Natural hazards. Hazardous natural phenomena (HAP) on the territory of the Russian Federation and emergencies that have arisen

The classification of natural includes the main types of extraordinary events of natural origin.

An analysis of the development of natural catastrophic phenomena on Earth shows that, despite scientific and technological progress, the protection of people and the technosphere from natural hazards does not increase. The number of victims in the world from destructive natural phenomena in last years increases annually by 4.3%, and the number of victims - by 8.6%. Economic losses are growing by an average of 6% per year. Currently, there is an understanding in the world that natural disasters are global problem, which is the source of the deepest humanitarian shocks and is one of the critical factors that determine the sustainable development of the economy. The main reasons for the preservation and aggravation of natural hazards may be an increase in anthropogenic impact on the natural environment; irrational placement of objects of the economy; resettlement of people in areas of potential natural danger; insufficient efficiency and underdevelopment of environmental monitoring systems; weakening state systems observation of natural processes and phenomena; absence or poor condition of hydraulic engineering, anti-landslide, anti-mudflow and other protective engineering structures as well as protective afforestation; insufficient volumes and low rates of earthquake-resistant construction, strengthening of buildings and structures in earthquake-prone areas; lack or inadequacy of inventories potentially dangerous areas(regularly flooded, especially earthquake hazardous, mudflow hazardous, avalanche hazardous, landslide, tsunami hazardous, etc.).

On the territory of Russia, there are more than 30 dangerous natural phenomena and processes, among which the most destructive are floods, storm winds, downpours, hurricanes, tornadoes, earthquakes, forest fires, landslides, mudflows, avalanches. Most of the social and economic losses are associated with the destruction of buildings and structures due to insufficient reliability and protection from hazardous natural influences. The most frequent in Russia are natural catastrophic phenomena of an atmospheric nature - storms, hurricanes, tornadoes, squalls (28%), followed by earthquakes (24%) and floods (19%). Hazardous geological processes such as landslides and avalanches account for 4%. The remaining natural disasters, among which forest fires have the highest frequency, in total are equal to 25%. Total annual economic damage from development 19 most dangerous processes in urban areas in Russia is 10-12 billion rubles. in year.

Of the geophysical extraordinary events, earthquakes are one of the most powerful, terrible and destructive natural phenomena. They appear suddenly, it is extremely difficult to predict the time and place of their appearance, and even more so to prevent their development, and most often it is impossible. In Russia, zones of increased seismic hazard occupy about 40% of the total area, including 9% of the territory belong to 8-9-point zones. More than 20 million people live in seismically active zones (14% of the country's population).

Within the seismically dangerous regions of Russia there are 330 settlements, including 103 cities (Vladikavkaz, Irkutsk, Ulan-Ude, Petropavlovsk-Kamchatsky, etc.). Most dangerous consequences earthquakes are the destruction of buildings and structures; fires; releases of radioactive and emergency chemical hazardous substances due to the destruction (damage) of radiation and chemically hazardous objects; transport accidents and disasters; defeat and loss of life.

A striking example of the socio-economic consequences of strong seismic events is the Spitak earthquake in Northern Armenia on December 7, 1988. This earthquake (magnitude 7.0) affected 21 cities and 342 villages; 277 schools, 250 health care facilities were destroyed or were in disrepair; more than 170 industrial enterprises ceased to function; about 25 thousand people died, 19 thousand received varying degrees injury and injury. Total economic losses amounted to $ 14 billion.

From geological extraordinary events great danger due to the massive nature of distribution represent landslides and mudflows... The development of landslides is associated with displacement of large masses rocks on the slopes under the influence of gravitational forces. Precipitation and earthquakes contribute to the formation of landslides. V Russian Federation annually from 6 to 15 emergencies associated with the development of landslides are created. Landslides are widespread in the Volga region, Transbaikalia, the Caucasus and Ciscaucasia, Sakhalin and other regions. Urbanized areas are particularly affected: 725 Russian cities are affected by landslides. Mudflows are powerful streams saturated solid materials descending mountain valleys from great speed... The formation of mudflows is accompanied by rainfall in the mountains, intensive melting of snow and glaciers, as well as the breakthrough of dammed lakes. Mudflow processes occur on 8% of the territory of Russia and develop in the mountainous regions of the North Caucasus, Kamchatka, the Northern Urals and the Kola Peninsula. There are 13 cities under the direct threat of mudflows in Russia, and 42 more cities are located in potentially mudflow-prone areas. The unexpected nature of the development of landslides and mudflows often leads to the complete destruction of buildings and structures, accompanied by casualties and large material losses. Among hydrological emergencies, floods can be one of the most common and dangerous natural phenomena. In Russia, floods rank first among natural Disasters in frequency, area of ​​distribution, material damage and second place after earthquakes in the number of victims and specific material damage (damage per unit of affected area). One severe flood covers an area of ​​the river basin of about 200 thousand km2. On average, every year up to 20 cities are flooded and up to 1 million inhabitants are affected, and in 20 years almost the entire territory of the country is covered by serious floods.

On the territory of Russia, from 40 to 68 crisis floods occur annually. The threat of floods exists for 700 cities and tens of thousands of settlements, a large number of economic facilities.

Floods are associated with significant material losses every year. In recent years, the two largest floods have occurred in Yakutia on the river. Lena. In 1998, 172 settlements were flooded here, 160 bridges, 133 dams, 760 km of roads were destroyed. The total damage amounted to 1.3 billion rubles.

The flood in 2001 was even more destructive. During this flood, the water in the r. Lena rose 17 m and flooded 10 administrative districts of Yakutia. Lensk was completely flooded. About 10,000 houses were submerged, about 700 agricultural and more than 4,000 industrial facilities were damaged, and 43,000 people were relocated. The total economic damage amounted to 5.9 billion rubles.

Significant role in increasing the frequency and destructive force floods play - deforestation, irrational agriculture and economic development of floodplains. Inappropriate implementation of flood protection measures, leading to the breakage of dams, can lead to the formation of floods; destruction of artificial dams; emergency discharges of reservoirs. The aggravation of the problem of floods in Russia is also associated with the progressive aging of the fixed assets of the water sector, the placement of household facilities and housing in flood-prone areas. In this regard, the development and implementation of effective flood prevention and protection measures may be an urgent task.

Among the atmospheric hazardous processes taking place on the territory of Russia, the most destructive are hurricanes, cyclones, hail, tornadoes, heavy showers, snowfalls.

A traditional disaster in Russia is a forest fire. Annually, from 10 to 30 thousand forest fires occur on the territory of the country on an area of ​​0.5 to 2 million hectares.

Preliminary forecast of the main dangers and threats for Russia in early XXI v. indicates that by 2010 destructive earthquakes may occur in three seismological regions: Kamchatka - Kurile Islands, The Baikal region and the North Caucasus. One devastating earthquake may occur in each of these regions. Without preventive measures, tens of thousands of lives could be lost and damage of the order of US $ 10 billion. Today we cannot exclude the occurrence of 3-5 man-made earthquakes, one devastating tsunami on the Pacific coast, one or two catastrophic floods, as well as an increase in the number of forest and peat fires.

All processes in nature are cyclical. At a certain time, there is a change of seasons, each of which is beautiful in its own way and for a certain season has its own natural phenomena... Some phenomena seem so simple and natural that we do not notice them and take them for granted, and, meanwhile, each phenomenon of nature is unique, even the most familiar of them is subject to the corresponding laws of nature.
Consider natural phenomena, common and rare, characteristic of our latitudes.

Dew... The air contains water vapor, which condenses as it sinks to the ground. Dew appears on cool summer evenings and early mornings on the leaves and stems of plants. When the thermometer drops below zero, frost forms.

Rainbow is an optical natural phenomenon that occurs in the atmosphere as a result of the refraction of sunlight by raindrops. A rainbow can be observed during or immediately after a summer rain, when sunlight passes through the rain streams.

Storm is electrical discharges that collect in the atmosphere.
A thundercloud is charged with positive and negative particles. Lightning occurs as a result of the collision of clouds with the signs "-" and "+".
An electric field arises between the ground and the cloud, and the air is ionized. When the incandescence reaches its peak, breakdown occurs and lightning strikes the ground.
Sound waves during electrical discharges create an echo, i.e. thunder rolls.
There are lightning different types: linear, the most common, as well as more rare, pearl and ball. Ball lightning has the shape of a ball or oval. The phenomenon appears quickly and disappears just as quickly. It is almost impossible to predict the trajectory of the fireball.
Pearl Lightning appear after the linear and have a rounded shape, accompanied by thunder.

Another wonderful and mysterious phenomenon that can be observed almost all year round is meteorite or star Rain... On a dark, clear night, bright light rays line the sky. The intensity of the streams is different, depending on the season, and such stellar showers are repeated every year at about the same time, only the intensity and brightness are different. The most spectacular starfall can be observed on August 12 and the peak of the Perseid activity.

northern Lights- a fascinating and very spectacular phenomenon of nature.
On the territory of our country, the northern lights can be seen in almost all regions located near the Arctic Circle, from Murmansk to Chukotka.
Aurora Borealis is a bright glow in the dark sky, which is formed due to the interaction of the upper atmosphere with charged particles from the sun.
The more active the sun, the more likely the onset of the northern lights. The spectacle is accompanied by a crash.

Halo... This phenomenon is scientifically based and is not rare. Sometimes a bright circle of light can be observed in the sky, formed by the refraction of the sun's rays in the ice crystals contained in the body of the cloud. In the immediate vicinity of the main circle, luminous circles of a smaller diameter can be observed. The halo phenomenon looks very impressive.

Eclipse occurs when the glow of one object is overlapped by another object.
Moon eclipse occurs when the Moon is in the cone-shaped area of ​​the shadow cast by the Earth.
Solar eclipse happens when the Moon is between the observation point and the Sun and obscures it. Immediately before the eclipse, the Moon looks at the Earth with an unlit side and before the eclipse there is a new moon, the moon is not visible in the sky.

Natural phenomena are truly unique and are of great interest to researchers and amateurs. Dangerous phenomena also occur, such as, for example, a volcanic eruption, a hurricane or a flood. They have a powerful destructive force, before which a person is helpless. Nature is fraught with a myriad of mysteries and questions, the answers to which will have to be given to future generations of scientists and researchers.

The earth is fraught with many unusual and sometimes unexplained phenomena, and from time to time throughout the territory the globe all sorts of phenomena and even cataclysms occur, most of which can hardly be called ordinary and familiar to humans. Some cases have quite explainable reasons, but there are some that even experienced scientists have not been able to interpret for many decades in a row. True, of this kind natural disasters do not happen often, only a few times during the year, but, nevertheless, humanity's fear of them does not disappear, but, on the contrary, grows.

The most dangerous natural phenomena

These include the following types disasters:

Earthquakes

This is a dangerous natural phenomenon in the ranking of the most dangerous natural anomalies. Tremors of the earth's surface, arising in places of ruptures of the earth's crust, provoke vibrations that turn into seismic waves of significant power. They are transmitted over considerable distances, but they become strongest near the immediate focus of tremors and provoke large-scale destruction of houses and buildings. Since there are a lot of buildings on the planet, there are millions of victims. For all the time, earthquakes have affected many more people in the world than from other cataclysms. In the last ten years alone, more than seven hundred thousand people have died from them in different countries of the world. Sometimes the tremors reached such force that entire settlements were destroyed in an instant.

Tsunami waves

Tsunamis are natural disasters that cause a lot of destruction and death. The huge heights and strength of the waves that occur in the ocean, or in other words, tsunamis, are the result of earthquakes. These giant waves usually arise in areas where seismic activity significantly increased. Tsunami moves very quickly, and as soon as it gets aground, it begins to grow rapidly in length. As soon as this huge fast wave reaches the coast, it is able to demolish everything in its path in a matter of minutes. The devastation caused by a tsunami is usually large-scale, and people who are caught off guard by the cataclysm often do not have time to escape.

Ball lightning

Lightning and thunder are common things, but such a type as ball lightning is one of the most terrible natural phenomena. Ball lightning is a powerful electrical discharge of current, and it can take absolutely any shape. Typically, this type of lightning resembles glowing balls, most often reddish or yellow in color. It is curious that these lightning bolts completely ignore all the laws of mechanics, appearing out of nowhere, usually before a thunderstorm, inside houses, on the street or even in the cockpit of an airplane that is flying. Ball-shaped lightning hovers in the air, and does it very unpredictably: for a few moments, then it becomes smaller, and then disappears altogether. It is strictly forbidden to touch ball lightning; it is also undesirable to move when meeting with it.

Tornadoes

This natural anomaly also belongs to the most terrible natural phenomena. Usually a tornado is called an air flow that swirls into a kind of funnel. Outwardly, it looks like a pillar-shaped cone-shaped cloud, inside which air moves in a circle. All objects that fall into the tornado zone also begin to move. The speed of the air flow inside this funnel is so huge that it can easily lift very heavy objects weighing several tons into the air and even houses.

Sand storms

This type of storm occurs in deserts due to strong winds. Dust and sand, and sometimes particles of soil, carried by the wind, can reach several meters in height, and in the area where the storm broke out, there will be a sharp deterioration in visibility. Travelers, caught in such a storm, risk dying, because the sand gets into the lungs and eyes.

Bloody rains

This unusual natural phenomenon owes its threatening name to a strong water tornado, which sucked out particles of red algae spores from the water in reservoirs. When they mix with the watery masses of a tornado, the rain takes on an awful red hue, very reminiscent of blood. This anomaly was observed by the inhabitants of India for several weeks in a row, rain color human blood caused fear and panic in people.

Fire tornado

Natural events and disasters are often unpredictable. These include one of the worst - fire tornado... This kind of tornado is already dangerous, but , if it occurs in a fire zone, it should be even more feared. Near several fires, when a strong wind occurs, the air above the fires begins to heat up, its density becomes less, and it begins to rise upward along with the fire. In this case, the air currents twist into a kind of spiral, and the air pressure acquires a tremendous speed.

The fact that the most terrible natural phenomena are poorly predicted. They often come suddenly, catching people and authorities by surprise. Scientists are working to create advanced technologies that can predict upcoming events... Today, the only guaranteed way to avoid the "whims" of the weather is only moving to areas where such phenomena are observed as rarely as possible or have not been recorded earlier.

Natural phenomena are common, sometimes even supernatural, climatic and meteorological events that occur naturally in all corners of the planet. It can be snow or rain familiar from childhood, or it can be incredible destructive or earthquakes. If such events take place away from the person and do not cause him material damage, they are considered not important. Nobody will focus on this. Otherwise, dangerous natural phenomena are considered by humanity as natural disasters.

Research and observation

People began to study characteristic natural phenomena back in deep antiquity... However, it was possible to systematize these observations only in the 17th century; even a separate section of science (natural science) was formed that studies these events. However, despite many scientific discoveries, to this day, some natural phenomena and processes remain poorly understood. Most often we see the consequence of this or that event, and we can only guess about the root causes and build various theories... Researchers in many countries are working on making forecasts of their occurrence, and most importantly, preventing their possible occurrence, or at least reducing the damage caused by natural phenomena. And yet, despite all the destructive power of such processes, a person always remains a person and seeks to find something beautiful, sublime in this. What is the most fascinating natural phenomenon? They can be enumerated for a long time, but, perhaps, it should be noted such as volcanic eruptions, tornadoes, tsunamis - they are all beautiful, despite the destruction and chaos that remain after them.

Weather phenomena of nature

Natural phenomena characterize the weather with its seasonal changes. Each season is distinguished by its own set of events. So, for example, in spring the following snowmelt, flood, thunderstorms, clouds, wind, and rains are observed. In the summer, the sun gives the planet an abundance of warmth, natural processes at this time are most favorable: clouds, warm wind, rains and, of course, a rainbow; but they can also be severe: thunderstorms, hail. In autumn they change, the temperature drops, the days become cloudy, with rains. During this period, the following phenomena prevail: fog, leaf fall, frost, first snow. In winter, the flora falls asleep, some animals go into hibernation. The most frequent natural phenomena are: freeze-up, blizzard, blizzard, snow, appear on the windows

All these events are commonplace for us, we have not paid attention to them for a long time. Now let's look at the processes that remind humanity that it is not the crown of everything, and planet Earth just sheltered it for a while.

Dangerous natural phenomena

These are extreme and severe climatic and meteorological processes that occur in all parts of the world, but some regions are considered more vulnerable to certain types of events than others. Hazardous natural phenomena become disasters when infrastructure is destroyed and people die. These losses represent the main obstacles to human development. It is practically impossible to prevent such cataclysms, all that remains is timely forecasting of events in order to prevent casualties and material damage.

However, the difficulty lies in the fact that hazardous natural phenomena can occur at different scales and at different times. In fact, each of them is unique in its own way, and therefore it is very difficult to predict it. For example, flash floods and tornadoes are destructive but short-lived events that affect relatively small areas. Other dangerous disasters, such as droughts, can develop very slowly, but they affect entire continents and entire populations. Such disasters last for several months, and sometimes years. In order to control and predict these events for some national hydrological and meteorological services and special specialized centers are entrusted with the tasks of studying dangerous geophysical phenomena. This includes volcanic eruptions, airborne ash transport, tsunamis, radioactive, biological, chemical pollution, etc.

Now let's take a closer look at some natural phenomena.

Drought

The main reason for such a cataclysm is the lack of precipitation. Drought is very different from other natural disasters in its slow development, often its onset is hidden by various factors. In world history, there are even recorded cases when this disaster lasted for many years. Drought often has dire consequences: first, water sources (streams, rivers, lakes, springs) dry up, many crops cease to grow, then animals die, and poor health and malnutrition become widespread realities.

Tropical cyclones

These natural phenomena are areas of very low atmospheric pressure over subtropical and tropical waters, forming a colossal rotating system of thunderstorms and winds hundreds (sometimes thousands) of kilometers across. The speed of surface winds in a tropical cyclone zone can reach two hundred kilometers per hour or even more. The interaction of low pressure and wind-induced waves often leads to coastal storm surge - a huge volume of water washed ashore with tremendous force and speed, which washes everything in its path.

Air pollution

These natural phenomena arise as a result of the accumulation of harmful gases or particles of substances in the air resulting from cataclysms (volcanic eruptions, fires) and human activities (the work of industrial enterprises, vehicles, etc.). Haze and smoke appear as a result of fires in undeveloped lands and forests, as well as the burning of agricultural crops and logging residues; in addition, due to the formation of volcanic ash. These elements polluting the atmosphere have very serious consequences for the human body. As a result of such cataclysms, visibility is reduced, there are interruptions in the operation of road and air transport.

Desert locust

Such natural phenomena cause serious damage in Asia, the Middle East, Africa and the southern part of the European continent. When environmental and weather conditions are favorable for the reproduction of these insects, they tend to concentrate in small areas. However, with an increase in the number of locusts, they cease to be an individual being and turn into a single living organism. From small groups, huge flocks are formed, moving in search of food. The length of such a jamb can reach tens of kilometers. In a day, he can cover distances of up to two hundred kilometers, sweeping away all the vegetation in his path. So, one ton of locusts (this is a small part of the flock) can eat as much food per day as ten elephants or 2500 people eat. These insects threaten millions of pastoralists and farmers living in vulnerable environments.

Short-term flash floods and floods

Data can happen anywhere after heavy rainfall. Any river floodplains are vulnerable to flooding, and severe storms cause flash floods. In addition, short-term floods are sometimes even observed after periods of drought, when very heavy rainfall falls on a hard and dry surface through which water flow cannot seep into the ground. These natural events are characterized by the most various types: from violent small floods to a thick layer of water that covers vast territories. They can be caused by tornadoes, severe thunderstorms, monsoons, extratropical and tropical cyclones (their strength can be increased by exposure to warm current El Niño), melting snow and ice jams. In coastal areas, storm surges often result in flooding due to tsunamis, cyclones or rising river levels due to unusually high tides. The flooding of huge areas below the barrier dams is often caused by floods in rivers, which are caused by melting snow.

Other natural hazards

1. Mudflow (mud) stream or landslide.

5. Lightning.

6. Extreme temperatures.

7. Tornado.

10. Fires in undeveloped land or forests.

11. Heavy snow and rain.

12. Strong winds.

Grishin Denis

Natural disasters have threatened the inhabitants of our planet since the beginning of civilization. Somewhere more, somewhere less. One hundred percent security does not exist anywhere. Natural disasters can cause colossal damage. In recent years, the number of earthquakes, floods, landslides and other natural disasters has been steadily increasing. In my essay, I want to consider hazardous natural processes in Russia.

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ADMINISTRATION OF THE CITY OF NIZHNY NOVGOROD

Municipal budgetary educational institution

secondary school number 148

Scientific Society of Students

Hazardous natural phenomena in Russia

Completed by: Grishin Denis,

6a grade student

Supervisor:

Sinyagina Marina Evgenievna,

geography teacher

Nizhny Novgorod

27.12.2011

PLAN

P.

Introduction

Chapter 1. Dangerous natural phenomena (natural emergencies).

1.1. Emergencies concept.

1.2 Geographic natural disasters.

1.3 Natural disasters of a meteorological nature.

1.4 Natural disasters of a hydrological nature.

1.5 Natural fires.

Chapter 2. Natural disasters in the Nizhny Novgorod region.

Chapter 3: Measures for dealing with natural disasters.

Conclusion

Literature

Applications

Introduction

In my essay, I want to consider hazardous natural processes.

Natural disasters have threatened the inhabitants of our planet since the beginning of civilization. Somewhere more, somewhere less. One hundred percent security does not exist anywhere. Natural disasters can cause colossal damage.

Natural emergencies (natural disasters) have tended to grow in recent years. The actions of volcanoes (Kamchatka) become more active, the cases of earthquakes (Kamchatka, Sakhalin, Kuriles, Transbaikalia, North Caucasus) become more frequent, their destructive power increases. Floods have become almost regular ( Far East, Caspian lowland, Southern Urals, Siberia), landslides are frequent along rivers and in mountainous regions. Ice, snow drifts, storms, hurricanes and tornadoes visit Russia every year.

Unfortunately, in the zones of periodic flooding, the construction of multi-storey buildings continues, which increases the concentration of the population, underground communications are being laid, and dangerous industries are functioning. All this leads to the fact that the usual forfloods in these places are causing more and more catastrophic consequences.

In recent years, the number of earthquakes, floods, landslides and other natural disasters has been steadily increasing.

The purpose of my essay is to study natural emergencies.

The task of my work is to study dangerous natural processes (natural emergencies) and measures to protect against natural disasters.

1. Natural emergencies concept

1.1 Natural emergencies -the situation in a certain territory or water area as a result of a source of natural emergencies that may or will entail human casualties, damage to human health or the environment, significant losses and disruption of the living conditions of people.

Natural emergencies are distinguished by the nature of the source and the scale.

Natural emergencies themselves are very diverse. Therefore, based on the reasons (conditions) of occurrence, they are divided into groups:

1) dangerous geophysical phenomena;

2) dangerous geological phenomena;

3) dangerous meteorological phenomena;

4) marine hazardous hydrometeorological phenomena;

5) hazardous hydrological phenomena;

6) natural fires.

Below I want to take a closer look at these types of natural emergencies.

1.2. Natural disasters of a geophysical nature

Natural disasters related to geological natural phenomena are subdivided into disasters caused by earthquakes and volcanic eruptions.

EARTHQUAKES - these are tremors and vibrations of the earth's surface, caused mainly by geophysical reasons.

Complex processes are constantly taking place in the bowels of the earth. Under the action of deep tectonic forces, stresses arise, layers of earth rocks are deformed, compressed into folds and, with the onset of critical overloads, are displaced and torn, forming faults in the earth's crust. The break is made by an instantaneous impact or by a series of impacts having the character of a blow. During an earthquake, the energy accumulated in the bowels is discharged. The energy released at depth is transmitted by means of elastic waves in the thickness of the earth's crust and reaches the surface of the Earth, where destruction occurs.

There are two main seismic belts: the Mediterranean-Asian and the Pacific.

The main parameters characterizing an earthquake are their intensity and source depth. The intensity of the manifestation of an earthquake on the Earth's surface is estimated in points (see. Table 1 in the Appendices).

Earthquakes are also classified by reason of their occurrence. They can arise as a result of tectonic and volcanic manifestations, landslides (rock bumps, landslides) and, finally, as a result of human activities (filling reservoirs, pumping water into wells).

Of considerable interest is the classification of earthquakes not only by their magnitude, but also by their number (frequency of recurrence) throughout the year on our planet.

Volcanic activity

arises as a result of constant active processes occurring in the depths of the Earth. After all interior is constantly in a heated state. During tectonic processes in earth crust cracks are formed. Magma rushes along them to the surface. The process is accompanied by the release of water vapors and gases, which create tremendous pressure, removing obstacles in its path. When it comes to the surface, part of the magma turns into slag, and the other part is poured out in the form of lava. From the vapors and gases released into the atmosphere, volcanic rocks called tephra are deposited on the ground.

According to the degree of activity, volcanoes are classified into active, dormant and extinct. The active ones include those that erupted in historical time. The extinct ones, on the contrary, did not erupt. The dormant ones are characterized by the fact that they periodically manifest themselves, but the matter does not come to an eruption.

Most dangerous phenomena accompanying volcanic eruptions are lava flows, tephra fallout, volcanic mud flows, volcanic floods, scorching volcanic clouds and volcanic gases.

Lava flows - these are molten rocks with a temperature of 900 - 1000 °. The flow rate depends on the slope of the cone of the volcano, the degree of viscosity of the lava and its amount. The range of speeds is quite wide: from a few centimeters to several kilometers per hour. In some and the most dangerous cases, it reaches 100 km, but more often it does not exceed 1 km / h.

Tephra is composed of solidified lava fragments. The largest are called volcanic bombs, the smaller ones are called volcanic sand, and the smallest are called ash.

Mud streams - These are thick layers of ash on the slopes of the volcano, which are in an unstable position. When new portions of ash fall on them, they slide down the slope.

Volcanic floods... When glaciers melt during eruptions, huge amounts of water can form very quickly, leading to floods.

A scorching volcanic cloud is a mixture of hot gases and tephra. Its striking effect is due to the occurrence shock wave (strong wind), spreading at a speed of up to 40 km / h, and a shaft of heat with a temperature of up to 1000 °.

Volcanic gases... The eruption is always accompanied by the release of gases mixed with water vapor - a mixture of sulfurous and sulfuric oxides, hydrogen sulfide, hydrochloric and hydrofluoric acids in gaseous state, as well as carbon dioxide and carbon monoxide in high concentrations, fatal to humans.

Classification of volcanoesis made according to the conditions of their occurrence and the nature of the activity. On the first basis, four types are distinguished.

1) Volcanoes in subduction zones or zones of subduction of the oceanic plate under the mainland. Due to thermal concentration in the bowels.

2) Volcanoes in rift zones. They arise in connection with the weakening of the earth's crust and the bulging of the boundary between the crust and mantle of the Earth. The formation of volcanoes here is associated with tectonic phenomena.

3) Volcanoes in large fault zones. In many places of the earth's crust there are breaks (faults). There is a slow accumulation of tectonic forces that can turn into a sudden seismic explosion with volcanic manifestations.

4) Volcanoes of "hot spot" zones. In some areas under the ocean floor, "hot spots" are formed in the earth's crust, where especially high thermal energy is concentrated. In these places, rocks are melted and come to the surface in the form of basalt lava.

By the nature of their activity, volcanoes are divided into five types (see. Table 2)

1.3. Natural disasters of a geological nature

Natural disasters of a geological nature include landslides, mudflows, avalanches, landslides, subsidence of the earth's surface as a result of karst phenomena.

Landslides is a sliding displacement of rock masses down the slope under the influence of gravity. They are formed in various rocks as a result of imbalance or weakening of strength. Caused by both natural and artificial (man-made) causes. Natural include: an increase in the steepness of slopes, washing away their foundations by sea and river waters, seismic tremors... The destruction of slopes by road excavations, excessive soil removal, deforestation, and unreasonable farming on the slopes are artificial. According to international statistics, up to 80% of modern landslides are associated with human activities. they are at any time of the year, but most of in the spring and summer.

Landslides are classifiedby the scale of the phenomenon, speed of movement and activity, the mechanism of the process, power and place of formation.

In terms of scale, landslides are classified into large, medium and small-scale.

Large ones are caused, as a rule, by natural causes and are formed along the slopes for hundreds of meters. Their thickness reaches 10 - 20 meters and more. The landslide body often retains its solidity.

Medium and small-scale are smaller and are typical for anthropogenic processes.

The scale is often characterized by the area involved. The movement speed is very diverse.

According to their activity, landslides are subdivided into active and inactive. The main factors here are the rocks of the slopes and the presence of moisture. Depending on the amount of moisture, they are divided into dry, slightly moist, moist and very moist.

By the mechanism of the process, they are subdivided into: shear landslides, extrusion, viscoplastic, hydrodynamic carryover, sudden liquefaction. They often show signs of a combined mechanism.

According to the place of formation, they are subdivided into mountain, underwater, adjacent and artificial earth structures (pits, canals, rock dumps).

Mudflow (mudflow)

A turbulent mud or mud-stone stream, consisting of a mixture of water and rock debris, suddenly arises in the basins of small mountain rivers... It is characterized by a sharp rise in the water level, wave movement, short duration of action (on average from one to three hours), significant erosion-accumulative destructive effect.

The immediate causes of the emergence of graying are showers, intense snow melting, the breakthrough of water bodies, less often earthquakes, volcanic eruptions.

All mudflows are subdivided into three types according to the origin mechanism: erosional, breakthrough and landslide-landslide.

In case of erosion, the water flow is initially saturated with detrital material due to washout and erosion of the adjacent soil, and then a mudflow wave is formed.

When a landslide landslide, the mass breaks down to saturated rocks (including snow and ice). The flow saturation in this case is close to maximum.

In recent years, man-made factors have been added to the natural causes of the formation of mudflows: violation of the rules and norms of the work of mining enterprises, explosions during the laying of roads and the construction of other structures, felling of forests, improper agricultural work and violation of soil and vegetation cover.

When driving, the mudflow is a continuous stream of mud, stones and water. On the basis of the main factors of occurrence, mudflows are classified as follows;

Zonal manifestation. The main factor of formation is climatic conditions (precipitation). They are of a zonal character. The gathering takes place systematically. The paths of movement are relatively constant;

Regional manifestation. The main factor of formation is geological processes. The descent occurs sporadically, and the paths of movement are unstable;

Anthropogenic. This is the result economic activity person. Occur where the greatest stress on the mountainous landscape. New mudflow basins are being formed. The gathering is episodic.

Snow avalanches - snow masses falling from the slopes of the mountains under the influence of gravity.

Snow that accumulates on the slopes of the mountains, under the influence of the severity and weakening of structural bonds within the snow mass, slides or crumbles from the slope. Having started its movement, it quickly picks up speed, capturing new snow masses, stones and other objects along the way. The movement continues to flatter areas or the bottom of the valley, where it slows down and stops.

The formation of avalanches occurs within the avalanche center. An avalanche center is an area of ​​a slope and its foot, within which an avalanche moves. Each focus consists of 3 zones: initiation (avalanche collection), transit (tray), avalanche stop (fan cone).

The avalanche-forming factors include: the height of the old snow, the state of the underlying surface, the increase in fresh snow, the density of snow, the intensity of the snowfall, the subsidence of the snow cover, the redistribution of the snow cover, the temperature of the air and snow cover.

The throw distance is important for assessing the possibility of hitting objects located in avalanche-prone areas. Distinguish maximum range emission and the most probable, or average annual. The most probable throw range is determined directly on the ground. It is assessed if it is necessary to place structures in the area of ​​avalanche action on a long period... It coincides with the boundary of the avalanche alteration cone.

The frequency of avalanches is an important temporal characteristic of avalanche activity. Distinguish between the average annual and annual frequency of descent. The density of avalanche snow is one of the most important physical parameters, on which the impact force of the snow mass, labor costs for its clearing or the ability to move along it depend.

How are they classified?

By the nature of the movement and depending on the structure of the avalanche center, the following three types are distinguished: trough (moves along a certain drain channel or avalanche trough), axial ( snow landslide, does not have a specific drainage channel and slides over the entire width of the site), jumping (arises from troughs where there are sheer walls or areas with a sharply increasing steepness in the drainage channel).

According to the degree of repeatability, they are divided into two classes - systematic and sparodic. Systematic ones come off every year or once every 2-3 years. Sparodic - 1-2 times in 100 years. It is rather difficult to determine their location in advance.

1.4. Natural disasters of a meteorological nature

They are all subdivided into disasters caused by:

By the wind including a storm, hurricane, tornado (at a speed of 25 m / s or more, for the Arctic and Far Eastern seas - 30 m / s or more);

Heavy rain (with an amount of precipitation of 50 mm or more for 12 hours or less, and in mountainous, mudflow and storm-hazardous areas - 30 mm or more for 12 hours or less);

Large hail (with a hailstone diameter of 20 mm or more);

Heavy snowfall (with an amount of precipitation of 20 mm or more in 12 hours or less);

- strong blizzards(wind speed 15 m / s and more);

Dust storms;

Frozen (with a decrease in air temperature during the growing season on the soil surface below 0 ° C);

- severe frost or extreme heat.

These natural phenomena, in addition to tornadoes, hail and squalls, lead to natural disasters, as a rule, in three cases: when they occur in one third of the territory of the region (territory, republic), cover several administrative districts and last at least 6 hours.

Hurricanes and storms

In the narrow sense of the word, a hurricane is defined as a wind of great destructive force and long duration, the speed of which is approximately 32 m / s or more (12 points on the Beaufort scale).

A storm is a wind that is slower than the speed of a hurricane. Losses and destruction from storms are significantly less than from hurricanes. Sometimes a violent storm is called a storm.

The most important characteristic hurricane is the speed of the wind.

The average duration of a hurricane is 9 to 12 days.

A storm is characterized by a lower wind speed than a hurricane (15 -31 m / s). Duration of storms- from several hours to several days, width - from tens to several hundred kilometers. Both those and others are often accompanied by a fairly significant precipitation.

Hurricanes and stormy winds in winter conditions often lead to snowstorms, when huge masses of snow move from one place to another at high speed. Their duration can be from several hours to several days. Especially dangerous are snowstorms that occur simultaneously with snowfall, at low temperatures or with sharp drops.

Classification of hurricanes and storms.Hurricanes are usually subdivided into tropical and extratropical. In addition, tropical hurricanes are often subdivided into hurricanes originating over the Atlantic Ocean and over the Pacific. The latter are usually called typhoons.

There is no generally accepted, established classification of storms. Most often they are divided into two groups: vortex and flow. Vortex are complex vortex formations caused by cyclonic activity and spread over large areas. Streaming are local phenomena of little spread.

Eddy storms are subdivided into dust, snow and squall storms. In winter, they turn into snowy ones. In Russia, such storms are often called blizzards, blizzards, blizzards.

Tornado is an upward vortex consisting of extremely rapidly rotating air mixed with particles of moisture, sand, dust and other suspended matter.It is a rapidly rotating air vortex hanging from a cloud and falling to the ground in the form of a trunk.

They arise both over water surface and over land. Most often - during hot weather and high humidity, when the instability of the air in the lower layers of the atmosphere appears especially sharply.

Funnel - main component tornado. It is a spiral vortex. Its internal cavity in diameter is from tens to hundreds of meters.

It is extremely difficult to predict the place and time of the tornado's appearance.Classification of tornadoes.

Most often they are subdivided according to their structure: dense (sharply limited) and vague (unclearly limited). In addition, tornadoes are divided into 4 groups: dust whirlwinds, small short-acting, small long-acting, hurricane whirlwinds.

Small tornadoes of short action have a path length of no more than a kilometer, but they have significant destructive power. They are relatively rare. The path length of small long-acting tornadoes is estimated at several kilometers. Hurricane vortices are larger tornadoes and travel several tens of kilometers during their movement.

Dust (sand) stormsaccompanied by the transfer of large amounts of soil and sand particles. They arise in desert, semi-desert and plowed steppes and are capable of transferring millions of tons of dust over hundreds and even thousands of kilometers, covering an area of ​​several hundred thousand square kilometers.

Dustless storms. They are characterized by the absence of dust entrainment into the air and a relatively smaller scale of destruction and damage. However, further movement may turn them into dusty or snow storm depending on the composition and condition of the earth's surface and the presence of snow cover.

Snow storms characterized by significant wind speeds, which contributes to the movement of huge masses of snow through the air in winter. Their duration ranges from several hours to several days. They have a relatively narrow range of action (up to several tens of kilometers).

1.5. Natural disasters of a hydrological nature and marine hazardous hydrometeorological phenomena

These natural phenomena are subdivided into disasters caused by:

High water level - floods, in which lower parts of cities and other settlements are inundated, agricultural crops, damage to industrial and transport facilities;

Low water level, when shipping, water supply to cities and national economic facilities, irrigation systems are disturbed;

Mudflows (during the breakthrough of dammed and moraine lakes that threaten settlements, road and other structures);

Snow avalanches (with a threat to settlements, automobile and railways, power lines, industrial and agricultural facilities);

Early freeze-up and the appearance of ice on navigable water bodies.

Marine hydrological phenomena: tsunamis, strong waves in the seas and oceans, tropical cyclones(typhoons), ice pressure and their intense drift.

Floods - this is flooding of the area adjacent to a river, lake or reservoir with water, which causes material damage, damages the health of the population or leads to the death of people. If flooding is not accompanied by damage, this is an overflow of a river, lake, reservoir.

Especially dangerous floods are observed on rivers fed by rain and glaciers, or with a combination of these two factors.

High water is a significant and rather long rise in the water level in the river, which is repeated annually in the same season. Usually floods are caused by spring melting of snow on the plains or by rainfall.

A flood is an intense, relatively short-term rise in the water level. It is formed by heavy rains, sometimes by melting snow during winter thaws.

The most important main characteristics are the maximum level and maximum flow rate during the flood. WITH the maximum level is related to the area, layer and duration of the area flooding. One of the main characteristics is the rate at which the water level rises.

For large river basins, one or another combination of flood waves of individual tributaries is an important factor.

For flood cases, the factors influencing the values ​​of the main characteristics include: precipitation amount, intensity, duration, coverage area preceding precipitation, basin moisture content, soil permeability, basin relief, river slopes, presence and depth of permafrost.

Ice jams and ice jams on rivers

Congestion - This is the accumulation of ice in the channel, limiting the flow of the river. As a result, water rises and spills.

The congestion usually forms at the end of winter and in spring when rivers open up during the destruction of the ice cover. It consists of large and small ice floes.

Spark - a phenomenon similar to ice jam. However, firstly, the jam consists of an accumulation of loose ice (slush, small pieces of ice), while a jam is an accumulation of large and, to a lesser extent, small ice floes. Secondly, ice jam occurs at the beginning of winter, while ice jam occurs at the end of winter and spring.

The main reason for the formation of the blockage is the delay in breaking up the ice on those rivers where the edge of the ice cover in the spring moves from top to bottom. At the same time, the crushed ice moving from above meets the still undisturbed ice cover on its way. A top-downstream sequence is necessary, but insufficient condition congestion. The main condition is created only when the surface velocity of water flow during opening is quite significant.

Gaps are formed on rivers during the formation of the ice cover. A necessary condition for the formation is the occurrence of intra-water ice in the channel and its entrainment under the edge of the ice cover. The surface current velocity and the air temperature during the freezing period are of decisive importance.

Surges - This is a rise in water level caused by the impact of wind on the water surface. Such phenomena happen in sea estuaries. large rivers as well as on large lakes and reservoirs.

The main condition for the occurrence is a strong and prolonged wind, which is characteristic of deep cyclones.

Tsunami - these are long waves arising from underwater earthquakes, as well as volcanic eruptions or landslides on the seabed.

Their source is at the bottom of the ocean,

In 90% of cases, tsunamis occur due to underwater earthquakes.

Often, before the onset of a tsunami, water recedes far from the coast, exposing the seabed. Then the looming one becomes visible. At the same time, thunderous sounds are heard, created by the air wave, which the water mass carries in front of it.

The possible scale of the consequences is classified by the score:

1 point - the tsunami is very weak (the wave is recorded only by instruments);

2 points - weak (it can flood a flat coast. It is noticed only by specialists);

3 points - average (noted by all. The flat coast is flooded. Light ships may be thrown ashore. Port facilities may be slightly damaged);

4 points - strong (the coast is flooded. Coastal structures are damaged. Large sailing and small motorized vessels can be thrown ashore and then washed back into the sea. Human casualties are possible);

5 points - very strong (coastal areas are flooded. Breakwaters and breakwaters are badly damaged, Large ships are thrown ashore. There are casualties. Material damage is great).

1.6. Natural fires

This concept includes forest fires, fires of steppe and grain fields, peat and underground fires of fossil fuels. We will focus only on forest fires, as the most widespread phenomenon that causes colossal losses and sometimes leads to human casualties.

Forest fires - This is an uncontrolled burning of vegetation, spontaneously spreading over the forest area.

In hot weather, if there is no rain for 15 - 18 days, the forest becomes so dry that any careless handling of fire causes a fire that quickly spreads through the forest area. From lightning discharges and spontaneous combustion of peat chips, a negligible number of fires occur. The possibility of forest fires is determined by the degree of fire hazard. For this, a "Scale for assessing forest areas according to the degree of danger of fires in them" has been developed (see. Table 3)

Classification of forest fires

Depending on the nature of the fire and the composition of the forest, fires are subdivided into grass-roots, high-altitude, and soil fires. Almost all of them at the beginning of their development have the character of grassroots and, if certain conditions are created, they turn into upstream or soil ones.

The most important characteristics are the speed of propagation of ground and top fires, the depth of burnt underground. Therefore, they are divided into weak, medium and strong. According to the speed of propagation of fire, the grassroots and horsebacks are subdivided into stable and fugitive. The intensity of combustion depends on the condition and stock of combustible materials, the slope of the terrain, time of day and especially the strength of the wind.

2. Natural emergencies in the Nizhny Novgorod region.

The territory of the region has enough great variety climatic, landscape and geological conditions, which determines the emergence of various natural phenomena. The most dangerous of them are those that can cause significant material damage and lead to the death of people.

- dangerous meteorological processes:squally and hurricane winds, heavy rain and snow, showers, large hail, severe blizzard, severe frost, ice and frost deposits on wires, extreme heat (high fire hazard due to weather conditions);agrometeorological,such as frost, drought;

- hazardous hydrological processes,such as high water (in the spring period the rivers of the region are characterized by high water levels, the separation of coastal ice floes, blockages are possible), rain floods, low water levels (in summer, autumn and winter water levels are likely to decrease to unfavorable and dangerous levels);hydrometeorological(separation of coastal ice floes with people);

- wildfires(forest, peat, steppe and wetland fires);

- hazardous geological phenomena and processes:(landslides, karsts, subsidence of loess rocks, erosion and abrasion processes, slope washouts).

Over the past thirteen years, of all registered natural phenomena that had a negative impact on the life of the population and the operation of economic facilities, the share of meteorological (agrometeorological) hazards amounted to 54%, exogenous-geological - 18%, hydrometeorological - 5%, hydrological - 3%, large forest fires - 20%.

The frequency of occurrence and the territory of distribution of the above natural phenomena in the region are not the same. Actual data from 1998 to 2010 make it possible to classify meteorological phenomena (damaging squall wind gains, the passage of thunderstorm fronts with hail, ice and frost deposits on wires) to the most widespread and often observed - an average of 10-12 cases are recorded annually.

At the end of winter and in the spring of every year, measures are taken to rescue people from the detached coastal ice floes.

Natural fires occur annually and water levels rise during flood periods. Adverse consequences of the passage of forest fires and high levels waters are recorded quite rarely, which is due to the pre-planned preparation for the flood and fire hazardous period.

Spring flood

The passage of floods in the region is observed from the end of March to May. According to the degree of danger, flood in the region belongs to moderate dangerous type when the maximum levels of water rise by 0.8 - 1.5 m exceed the levels of the onset of flooding, flooding of coastal areas (emergency situations of the municipal level). The floodplain area of ​​the river is 40 - 60%. The settlements are, as a rule, subject to partial flooding. The recurrence of the excess of the water level above the critical level is every 10 - 20 years. Exceedances of critical marks on most of the region's rivers were registered in 1994, 2005. To one degree or another, 38 districts of the region are affected by hydrological processes during the spring flood. The processes result in flooding and flooding of residential buildings, livestock and agricultural complexes, destruction of road sections, bridges, dams, dams, damage to power lines, activation of landslides. According to recent data, the areas most prone to flood events were Arzamassky, Bolsheboldinsky, Buturlinsky, Vorotynsky, Gaginsky, Kstovsky, Perevozsky, Pavlovsky, Pochinkovsky, Pilninsky, Semenovsky, Sosnovsky, Urensky and Shatkovsky.

Increased ice thickness can cause blockages in rivers during the break-up period. The number of ice jams on the rivers of the region on average reaches 3 - 4 per year. The flooding (flooding) caused by them is most likely in settlements located along the banks of rivers flowing from south to north, the opening of which occurs in the direction from the source to the mouth.

Forest fires

In total, there are 304 settlements in the region in 2 urban districts and 39 municipal areas that may be exposed negative impact peat forest fires.

The danger of wildfires is associated with the occurrence of large wildfires. Fires, whose area reaches 50 hectares, account for 14% of the total number of large forest fires, fires from 50 to 100 hectares occupy 6% of the total, fires from 100 to 500 hectares - 13%; the share of large forest fires exceeding 500 hectares is small - 3%. This ratio changed significantly in 2010, when the bulk (42%) of large forest fires reached an area of ​​more than 500 hectares.

The number and area of ​​wildfires varies significantly from year to year, because they directly depend on weather conditions and anthropogenic factor(forest attendance, preparation for the fire season, etc.).

It should be noted that practically throughout the entire territory of Russia in the period up to 2015. an increase in the number of days from high values air temperature. At the same time, the probabilities of extremely long periods with critical values ​​of air temperature will increase significantly. In this regard, by 2015. in comparison with the current values, an increase in the number of days with a fire hazard is predicted.

1. DISASTER PROTECTION.

For many centuries, mankind has developed a fairly harmonious system of measures to protect against natural disasters, the implementation of which in various parts of the world could significantly reduce the number of human victims and the amount of material damage. But to this day, unfortunately, we can only talk about individual examples of successful opposition to the elements. Nevertheless, it is advisable to re-enumerate the main principles of protection against natural disasters and compensation for their consequences. A clear and timely forecast of the time, place and intensity of a natural disaster is required. This makes it possible to promptly notify the population about the expected impact of the elements. A properly understood warning allows people to prepare for a hazardous event either by temporary evacuation, by building protective engineering structures, or by strengthening their own homes, livestock quarters, etc. The experience of the past must be taken into account, and its hard lessons must be brought to the attention of the population with an explanation that such a disaster could recur. In some countries, the state buys land in areas of possible natural disasters and organizes subsidized transfers from hazardous areas. Insurance is essential to reduce losses from natural disasters.

An important role in the prevention of damage from natural disasters belongs to the engineering and geographic zoning of areas of possible natural disaster, as well as the development of building codes and rules that strictly regulate the type and nature of construction.

V different countries sufficiently flexible legislation on economic activity in natural disaster zones has been developed. If a natural disaster occurred in a populated area and the population was not evacuated in advance, rescue operations are carried out, followed by repair and recovery operations.

Conclusion

So I studied natural emergencies.

I have come to the conclusion that there is a wide variety of natural disasters. These are dangerous geophysical phenomena; dangerous geological phenomena; dangerous meteorological phenomena; marine hazardous hydrometeorological phenomena; hazardous hydrological phenomena; natural fires. There are 6 types and 31 species in total.

Natural emergencies can lead to loss of life, damage to human health or the natural environment, significant losses and disruption of the living conditions of people.

From the point of view of the possibility of carrying out preventive measures, hazardous natural processes, as a source of emergency situations, can be predicted with a very short lead time.

In recent years, the number of earthquakes, floods, landslides and other natural disasters has been steadily increasing. This cannot go unnoticed.

List of used literature

1. V.Yu. Mikryukov "Ensuring life safety" Moscow - 2000.

2. Hwang T.A., Hwang P.A. Life safety. - Rostov n / a: "Phoenix", 2003. - 416 p.

3. Reference data on emergencies of technogenic, natural and ecological origin: At 3 o'clock - Moscow: GO USSR, 1990.

4. Emergency situations: a brief description of and classification: Textbook. manual / Ed. A.P. Zaitsev. - 2nd ed., Rev. and add. - M .: Zhurn. "Military knowledge", 2000.