding. Partially flooded cities: Samara, Syzran, Kinel, Okgjabrsk; 200 settlements, on the territory of which 417 thousand people live; 83 objects of the economy; 32 km of the railway and some sections of roads.

Based on the analysis of the state of the structures of the waterworks and the study of statistics and causes of accidents of domestic and foreign GTS, the following accident scenarios are defined.

Scenario 1. Overflowing through the crest of the spillway dam.

Conditions and causes of the accident:

1) the onset of a catastrophic design flood, with a 0.01% security (once in 100 years); The forced rise of the upper tail (WB) to 55.3 m;

2) decrease in the throughput capacity of weirs, due to sedimentation of structures on the pressure front;

3) failure of electrical equipment of one of the cranes of the spillway dam; Damage to mechanical structures of the crane and shutter; incomplete opening of the gates of extreme sections No. 3 and 4; increase of the WB level above the calculated one;

4) overflow through the crest of a spillway and a dam; damage to water and erosion in the zone of interface with a ground dam.

Scenario 2. Breakthrough of the pressure head of the hydroelectric dam due to loss of stability of the base of the spillway dam section.

Conditions and causes of the accident:

1) the onset of a catastrophic design flood, with a 0.01% supply; The forced rise of the WB to 55.3 m;

2) the appearance of a faulty flow due to uneven erosion in the bed, ladle, or due to malfunctions of the normal opening of the gates, due to the failure of the crane serving the gates;

3) deep erosion in front of 3-4 sections of the spillway dam; destruction of the apron, waterbird;

4) violations of the underground anti-filtration circuit;

5) untimely adoption of security measures (termination of discharges on sections 2, 3 and 4) due to low working capacity of a part of instrumentation;

6) the erosion and erosion of the base of the sections; slope of section No. 4, incompatible with normal operating conditions; breaking the keys.

As a result of the examination carried out according to the Methodology for assessing the level of safety of the GTS operated using the data on the status of the main subsystems of the hydrosystem, it was established that, in general, the parameters of the hydroelectric complex, which determine the main factors of its safety, comply with the norms that exclude the possibility of accidents under scenarios 1 and 2.

The capacity of the hydrosystem at the forced rise of the water level to 55.3 m and the full opening of all spillways and water conduits is 83 100 m3/s. Thus, the capacity of the hydrosystem significantly exceeds the maximum discharge rate for a catastrophic flood estimate, with a 0.01% supply, and excludes the possibility of a catastrophic flood in the operation of the gas transmission system under design conditions.

According to the Building Code, Construction in Seismic Areas (SNiP 11-7-81), the area of ​​the hydrosystem is not included in the lists of areas with a seismicity of 6 points or higher, which excludes the probability of destruction of the dam from an earthquake.

However, the state of the separate subsystems of the hydroelectric complex causes some concerns, which affects the safety factors and requires additional calculations and maintenance and preventive maintenance at the hydrosystem.

In Europe (in particular, in Switzerland), the size of the responsibility of the owner of the GTS is determined depending on the installed capacity of hydroelectric power plants and the volume of the reservoir, but in any case, the amount of liability does not exceed 200-300 million dollars. Insurance is carried out under the conditions of general civil insurance responsibility. In a number of cantons in Switzerland, local laws have been enacted requiring the owners of the GTS to insure their civil liability for the above amounts. The criterion for assigning the sum insured is the installed capacity of the hydroelectric units and the volume of the reservoir. The principles of assigning insurance amounts to insurers are not disclosed.

In the case of civil liability insurance, the limits of liability for individuals up to $ 5 million can be established on the basis of the application form. For medium and small businesses, the limits of $ 30-50 million, can be set by the insurers also on the application form of the insured. However, if the liability limit exceeds the mentioned values ​​or if there is information in the application about the possibility of causing damage to more significant amounts, the insurance company shall appoint an expert examination. During the examination, the possible damage is assessed, the maximum possible damage and the most likely damage are determined. The values ​​of these two values ​​serve to determine the liability limit and insurance premium under the insurance contract.

The size of the most likely damage is determined taking into account the susceptibility of objects falling into the affected area, the impact of damaging factors and their resistance to water flow, in the event of a flood (breakthrough wave) in the event of a hydrotechnical structure failure.

Risks of extremely rare events are usually not taken into account when rating in insurance.

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