Natural phenomena and their classification. Classification of hazardous natural phenomena Names of hazardous natural phenomena

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 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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ADMINISTRATION OF THE CITY OF NIZHNY NOVGOROD

Municipal budgetary educational institution

Secondary school No. 148

Students' Scientific Society

Natural hazards in Russia

Completed by: Grishin Denis,

6a grade student

Supervisor:

Sinyagina Marina Evgenievna,

geography teacher

Nizhny Novgorod

27.12.2011

PLAN

Page

Introduction

Chapter 1. Natural hazards (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, somewhere less. One hundred percent security does not exist anywhere. Natural disasters can cause enormous damage.

Natural emergencies (natural disasters) have been on the rise in recent years. The activities of volcanoes are intensifying (Kamchatka), earthquakes are becoming more frequent (Kamchatka, Sakhalin, Kuril Islands, Transbaikalia, North Caucasus), and their destructive power is increasing. Floods have become almost regular (the Far East, the Caspian lowland, the Southern Urals, Siberia), and landslides along rivers and in mountainous areas are not uncommon. Ice, snow drifts, storms, hurricanes and tornadoes visit Russia every year.

Unfortunately, in areas of periodic flooding, the construction of multi-story buildings continues, which increases the concentration of the population, underground communications are laid, and dangerous industries operate. All this leads to the fact that the usualFloods 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 constantly increasing.

The purpose of my essay is to study natural emergencies.

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

  1. 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 can or will result in human casualties, damage to human health or the natural environment, significant losses and disruption of people’s living conditions.

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

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

1) dangerous geophysical phenomena;

2) dangerous geological phenomena;

3) dangerous meteorological phenomena;

4) marine hazardous 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.

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 influence of deep tectonic forces, stress arises, layers of earth's rocks are deformed, compressed into folds and, with the onset of critical overloads, they shift and tear, forming faults in the earth's crust. The rupture is accomplished 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.

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

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

Earthquakes are also classified by the reason they occur. They can arise as a result of tectonic and volcanic manifestations, landslides (rockbursts, 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 severity, 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, eliminating obstacles in its path. When reaching the surface, part of the magma turns into slag, and the other part flows out in the form of lava. From the vapors and gases released into the atmosphere, volcanic rocks called tephra settle onto the ground.

According to the degree of activity, volcanoes are classified into active, dormant and extinct. Active ones include those that erupted in historical times. Extinct ones, on the contrary, did not erupt. Dormant ones 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 speed depends on the slope of the volcano cone, the degree of viscosity of the lava and its quantity. The speed range is quite wide: from a few centimeters to several kilometers per hour. In some and the most dangerous cases it reaches 100 km, but most often it does not exceed 1 km/h.

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

Mud flows - 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, which leads to floods.

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

Volcanic gases. An 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, which are deadly to humans.

Classification of volcanoesis carried out according to the conditions of their occurrence and the nature of the activity. According to the first sign, 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 depths.

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

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

4) Volcanoes in “hot spot” zones. In certain areas under the ocean floor, “hot spots” are formed in the earth’s crust, where particularly high thermal energy is concentrated. In these places, rocks melt and emerge to the surface in the form of basaltic lava.

According to the nature of 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, and subsidence of the earth's surface as a result of karst phenomena.

Landslides is a sliding displacement of rock masses down a slope under the influence of gravity. They are formed in various rocks as a result of an imbalance or weakening of their strength. Caused by both natural and artificial (anthropogenic) reasons. Natural ones include: increasing the steepness of slopes, eroding their bases with sea and river waters, seismic tremors. Artificial causes include the destruction of slopes by road cuttings, excessive removal of soil, deforestation, and unwise farming on slopes. According to international statistics, up to 80% of modern landslides are associated with human activity. They occur at any time of the year, but mostly in the spring and summer.

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

Based on their scale, landslides are classified into large, medium and small-scale.

Large ones are usually caused by natural causes and form along slopes for hundreds of meters. Their thickness reaches 10 - 20 meters or more. The landslide body often retains its solidity.

Medium and small-scale ones are smaller in size and are characteristic of anthropogenic processes.

Scale is often characterized by the area involved. The speed of movement is very varied.

Based on 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 landslides, viscoplastic landslides, hydrodynamic landslides, and sudden liquefaction landslides. Often have signs of a combined mechanism.

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

Mudflow (mudflow)

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

The immediate causes of the formation of gray lakes are rainfall, intense snow melting, outburst of reservoirs, and, less commonly, earthquakes and volcanic eruptions.

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

With erosion, the water flow is first saturated with debris due to the washout and erosion of the adjacent soil, and then a mudflow wave is formed.

During a landslide, the mass is torn 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 regulations of mining enterprises, explosions during the construction of roads and the construction of other structures, logging, improper agricultural practices and disturbance of soil and vegetation cover.

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

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

Regional manifestation. The main formation factor is geological processes. The descent occurs sporadically, and the paths of movement are not constant;

Anthropogenic. This is the result of human economic activity. Occur where there is the greatest load on the mountain landscape. New mudflow basins are formed. The gathering is episodic.

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

Snow accumulating on mountain slopes, under the influence of gravity and weakening of structural bonds within the snow column, slides or crumbles down the slope. Having started its movement, it quickly picks up speed, capturing more and more 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.

Avalanches form within the avalanche source. An avalanche source is a section of a slope and its foot within which an avalanche moves. Each source consists of 3 zones: origin (avalanche collection), transit (trough), and stopping of the avalanche (alluvial cone).

Avalanche-forming factors include: the height of old snow, the condition of the underlying surface, the increase in freshly fallen snow, snow density, snowfall intensity, subsidence of snow cover, snowstorm redistribution of snow cover, air and snow cover temperatures.

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

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

How are they classified?

According to the nature of the movement and depending on the structure of the avalanche source, the following three types are distinguished: flume (moves along a specific drainage channel or avalanche chute), wasp (snow landslide, does not have a specific drainage channel and slides across the entire width of the area), jumping (arising from flume where the drainage channel has steep walls or areas with sharply increasing steepness).

According to the degree of repeatability, they are divided into two classes - systematic and sporadic. Systematic ones go every year or once every 2-3 years. Sporadic - 1-2 times per 100 years. It is quite difficult to determine their location in advance.

1.4. Natural disasters of a meteorological nature

All of them are divided 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 precipitation of 50 mm or more in 12 hours or less, and in mountainous, mudflow and storm-prone areas - 30 mm or more in 12 hours or less);

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

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

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

Dust storms;

frosts (when the air temperature drops 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 (region, republic), cover several administrative districts and last for 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 significant duration, the speed of which is approximately 32 m/s or more (12 points on the Beaufort scale).

A storm is a wind whose speed is less than the speed of 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 wind speed.

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

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

Hurricanes and stormy winds in winter often lead to snow storms, when huge masses of snow move from one place to another at high speed. Their duration can be from several hours to several days. Snowstorms that occur simultaneously with snowfall, at low temperatures or with sudden changes in temperature are especially dangerous.

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 Ocean. 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 formations are complex vortex formations caused by cyclonic activity and spreading over large areas. Streams are local phenomena of small distribution.

Vortex storms are divided into dust, snow and squall. In winter they turn into snow. In Russia, such storms are often called blizzards, blizzards, and blizzards.

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

They occur both over 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 internal cavity is from tens to hundreds of meters in diameter.

It is extremely difficult to predict the location and time of a tornado.Classification of tornadoes.

Most often they are divided according to their structure: dense (sharply limited) and vague (vaguely limited). In addition, tornadoes are divided into 4 groups: dust devils, small short-acting ones, small long-acting ones, 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 path length of small long-acting tornadoes is several kilometers. Hurricane vortices 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 occur in desert, semi-desert and plowed steppes and are capable of transporting 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.

Blizzards 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 (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 levels - floods, which cause flooding of low-lying parts of cities and other populated areas, agricultural crops, damage to industrial and transport facilities;

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

Mudflows (during the breakthrough of dammed and moraine lakes that threaten populated areas, roads and other structures);

Snow avalanches (if there is a threat to populated areas, roads and railways, power lines, industrial and agricultural facilities);

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

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

Floods - is the flooding of water adjacent to a river, lake or reservoir, which causes material damage, damages public health or leads to death. If flooding is not accompanied by damage, it is a flood of a river, lake, or reservoir.

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

Flood is a significant and rather prolonged rise in the water level in the river that occurs annually in the same season. Typically, floods are caused by spring melting of snow on the plains or by rainfall.

A flood is an intense, relatively short-term rise in water level. 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 a flood. WITH The maximum level is related to the area, layer and duration of flooding of the area. One of the main characteristics is the rate of water level rise.

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

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

Ice jams and jams on rivers

Congestion - This is an accumulation of ice in the riverbed that limits the flow of the river. As a result, water rises and spills.

Jams usually form 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.

Zazhor - a phenomenon similar to ice jam. However, firstly, a 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 jams are observed at the beginning of winter, while ice jams occur at the end of winter and spring.

The main reason for the formation of ice jams is the delay in the opening of ice on those rivers where the edge of the ice cover in the spring moves from top to bottom downstream. In this case, the crushed ice moving from above encounters an undisturbed ice cover on its way. The sequence of river opening from top to bottom downstream 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 at the opening is quite significant.

Ice jams form on rivers during the formation of ice cover. A necessary condition for formation is the appearance of inland ice in the channel and its involvement under the edge of the ice cover. The surface velocity of the current, as well as the air temperature during the freezing period, are of decisive importance.

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

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

Tsunami - These 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, the water recedes far from the shore, exposing the seabed. Then the approaching one becomes visible. At the same time, thunderous sounds are heard created by the air wave that the water mass carries in front of it.

Possible scales of consequences are classified by points:

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

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

3 points - average (noted by everyone. 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 jetties are severely damaged, Large ships are thrown ashore. There are casualties. There is great material damage).

1.6. Wildfires

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, causing colossal losses and sometimes leading to human casualties.

Forest fires is an uncontrolled burning of vegetation that spontaneously spreads throughout 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 throughout the forest area. A negligible number of fires occur from lightning discharges and spontaneous combustion of peat crumbs. 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 fire danger 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 divided into ground fires, crown fires, and soil fires. Almost all of them at the beginning of their development have a grassroots character and, if certain conditions are created, they turn into upland or soil ones.

The most important characteristics are the speed of spread of ground and crown fires and the depth of underground burning. Therefore, they are divided into weak, medium and strong. Based on the speed of fire spread, ground and top fires are divided into stable and fugitive. The intensity of combustion depends on the condition and supply 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 region's territory has a fairly wide 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.

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

- hazardous hydrological processes,such as floods (in the spring, rivers in the region are characterized by high water levels, coastal ice floes may break off, ice jams 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);

- natural fires(forest, peat, steppe and fires in wetlands);

- 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 livelihoods 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 area 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 (harmful squally winds, the passage of thunderstorm fronts with hail, ice and frost deposits on wires) as the most common and frequently observed - an average of 10 - 12 cases are recorded annually.

At the end of winter and spring of each year, events are carried out to rescue people from broken coastal ice floes.

Natural fires occur every year and water levels rise during flood periods. Adverse consequences of forest fires and high water levels are recorded quite rarely, which is due to pre-planned preparations for floods and fire hazard periods.

Spring flood

The passage of floods in the region is observed from the end of March to May. In terms of the degree of danger, floods in the region are of the moderately dangerous type, when the maximum levels of water rise are 0.8 - 1.5 m higher than the levels at which flooding begins, flooding of coastal areas (emergency situations at the municipal level). The flood area of ​​the river floodplain is 40 - 60%. Settled areas are usually subject to partial flooding. The frequency of water level exceeding the critical level is every 10 - 20 years. Excesses of critical levels on most rivers in the region were recorded in 1994 and 2005. To one degree or another, 38 districts of the region are exposed to hydrological processes during the spring flood period. The results of the processes are flooding and flooding of residential buildings, livestock and agricultural complexes, destruction of sections of roads, bridges, dams, dams, damage to power lines, and increased landslides. According to recent data, the areas most susceptible to flood phenomena 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 break-up period. The number of ice jams on the region's rivers averages 3 - 4 per year. The flooding (flooding) caused by them is most likely in populated areas 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 subject to the negative impact of forest-peat fires.

Wildfire hazards involve 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 ​​natural fires vary significantly from year to year, because they directly depend on weather conditions and anthropogenic factors (visitation of forests, preparation for the fire season, etc.).

It should be noted that almost throughout the entire territory of Russia in the period up to 2015. One should expect an increase in the number of days with high air temperatures in summer. At the same time, the likelihood of extremely long periods with critical air temperatures will increase significantly. In this regard, by 2015 Compared to current values, an increase in the number of days with fire danger is predicted.

  1. MEASURES FOR PROTECTION AGAINST NATURAL DISASTERS.

Over 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 isolated examples of successful resistance to the elements. Nevertheless, it is advisable to once again list the main principles of protection against natural disasters and compensation for their consequences. Clear and timely forecasting of the time, location and intensity of a natural disaster is necessary. This makes it possible to promptly notify the population about the expected impact of the elements. A correctly understood warning allows people to prepare for a dangerous phenomenon by either temporary evacuation, or the construction of protective engineering structures, or strengthening their own homes, livestock premises, 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 can happen again. In some countries, the state buys land in areas of potential natural disasters and organizes subsidized travel from hazardous areas. Insurance is important to reduce losses due to natural disasters.

An important role in preventing damage from natural disasters belongs to the engineering-geographical zoning of potential disaster zones, as well as the development of building codes and regulations that strictly regulate the type and nature of construction.

Various countries have developed fairly flexible legislation on economic activities in disaster zones. If a natural disaster occurs in a populated area and the population was not evacuated in advance, rescue operations are carried out, followed by repair and restoration work.

Conclusion

So I studied natural emergencies.

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

Natural emergencies can result in loss of life, 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 very little advance notice.

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., Khwang P.A. Life safety. - Rostov n/d: “Phoenix”, 2003. - 416 p.

3. Reference data on emergencies of man-made, natural and environmental origin: In 3 hours - M.: GO USSR, 1990.

4. Emergency situations: Brief description and classification: Textbook. allowance / Author. benefits A.P. Zaitsev. - 2nd ed., rev. and additional - M.: Journal "Military knowledge", 2000.

A hazardous geological phenomenon is an event that occurs as a result of the activity of geological processes that occur in the earth's crust under the influence of various geological or natural factors or their combination, and have a negative impact on plants, people, animals, the natural environment, and economic objects. Most often, geological phenomena are associated with the movement of lithospheric plates and changes occurring in the lithosphere.

Types of hazardous phenomena

Geological hazards include the following:

  • screes and landslides;
  • sat down;
  • subsidence or failure of the earth's surface as a result of karst;
  • kurums;
  • erosion, abrasion;
  • avalanches;
  • flushes;
  • landslides.

Each type has its own characteristics.

Landslides

Landslides are a geological hazard that is a sliding displacement of rock masses along slopes under the influence of their own weight. This phenomenon occurs as a result of erosion of the slope, due to seismic shocks or under other circumstances.

Landslides occur on the slopes of hills and mountains, and on steep river banks. They can be caused by a variety of natural phenomena:

  • earthquakes;
  • intense precipitation;
  • uncontrolled plowing of slopes;
  • cutting slopes when laying roads;
  • as a result of deforestation;
  • during blasting operations;
  • during abrasion and river erosion, etc.

Causes of landslides

Landslides are a dangerous geological phenomenon that most often occurs as a result of the impact of water. It seeps into cracks in ground rocks, causing destruction. All loose deposits are saturated with moisture: the resulting layer acts as a lubricant between layers of earthen rocks. When the inner layers rupture, the detached mass begins to float down the slope, as it were.

Landslide classification

There are several types of dangerous geological phenomena, divided by speed of movement:

  1. Very fast. They are characterized by mass movement at a speed of 0.3 m/min.
  2. Fast ones are characterized by the movement of masses at a speed of 1.5 m/day.
  3. Moderate - landslides occur at a speed of up to one and a half meters per month.
  4. Slow - movement speed - up to one and a half meters per year.
  5. Very slow - 0.06 m/year.

In addition to the speed of movement, all landslides are divided by size. According to this criterion, this phenomenon is divided as follows:

  • grandiose, occupying an area of ​​more than four hundred hectares;
  • very large - landslide area - about two hundred hectares;
  • large - area - about a hundred hectares;
  • small - 50 hectares;
  • very small - less than five hectares.

The thickness of a landslide is characterized by the volume of displaced rocks. This figure can reach several million cubic meters.

Mudflows

Another dangerous geological phenomenon is a mudflow, or mudflow. This is a temporary rapid mountain stream of water mixed with clay, sand, stones, etc. A mudflow is characterized by a sharp rise in water level, occurring in wave movements. Moreover, this phenomenon does not last long - for a couple of hours, but has a strong destructive effect. The area affected by a mudflow is called a mudflow basin.

For this dangerous geological natural phenomenon to occur, three conditions must be met simultaneously. Firstly, there should be a lot of sand, clay and small diameter stones on the slopes. Secondly, to wash it all off the slope, you need a lot of water. Thirdly, mudflows can only occur on steep slopes, with a slope angle of about twelve degrees.

Causes of mudflows

A dangerous mudflow can occur for various reasons. Most often, this phenomenon is observed as a result of intense rains, rapid melting of glaciers, as well as as a result of tremors and volcanic activity.

Mudflows can occur as a result of human activities. An example of this is deforestation on mountain slopes, quarrying or mass construction.

snow avalanche

A snow avalanche is also a dangerous geological natural phenomenon. During an avalanche, a mass of snow slides down the steep slopes of mountains. Its speed can reach one hundred meters per second.

During the fall of an avalanche, a pre-avalanche air wave is formed, causing great damage to the surrounding nature and any objects built in the path of the phenomenon.

Why does an avalanche happen?

There are several reasons why an avalanche begins. These include:

  • intensive snow melting;
  • long snowfall, which results in a large snow mass that is unable to stay on the slopes;
  • earthquakes.

Avalanches can occur due to strong noise. This phenomenon is provoked by air vibrations resulting from sounds emitted at a certain frequency and with a certain strength.

As a result of an avalanche, buildings and engineering structures are destroyed. Any obstacles in its path are destroyed: bridges, power lines, oil pipelines, roads. This phenomenon causes great damage to agriculture. If there are people in the mountains when the snow melts, they may die.

Snow avalanches in Russia

Knowing the geography of Russia, you can accurately determine where the most dangerous avalanche areas are. The most dangerous areas are mountains with a lot of snowfall. These are Western and Eastern Siberia, the Far East, the Urals, as well as the North Caucasus and the mountains of the Kola Peninsula.

Avalanches account for approximately half of all mountain accidents. The most dangerous periods of the year are considered to be winter and spring. During these periods, up to 90% of snow melting is recorded. An avalanche can occur at any time of the day, but most often the snow melts during the day, and rarely in the evening. The impact force of the snow mass can be estimated at tens of tons per square meter! While driving, the snow sweeps away everything in its path. If a person falls over, he will not be able to breathe, since the snow clogs the airways, penetrating dust into the lungs. People can freeze, get severe injuries, and frostbite of internal organs.

Collapses

And what other phenomena are classified as geological hazards and what are they? These include collapses. These are detachments of large masses of rocks onto river valleys and sea coasts. Landslides occur due to the separation of masses from the maternal base. Landslides can block or destroy roads and cause huge amounts of water to overflow from reservoirs.

Landslides are small, medium and large. The latter include rock detachments weighing more than ten million cubic meters. Medium debris includes debris with a volume of one hundred thousand to ten million cubic meters. The mass of small landslides reaches tens of cubic meters.

Landslides can occur as a result of the geological structure of the area, as well as cracks on the mountain slopes. The cause of landslides can be human activity. This phenomenon is observed during crushing of rocks, as well as due to a large amount of moisture.

As a rule, collapses occur suddenly. Initially, a crack forms in the rock. Gradually it increases, causing the breed to separate from the parent formation.

Earthquakes

When asked: “Indicate dangerous geological phenomena,” the first thing that comes to mind is earthquakes. This species is considered one of the most terrible, destructive manifestations of nature.

To understand the reasons for this phenomenon, you need to know the structure of the Earth. As is known, it has a solid shell - the earth's crust, or lithosphere, mantle and core. The lithosphere is not a whole formation, but several huge plates, as if floating on the mantle. These plates move, collide, and overlap each other. Earthquakes occur in the zones of their interaction. However, tremors can occur not only at the edges of the plates, but also in their central part. Other reasons that cause tremors include volcanic eruptions and man-made factors. In some regions, seismic activity is clearly visible due to fluctuations in the water in the reservoir.

The results of earthquakes can be landslides, subsidence, tsunamis, avalanches and much more. One of the dangerous manifestations is soil liquefaction. With this phenomenon, the earth is oversaturated with water, and with tremors lasting ten seconds or more, the soil becomes liquid and loses its bearing capacity. As a result of this, roads are destroyed, houses sag and collapse. One of the most striking examples of this phenomenon is the liquefaction of soil in 1964 in Japan. The event caused several multi-story buildings to slowly tilt. They didn't have any injuries.

Another manifestation of tremors may be subsidence of the soil. This phenomenon occurs due to particle vibration.

Serious consequences of earthquakes can include ruptures of dams, as well as the occurrence of floods, tsunamis and more.

natural catastrophic danger emergency

More than 30 dangerous natural phenomena and processes occur on the territory of Russia, among which the most destructive are floods, storm winds, rainstorms, hurricanes, tornadoes, earthquakes, forest fires, landslides, mudflows, and 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 common natural catastrophic phenomena of an atmospheric nature in Russia are storms, hurricanes, tornadoes, squalls (28%), followed by earthquakes (24%) and floods (19%). Dangerous geological processes such as landslides and collapses account for 4%. The remaining natural disasters, among which forest fires have the highest frequency, total 25%. The total annual economic damage from the development of 19 of the most dangerous processes in urban areas in Russia is 10-12 billion rubles. in year.

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

Within seismically dangerous regions of Russia there are 330 settlements, including 103 cities (Vladikavkaz, Irkutsk, Ulan-Ude, Petropavlovsk-Kamchatsky, etc.). The most dangerous consequences of earthquakes are the destruction of buildings and structures; fires; releases of radioactive and emergency chemically hazardous substances due to 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 phenomena is the Spitak earthquake in Northern Armenia, which occurred on December 7, 1988. During this earthquake (magnitude 7.0), 21 cities and 342 villages were affected; 277 schools and 250 healthcare facilities were destroyed or found to be in disrepair; More than 170 industrial enterprises ceased to function; About 25 thousand people died, 19 thousand received varying degrees of injury and injury. Total economic losses amounted to $14 billion.

Among geological emergency events, landslides and mudflows represent the greatest danger due to the massive nature of their spread. The development of landslides is associated with the displacement of large masses of rocks along the slopes under the influence of gravitational forces. Precipitation and earthquakes contribute to the formation of landslides. In the Russian Federation, from 6 to 15 emergencies associated with the development of landslides are created annually. Landslides are widespread in the Volga region, Transbaikalia, the Caucasus and Ciscaucasia, Sakhalin and other regions. Urbanized areas are especially hard hit: 725 Russian cities are exposed to landslide phenomena. Mudflows are powerful streams, saturated with solid materials, descending through mountain valleys at tremendous speed. The formation of mudflows occurs with 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, Northern Urals and the Kola Peninsula. There are 13 cities under direct threat of mudflows in Russia, and another 42 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. Of the hydrological extreme events, floods can be one of the most common and dangerous natural phenomena. In Russia, floods rank first among natural disasters in terms of frequency, area of ​​distribution, and material damage, and second after earthquakes in terms of 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, up to 20 cities are flooded every year and up to 1 million residents are affected, and within 20 years, serious floods cover almost the entire territory of the country.

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, and a large number of economic facilities.

Floods are associated with significant material losses every year. In recent years, two major floods occurred in Yakutia on the river. Lena. In 1998, 172 settlements were flooded here, 160 bridges, 133 dams, and 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 river. The Lene rose 17 m and flooded 10 administrative districts of Yakutia. Lensk was completely flooded. About 10,000 houses were under water, about 700 agricultural and more than 4,000 industrial facilities were damaged, and 43,000 people were displaced. The total economic damage amounted to 5.9 billion rubles.

A significant role in the increase in the frequency and destructive power of floods is played by anthropogenic factors - deforestation, irrational agriculture and economic development of floodplains. The formation of floods can be caused by improper implementation of flood protection measures, leading to the breach of dams; destruction of artificial dams; emergency releases of reservoirs. The aggravation of the flood problem in Russia is also associated with the progressive aging of fixed assets of the water sector and the placement of economic 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 occurring in Russia, the most destructive are hurricanes, cyclones, hail, tornadoes, heavy rains, and snowfalls.

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

Dangerous natural phenomenon

an event of natural origin or the state of elements of the natural environment, as a result of the activity of natural processes, which, by their intensity, scale of distribution and duration, can cause a damaging effect on people, economic objects and the environment. O.p.i. are divided: according to the nature of the manifestation - into direct and indirect; by scale - object, local, regional, national and global; by type of manifestation - constant, periodic, episodic and instantaneous; according to the direction of development - increasing and decreasing, etc.


EdwART. Glossary of terms of the Ministry of Emergency Situations, 2010

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