Grishin Denis

Natural disasters have threatened the inhabitants of our planet since the beginning of civilization. Somewhere more, elsewhere less. There is no 100% security anywhere. Natural disasters can cause enormous damage. In recent years, the number of earthquakes, floods, landslides and other natural disasters has been constantly increasing. In my essay, I want to consider dangerous natural processes in Russia.

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NIZHNY NOVGOROD CITY ADMINISTRATION

Municipal budgetary educational institution

secondary school No. 148

Scientific Society of Students

Dangerous natural phenomena in Russia

Completed by: Grishin Denis,

6th grade student

Supervisor:

Sinyagina Marina Evgenievna,

geography teacher

Nizhny Novgorod

27.12.2011

PLAN

Page

Introduction

Chapter 1. Dangerous natural phenomena (natural emergencies).

1.1. The concept of emergency situations.

1.2 Natural disasters of a geographical nature.

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 to combat natural disasters.

Conclusion

Literature

Applications

Introduction

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

Natural disasters have threatened the inhabitants of our planet since the beginning of civilization. Somewhere more, elsewhere less. There is no 100% security anywhere. Natural disasters can cause enormous damage.

Natural emergencies (natural disasters) have been on the rise in recent years. Volcanoes are becoming more active (Kamchatka), earthquakes are becoming more frequent (Kamchatka, Sakhalin, the Kuriles, Transbaikalia, the North Caucasus), and their destructive power is increasing. Floods have become almost regular (the Far East, the Caspian lowland, the Southern Urals, Siberia), landslides along rivers and mountainous areas are not uncommon. Ice, snowdrifts, 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 operating. All this leads to the fact that the usualfloods in these places, causing more and more catastrophic consequences.

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

The purpose of my essay is to study natural emergencies.

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

1. The concept of natural emergencies

1.1.Natural emergencies -the situation in a certain territory or water area as a result of the occurrence 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 people's living conditions.

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

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

1) dangerous geophysical phenomena;

2) dangerous geological phenomena;

3) dangerous meteorological phenomena;

4) marine dangerous hydrometeorological phenomena;

5) dangerous 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 associated with geological natural phenomena are divided into disasters caused by earthquakes and volcanic eruptions.

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

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

Two main seismic belts are known: the Mediterranean-Asian and the Pacific.

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

Earthquakes are also classified according to the reason they occur. They can arise as a result of tectonic and volcanic manifestations, landslides (rock bursts, landslides) and, finally, as a result of human activity (filling reservoirs, pumping water into wells).

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

Volcanic activity

arises as a result of constant active processes occurring in the depths of the Earth. After all, the inside is constantly in a heated state. During tectonic processes, cracks form in the earth's crust. Magma rushes along them to the surface. The process is accompanied by the release of water vapor and gases, which create enormous pressure, removing obstacles in their path. When reaching the surface, part of the magma turns into slag, and the other part pours 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. Extinct, on the contrary, did not erupt. Dormers are characterized by the fact that they periodically manifest themselves, but it does not come to an eruption.

The most dangerous phenomena that accompany 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 speed range is quite wide: from a few centimeters to several kilometers per hour. In some and most dangerous cases, it reaches 100 km, but most often does not exceed 1 km / h.

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

mud streams - these are powerful 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, which leads to floods.

A scorching volcanic cloud is a mixture of hot gases and tephra. Its damaging effect is due to the occurrence of a shock wave (strong wind), propagating at a speed of up to 40 km / h, and a wave 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 sulfur and sulfur oxides, hydrogen sulfide, hydrochloric and hydrofluoric acids in a gaseous state, as well as carbon dioxide and carbon monoxide in high concentrations, deadly to humans.

Classification of volcanoesproduced 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 continental one. 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 zones of large faults. There are ruptures (faults) in many places in the earth's crust. There is a slow accumulation of tectonic forces that can turn into a sudden seismic explosion with volcanic manifestations.

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

According to the nature of activity, volcanoes are divided into five types (see Fig. Table 2)

1.3. Natural disasters of a geological nature

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

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

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

Landslides are classified according to their scale 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 or more meters. The landslide body often retains its solidity.

Medium and small scale are smaller and are characteristic of anthropogenic processes.

The scale is often characterized by the area involved in the process. The speed of movement is very different.

By activity, landslides are divided 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 wet, wet and very wet.

According to the mechanism of the process, they are divided into: shear landslides, extrusion, viscoplastic, hydrodynamic removal, sudden liquefaction. Often have signs of a combined mechanism.

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

Mudflow (mudflow)

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

The immediate causes of graying are showers, intense snowmelt, breakthrough of reservoirs, less often earthquakes, volcanic eruptions.

All mudflows are divided into three types according to the mechanism of origin: erosion, breakthrough and landslide-landslide.

In the case of erosion, the water flow is first saturated with clastic material due to flushing and erosion of the adjacent soil, and then a mudflow wave is already formed.

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

In recent years, technogenic 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, logging, improper agricultural work and violation of the soil and vegetation cover.

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

Zonal manifestation. The main factor in the formation is climatic conditions (precipitation). They are zonal. The descent occurs systematically. The paths of movement are relatively constant;

regional manifestation. The main factor of formation is geological processes. The descent occurs episodically, and the paths of movement are inconsistent;

Anthropogenic. It is the result of human activity. Occur where the greatest load on the mountain 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 accumulating on mountain slopes, under the influence of gravity and weakening of structural bonds within the snow mass, slides or falls off 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 more gentle sections or the bottom of the valley, where it slows down and stops.

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

Avalanche-forming factors include: the height of old snow, the state of the underlying surface, the growth of freshly fallen snow, snow density, snowfall intensity, snow cover settling, snowstorm redistribution of snow cover, air temperature and snow cover.

The release range is important for assessing the possibility of hitting objects located in avalanche zones. Distinguish between the maximum range of the release and the most probable, or long-term average. The most probable range of release is determined directly on the ground. It is evaluated if it is necessary to place structures in the avalanche zone for a long period. It coincides with the boundary of the avalanche source fan.

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

How are they classified?

According to the nature of movement and depending on the structure of the avalanche source, the following three types are distinguished: trough (moves along a specific runoff channel or avalanche chute), wasp (snow landslide, does not have a specific runoff channel and slides across the entire width of the site), jumping (arises from trough where there are sheer walls or sections with a sharply increasing steepness in the drain channel).

According to the degree of repetition, they are divided into two classes - systematic and sporadic. Systematic descend every year or once every 2-3 years. Sporadic - 1-2 times in 100 years. It is rather difficult to determine their place in advance.

1.4. Natural disasters of a meteorological nature

All of them are divided into disasters caused by:

blown by the wind including a storm, a hurricane, a 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 precipitation of 50 mm or more for 12 hours or less, and in mountainous, mudflow and rainy areas - 30 mm or more for 12 hours or less);

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

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

- heavy snowstorms(wind speed 15 m/s or more);

dust storms;

frost (when the air temperature drops below 0°C during the growing season on the soil surface);

- 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 (krai, republic), cover several administrative regions 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 power and considerable duration, the speed of which is approximately equal to 32 m/s or more (12 points on the Beaufort scale).

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

The most important characteristic of a hurricane is its wind speed.

The average duration of a hurricane is 9 - 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 hundreds of kilometers. Both of them are often accompanied by fairly significant precipitation.

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

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

There is no generally accepted, established classification of storms. Most often they are divided into two groups: vortex and flow. Vortexes are complex eddy formations caused by cyclonic activity and spreading over large areas. Streams are local phenomena of small distribution.

Vortex storms are subdivided into dust, snow and squall storms. In winter they turn into snow. In Russia, such storms are often called blizzard, snowstorm, snowstorm.

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

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

A funnel is the main component of a tornado. It is a spiral vortex. Its inner cavity in diameter is from tens to hundreds of meters.

It is extremely difficult to predict the place and time of the appearance of a tornado.Tornado classification.

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

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

Dust (sand) stormsaccompanied by the transfer of large quantities of soil and sand particles. They arise in desert, semi-desert and plowed steppes and are capable of carrying 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, with further movement, they can turn into a dust 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 varies from several hours to several days. They have a relatively narrow band 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 divided into disasters caused by:

High water level - floods, in which the lowered parts of cities and other settlements, crops are flooded, damage to industrial and transport facilities;

Low water level, when navigation, water supply of cities and national economic facilities, irrigation systems are disrupted;

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

Snow avalanches (in case of a threat to settlements, roads and railways, power lines, industrial and agricultural facilities);

Early freezing and the appearance of ice on navigable water bodies.

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

floods - this is flooding with water adjacent to a river, lake or reservoir area, which causes material damage, damages the health of the population or leads to death of people. If flooding is not accompanied by damage, it is a flood of rivers, lakes, reservoirs.

Particularly dangerous floods are observed on the rivers of rain and glacier feeding or a combination of these two factors.

High water is a significant and rather long rise in the water level in the river, which repeats annually in the same season. Usually floods are caused by spring snowmelt on the plains or 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 basic characteristics are the maximum level and maximum flow of water during the flood. With the area, layer and duration of flooding of the area are related to the maximum level. One of the main characteristics is the rate of rise of the water level.

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

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

Ice jams and ice jams on rivers

Congestion An accumulation of ice in a channel that limits the flow of a river. As a result, water rises and spills.

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

Zazhor - a phenomenon similar to ice jam. However, firstly, a jam consists of an accumulation of loose ice (sludge, small ice floes), 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 in spring.

The main reason for the formation of congestion is the delay in the opening of ice on those rivers where the edge of the ice cover in the spring shifts from top to bottom. At the same time, crushed ice moving from above meets on its way an ice cover that has not yet been broken. The sequence of breaking up the river from top to bottom is a necessary but not sufficient condition for the occurrence of a jam. The main condition is created only when the surface velocity of the water flow during the opening is quite significant.

Zazhors are formed on the rivers during the formation of the ice cover. A necessary condition for the formation is the occurrence of in-water ice in the channel and its involvement under the edge of the ice cover. In this case, the surface velocity of the current, as well as the air temperature during the freezing period, are of decisive importance.

Surges is the rise in water level caused by the action of wind on the water surface. Such phenomena occur in the sea mouths of large rivers, as well as on large lakes and reservoirs.

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

Tsunami are long waves resulting 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 are caused by underwater earthquakes.

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

The possible scale of consequences is classified by severity:

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

2 points - weak (it can flood a flat coast. Only specialists notice it);

3 points - average (noted by all. The flat coast is flooded. Light ships may be washed ashore. Port facilities may receive minor damage);

4 points - strong (the coast is flooded. Coastal buildings are damaged. Large sailing and small motor vessels can be washed 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 washed ashore. There are casualties. Material damage is great).

1.6. natural fires

This concept includes forest fires, fires of steppe and grain massifs, peat and underground fires of fossil fuels. We will focus only on forest fires, as the most common phenomenon that brings enormous losses and sometimes leads to human casualties.

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

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

Forest fire classification

Depending on the nature of the fire and the composition of the forest, fires are divided into grassroots, riding, soil. Almost all of them at the beginning of their development are grassroots and, if certain conditions are created, they pass into upland or soil.

The most important characteristics are the speed of propagation of ground and crown fires, the depth of burning underground. Therefore, they are divided into weak, medium and strong. According to the speed of the spread of fire, grassroots and horseback are divided into stable and runaway ones. The intensity of burning depends on the state and stock of combustible materials, the slope of the terrain, the time of day, and especially the strength of the wind.

2. Natural emergencies in the Nizhny Novgorod region.

The territory of the region has a fairly large variety of climatic, landscape and geological conditions, which causes the occurrence of various natural phenomena. The most dangerous of them are those that can cause significant material damage and lead to death of people.

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

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

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

- dangerous 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 was 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. The actual data of 1998 - 2010 make it possible to classify meteorological phenomena (damaging squally wind increases, the passage of thunderstorm fronts with hail, ice-frost deposits on wires) as the most common and frequently observed - annually, on average, 10 - 12 cases are recorded.

At the end of winter and the spring period of each year, events are held to rescue people from detached coastal ice floes.

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

spring flood

The passage of high water in the region is observed from the end of March to May. According to the degree of danger, the flood in the region belongs to a moderately dangerous type, when the maximum levels of water rise by 0.8 - 1.5 m exceed the levels of the beginning of flooding, flooding of coastal areas (emergency situations at the municipal level). The floodplain area of ​​the river is 40 - 60%. Settlements are usually subject to partial flooding. The frequency of exceeding the water level above the critical level is every 10 - 20 years. Excesses of critical levels on most of the region's rivers were registered in 1994, 2005. In varying degrees, 38 districts of the region are subject to the action of hydrological processes during the spring flood. The results of the processes are flooding and flooding of residential buildings, livestock and agricultural complexes, destruction of road sections, bridges, dams, dams, damage to power lines, and activation of landslides. According to recent data, the areas most prone to floods were Arzamas, Bolsheboldinsky, Buturlinsky, Vorotynsky, Gaginsky, Kstovsky, Perevozsky, Pavlovsky, Pochinkovsky, Pilninsky, Semenovsky, Sosnovsky, Urensky and Shatkovsky.

Increased ice thickness can cause congestion on rivers during the opening period. The number of ice jams on the rivers of the region reaches an average of 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 districts that may be subject to the negative impact of forest and peat fires.

The danger of wildfires is associated with the occurrence of large wildfires. Fires, the area of ​​which 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 proportion 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 ha.

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

It should be noted that in almost the entire territory of Russia in the period up to 2015. in summer periods, an increase in the number of days with high air temperatures should be expected. At the same time, the probabilities of extremely long periods with critical air temperatures will increase significantly. As a result, by 2015 compared to the current values, an increase in the number of days with a fire hazard is predicted.

1. DISASTER PROTECTION MEASURES.

For many centuries, humanity has developed a fairly coherent 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 casualties and the amount of material damage. But until today, unfortunately, we can only talk about individual examples of successful opposition to the elements. Nevertheless, it is advisable to once again list 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 necessary. This makes it possible to timely notify the population about the expected impact of the elements. A properly understood warning allows people to prepare for a dangerous event by either temporary evacuation, or building protective engineering structures, or strengthening their own homes, livestock buildings, 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 the explanation that such a disaster may happen again. In some countries, the state is buying up land in areas of potential natural disasters and organizing 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-geographical zoning of zones of possible natural disasters, as well as the development of building codes and regulations that strictly regulate the type and nature of construction.

Quite flexible legislation on economic activity in areas of natural disasters has been developed in various countries. If a natural disaster occurred in a populated area and the population was not evacuated in advance, emergency rescue operations are carried out, followed by repair and restoration.

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 dangerous hydrometeorological phenomena; dangerous hydrological phenomena; natural fires. There are 6 types and 31 species in total.

Natural emergencies can lead to human casualties, damage to human health or the environment, significant losses and disruption of people's living conditions.

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 constantly 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 - M.: GO USSR, 1990.

4. Emergencies: Brief description and classification: Proc. allowance / Ed. allowances A.P. Zaitsev. - 2nd ed., corrected. and additional - M.: Zhurn. "Military knowledge", 2000.

Natural hazards are extreme climatic or meteorological phenomena that occur naturally at one point or another on the planet. In some regions, such hazards may occur with greater frequency and destructive force than in others. Dangerous natural phenomena develop into natural disasters when the infrastructure created by civilization is destroyed and the people themselves die.

1. Earthquakes

Among all natural hazards, the first place should be given to earthquakes. In places of breaks in the earth's crust, tremors occur, which cause vibrations of the earth's surface with the release of gigantic energy. The resulting seismic waves are transmitted over very long distances, although these waves have the greatest destructive power in the epicenter of the earthquake. Due to strong vibrations of the earth's surface, mass destruction of buildings occurs.
Since there are quite a lot of earthquakes, and the surface of the earth is quite densely built up, the total number of people in history who died precisely as a result of earthquakes exceeds the number of all victims of other natural disasters and amounts to many millions. For example, over the past decade around the world, about 700 thousand people have died from earthquakes. From the most devastating shocks, entire settlements instantly collapsed. Japan is the most earthquake-affected country, and one of the most catastrophic earthquakes occurred there in 2011. The epicenter of this earthquake was in the ocean near the island of Honshu, according to the Richter scale, the magnitude of the shocks reached 9.1 points. Powerful aftershocks and the subsequent devastating tsunami disabled the nuclear power plant in Fukushima, destroying three of the four power units. Radiation covered a large area around the station, rendering densely populated areas so valuable in Japanese conditions uninhabitable. A colossal tsunami wave turned into a mess what the earthquake could not destroy. More than 16 thousand people officially died, among which another 2.5 thousand who are considered missing can be safely added. In this century alone, devastating earthquakes have occurred in the Indian Ocean, Iran, Chile, Haiti, Italy, and Nepal.

2. Tsunami waves

A specific water disaster in the form of tsunami waves often results in numerous casualties and catastrophic destruction. As a result of underwater earthquakes or shifts of tectonic plates in the ocean, very fast, but hardly noticeable waves arise, which grow into huge ones as they approach the coast and enter shallow water. Most often, tsunamis occur in areas with increased seismic activity. A huge mass of water, quickly moving ashore, blows everything in its path, picks it up and carries it deep into the coast, and then carries it back to the ocean with a reverse current. Humans, unable to feel danger like animals, often do not notice the approach of a deadly wave, and when they do, it is too late.
A tsunami usually kills more people than the earthquake that caused it (the latter in Japan). In 1971, the most powerful tsunami ever observed occurred there, the wave of which rose 85 meters at a speed of about 700 km / h. But the most catastrophic was the tsunami observed in the Indian Ocean (the source is an earthquake off the coast of Indonesia), which claimed the lives of about 300 thousand people along a significant part of the coast of the Indian Ocean.

A tornado (in America this phenomenon is called a tornado) is a fairly stable atmospheric vortex, most often occurring in thunderclouds. He is a visa...

3. Volcanic eruption

Throughout its history, mankind has remembered many catastrophic volcanic eruptions. When the pressure of magma exceeds the strength of the earth's crust in the weakest places, which are volcanoes, this ends with an explosion and outpourings of lava. But the lava itself is not so dangerous, from which you can simply get away, as hot pyroclastic gases rushing from the mountain, pierced here and there by lightning, as well as a noticeable effect on the climate of the strongest eruptions.
Volcanologists count about half a thousand dangerous active volcanoes, several dormant supervolcanoes, not counting thousands of extinct ones. So, during the eruption of the Tambora volcano in Indonesia, for two days the surrounding lands were plunged into darkness, 92 thousand inhabitants died, and a cold snap was felt even in Europe and America.
List of some strong volcanic eruptions:

• Volcano Laki (Iceland, 1783). As a result of that eruption, a third of the population of the island died - 20 thousand inhabitants. The eruption lasted for 8 months, during which flows of lava and liquid mud erupted from volcanic cracks. The geysers have never been more active. Living on the island at that time was almost impossible. The crops were destroyed, and even the fish disappeared, so the survivors experienced hunger and suffered from unbearable living conditions. This may be the longest eruption in human history.
• Volcano Tambora (Indonesia, Sumbawa Island, 1815). When the volcano exploded, the sound of this explosion spread over 2,000 kilometers. Ash covered even the remote islands of the archipelago, 70 thousand people died from the eruption. But even today, Tambora is one of the highest mountains in Indonesia that retains volcanic activity.
• Volcano Krakatoa (Indonesia, 1883). 100 years after Tambora, another catastrophic eruption occurred in Indonesia, this time "blowing the roof off" (literally) the Krakatoa volcano. After the catastrophic explosion that destroyed the volcano itself, frightening peals were heard for another two months. A huge amount of rocks, ash and hot gases were thrown into the atmosphere. The eruption was followed by a powerful tsunami with a wave height of up to 40 meters. These two natural disasters together destroyed 34,000 islanders along with the island itself.
• Volcano Santa Maria (Guatemala, 1902). After a 500-year hibernation in 1902, this volcano woke up again, starting the 20th century with the most catastrophic eruption, which resulted in the formation of a one and a half kilometer crater. In 1922, Santa Maria again reminded of itself - this time the eruption itself was not too strong, but a cloud of hot gases and ash brought death to 5 thousand people.

4. Tornadoes

Throughout the history of mankind, the strongest earthquakes have repeatedly caused enormous damage to people and caused a huge number of casualties among the population ...

A tornado is a very impressive natural phenomenon, especially in the USA, where it is called a tornado. This is an air stream twisted in a spiral into a funnel. Small tornadoes resemble slender narrow pillars, and giant tornadoes can resemble a mighty carousel directed to the sky. The closer to the funnel, the stronger the wind speed, it begins to drag along ever larger objects, up to cars, wagons and light buildings. In the "tornado alley" of the United States, entire city blocks are often destroyed, people die. The most powerful vortices of category F5 reach a speed of about 500 km/h in the center. The state of Alabama suffers the most every year from tornadoes.

There is a kind of fire tornado, which sometimes occurs in the area of ​​massive fires. There, from the heat of the flame, powerful ascending currents are formed, which begin to twist into a spiral, like an ordinary tornado, only this one is filled with flame. As a result, a powerful draft is formed near the surface of the earth, from which the flame grows even stronger and incinerates everything around. When the catastrophic earthquake hit Tokyo in 1923, it caused massive fires that led to the formation of a fiery tornado that rose 60 meters. The column of fire moved towards the square with frightened people and burned 38 thousand people in a few minutes.

5. Sandstorms

This phenomenon occurs in sandy deserts when a strong wind rises. Sand, dust and soil particles rise to a sufficiently high height, forming a cloud that dramatically reduces visibility. If an unprepared traveler gets into such a storm, he can die from grains of sand falling into the lungs. Herodotus described history as 525 BC. e. in the Sahara, a 50,000-strong army was buried alive by a sandstorm. In Mongolia, 46 people died as a result of this natural phenomenon in 2008, and two hundred people suffered the same fate the year before.

Occasionally, tsunami waves occur in the ocean. They are very insidious - they are completely invisible in the open ocean, but as soon as they approach the coastal shelf, they ...

6. Avalanches

From the snow-covered mountain peaks, snow avalanches periodically descend. Climbers especially often suffer from them. During World War I, up to 80,000 people died from avalanches in the Tyrolean Alps. In 1679, five thousand people died in Norway from snowmelt. In 1886, there was a major disaster, as a result of which the "white death" claimed 161 lives. The records of the Bulgarian monasteries also mention the human victims of snow avalanches.

7 Hurricanes

They are called hurricanes in the Atlantic and typhoons in the Pacific. These are huge atmospheric vortices, in the center of which the strongest winds and sharply reduced pressure are observed. A few years ago, the devastating Hurricane Katrin swept over the United States, which especially affected the state of Louisiana and the densely populated New Orleans located at the mouth of the Mississippi. 80% of the city was flooded, killing 1836 people. Notable destructive hurricanes have also become:

• Hurricane Ike (2008). The diameter of the eddy was over 900 km, and in its center the wind was blowing at a speed of 135 km/h. In the 14 hours that the cyclone moved across the United States, it managed to cause $30 billion worth of damage.
• Hurricane Wilma (2005). This is the largest Atlantic cyclone in the history of meteorological observations. A cyclone that originated in the Atlantic made landfall several times. The amount of damage inflicted by him amounted to $ 20 billion, 62 people died.
• Typhoon Nina (1975). This typhoon was able to breach China's Bankiao Dam, causing the dams below to collapse and causing catastrophic flooding. The typhoon killed up to 230,000 Chinese.

8. Tropical cyclones

These are the same hurricanes, but in tropical and subtropical waters, which are huge low-pressure atmospheric systems with winds and thunderstorms, often exceeding a thousand kilometers in diameter. Near the surface of the earth, winds in the center of the cyclone can reach speeds of over 200 km/h. Low pressure and wind cause the formation of a coastal storm surge - when colossal masses of water are thrown ashore at high speed, washing everything in their path.

Environmental disasters have their own specifics - during them not a single person may die, but at the same time a very significant amount will be inflicted ...

9. Landslide

Prolonged rains can cause landslides. The soil swells, loses its stability and slides down, taking with it everything that is on the surface of the earth. Most often, landslides occur in the mountains. In 1920, the most devastating landslide occurred in China, under which 180 thousand people were buried. Other examples:

• Bududa (Uganda, 2010). Due to mudflows, 400 people died, and 200 thousand had to be evacuated.
• Sichuan (China, 2008). Avalanches, landslides and mudflows caused by an 8-magnitude earthquake claimed 20,000 lives.
• Leyte (Philippines, 2006). The downpour caused a mudflow and a landslide that killed 1,100 people.
• Vargas (Venezuela, 1999). Mudflows and landslides after heavy rains (almost 1000 mm of precipitation fell in 3 days) on the northern coast led to the death of almost 30 thousand people.

10. Fireballs

We are accustomed to ordinary linear lightning accompanied by thunder, but ball lightning is much rarer and more mysterious. The nature of this phenomenon is electrical, but scientists cannot yet give a more accurate description of ball lightning. It is known that it can have different sizes and shapes, most often these are yellowish or reddish luminous spheres. For unknown reasons, ball lightning often ignores the laws of mechanics. Most often they occur before a thunderstorm, although they can appear in absolutely clear weather, as well as indoors or in the cockpit. The luminous ball hangs in the air with a slight hiss, then it can start moving in an arbitrary direction. Over time, it seems to shrink until it disappears altogether or explodes with a roar. But the damage ball lightning can bring is very limited.

| Materials for life safety lessons for grade 7 | Schedule for the academic year | Natural emergencies

Fundamentals of life safety
7th grade

Lesson 1
Natural emergencies

Distinguish concepts "dangerous natural phenomenon" and "disaster".

Dangerous natural phenomenon - this is an event of natural origin or the result of the activity of natural processes, which, by their intensity, scale of distribution and duration, can have a damaging effect on people, economic facilities and the natural environment.

To natural hazards include earthquakes, volcanic eruptions, floods, tsunamis, hurricanes, storms, tornadoes, landslides, mudflows, forest fires, sharp thaws, sharp cold snaps, warm winters, severe thunderstorms, droughts, etc. But not all, but only those that adversely affect people's livelihoods, the economy and the environment.

Such phenomena cannot include, for example, an earthquake in a desert area where no one lives, or a powerful landslide in an uninhabited mountainous area. They also do not include phenomena that occur in places where people live, but do not cause a sharp change in their living conditions, do not lead to the death or injury of people, the destruction of buildings, communications, etc.

Disaster - this is a destructive natural and (or) natural-anthropogenic phenomenon or process of a significant scale, as a result of which a threat to life and health of people may arise or arise, destruction or destruction of material assets and components of the natural environment may occur.

They arise under the influence of atmospheric phenomena (hurricanes, heavy snowfalls, heavy rains), fire (forest and peat fires), changes in water levels in reservoirs (floods, floods), processes occurring in the soil and the earth's crust (volcanic eruptions, earthquakes, landslides , mudflows, landslides, tsunamis).

An approximate ratio of the frequency of occurrence of natural hazards by their types.

Natural disasters are usually natural emergencies. They can occur independently of each other, and sometimes one natural disaster leads to another. As a result of earthquakes, for example, avalanches or landslides can occur. And some natural disasters happen due to human activity, sometimes unreasonable (a cigarette butt left unextinguished or an unextinguished fire, for example, often leads to a forest fire, explosions in mountainous areas when laying roads - to landslides, landslides, snow avalanches).

So, the occurrence of a natural emergency is a consequence of a natural phenomenon, in which there is a direct threat to the life and health of people, material values ​​​​and the natural environment are destroyed and destroyed.

Typification of natural phenomena according to the degree of danger

Such phenomena can have a different origin, which became the basis for the classification of natural emergencies shown in Scheme 1.

Each natural disaster affects a person and his health in its own way. People suffer the most from floods, hurricanes, earthquakes and droughts. And only about 10% of the damage caused by them falls on other natural disasters.

The territory of Russia is exposed to various types of natural hazards. At the same time, there are significant differences in their manifestation in comparison with other countries. Thus, the historically established zone of the main settlement of the population of Russia (from the European part along the south of Siberia to the Far East) approximately coincides with the zone of the least manifestation of such natural hazards as earthquakes, hurricanes and tsunamis (except for the Far East). At the same time, the high prevalence of unfavorable and dangerous natural processes and phenomena is associated with cold, snowy winters. In general, the damage caused by natural emergencies in Russia is below the world average due to a significantly lower population density and the location of hazardous industries, as well as as a result of the adoption of preventive measures.

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Natural emergencies: types and classification

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Under an emergency (ES) It is customary to understand the situation in a certain area that has developed as a result of an accident, natural or other disaster that may or have caused human casualties, damage to human health or the environment, significant material losses and violation of the living conditions of the population. Emergencies do not occur immediately, as a rule, they develop gradually from man-made, social or natural incidents.

Natural disasters are usually unexpected. In a short time they destroy territories, dwellings, communications, and bring hunger and disease in their wake. In recent years, emergencies of natural origin have been on the rise. In all cases of earthquakes, floods, landslides, their destructive power increases.

Natural emergencies are subdivided

• Geophysical (endogenous) hazardous phenomena: volcanic and geyser eruptions, earthquakes, underground gas releases to the surface of the earth;
• Geological (exogenous) hazardous phenomena: collapses, scree, landslides, avalanches, mudflows, slope washout, subsidence of loess rocks, soil erosion, abrasion, subsidence (failure) of the earth's surface as a result of karst kurum, dust storms;
• Meteorological hazards: hurricanes (12 - 15 points), storms, storms (9 - 11 points), tornadoes (tornadoes), squalls, vertical whirlwinds, large hail, heavy rain (shower), heavy snowfall, heavy ice, severe frost, severe snowstorm, severe heat, heavy fog, drought, dry winds, frosts;
• Hydrological hazards: high water levels (floods), high water, rain floods, traffic jams and ice dams, wind surges, low water levels, early freezing and ice formation on navigable reservoirs and rivers;
• Marine hydrological hazards: tropical cyclones (typhoons), tsunamis, strong waves (5 points or more), strong fluctuations in sea level, strong draft in ports, early ice cover and fast ice, pressure and intense ice drift, impenetrable (hard to pass) ice, icing of ships and port facilities , detachment of coastal ice;
• Hydrogeological hazards: low groundwater levels, high groundwater levels;
• Natural fires: forest fires, peat fires, fires of steppe and grain massifs, underground fires of fossil fuels;
• Infectious diseases in humans: isolated cases of exotic and especially dangerous infectious diseases, group cases of dangerous infectious diseases, epidemic outbreak of dangerous infectious diseases, epidemic, pandemic, infectious diseases of people of unknown etiology;
• Infectious diseases of animals: isolated cases of exotic and especially dangerous infectious diseases, epizootics, panzootics, enzootics; infectious diseases of farm animals of unknown etiology;
• Infectious plant diseases: progressive epiphytoty, panphytoty, agricultural plant diseases of unknown etiology, mass distribution of plant pests.

Patterns of natural phenomena

• Each type of emergency is facilitated by a certain spatial confinement;
• The more intense the dangerous natural phenomenon, the less often it happens;
• Each natural origin has predecessors - specific features;
• The appearance of a natural emergency, for all its unexpectedness, can be predicted;
• It is often possible to provide for both passive and active protection measures against natural hazards.

The role of anthropogenic influence on the manifestation of natural emergencies is great. Human activity disturbs the balance in the natural environment. Now, when the scale of the use of natural resources has sharply increased, the features of the global ecological crisis have become very noticeable. An important preventive factor that makes it possible to reduce the number of natural emergencies is the observance of natural balance.

All natural disasters are interconnected, these are earthquakes and tsunamis, tropical cyclones and floods, volcanic eruptions and fires, poisoning of pastures, death of livestock. Taking protective measures against natural disasters, it is necessary to minimize the secondary consequences, and with the help of appropriate training, if possible, eliminate them completely. The study of the causes and mechanisms of natural emergencies is a prerequisite for successful protection against them, the possibility of their prediction. An accurate and timely forecast is an important condition for effective protection against hazardous phenomena. Protection from natural phenomena can be active (construction of engineering structures, reconstruction of natural objects, etc.) and passive (use of shelters),

Dangerous geological natural phenomena

• earthquakes,
• landslides,
• sat down,
• snow avalanches,
• collapses,
• precipitation of the earth's surface as a result of karst phenomena.

earthquakes- these are underground shocks and vibrations of the earth's surface, resulting from tectonic processes, transmitted over long distances in the form of elastic vibrations. Earthquakes can cause volcanic activity, the fall of small celestial bodies, collapses, dam breaks, and other causes.

The causes of earthquakes are not fully understood. Stresses arising under the action of deep tectonic forces deform the layers of earth rocks. They shrink into folds, and when overloads reach critical levels, they tear and mix. A break in the earth's crust is formed, which is accompanied by a series of shocks and the number of shocks, and the intervals between them are very different. Shocks include foreshocks, mainshock and aftershocks. The main push has the greatest force. People perceive it as very long, although it usually lasts a few seconds.

As a result of research, psychiatrists and psychologists have obtained data that often aftershocks have a much more severe mental impact on people than the main shock. There is a feeling of inevitability of trouble, a person is inactive, while he should defend himself.

The epicenter of the earthquake- is called a certain volume in the thickness of the Earth, within which energy is released.

the center of the hearth is a conditional point - hypocenter or focus.

Earthquake epicenter is the projection of the hypocenter onto the Earth's surface. The greatest destruction occurs around the epicenter, in the pleistoseist region.

The energy of earthquakes is estimated by magnitude (lat. value). is a conditional value that characterizes the total amount of energy released in the earthquake source. The strength of the earthquake is estimated according to the international seismic scale MSK - 64 (Merkalli scale). It has 12 conditional gradations - points.

Earthquakes are predicted by recording and analyzing their "predecessors" - foreshocks (preliminary weak shocks), deformation of the earth's surface, changes in the parameters of geophysical fields, changes in the behavior of animals. Until now, unfortunately, there are no methods for reliable earthquake prediction. The time frame for the beginning of an earthquake can be 1-2 years, and the accuracy of predicting the location of an earthquake varies from tens to hundreds of kilometers. All this reduces the effectiveness of earthquake protection measures.

In seismically hazardous areas, the design and construction of buildings and structures is carried out taking into account the possibility of earthquakes. Earthquakes of 7 points and above are considered dangerous for structures, so construction in areas with a 9-point seismicity is uneconomical.

Rocky soils are considered the most reliable in seismic terms. The stability of structures during earthquakes depends on the quality of building materials and work. There are requirements to limit the size of buildings, as well as requirements to take into account the relevant rules and regulations (SP and N), which boil down to strengthening the structure of structures built in seismic zones.

Groups of anti-seismic measures

1. Preventive, preventive measures are the study of the nature of earthquakes, the determination of their predecessors, the development of methods for predicting earthquakes;
2. Activities that are carried out immediately before the start of an earthquake, during it and after it ends. The effectiveness of actions in earthquake conditions depends on the level of organization of rescue operations, the training of the population and the effectiveness of the warning system.

A very dangerous immediate consequence of an earthquake is panic, during which people, out of fear, cannot meaningfully take measures for salvation and mutual assistance. Panic is especially dangerous in crowded places - at enterprises, in educational institutions and in public places.

Death and injury occur when debris from destroyed buildings falls, as well as as a result of people being in the rubble and not receiving timely assistance. Earthquakes can cause fires, explosions, emissions of hazardous substances, traffic accidents and other dangerous phenomena.

Volcanic activity- This is the result of active processes that constantly occur in the bowels of the Earth. called a set of phenomena that are associated with the movement of magma in the earth's crust and on its surface. Magma (Greek thick ointment) is a molten mass of silicate composition, which is formed in the depths of the Earth. When magma reaches the earth's surface, it erupts as lava.

Lava does not contain gases that escape during an eruption. This is what distinguishes it from magma.

Types of winds

Vortex storms are caused by cyclonic activity and spread over large areas.

Among the vortex storms are distinguished:

• dusty,
• snowy.
• squall.

Dust (sand) storms occur in deserts, in plowed steppes and are accompanied by the transfer of huge masses of soil and sand.

snow storms move large masses of snow through the air. They operate on a strip from several kilometers to several tens of kilometers. Snow storms of great strength occur in the steppe part of Siberia and on the plains of the European part of the Russian Federation. In Russia in winter, snow storms are called snowstorms, blizzards, snowstorms.

Flurries– short-term wind amplification up to the speed of 20-30m/s. They are characterized by a sudden beginning and the same sudden end, a short duration of action and great destructive power.

Squall storms operate in the European part of Russia both on land and at sea.

stream storms- local phenomena with a small distribution. They are divided into stock and jet. During katabatic storms, air masses move down the slope from top to bottom.

jet storms characterized by horizontal movement of air or its movement up the slope. Most often they occur between chains of mountains that connect valleys.

A tornado (tornado) is an atmospheric vortex that occurs in a thundercloud. Then it spreads in the form of a dark "sleeve" towards land or sea. The upper part of the tornado has a funnel-shaped extension that merges with the clouds. When a tornado descends to the Earth's surface, its lower part sometimes expands, resembling an overturned funnel. The height of the tornado is from 800 to 1500m. Rotating counterclockwise at a speed of up to 100 m/s and rising in a spiral, the air in the tornado draws dust or water. The decrease in pressure inside the tornado leads to the condensation of water vapor. Water and dust make the tornado visible. Its diameter above the sea is measured in tens of meters, and above land - hundreds of meters.

According to the structure, tornadoes are divided into dense (sharply limited) and vague (indistinctly limited); in time and spatial effect - on small tornadoes of mild action (up to 1 km), small (up to 10 km) and hurricane whirlwinds (more than 10 km).

Hurricanes, storms, tornadoes are extremely powerful elemental forces, in their destructive effect they are comparable only to an earthquake. It is very difficult to predict the place and time of the appearance of a tornado, which makes them especially dangerous and does not allow predicting their consequences.

Hydrological disasters

high water- annually recurring seasonal rise in water level.

high water- a short-term and non-periodic increase in the water level in a river or reservoir.

Floods following one after another can cause floods, and the last floods.

Flooding is one of the most common natural hazards. They arise from a sharp increase in the amount of water in the rivers as a result of the melting of snow or glaciers, due to heavy rains. Floods are often accompanied by blockage of the river bed during ice drift (jam) or blockage of the river bed by an ice plug under a fixed ice cover (jamming).

On sea coasts, floods can be caused by earthquakes, volcanic eruptions, and tsunamis. Floods caused by the action of winds that drive water from the sea and raise the water level due to its retention at the mouth of the river are called surge floods.

Experts believe that people are in danger of flooding if the water layer reaches 1m and its flow speed is more than 1m/s. If the rise of water reaches 3 m, this leads to the destruction of houses.

Flooding can occur even when there is no wind. It can be caused by long waves arising in the sea under the influence of a cyclone. In St. Petersburg, the islands in the Neva delta have been flooded since 1703. more than 260 times.

Floods on rivers differ in the height of the water rise, the area of ​​flooding and the magnitude of damage: low (small), high (medium), outstanding (large), catastrophic. Low floods can be repeated in 10-15 years, high ones in 20-25 years, outstanding ones in 50-100 years, catastrophic ones in 100-200 years.

They can last from several to 100 days.

The flood in the valley of the Tigris and Euphrates rivers in Mesopotamia, which happened 5600 years ago, had very serious consequences. In the Bible, the flood was called the Flood.

Tsunamis are marine gravity waves of great length, resulting from shifts of large areas of the bottom during underwater earthquakes, volcanic eruptions or other tectonic processes. In the area of ​​their occurrence, waves reach a height of 1-5 m, near the coast - up to 10 m, and in bays and river valleys - more than 50 m. Tsunamis propagate inland to a distance of up to 3 km. The coast of the Pacific and Atlantic Oceans is the main area of ​​tsunami manifestation. They produce very large destruction and pose a threat to people.

Breakwaters, embankments, harbors and jetties protect against tsunamis only partially. On the high seas, tsunamis are not dangerous for ships.

Protection of the population from tsunamis - warnings of special services about the approach of waves, based on advanced registration of earthquakes by coastal seismographs.

Forest, steppe, peat, underground fires are called landscape or natural fires. Forest fires are the most common, causing huge losses and leading to human casualties.

Forest fires are uncontrolled burning of vegetation, which spontaneously spreads through the forest area. In dry weather, the forest dries up so much that any careless handling of fire can cause a fire. In most cases, the culprit of the fire is a person. Forest fires are classified according to the nature of the fire, the speed of propagation and the size of the area covered by the fire.

Depending on the nature of the fire and the composition of the forest, fires are divided into grassroots, riding and soil fires. At the beginning of their development, all fires are ground fires, and when certain conditions arise, they turn into crown or soil fires. Crown fires are subdivided according to the parameters of the edge advancement (burning band bordering the outer contour of the fire) into weak, medium and strong. Ground and crown fires are divided into stable and runaway fires according to the speed of fire spread.

Methods of fighting forest fires. The main conditions for the effectiveness of fighting forest fires are the assessment and forecast of fire danger in the forest. State forestry authorities control the state of protection in the territory of the forest fund.

To organize fire extinguishing, it is necessary to determine the type of fire, its characteristics, the direction of its spread, natural barriers (places that are especially dangerous for intensifying the fire), the forces and means necessary to fight it.

When extinguishing a forest fire, the following main stages are distinguished: stopping, extinguishing the fire and guarding the conflagration (preventing the possibility of catching fire from unexplained sources of combustion).

There are two main methods of fighting a fire according to the nature of the impact on the combustion process: direct and indirect fire extinguishing.

The first method is used when extinguishing medium and low intensity with a propagation speed of up to 2 m / min. and a flame height of up to 1.5 m. An indirect method of extinguishing a fire in a forest is based on the creation of barrier strips along the path of its spread.

An epidemic is a widespread infectious disease among people, significantly exceeding the incidence rate usually recorded in a given area.

- an unusually large spread of morbidity, both in terms of level and scale of distribution, covering a number of countries, entire continents and even the entire globe.

All infectious diseases are divided into four groups:

• intestinal infections;
• respiratory tract infections (aerosol);
• blood (transmissible);
• infections of the outer integument (contact).

Types of biological emergencies

Epizootics. Infectious animal diseases are a group of diseases that have such common features as the presence of a specific pathogen, the cyclical nature of development, the ability to be transmitted from an infected animal to a healthy one, and to take on epizootic spread.

All infectious diseases of animals are divided into five groups:

• The first group - alimentary infections are transmitted through soil, feed, water. The organs of the digestive system are mainly affected. Pathogens are transmitted through infected feed, soil, manure. Such infections include anthrax, foot and mouth disease, glanders, brucellosis.
• The second group - respiratory infections - damage to the mucous membranes of the respiratory tract and lungs. These include: parainfluenza, exotic pneumonia, sheep and goat pox, canine distemper.
• The third group - transmissible infections, the mechanism of their transmission is carried out with the help of blood-sucking arthropods. These include: encephalomyelitis, tularemia, infectious anemia of horses.
• The fourth group - infections, the causative agents of which are transmitted through the outer integument without the participation of carriers. These include: tetanus, rabies, cowpox.
• Fifth group - infections with unexplained pathways of damage, i.e. unqualified group.

Epiphytotics. To assess the scale of plant diseases, the following concepts are used epiphytoty and panphytoty.

Epiphytoty – the spread of infectious diseases over large areas over a period of time.

Hazardous natural phenomena include all those that deviate the state of the natural environment from the range that is optimal for human life and for their economy. They represent catastrophic processes of endogenous and exogenous origin: earthquakes, volcanic eruptions, floods, avalanches and mudflows, as well as landslides, soil subsidence.

In terms of the size of the one-time damage of the impact, hazardous natural phenomena vary from minor to those that create natural disasters.

A natural disaster is any unavoidable terribly destructive natural phenomenon that causes economic damage and poses a threat to the health and life of people. When it comes to measuring losses, the term is used - an emergency situation (ES). In emergencies, first of all, absolute losses are measured - for a quick response, to decide on the necessary external assistance to the affected area, etc.

Catastrophic earthquakes (9 points or more) cover the areas of Kamchatka, the Kuril Islands, Transcaucasia and a number of other mountainous regions. In such areas, engineering construction, as a rule, is not carried out.

Strong (from 7 to 9 points) earthquakes occur in a territory stretching in a wide strip from Kamchatka to, including the Baikal region, etc. Only earthquake-resistant construction should be carried out here.

Most of the territory of Russia belongs to the zone in which earthquakes of small magnitude are extremely rare. So, in 1977, shocks of magnitude 4 were registered in Moscow, although the epicenter of the earthquake itself was in the Carpathians.

Despite the great work done by scientists in seismic hazard prediction, earthquake prediction is a very difficult problem. To solve it, special maps, mathematical models are built, a system of regular observations is organized using seismic instruments, a description of past earthquakes is compiled based on a study of a complex of factors, including the behavior of living organisms, analyzing their geographical distribution.

The most effective ways to deal with floods are flow regulation, as well as the construction of protective dams and dams. So, the length of dams and dikes is more than 1800 miles. Without this protection, 2/3 of its territory would be flooded every day by the tide. A dam was built to protect against floods. The peculiarity of this implemented project lies in the fact that it requires high-quality wastewater treatment of the city and the normal functioning of culverts in the dam itself, which was not provided for in the dam project in due measure. The construction and operation of such engineering facilities also require an assessment of possible environmental consequences.

Floods - an annual recurring seasonal long and significant increase in the water content of rivers, which are accompanied by an increase in the water level in the channel and flooding of the floodplain - one of the main causes of floods.

Large floodplain floods during floods are observed in most of the territory of the CIS, and in Eastern Europe.

sat down — mud or mud-stone flows that suddenly arise in the channels of mountain rivers and are characterized by a sharp short-term (1-3 hours) rise in the water level in the rivers, undulating movement and the absence of a complete periodicity. Mudflow can occur when heavy rains fall, intense melting of snow and ice, less often due to volcanic eruptions, breakthroughs of mountain lakes, as well as as a result of human economic activity (blasting, etc.). The prerequisites for the formation are: a cover of slope deposits, significant slopes of mountain slopes, increased soil moisture. According to the composition, mud-stone, water-stone, mud and water-grown mudflows are distinguished, in which the content of solid material ranges from 10-15 to 75%. Separate fragments carried by mudflows weigh more than 100-200 tons. The speed of mudflows reaches 10 m/s, and the volume is hundreds of thousands, and sometimes even millions of cubic meters. Having a large mass and speed of movement, mudflows often bring destruction, acquiring the nature of a natural disaster in the most catastrophic cases. So, in 1921, a catastrophic mudflow destroyed Alma-Ata, killing about 500 people. At present, this city is reliably protected by an anti-mudflow dam and a complex of special engineering structures. The main measures to combat mudflows are associated with fixing the vegetation cover on the mountain slopes, with the preventive descent of the mountainous ones threatening a breakthrough, with the construction of dams and various mudflow protection structures.

Avalanches — masses of snow falling down steep mountain slopes. Especially often avalanches descend in cases where snow masses form ramparts or snow cornices hanging over the underlying slope. Avalanches occur when snow stability is disturbed on a slope under the influence of heavy snowfalls, intensive snowmelt, rains, non-crystallization of the snow mass with the formation of a weakly connected deep horizon. Depending on the nature of the movement of snow along the slopes, there are: axial - snow landslides sliding along the entire surface of the slope; flume avalanches - moving along hollows, logs and erosion furrows, jumping from ledges. When leaving the dry snow, a destructive air wave propagates ahead. Avalanches themselves have enormous destructive power, since their volume can reach 2 million m 3, and the impact force is 60-100 t/m2. Usually, avalanches, although with varying degrees of constancy, are confined year after year to the same places - foci of different sizes and configurations.

To combat avalanches, protection systems have been developed and are being created that provide for the placement of snow shields, the prohibition of felling and forest planting on avalanche-prone slopes, the shelling of dangerous slopes from artillery, the construction of avalanche ramparts and ditches. The fight against avalanches is very difficult and requires large material costs.

In addition to the catastrophic processes described above, there are also such as collapse, landslide, sinking, subsidence, destruction of coasts, etc. All these processes lead to the movement of matter, often on a large scale. The fight against these phenomena should be aimed at weakening and preventing (where possible) the processes that cause a negative impact on the stability of engineering structures that endanger people's lives.