From Big Medical Encyclopedia

NATURAL DISASTERS — the catastrophic situations arising, as a rule, suddenly, as a result of action of forces of nature and leading to disturbance of daily tenor of life of considerable groups of people, in some cases followed by the human victims and destruction of material values. To S. mass forest, peat and other fires belong, floods (see), tsunami (see), earthquakes (see), eruptions of volcanoes, mud streams, landslides, collapses, avalanches and drifts, hurricanes, storms and tornadoes, droughts. Emergence nek-ry of the called phenomena (the fires, collapses, landslides) can be promoted by actions of people.

The fire — the uncontrollable process of burning which is followed by destruction of material values and creating health hazard and lives of people. It is characterized by allocation of a large amount of heat and intensive gas exchange of products of combustion. The space captured by the fire is conditionally divided into zones of active burning, thermal influence and smoke. In a zone of thermal impact of the fire temperature of mix of air and light-end products of combustion makes from 60 to 900 °, and the surface density of a thermal flow exceeds 4 kw/sq.m (60 kkal/min-sq.m). In a zone of smoke the major striking factors are products of combustion, many from to-rykh have hypertoxity. Especially the toxics which are formed during the burning of polymers. In nek-ry cases products of incomplete combustion can form gas and explosive mixtures with oxygen. At emergence of the fires people can get thermal and mechanical injuries of varying severity, and also poisonings with toxic products of combustion are possible (see. Burns , Poisonings , Politravma , Shock ).

At a flood (considerable temporary flooding of the area water) can be the main effects for the person drowning (see), mechanical injuries, overcooling (see. Cooling of an organism ). The earthquake can be followed by mechanical injuries, and at simultaneous emergence of the fires — and numerous thermal defeats. Similar effects are possible at eruptions of volcanoes, at to-rykh on the Earth's surface gases, ashes, fragments of rocks are thrown out and the lava streams.

A mudflow (from the Arab, sayl a rough flow) — suddenly forming in beds of the mountain rivers temporary mud or the muddy-debris flow with high content (to 75%) rocks resulting from intensive and long heavy rains, rough thawing of glaciers or a seasonal snow cover. As a rule, mudflows move separate waves with a speed up to 10 m/s and more, transferring a huge number of a fine earth, pebble and large stones (to 3 — 4 m in the diameter and weighing 100 — 200 m), and quite often make large destructions on the way of the movement. On the mechanism of education and action the landslides, avalanches, collapses most often representing the rocks or snow masses moving with high speed downhill are close to a mudflow.

Cyclones (from Greek kyklon turned, rotating) — huge atmospheric whirlwinds, in to-rykh air (its pressure decreases to the center) circulates around the center counterclockwise (in the Northern hemisphere) or clockwise (in the Southern hemisphere). At a cyclone cloudy weather with strong winds prevails. The greatest danger is constituted by a tropical cyclone with storm and gale-force winds and force of the movement of air respectively 9 and 12 points on Beaufort's scale; speed of wind at strong upward movement of air sometimes reaches 70 m/s, and its separate rushes — 100 m/s, powerful cloudiness with plentiful showers (to 1000 mm and more in days) and thunder-storms develops. In Southeast Asia tropical cyclones are called typhoons, and near the Caribbean Sea — hurricanes. At thunder-storms quite often in a storm cloud the atmospheric whirlwinds extending down are formed, it is frequent to the Earth's surface; their diameter can make tens of meters over the sea and hundreds — over the land. Such whirlwind is called a tornado, blood clot (a tornado in the USA). Air in a tornado rotates with a speed several tens of meters in 1 sec., at the same time rising up a spiral to 800 — 1500 m. The tornado passes 40 — 60 km, is followed by a thunder-storm, heavy rain, a hail and if reaches the Earth's surface, almost always makes big destructions, involving in itself the dust, water and objects which are found on its way, lifting them highly up and transferring to long distances.

S.'s centers. (affected by striking S.'s factors. the territory with the buildings located on it, special constructions, engineering networks and communications, the equipment, the equipment and the population) depending on scales of disaster differ with the sizes, a form and character. Actions of several striking factors would result the difficult centers of S. E.g., the earthquake and a hurricane, in addition to destruction of constructions, can cause flooding of a coastal strip, the fires at short circuit of electric wires, to strike people as a result of leak of strong toxic agents etc. Defeats of the population in the difficult center of S. can be the most various. Along with defeats and injuries at the people who appeared in S.'s center., there can be psychological reactions — reactive psychoses (see).

In the USSR assistance to victims of S., their evacuation, mitigation of consequences of S. will be organized and are financially provided with the state. For the leadership in rescue and urgent emergency recovery operations (CHABP), for normalization of life and activity of people in S.'s districts. the government commissions with large powers are created. In the CHABP system usually carry to medical actions: medical investigation of the center of S.; search, rendering the first medical and first medical assistance struck and the patient; their medical evacuation in to lay down. institutions, cleansing and treatment; participation of medical formations in prevention of impact on people of the striking this S.'s factors. Attract able-bodied population, S. which are in the center to performance of these actions. not paramilitary forces of GO, special services of the territorial organizations. In some cases use parts and connections of Armed Forces, and also various organizations of other administrative districts of the country.

Directly in S.'s center. rendering the first medical and first medical assistance to victims, and in located to lay down outside the center will be organized. institutions — specialized medical aid. The first medical aid turns out on site defeats in an order most and mutual assistance by the population, and in the subsequent — the arriving sandruzhina, to-rye usually work together with other formations of GO (see. Health service of civil protection ). Victims after rendering the first medical aid to them if necessary are sent in remained to lay down. institutions or in groups of first aid (see). The easily struck (easily patients) can be sent on foot (better by small groups), and take out the persons which are in a serious and moderately severe condition on the available transport, is preferential — on sanitary. Responsibility for evacuation of victims is born by commanders of summary groups, heads of objects of the national economy or representatives of executive bodies of Councils of People's Deputies. Commanders sandruzhin together with medics participate in evacuation and transport sorting of struck, control correctness of loading of vehicles. In a way of victims sandruzhinnitsa accompany. In OPM developed at mass defeats of the population and in remained to lay down. institutions reception and medical sorting arriving struck and patients, rendering the first medical assistance to them (including carrying out urgent surgical interventions), temporary isolation inf will be organized. patients and persons with disturbances of mentality; training of victims for evacuation is carried out in to lay down. institutions for rendering specialized medical aid and treatment till the outcome of a disease (defeat).

A situation in S.'s districts. the dignity can be complicated by sharp deterioration. states and the danger of emergence and distribution connected with it infectious (hl. obr. intestinal) diseases. Therefore along with rendering medical aid around S. particularly important during elimination of its effects become anti-epidemic and a dignity. - a gigabyte. actions (see. Anti-epidemic actions , Sanitary and preventive actions ), the medical services GO organized and carried out by bodies of health care and formations. Efficiency of these actions is in direct dependence on observance by the population of rules of personal and collective hygiene, and also on correctness of use of methods of protection from inf. diseases.

Adverse effects of Page 6. can be considerably reduced by means of actions for their forecasting, prevention, and also the timely notification of the population about their approach and the appropriate measures of protection. In a number of the states intensive searches of reliable ways of forecasting of S. would be conducted. and accidents and accidents, possible in connection with them. E.g., in the USSR on a national scale and as the international cooperation hurricanes, typhoons, eruptions of volcanoes, mudflows predict by means of these meteorological satellites of Earth. Widely forecasting of the fires on a complex indicator on the basis of summing of the coefficients considering heating, weather, geographical and other environments practices.

Bibliography: Altunin A. T. Formations of civil protection in disaster management, M., 1978; And with with and p M. The guide to sanitary measures at natural disasters, the lane with English, M., 1972; Zaytsev A. P., etc. Civil protection, M., 1981; Egorov P. T., Shlyakhov I. A. and Alabin N. I. Civil protection, M., 1977, bibliogr.; M and x N about E. P. Mitigation of consequences of accidents and natural disasters, M., 1979, bibliogr.; N and l and in to and D. V N. Hurricanes, storms and tornadoes, JI., 1969, bibliogr.

O. S. Lobastov, V. I. Medvedev.