Precursors of natural disasters. Living harbingers of natural disasters. What to do during an earthquake

It is known that many animals anticipate natural disasters long before the appropriate instruments can detect them. This is explained by the fact that some particularly sensitive people, as well as almost all animals, are able to perceive gravitational and electromagnetic disturbances, changes in tension electric field, which precede the onset of earthquakes or volcanic eruptions, etc.

These disturbances cause anxiety, sleep disturbances, increased nervousness, and a general deterioration in well-being in particularly sensitive people. Unlike people, animals, sensing all such negative factors, act intuitively and leave dangerous areas. People are accustomed to trusting not intuition, but the conjectures of reason, and therefore often refuse intuitively correct decisions. For example, before the earthquake in Neftegorsk, many residents of this city could not sleep and experienced anxiety.

Something similar was discovered by specialists from the Hungarian Institute of Seismology in the Hungarian Carpathians - Matra in elderly people, most of whom were women. About five to six hours before the earthquake, these people experienced weakness, severe headaches and dizziness, increased heart rate, severe tinnitus, a burnt taste in the mouth, and an inexplicable feeling of anxiety.

Knowing such symptoms, you can leave densely built areas in advance, turn off gas and fuel lines, which will reduce the number of victims and the likelihood of technological accidents and fires as a result of earthquakes and other natural disasters. Sometimes tremors are accompanied by a clearly audible low hum when the frequency of seismic vibrations lies in the range perceived by the human ear. Sometimes such sounds are heard even in the absence of shocks.

Therefore, if similar symptoms are detected in people, it is also necessary to monitor the behavior of animals. Thus, it was noticed that an hour before the earthquake in Belgrade in 1973, cats, dogs and birds showed great anxiety. In the city of Saint-Pierre on the island of Martinique, destroyed by the Mont Pelee volcano in 1902, 30 thousand people and only one cat died. All other domestic animals, as well as animals and birds, left the danger zone in advance.

Also, a few days before the tragedy, mass migrations of birds and snakes from dangerous areas were observed. During calm periods, deep waves appeared in the sea, and the water suddenly became warmer. In 1948, two days before the Ashgabat earthquake, old Turkmens warned the party leadership about the impending danger based on observations of animal behavior (snakes and lizards left their holes)

It is known that animals and birds anticipate the danger of natural disasters in the period from several weeks to several days and hours before their onset. The human body is also capable of detecting these danger signals.

If you are interested in this topic, then more detailed information about the harbingers natural disasters can be read on the website

Under natural disasters understand natural phenomena that cause an emergency situation characterized by a sudden disruption of the normal functioning of significant groups of the population, a threat to life

people and destruction of material assets.

Natural disasters can occur either independently of each other or in conjunction, one of them can lead to the other. Regardless of the source of a natural disaster, they are characterized by significant scales and varying durations - from several minutes and seconds (earthquakes, avalanches) to several hours (mudflows), days (landfalls) and months (floods).

Natural disasters include:

· geological and geophysical phenomena (earthquakes, landslides, mudflows, subsidence of the earth's surface);

· hydrological and hydrogeological phenomena (floods, floods);

meteorological phenomena:

a) aerodynamic (hurricanes, storms, storms, tornadoes, cyclones, etc.);

b) agrometeorological (hail, rain, frost, drought);

c) natural fires (forest, steppe, peat, etc.);

· space (fall of meteorites, remnants of comets).

Earthquakes- these are strong vibrations of the earth's crust caused by tectonic or volcanic causes and leading to the destruction of buildings, structures, fires and human casualties.

The main characteristics of earthquakes are: depth of source, magnitude and intensity of energy on the earth's surface.

The depth of the earthquake source usually ranges from 10 to 30 km, in some cases it can be much greater.

Magnitude characterizes the total energy of an earthquake. The Richter magnitude varies from 0 to 9 (the strongest earthquake). Increasing it by one means a tenfold increase in the amplitude of vibrations in the soil (or soil displacement) and an increase in earthquake energy by 30 times.

The intensity of energy on the earth's surface is measured in points. It depends on the depth of the source, magnitude, distance from the epicenter, geological structure of the soil and other factors. To measure the intensity of earthquake energy in our country, a 12-point Richter scale has been adopted.

Earthquakes cause great material damage and claim thousands of human lives. They also cause other natural disasters, such as landslides, avalanches, mudflows, tsunamis, floods (due to dam failures), fires (damage to oil storage facilities and rupture of gas pipelines), damage to communications, power, water supply and sewerage lines, accidents at chemical enterprises with leakage (spill) of explosive substances, as well as at nuclear power plants with leakage (release) of radioactive substances into the atmosphere, etc.

Currently, there are no sufficiently reliable methods for predicting earthquakes and their consequences. However, according to the change characteristic properties earth, as well as the unusual behavior of living organisms before an earthquake (they are called harbingers), scientists are often able to make predictions. The harbingers of earthquakes are: a rapid increase in the frequency of weak tremors (vents); deformation of the earth's crust, determined by satellite observation from space or shooting on the earth's surface using laser sources light: change in the ratio of the propagation speeds of longitudinal and transverse waves on the eve of an earthquake; changes in electrical resistivity of rocks, groundwater levels in wells, radon content in water, etc.

The unusual behavior of animals on the eve of an earthquake is expressed in the fact that, for example, cats leave villages and carry kittens to meadows, and birds in cages within 10-15 minutes. before the earthquake begins to fly; before the shock, unusual cries of birds are heard; domestic animals in barns panic, etc. The most likely reason for this behavior of animals is considered to be anomalies electro magnetic field before the earthquake.

To protect against earthquakes, seismically dangerous zones in various regions of the country are identified in advance, i.e. so-called seismic zoning is carried out. Seismic zoning maps usually highlight areas that are threatened by earthquakes with an intensity higher than 7-8 on the Richter scale. In seismically hazardous areas, various protection measures are provided, starting from strict compliance with the requirements of the rules and regulations during the construction of reconstructions of buildings, structures and other objects to the suspension of hazardous industries(chemical plants, nuclear power plants, etc.).

Landslides- these are sliding displacements of masses of rocks down the slope, arising due to an imbalance caused by various reasons (undermining of rocks by water, weakening of their strength due to weathering or waterlogging by sediments and groundwater, systematic tremors, unreasonable economic activity person, etc.).

Landslides can occur on slopes with a steepness of 20º or more and at any time of the year. It differs not only in the speed of rock displacement, but also in its scale. The rate of slow rock displacement is several tens of centimeters per year, medium displacement is several meters per hour or day, and rapid displacement is tens of kilometers per hour. Rapid displacements include landslides-flows, when solid material is mixed with water, as well as snow and snow-rock avalanches. The volume of rocks displaced during landslides ranges from several hundred to many millions and even billions of cubic meters.

Landslides can destroy populated areas, destroy agricultural land, create danger during the operation of quarries and mining, damage communications, tunnels, pipelines, telephone and electrical networks, water management structures, mainly dams. In addition, they can block valleys, form dam lakes and contribute to floods. Thus, the economic damage they cause can be very significant. The most effective protection against landslides is their prevention. Among the complex of preventive measures, it should be noted the collection and disposal surface waters, artificial transformation of the relief, fixation of slopes using piles and construction of retaining walls.

Snow avalanches also often referred to as landslides. They occur in the same way as other landslide displacements. The adhesion forces of snow cross a certain limit and gravity causes the snow masses to shift along the slope. A snow avalanche is a mixture of snow crystals and air. Large avalanches occur on slopes of 25-60º. Smooth grassy slopes are the most prone to avalanches. Shrubs, large rocks and other obstacles inhibit avalanches.

Snow avalanches cause enormous material damage and are often accompanied by loss of life. So, on July 13, 1990, on Lenin Peak in the Pamirs, as a result of an earthquake and a large avalanche from the slope, a climbers’ camp at an altitude of 5300 m was demolished. 40 people died. There has never been such a tragedy in the history of domestic mountaineering.

Avalanche protection can be passive or active. With passive protection, avalanche slopes are avoided or barrier shields are placed on them. With active protection, avalanche-prone slopes are bombarded, causing small, harmless avalanches, and thus preventing the accumulation of critical masses of snow.

Sat down– these are floods with a very high concentration of mineral particles, stones and rock fragments (from 10-15 to 75% of the flow volume), occurring in the basins of small mountain rivers and dry ravines and caused, as a rule, by rainfall, less often by intense snow melting, as well as the breakthrough of moraine and dam lakes, landslides, landslides, and earthquakes.

The danger of mudflows lies not only in their destructive power, but also in the suddenness of their appearance. The consequences of mudflows can be catastrophic.

Methods of dealing with mudflows are very diverse. This is the construction of various dams to delay solid runoff and pass a mixture of water and small fractions of rocks, cascades of dams to destroy the mudflow and release it from hard material, retaining walls to strengthen slopes, etc.

Floods– these are significant flooding of the area as a result of rising water levels in a river, lake, reservoir, caused by various reasons (spring snowmelt, heavy rainfall and rainfall, ice jams on rivers, breakthrough of dams, dam lakes and enclosing dams, wind surge of water, etc. .P.). Floods cause enormous material damage and lead to casualties.

Direct material damage from floods consists of damage and destruction of residential and industrial buildings, roads and railways, power and communication lines, reclamation systems, loss of livestock and agricultural crops, damage and destruction of raw materials, fuel, food, feed, fertilizers, etc. .P.

Floods may be accompanied by fires due to breaks and short circuits of electrical cables and wires, as well as ruptures of water and sewer pipes, electrical, television and telegraph cables located in the ground due to subsequent uneven settlement of the soil.

The main direction of flood control is to reduce the maximum water flow in the river by redistributing the flow over time (planting forest protection belts, plowing land across slopes, preserving coastal water protection strips of vegetation, terracing slopes, etc.).

A certain effect is also achieved by installing ponds, tanks and other containers in logs, gullies and gullies to intercept melt and rain water. For medium and large rivers the only radical solution is to regulate flood flow using reservoirs.

In addition, a long-known method, the construction of dams, is widely used to protect against floods. To eliminate the danger of jams, certain sections of the river bed are straightened, cleared and deepened, as well as the ice is destroyed by explosions 10-15 days before its opening.

Hurricanes– these are winds of force 12 on the Beaufort scale, i.e. winds whose speed exceeds 32.6 m/s (117.3 km/h). Hurricanes are also called tropical cyclones , arising in the Pacific Ocean near the coast of Central America; on Far East and in the Indian Ocean regions hurricanes (cyclones) are called typhoons , in Japan - a tsunami. During tropical cyclones, wind speeds often exceed 50 m/s. Cyclones and typhoons are usually accompanied by intense rainfall.

A hurricane on land destroys buildings, communication and power lines, damages transport communications and bridges, breaks and uproots trees; when spread over the sea, it causes huge waves 10-12 m or more in height, damaging or even leading to the death of the ship.

Hurricanes and storm winds (their speed on the Beaufort scale from 20.8 to 32.6 m/s) in winter can lift huge masses of snow into the air and cause snow storms, which leads to skidding, stopping the movement of automobiles and railway transport, disruption of water, gas, electricity and communication systems.

Modern methods Weather forecasts make it possible to warn the population of cities or entire coastal areas several hours and even days in advance about an impending hurricane (storm), and civil defense services (CD) and the Ministry of Emergency Situations (MES) can provide the necessary information about the possible situation and the required actions in the current conditions .

Natural emergencies include:

Geophysical emergencies (earthquakes, volcanic eruptions);

Geological emergencies (landslides, avalanches, mudflows);

Meteorological emergencies (hurricanes, cyclones, showers, tornadoes, snowfalls);

Hydrological emergencies (floods, sharp decline in groundwater levels (drought), tsunami);

natural fires.

Earthquakes

Earthquake called tremors and shifts in earth's crust and the upper part of the mantle, transmitted over long distances in the form of elastic vibrations.

The main criteria for an earthquake are the depth of the source and the intensity of the release of energy to the surface of the earth.

An earthquake is a natural phenomenon associated with geological processes occurring in the Earth's lithosphere. An earthquake manifests itself in the form of tremors and vibrations of the earth's surface, resulting from sudden displacements and ruptures in the earth's crust or in the upper part of the mantle. These displacements and ruptures are caused by deep processes occurring in the lithosphere and associated with the movement of lithospheric plates. In and near mountain belts, intraterrestrial stress increases and increases until it exceeds the resistance of rocks, resulting in rock rupture and displacement. Intraterrestrial tension is abruptly released. The potential energy of deformation turns into kinetic energy, which is dissipated in different directions from the rupture site in the form of seismic waves. Seismic waves vibrate the Earth.

The magnitude of an earthquake is a value that characterizes the energy released during an earthquake in the form of seismic waves.

Intensity is a qualitative characteristic of an earthquake and indicates the nature and scale of the impact of earthquakes on the surface of the earth, on people, animals, as well as on natural and artificial structures in the earthquake area.

Accordingly, for assessing earthquakes, there are two types of scales - magnitude scales And intensity scales.

Magnitude scales are designed to estimate the magnitude of an earthquake, i.e. energy released during an earthquake. These scales have no upper limit. The magnitude scales are the Richter scale and the Kanamori scale.

Richter scale. Charles Richter in 1935 proposed to estimate the strength of an earthquake (at its epicenter) the decimal logarithm of the displacement (in micrometers) of the needle of a standard Wood-Anderson seismograph located at a distance of no more than 600 km from the epicenter: M L= log A+f, where f is the correction function calculated from the table depending on the distance to the epicenter. The energy of an earthquake is approximately proportional to A 3/2, that is, an increase in magnitude by 1.0 corresponds to an increase in the amplitude of oscillations by 10 times and an increase in energy by approximately 32 times.

The Richter scale and derived Richter scales do not work well for the largest earthquakes - at magnitude M ~ 8 the scale saturates.

Kanamori scale. In 1977, Kanamori proposed a fundamentally different estimate of earthquake magnitude, based on the concept of seismic moment. The Kanamori scale agrees well with the Richter scale at magnitude 3< М < 7 и лучше подходит для оценки крупных землетрясений.

Magnitude characterizes an earthquake as an integral, global event and is not a measure of the intensity of an earthquake felt at a specific point on the Earth's surface. The intensity of an earthquake, measured in points, not only strongly depends on the distance to the source; Depending on the depth of the center and the type of rocks, the strength of earthquakes with the same magnitude can differ by 2-3 points.

Magnitude is a dimensionless quantity, it is not measured in points.

Correct usage: « earthquake with magnitude 6.0», « earthquake measuring 5 magnitudes on the Richter scale»

Misuse: « earthquake with magnitude 6.0», « earthquake measuring 6.0 on the Richter scale».

The strongest recorded earthquake occurred in Chile in 1960—later estimates put Kanamori's magnitude at 9.5. It is believed that earthquakes on Earth cannot have a magnitude significantly higher than 9.5 because rocks cannot store more energy without collapsing. Higher energy seismic events can be caused by a meteorite impact.

Intensity scales

Several intensity scales are used in the world: in the USA - the Modified Mercalli scale (MM), in Russia and CIS countries - MSK-64 (Medvedev-Sponheuer-Karnik scale), in Europe - the European Macroseismic Scale (EMS), in Japan - the Shindo scale (Shindo).

The 12-point Medvedev-Sponheuer-Karnik scale was developed in 1964 and became widespread in Europe and the USSR. Since 1996, the European Union has used the more modern European Macroseismic Scale (EMS). MSK-64 is the basis of SNiP II-7-81 “Construction in seismic areas” and continues to be used in Russia and the CIS countries.

Characteristics of earthquakes on the MSK-64 scale

Point	Earthquake strength	A brief description of
	Not felt.	Marked only by seismic instruments.
	Very weak tremors	Marked by seismic instruments. It is felt only by certain people who are in a state of complete peace in the upper floors of buildings, and by very sensitive pets.
		It is felt only inside some buildings, like a shock from a truck.
	Moderate	Recognized by slight rattling and vibration of objects, dishes and window glass, creaking of doors and walls. Inside the building, most people feel the shaking.
	Quite strong	In the open air it is felt by many, inside houses - by everyone. General shaking of the building, vibration of furniture. The clock pendulums stop. Cracks in window glass and plaster. Awakening the Sleepers. It can be felt by people outside buildings; thin tree branches are swaying. Doors slam.
		It is felt by everyone. Many people run out into the street in fear. Pictures fall from the walls. Individual pieces of plaster are breaking off.
	Very strong	Damage (cracks) in the walls of stone houses.
	Anti-seismic, as well as wooden and wattle fence buildings remain unharmed.	Destructive
	Cracks on steep slopes and wet soil.	Monuments move out of place or topple over. Houses are heavily damaged.
	Devastating	Severe damage and destruction of stone houses. Old wooden houses are crooked.
	Destructive	Cracks in the soil are sometimes up to a meter wide. Landslides and falls from slopes. Destruction of stone buildings. Curvature of railway rails.
	Catastrophe	Wide cracks in the surface layers of the earth.

Detection and recording of all types of seismic waves is carried out using a special measuring device - a seismograph. In most cases, the seismograph has a weight with a spring attachment, which during an earthquake remains motionless, while the rest of the device (body, support) begins to move and shifts relative to the load.

Harbingers, signs of an approaching earthquake the following phenomena may occur: deformation of the earth's surface, changes in the regime and composition of groundwater and gases, unusual behavior of animals, faint glow of switched off fluorescent lamps, sparking of nearby (but not touching) electrical wires, lightning, the smell of gas in areas where this was not previously possible noted.

Flashes of lightning, glow of fluorescent lamps and sparking of wires are associated with disturbance of the geoelectric field above the future epicenter of the earthquake. Such optical phenomena have been observed before some major earthquakes.

Tsunami

Tsunamis are long waves that arise as a result of a powerful impact on the entire thickness of water.

In most cases, tsunamis are caused by earthquakes that occur under the ocean floor or near its coast. However, tsunamis occur only after earthquakes that are associated with the rapid formation of faults, landslides and landslides on the ocean floor. A fault is a rapid displacement of blocks of bottom rocks of the earth's crust.

In Russia, the eastern coast of Kamchatka and the Kuril Islands, Sakhalin Island and the coast are most exposed to tsunamis. Pacific Ocean. Having a high speed of movement and a huge mass of water, a tsunami has colossal destructive power. Running into oncoming coastal obstacles, the wave unleashes all its energy on them, rising above them like a huge wall of water, crushing, destroying and destroying everything that gets in its way.

The height of waves generated by the wind is usually no more than 4–6 m, the largest is about 30 m. The length of wind waves is 100–250 m, extremely rarely – up to 500 m.

In the open Ocean, the wavelength of a tsunami is measured in hundreds of kilometers (200 - 300) at a height of about 1 m. Therefore, in the open Ocean they are usually invisible to ships. Tsunami waves propagate in all directions from the point of origin at a speed of 700 - 800 km/h. Near the coast, the speed of the tsunami decreases, and the height increases (up to 30 m or more).

Floods

Flood- This is a temporary flooding of a significant part of the land, causing significant material damage, leading to the death of plants, animals, and people.

During a flood, water quickly rises and the surrounding area is flooded. The consequences of this are: damage to buildings, structures and communications; disruption of agricultural activities and crop loss; landscape change; death of people, domestic and wild animals; loss of material and cultural values; washing away and flooding of fertile soils.

Flood types:

1. Floods caused by melting snow (floods), heavy rains (floods).

2. Floods caused by storm surges of water - surge floods.

3. Floods caused by congestion in river sections (as a rule, mountainous ones), ice jams (accumulation of inland ice in the river before freeze-up). These are jam and glutton floods.

4. Floods caused by the destruction of hydraulic structures.

5. Floods caused by tsunamis.

By flooding is the penetration of water into the basements of buildings through the sewer network (when the sewer is connected to the river), through ditches and trenches, as well as due to significant backwater of groundwater.

Flooding- This is the covering of the surrounding area with a layer of water, flooding courtyards, streets of populated areas and the lower floors of buildings.

According to the Russian Ministry of Emergency Situations, floods rank first in Russia among known natural disasters in terms of frequency, area of ​​distribution, and total average annual damage. In terms of the number of human casualties, they rank second after earthquakes.

In Russia, floods threaten almost 40 cities and several thousand other settlements. The frequency of floods on average ranges from once every 5–10 years to once every 15–20 years. But there are cities where floods occur once every 2–3 years (Ufa, Orsk, Kursk and a number of others).

Hurricanes, storms and tornadoes

Hurricane(at sea - typhoon) is a wind of enormous destructive power. Speed ​​more than 35 m/s (130 km/h). Lasts from several hours to several days.

Hurricane winds damage strong and demolish light buildings, break power lines, break and uproot trees. People caught in a hurricane may die or suffer varying degrees of injury.

Long-term meteorological observations show that wind speeds during hurricanes reached 30–50 m/s in most areas of the European part of Russia, and 60–90 m/s or more in the Far East.

The destructive power of a hurricane lies in the combined action of wind and water: the propelling action of high-speed wind pressure, powerful waves hitting the coast, catastrophic downpours and floods.

Storm- this is a strong wind, the speed of which is less than the speed of a hurricane, it reaches 15 - 20 m/s. (Note that a short-term increase in wind speed up to 20 - 30 m/s is called a squall.)

The main indicator that determines the destructive effect of these natural disasters is the speed of air masses. The kinetic energy contained in moving air determines its speed pressure and destructive power.

To determine the strength of the wind at the surface of the Earth, there is the Beaufort scale.

Francis Beaufort (1774 - 1857), an English military hydrographer and cartographer, rear admiral, in 1806 proposed estimating the strength of the wind by its effect on ground objects and by the roughness of the sea; for this purpose he developed a conditional 12-point scale.

Tornado is an atmospheric vortex that arises in a thundercloud and spreads down, often to the very surface of the Earth. Movement in a tornado is counterclockwise. Diameter from several meters to several tens of meters. The rotation speed reaches 100 - 200 m/s. Average travel speed is 50 – 60 km/h. Duration of existence - from several minutes to several hours.

A tornado is sometimes called a blood clot (provided it passes over land), a typhoon (over the sea), and in North America it is called a tornado.

The total length of a tornado's path can be hundreds of meters and reach hundreds of kilometers. The average width of the destruction zone is 300 – 500 m.

The destruction caused by a tornado is caused by a high-speed pressure of air rotating inside the funnel with a large pressure difference between the periphery and the inside of the funnel due to the enormous centrifugal force.

On the territory of Russia, tornadoes most often occur in the central regions, the Volga region, the Urals, Siberia, on the coasts and in the waters of the Black, Azov, Caspian and Baltic seas.

The most dangerous areas for the risk of tornadoes are the Black Sea coast and the Central Economic Region, including the Moscow region.

Wildfires

Natural fires:

Steppe;

Underground.

Forest fires: high and low.

Horse fire. In strong winds, the propagation speed is up to 50 km/day. A crown fire does not go down, but spreads through the treetops.

A ground fire is a continuous fire. The propagation speed is 3 – 4 km/day. The undergrowth burns out completely.

Underground fires may occur in layers of peat or coal. Peat fires are typical for Russia. Peat burns without access to oxygen - this is the danger. Peat fires can only be localized.

steppe fire dangerous due to rapid burning of the top turf layer of soil. The speed depends on the wind speed and ranges from 5 to 20 km/day. Accompanied by strong smoke.

The consequences of natural fires are: destruction of trees and vegetation by fire; violation of planned forest management and use of forest resources; destruction by fire of residential and public buildings in villages; destruction of communication and power transmission line supports, pipeline transport elements; damage to people, domestic and wild animals; disruption of human economic activity in large areas.

Sat down

Sel (from Arabic - stormy stream) is a temporary mud-stone stream that suddenly forms in the beds of mountain rivers. This mixture of water, mud, stones weighing up to 10 tons, trees and other objects rushes at speeds of up to 15 km/h, sweeping away, flooding or carrying bridges, buildings with it, destroying dams, dams, and collapsing villages. The duration of mudflows reaches 10 hours with a wave height of up to 15 m. Mudflows are formed as a result of prolonged rainfall, intense melting of snow (glaciers), dam breaks, improper blasting, earthquakes, and volcanic eruptions.

The main areas where mudflows occur in Russia are in Transbaikalia (the frequency of powerful mudflows is 6...12 years), in the BAM zone (once every 20 years), in the Far East and the Urals, and in the Caucasus.

In most cases, the population can be warned about the danger of a mudflow in just tens of minutes and less often in 1-2 hours or more. The approach of such a flow can be heard by the characteristic sound of boulders and fragments of stones rolling and colliding with each other, reminiscent of the roar of a train approaching at high speed.

If the population is notified of an approaching mudflow or a landslide, as well as at the first signs of their manifestation, it is necessary to leave the premises as quickly as possible, warn others about the danger, and go to a safe place. When leaving the premises, you should extinguish the stoves, turn off the gas taps, turn off the lights and electrical appliances. This will help prevent fires from occurring.

Mudflows and landslides pose a serious danger when they occur suddenly. In this case, panic is the worst thing. If someone is caught by a moving mudflow, the victim must be assisted with all available means. Such means may be poles, ropes or ropes given to those being rescued. Those being rescued must be taken out of the stream in the direction of the stream, gradually approaching its edge, otherwise the stones of the rushing stream will cripple the person being rescued.

Landslides During landslides, people may be buried under soil, struck and injured by falling objects, building structures, and trees. In these cases, it is necessary to quickly provide assistance to the victims, and, if necessary, give them artificial respiration.

– separation and sliding displacement of the upper layers of soil along the slope under the influence of gravity. Most often, landslides occur due to an increase in the steepness of mountain slopes, river valleys, high coastlines of seas, lakes, reservoirs and rivers when they are washed away by water.

The initial sign of the onset of landslide movements is the appearance of cracks on buildings, breaks in roads, coastal fortifications and embankments, bulging of the earth, displacement of the base of various high-rise structures and even trees in the lower part relative to the upper.

Anti-landslide measures in which the population should take part are the drainage of surface water, tree planting, installation of various supporting engineering structures, excavation of trenches in order to drain the soil of the landslide massif, unloading and leveling of the landslide slope. In addition, the population living in landslide-hazardous areas should not allow excessive leakage of water from taps, damaged water pipes or water intakes; It is necessary to arrange drainage drains in a timely manner when surface water accumulates (with the formation of puddles). Collapse

– separation and fall of masses of rocks down from the slopes of mountains under the influence of gravity. Landslides occur on the slopes of river banks and valleys, in the mountains, and on the shores of the seas. The main cause of large collapses is earthquakes. Rockfall

- a collapse of rocks in the mountains. Avalanche

- rapid, sudden movement of snow and (or) ice down steep mountain slopes.

Consequences of landslides, mudflows, landslides and avalanches: death of people and animals; blocking river channels and changing the landscape; destruction of buildings and structures; concealment of populated areas, national economic facilities, agricultural and forest lands by rock strata.

Snowfalls, snow drifts

With the announcement of a storm warning about possible snow drifts, it is necessary to limit movement, especially in rural areas, and create the necessary supply of food, water and fuel at home. In some areas, with the onset of winter, it is necessary to string ropes along the streets and between houses to help pedestrians navigate in a strong snowstorm and overcome strong winds. Snow drifts pose a particular danger to people caught on the road far from human habitation. Snow-covered roads and loss of visibility cause complete disorientation of the area.

When driving a car, you should not try to overcome snow drifts; you must stop, completely close the car blinds, and cover the engine on the radiator side. If possible, position the car's engine in the wind. From time to time you need to get out of the car and shovel the snow so as not to be buried under it. In addition, a car not covered with snow is a good reference point for the search group. The car engine must be periodically warmed up to prevent it from “defrosting”. When warming up the car, it is important to prevent exhaust gases from flowing into the cabin (body, interior); for this purpose, you must ensure that the exhaust pipe is not covered with snow.

If several people are traveling together (in several cars), it is advisable to get everyone together and use one car as shelter; The engines of other vehicles must be drained of water. Under no circumstances should you leave the shelter – the car. In a heavy snowfall (blizzard), landmarks that seem reliable at first glance can be lost after a few tens of meters.

Over the billions of years of our planet’s existence, certain mechanisms by which nature works have formed. Many of these mechanisms are subtle and harmless, while others are large-scale and cause enormous destruction. In this rating, we will talk about the 11 most destructive natural disasters on our planet, some of which can destroy thousands of people and an entire city in a few minutes.

11

A mudflow is a mud or mud-stone flow that suddenly forms in the beds of mountain rivers as a result of rainfall, rapid melting of glaciers or seasonal snow cover. The decisive factor in the occurrence may be deforestation in mountainous areas - tree roots hold the top of the soil, which prevents the occurrence of a mudflow. This phenomenon is short-term and usually lasts from 1 to 3 hours, typical for small watercourses up to 25-30 kilometers long. Along their path, streams carve deep channels that are usually dry or contain small streams. The consequences of mudflows can be catastrophic.

Imagine that a mass of earth, silt, stones, snow, sand, driven by a strong flow of water, fell on the city from the mountains. This stream will demolish the dacha buildings located at the foot of the city along with people and orchards. This entire stream will rush into the city, turning its streets into raging rivers with steep banks of destroyed houses. Houses will be torn off their foundations and, along with their people, will be carried away by a stormy stream.

10

Landslide is the sliding of masses of rocks down a slope under the influence of gravity, often while maintaining their coherence and solidity. Landslides occur on the slopes of valleys or river banks, in the mountains, on the shores of the seas, and the largest ones occur at the bottom of the seas. The displacement of large masses of earth or rock along a slope is caused in most cases by wetting the soil with rainwater so that the soil mass becomes heavier and more mobile. Such large landslides damage agricultural lands, enterprises, and populated areas. To combat landslides, bank protection structures and planting of vegetation are used.

Only rapid landslides, the speed of which is several tens of kilometers, can cause real natural disasters with hundreds of casualties when there is no time for evacuation. Imagine that huge pieces of soil are quickly moving from a mountain directly onto a village or city, and under tons of this earth, buildings are destroyed and people who did not have time to leave the landslide site die.

9

A sandstorm is an atmospheric phenomenon in which large quantities of dust, soil particles and grains of sand are transported by the wind several meters from the ground with a noticeable deterioration in horizontal visibility. In this case, dust and sand rise into the air and at the same time dust settles on large territory. Depending on the color of the soil in a given region, distant objects take on a grayish, yellowish or reddish tint. It usually occurs when the soil surface is dry and the wind speed is 10 m/s or more.

Most often, these catastrophic phenomena occur in the desert. A sure sign that a sandstorm is starting - sudden silence. Rustles and sounds disappear with the wind. The desert literally freezes. A small cloud appears on the horizon, which quickly grows and turns into a black and purple cloud. The missing wind rises and very quickly reaches speeds of up to 150-200 km/h. A sandstorm can cover streets within a radius of several kilometers with sand and dust, but the main danger of sandstorms is the wind and poor visibility, which causes car accidents in which dozens of people are injured and some even die.

8

An avalanche is a mass of snow falling or sliding down the slopes of mountains. Snow avalanches pose a significant danger, causing casualties among climbers, skiers and snowboarders and causing significant damage to property. Sometimes avalanches have catastrophic consequences, destroying entire villages and causing the death of dozens of people. Snow avalanches, to one degree or another, are common in all mountainous regions. In winter, they are the main natural danger of the mountains.

Tones of snow are held on top of mountains due to the force of friction. Large avalanches occur at the moment when the pressure force of the snow mass begins to exceed the force of friction. A snow avalanche is usually triggered by climatic reasons: sudden changes in weather, rain, heavy snowfalls, as well as mechanical effects on the snow mass, including the effects of rockfalls, earthquakes, etc. Sometimes an avalanche can begin due to a minor shock such as a weapon shot or pressure on the snow of a person. The volume of snow in an avalanche can reach several million cubic meters. However, even avalanches with a volume of about 5 m³ can be life-threatening.

7

A volcanic eruption is the process of a volcano throwing out earth's surface hot debris, ash, an outpouring of magma, which, pouring out to the surface, becomes lava. A major volcanic eruption can last from a few hours to many years. Hot clouds of ash and gases, capable of moving at speeds of hundreds of kilometers per hour and rising hundreds of meters into the air. The volcano emits gases, liquids and solids with high temperatures. This often causes the destruction of buildings and loss of life. Lava and other hot erupted substances flow down the slopes of the mountain and burn out everything they meet on their way, causing innumerable casualties and staggering material losses. The only protection against volcanoes is general evacuation, so the population must be familiar with the evacuation plan and unquestioningly obey the authorities if necessary.

It is worth noting that the danger from a volcanic eruption exists not only for the region around the mountain. Potentially, volcanoes threaten the lives of all life on Earth, so you shouldn’t be lenient towards these hot guys. Almost all manifestations of volcanic activity are dangerous. The danger of boiling lava goes without saying. But no less terrible is the ash, which penetrates literally everywhere in the form of continuous gray-black snowfall, which covers streets, ponds, and entire cities. Geophysicists say they are capable of eruptions hundreds of times more powerful than those ever observed. Major eruptions Volcanoes, however, have already occurred on Earth - long before the advent of civilization.

6

A tornado or tornado is an atmospheric vortex that arises in a thundercloud and spreads down, often to the very surface of the earth, in the form of a cloud arm or trunk with a diameter of tens and hundreds of meters. Typically, the diameter of a tornado funnel on land is 300-400 meters, but if a tornado occurs on the surface of water, this value can be only 20-30 meters, and when the funnel passes over land it can reach 1-3 kilometers. The largest number of tornadoes is recorded on the North American continent, especially in the central states of the United States. About a thousand tornadoes occur in the United States every year. The most strong tornado can last up to an hour or more. But most of them last no more than ten minutes.

On average, about 60 people die from tornadoes each year, mostly from flying or falling debris. However, it happens that huge tornadoes rush at a speed of about 100 kilometers per hour, destroying all buildings in their path. The maximum recorded wind speed in the largest tornado is about 500 kilometers per hour. During such tornadoes, the death toll can number in the hundreds and the number of injured in the thousands, not to mention the material damage. The reasons for the formation of tornadoes have not yet been fully studied.

5

A hurricane or tropical cyclone is a type of low-pressure weather system that occurs over a warm sea surface and is accompanied by severe thunderstorms, heavy rainfall and gale-force winds. The term “tropical” refers to both the geographic area and the formation of these cyclones in tropical air masses. It is generally accepted, according to the Beaufort scale, that a storm becomes a hurricane when wind speeds exceed 117 km/h. The strongest hurricanes can cause not only extreme downpours, but also large waves on the sea surface, storm surges and tornadoes. Tropical cyclones can arise and maintain their strength only over the surface of large bodies of water, while over land they quickly lose strength.

A hurricane can cause heavy rain, tornadoes, small tsunamis and floods. The direct effect of tropical cyclones on land is stormy winds that can destroy buildings, bridges and other man-made structures. The strongest sustained winds within the cyclone exceed 70 meters per second. The worst effect of tropical cyclones in terms of death toll has historically been storm surge, the rise in sea level caused by the cyclone, which on average accounts for about 90% of the casualties. Over the past two centuries, tropical cyclones have killed 1.9 million people worldwide. In addition to the direct effect on residential buildings and economic facilities, tropical cyclones destroy infrastructure, including roads, bridges, and power lines, causing enormous economic damage to the affected areas.

The most destructive and terrible hurricane in US history, Katrina, occurred at the end of August 2005. The heaviest damage was caused to New Orleans in Louisiana, where about 80% of the city's area was under water. The disaster killed 1,836 residents and caused economic losses of $125 billion.

4

Flood - flooding of an area as a result of rising water levels in rivers, lakes, seas due to rain, rapid snow melting, wind surge of water to the coast and other reasons, which damages people's health and even leads to their death, and also causes material damage . For example, in mid-January 2009, the largest flood in Brazil occurred. More than 60 cities were affected then. About 13 thousand people fled their homes, more than 800 people died. Floods and numerous landslides are caused by heavy rains.

Heavy monsoon rains continued into South-East Asia since mid-July 2001, causing landslides and floods in the Mekong River region. As a result, Thailand experienced its worst floods in half a century. Streams of water flooded villages, ancient temples, farms and factories. At least 280 people died in Thailand, and another 200 in neighboring Cambodia. Some 8.2 million people in 60 of Thailand's 77 provinces have been affected by the floods, and economic losses so far are estimated to exceed $2 billion.

Drought is a long period of stable weather with high air temperatures and low precipitation, which results in a decrease in soil moisture reserves and the suppression and death of crops. The onset of severe drought is usually associated with the establishment of a sedentary high anticyclone. The abundance of solar heat and gradually decreasing air humidity create increased evaporation, and therefore the reserves of soil moisture are depleted without replenishment by rain. Gradually, as soil drought intensifies, ponds, rivers, lakes, and springs dry up—a hydrological drought begins.

For example, in Thailand, almost every year, severe floods alternate with severe droughts, when a state of emergency is declared in dozens of provinces, and several million people feel the effects of the drought in one way or another. As for the victims of this natural phenomenon, in Africa alone, from 1970 to 2010, the death toll from droughts is 1 million people.

2

Tsunamis are long waves generated by a powerful impact on the entire thickness of water in the ocean or other body of water. Most tsunamis are caused by underwater earthquakes, during which a portion of the seabed suddenly shifts. Tsunamis are formed by an earthquake of any strength, but great strength reach those that occur due to strong earthquakes with a magnitude of more than 7 points on the Richter scale. As a result of an earthquake, several waves are propagated. More than 80% of tsunamis occur on the periphery of the Pacific Ocean. The first scientific description of the phenomenon was given by José de Acosta in 1586 in Lima, Peru, after a powerful earthquake, then a strong tsunami 25 meters high burst onto land at a distance of 10 km.

The largest tsunamis in the world occurred in 2004 and 2011. So, on December 26, 2004 at 00:58, a powerful earthquake of magnitude 9.3 occurred - the second most powerful of all recorded, which caused the deadliest tsunami of all known. Asian countries and African Somalia were hit by the tsunami. The total number of deaths exceeded 235 thousand people. The second tsunami occurred on March 11, 2011 in Japan after a strong earthquake of magnitude 9.0 with an epicenter caused a tsunami with a wave height exceeding 40 meters. In addition, the earthquake and subsequent tsunami caused the accident at the Fukushima I nuclear power plant. As of July 2, 2011, the official death toll from the earthquake and tsunami in Japan is 15,524 people, 7,130 people are missing, 5,393 people wounded.

1

An earthquake is an underground tremors and vibrations of the Earth's surface caused by natural causes. Small tremors can also be caused by the rise of lava during volcanic eruptions. About a million earthquakes occur throughout the Earth each year, but most are so small that they go unnoticed. The strongest earthquakes, capable of causing widespread destruction, occur on the planet approximately once every two weeks. Most of them fall on the bottom of the oceans, and therefore are not accompanied by catastrophic consequences if an earthquake occurs without a tsunami.

Earthquakes are best known for the devastation they can cause. Destructions of buildings and structures are caused by soil vibrations or giant tidal waves (tsunamis) that occur during seismic displacements on seabed. Powerful earthquake begins with the rupture and movement of rocks at some place deep in the Earth. This location is called the earthquake focus or hypocenter. Its depth is usually no more than 100 km, but sometimes it reaches 700 km. Sometimes the source of an earthquake can be near the surface of the Earth. In such cases, if the earthquake is strong, bridges, roads, houses and other structures are torn and destroyed.

The largest natural disaster is considered to be an earthquake of magnitude 8.2 on July 28, 1976 in the Chinese city of Tangshan, Hebei Province. According to official data from the PRC authorities, the death toll was 242,419 people, however, according to some estimates, the death toll reaches 800 thousand people. At 3:42 local time the city was destroyed by a strong earthquake. There was also destruction in Tianjin and Beijing, just 140 km to the west. As a result of the earthquake, about 5.3 million houses were destroyed or damaged so much that they were uninhabitable. Several aftershocks, the strongest of which had a magnitude of 7.1, led to even greater casualties. The Tangshan earthquake is the second-largest in history after the most destructive earthquake in Shaanxi in 1556. About 830 thousand people died then.

A natural disaster is a destructive phenomenon of enormous power, causing significant harm to the territory in which it occurs. During this type of disaster, a lot of damage is caused. These could be: earthquakes, tsunamis, landslides, droughts, floods, tornadoes, hurricanes and much more.

Classification of natural disasters

Or natural disasters, in Russia and other countries are usually classified as follows:

1. Geological phenomena.
2. Infectious diseases of people.
3. Hydrological phenomena.
4. Infectious diseases of livestock.
5. Geophysical hazards.
6. Damage to agricultural plants by pests and diseases.
7. Natural fires.
8. Marine hydrological phenomena.
9. Meteorological and agrometeorological phenomena:

• hurricanes;
• storms;
• squalls;
• tornadoes;
• vertical vortices;
• frost;
• tornado;
• showers;
• snowfalls;
• drought;
• snowstorms;
• fogs, etc.

Types of natural disasters are characterized by the magnitude of the disaster, as well as the number of victims and the amount of damage caused, and not the area of ​​the destroyed territory.

For example, even the strongest earthquakes that occur in a vast uninhabited area are not considered significant disasters, unlike weaker tremors that occur in densely populated regions.

Earthquakes

These are the most severe natural disasters in terms of the amount of damage caused, as well as the number of victims. In addition, it is quite difficult to protect against such disasters, since even taking into account the fact that seismologists make enormous efforts, earthquakes most often occur unexpectedly.

These natural disasters in Russia occur more often than it seems at first glance. In fact, half of the world's population lives in earthquake-prone regions.

How are earthquakes measured?

Thanks to seismographs, specialists record waves and vibrations of underground plates. Modern electronic devices make it possible to detect even the weakest shocks that cannot be felt.

In 1935, C. Richter created a scale, thanks to which it was possible to easily calculate and compare the power of underground vibrations. In fact, the American seismologist improved the invention of the Japanese scientist Wadachi. According to this 12-point scale, earthquakes are classified according to their power even today.

Prediction and protection

There are three: amateur, professional or scientific. There have been cases when sensitive people did the utmost accurate predictions regarding earthquakes.

The main disasters of this type are:

1. Identification of seismically active zones.
2. Study of changes in the composition of gases that come from the depths.
3. Study of the slightest changes in the relationship between the speed and duration of tremors.
4. Study of the distribution of foci in space and time.
5. Research of the magnetic field, as well as the electrical conductivity of rocks.

The consequences of natural disasters are prevented thanks to the developed protection measures. They are being developed by competent authorities specializing in the study of seismically hazardous regions in Russia.

What to do during an earthquake?

First of all, you should remain calm, as panic can only make the situation worse. If you're outdoors, try to stay away from billboards and tall spots. The people most at risk are those who run out of their homes in search of safer shelters. In fact, it is best to stay indoors with all electrical appliances turned off. It is strictly forbidden to enter the elevator during an earthquake. Such natural disasters begin as unexpectedly as they end, but nevertheless, after the last tremors, it is recommended to leave the shelter no earlier than 40 minutes later.

Tsunami

The name "tsunami" comes from a Japanese word that means "a large wave that washes away a bay." The scientific definition of this natural disaster is as follows - these are long waves of a catastrophic nature, arising mainly as a result of movement on the ocean floor.

Thus, we can say that this disaster is natural and is most often caused by an earthquake. Tsunami waves can reach lengths of 150 to 300 kilometers. In the open sea, such fluctuations are almost imperceptible. But when the wave reaches the shallow shelf, it becomes higher and practically turns into a huge moving wall. The power of the elements can destroy entire coastal cities. If the wave hits shallow bays or river mouths, it becomes even higher. In the same way that an earthquake is measured, there is a special scale that allows you to characterize the intensity of a tsunami.

• I - The tsunami is very weak. The wave is almost invisible and is recorded only by tide gauges.
• II - Tsunami is weak. May flood flat coasts.
• III - Medium strength tsunami. Floods flat coasts and can also wash light vessels ashore.
• IV - Strong tsunami. Completely floods the coast and damages coastal buildings and other structures. It throws large sailing ships and small motor boats ashore.
• V - Very strong tsunami. All coastal areas are flooded, and structures are severely damaged. Larger vessels are washed ashore and damage is also caused in inland parts of the coast. When a very strong tsunami occurs, human casualties most often occur. This type of natural disaster is quite common and affects thousands of people every year.
• VI - Catastrophic tsunami. The coast and coastal areas are completely devastated. The land and a significant area deep into the coast are completely flooded. Makes many sacrifices.

Prediction and protection

In the center of the Hawaiian Islands, in Honolulu, there is a special tsunami warning service. The organization processes data from the 31st seismic station, as well as records from more than 50 tide gauge stations. Among other things, the institution studies such natural disasters and emergencies. The service can predict the occurrence of a tsunami at the earliest 15-20 minutes before the incident. Therefore, the message must be transmitted immediately in order to have time to take all necessary security measures.

In order to protect yourself from a tsunami, you should remain calm, just as in the case of earthquakes. It is necessary to move as far as possible from the coastal strip and try to climb as high as possible. The most dangerous thing is that many people prefer to stay on the coast on the roofs of their houses. In fact, the force of the wave can be so crushing that it can easily wipe out even the most stable object from the face of the earth. A tsunami is a natural and extremely dangerous disaster.

Volcanic eruptions

Characterized by volcanic processes that can cause a disaster. These can be lava flows, eruptions, hot mud flows, scorching clouds and much more.

The greatest danger is posed by lava, which is molten rock heated to a temperature of more than 1000 degrees. This liquid flows directly from cracks in the ground or simply overflows over the edge of the crater and slowly flows to the foot. The consequences of natural disasters caused by a volcanic eruption are extremely dangerous for humans.

Lava flows are also a fairly serious threat. Despite the fact that the mass seems to move rather slowly, it is worth considering the fact that high temperatures generate hot air currents that can threaten human life even at a great distance.

Prediction and protection

Experience and practice suggest that lava flows can be eliminated by bombing from aircraft. Due to this, the speed of movement of hot flows slows down significantly.

Today, natural disasters such as “eruption” are eliminated thanks to artificial gutters that allow hot flows to be diverted. A fairly effective method is the construction of safety dams.

Besides this, there is another danger. Mechanical mud flows are actually much more dangerous than lava and, according to statistics, the number of victims affected by them is many times greater. The fact is that the ash layers are in a rather unstable position. If volcanic ash becomes saturated with water, it begins to resemble liquid porridge, which can roll down the slope at great speed. It is almost impossible to protect yourself from these mud flows, since they move quite quickly, and most often there is simply no time left for evacuation. Such natural disasters in Russia most often occur in Kamchatka, since it is in this region that the largest number of active volcanoes are located.

Weaker mud flows can be protected from by dams or specially designed gutters. In some Indonesian settlements, residents build artificial hills at the foot of the volcano. During a natural phenomenon that threatens serious danger, settlers climb these mounds and thus avoid the hot mud flows.

Another danger is that when glaciers melt from volcanic eruptions, they create a huge amount of water. This could lead to severe flooding in the future. Thus, disasters and natural disasters can provoke each other.

Volcanic gases are also dangerous. They contain impurities of sulfur dioxide, hydrogen sulfide and these combinations are deadly to humans.

The only protection against such gases is a gas mask.

Landslides

These phenomena are formed when natural processes (or, as most often happens, people) disrupt the stability of the slope.

At the moment when the force of rocks becomes less than the force of gravity, the entire earth mass begins to move. Sometimes such masses slide down the slopes almost unnoticed. But in some cases, their speed turns out to be quite high and can be more than 100 km/h.

The largest natural phenomenon of this type is considered to be an event that occurred in 1911 in the Pamirs in Russia. The giant landslide was triggered by an earthquake. According to researchers, more than 2.5 cubic kilometers of loose material slid that day. The village of Usoy and all 54 residents were completely overwhelmed. Such catastrophic types of natural disasters occur quite often not only in Russia, but also in many other countries.

If we talk about the number of victims, the worst landslide was a natural disaster that occurred in 1920 in China. Just like in the Pamirs, the phenomenon was caused by a strong earthquake, as a result of which loose material filled up the Kansu Valley and all its cities and villages. According to preliminary estimates, more than 200,000 people died.

Prediction and protection

The only way to truly protect against landslides is to prevent them. Specialists - engineers and geologists - have developed a special set of preventive measures designed to prepare the population for such phenomena, as well as to explain what an accident, catastrophe, natural disaster, etc. is.

But unfortunately, when the sliding has already begun, any methods of protection become ineffective. According to research, main reason landslides are caused by water, so the first stage of conservation work is the collection and removal of excess moisture.

It is quite difficult to predict such natural phenomena, since in this case the amount of precipitation does not affect the formation of landslides, just like the atmosphere. Natural disasters of this type can occur unexpectedly and result from earthquakes.

Snow avalanches

The largest avalanches have killed more than 10,000 people over the past decade. The fact is that the flow speed can vary from 25 to 360 km/h. There are three types of avalanches: large, medium and small.

The big ones demolish almost everything in their path, easily erasing villages and other objects from the face of the earth. Medium ones are dangerous only for people, since they are not able to destroy buildings. Small avalanches are practically not dangerous and, in principle, invisible to humans.

Prediction and protection

As in other situations, the most important role in protection is played by specialists who can easily identify avalanche-prone slopes and, most often, liquidation of the consequences of natural disasters is not necessary. In addition, most avalanches descend along the same routes.

In order to predict the approach of an avalanche, the direction of the wind and the amount of precipitation are studied in detail. If the snow falls 25 mm thick, then there is a small probability of such a disaster. If the height is 55 mm, then the possibility of an avalanche increases. And when 100 mm of fresh snow falls, there is the greatest likelihood of an avalanche within a few hours.

To protect against natural disasters, avalanche-prone slopes are protected with barrier shields. If it was not possible to stop the disaster, shelling of the snowy slopes is carried out. This provokes the gathering of smaller and less dangerous masses.

Floods and natural disaster - flood

There are two types of floods: river and sea. Today, these natural phenomena pose a threat to ¾ of the planet's population.

Similar natural disasters, which occurred between 1947 and 1967, killed more than 200,000 people. For residents of Russia, this issue is very relevant. For example, St. Petersburg was flooded 245 times. The largest of them occurred in 1824, and was even described by A. S. Pushkin in the poem “ Bronze Horseman" The fact is that the city is located at the bottom of the coastal plain, and as soon as the water rises by 150 cm, moisture begins to seep.

Prediction and protection

Natural disaster - flooding and its prevention requires compliance with land use rules and proper development settlements. By regulating river flows and protecting surrounding areas, the threat of flooding can be reduced to a minimum. These can also be stable barrier dams that will provide full or partial protection. In order to implement long-term protection from natural disasters, it is necessary to ensure regular maintenance and monitoring of coastal areas.

The main factor responsible for the intensity of floods is the amount of precipitation. For this purpose, morphological and biological factors are also studied.

To date, the World Emergency Commission has developed special instructions in case of floods and floods. Let's get acquainted with the most important of them.

1. Before a flood, you need to prepare sandbags and clean out sewers, as well as provide yourself with energy sources. It is important to stock up on drinking water and food. Elimination of natural disasters of this kind can take quite a long time.
2. During floods, you should avoid low-lying areas that may eventually become flooded. You must move with extreme caution. If the water is above your knees, you should never cross flooded areas. It is impossible to visually assess the strength of the flow.
3. After a flood, you should not eat foods that have been soaked by flood waters. They may contain bacteria. The same applies to drinking water, which should not be drunk without sanitary inspection.

When forecasting floods, storm surges and floods, meteorological factors are taken into account, as well as the movement of low pressure areas (cyclones and strong winds). The morphology of the coast is assessed, and the state of the water level is also taken into account according to the tide table.

Finally

In addition to the above natural phenomena, there is also a fire (natural disaster or as a consequence of human activity), tornado, hurricane and storm, which are extremely dangerous to human life.

In order to prevent and protect yourself from a disaster, you need to strictly follow all the recommendations of experts and always be prepared for such natural disasters.