Emergencies natural character threaten the inhabitants of our planet since the beginning of civilization. The amount of damage depends on the intensity of natural disasters, the level of development of society and living conditions.

Natural disasters are terrible because of their surprise, in a short period of time they devastate the territory, destroy homes, property, communications. One catastrophe, like an avalanche, is followed by others: hunger, infections, diseases.

Natural emergencies in last years, including in Russia, tend to increase. The actions of volcanoes (Kamchatka, Sakhalin, the Kuriles, Transbaikalia, the North Caucasus) are activated, their destructive power is increasing. Floods become almost regular, landslides along rivers and in mountainous areas are not uncommon. Ice, snowdrifts, storms, hurricanes and tornadoes occur in Russia every year. A number of catastrophes can be predicted, and some can be successfully resisted. However, this requires deep knowledge of the causes of their occurrence and the nature of their manifestation.

natural emergency(natural emergencies) is the situation on certain territory or water area formed as a result of a source of a natural emergency that may or has caused human casualties, damage to human health and (or) the environment natural environment, significant material losses and violation of the living conditions of people.

source A natural emergency is a dangerous natural phenomenon.

Dangerous natural phenomenon is considered to be such a natural phenomenon, 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.

The term " disaster"- a destructive natural phenomenon or process of a significant scale, as a result of which a threat to life and health of people has arisen or may arise, destruction or destruction of material assets and components of the natural environment.

All natural emergencies obey some general patterns :

• for each type of emergency situations, a certain spatial confinement is characteristic;
• the greater the intensity (power) of a dangerous natural phenomenon, the less often it happens;
• each natural emergency is preceded by some specific signs (harbingers);
• for all the unexpectedness of this or that natural emergency, its manifestation can be predicted;
• in many cases, passive and active protective measures against natural hazards can be envisaged.

Natural emergencies occur for various reasons, depending on this they are divided into the following groups:

1. Geological emergencies(landslides, mudflows, landslides, avalanches, etc.).

2. Geophysical emergencies(earthquakes, volcanic eruptions, etc.).

3. (storms, hurricanes, showers, thunderstorms, large hail, severe frost or heat, fog, etc.).

4. (floods, floods, congestion, low water levels, tsunamis, typhoons, etc.).

5. Hydrogeological emergencies(decrease or rise of groundwater).

6. natural fires(forest, steppe, peat, etc.).

7. biological emergency(infectious mass diseases of people, animals and plants).

8. Space emergencies(meteorites, comets, asteroids, etc.).

On the territory of Russia, which has an extremely wide variety of geological, climatic and landscape features, there are more than 30 natural hazards, among which the most destructive are: floods, earthquakes, landslides, mudflows, tornadoes. Every year, 230-250 natural disasters and emergencies occur in Russia, of which:

35% is due to floods;

21% - for landslides, landslides, mudflows and heavy snowfalls;

19% - for hurricanes, storms, storms, tornadoes;

14% - heavy and especially long rains;

8% - for earthquakes.

Over the past 15 years, 3.5 thousand people have died from natural hazards in Russia, and more than 270 thousand people have suffered. The total damage amounted to 6-7% of the gross national product.

Characteristics of natural emergencies and their consequences.

Geological emergencies

Landslides is the sliding displacement of the masses rocks downhill under the influence of gravity. According to international statistics, up to 80% of modern landslides are associated with human activities. A significant number of landslides occur in the mountains at an altitude of 1000 to 1700 m (90%). Landslides can occur on all slopes, starting from a steepness of 19° (for clayey soils, it is also possible at 5-7°).

They cause significant damage to the national economy (destruction of railway and highways, structures, buildings) and often lead to human casualties.

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.

The causes of mudflows are showers, intense snowmelt, breakthrough of reservoirs, less often - earthquakes, volcanic eruptions. When moving, mudflow is a continuous stream of mud, stones and water. In Russia, up to 20% of the territory is located in mudflow zones.

snow avalanches belong to landslides and occur in the same way as other landslide displacements: the adhesion forces of snow pass a certain limit, and the forces of gravity cause the snow masses to slide along the slope. The impact force of an avalanche can be up to 60-100 tons/sq.m. The speed of an avalanche can reach 100 m/s (360 km/h).

Geophysical emergencies

earthquakes- these are tremors and vibrations of the earth's surface, caused mainly by geophysical causes under the influence of tectonic forces. The size of an earthquake source usually ranges from a few tens of meters to hundreds of kilometers. They are located mainly in the earth's crust, as well as in the upper part of the Earth's mantle.

The main parameters characterizing earthquakes are their intensity and focus depth. The intensity of the manifestation of earthquakes in Russia is estimated on the Richter scale in points (from 1 to 12). For example:

At 4 points (moderate earthquake) there is a slight rattling and vibration of objects, dishes, glasses, creaking of doors;

With 8 points (destructive) - houses are badly damaged, partially collapse, monuments move;

With 12 points (severe catastrophe) - not a single building can withstand. There are huge cracks in the ground, numerous landslides and collapses, waterfalls, there is a change in the direction of the flow of rivers.

An earthquake is one of the worst natural disasters. He belongs to the first place in terms of damage and the number of casualties. Register annually for the globe hundreds of thousands of earthquakes.

In Russia, alarming zones, in which fluctuations were recorded earth's crust with a force of 8–9 points, are Altai, the North Caucasus, Transbaikalia, the Kuril Islands, the Kamchatka Peninsula, the Sayan Ridge and Sakhalin Island.

The most destructive in our country over the past 100 years is considered to be an earthquake on Sakhalin with a force of 7.6 points, which claimed the lives of 2040 people in 1995 and mercilessly wiped out the city of Neftegorsk, since the epicenter of the earthquake was located 25-30 kilometers from it.

Eruption- the process of ejection by a volcano on earth's surface red-hot debris, ash, an outpouring of magma, which, having poured onto the surface, becomes lava. Volcanic eruption can have a time period from several hours to many years. Volcanoes are divided into active, dormant and extinct.

Meteorological emergencies

Hurricanes, typhoons, storms, storms, tornadoes- these natural phenomena are extremely fast movements of air masses, often with catastrophic consequences.

The gradation of wind speeds is given on the Beaufort scale. It adopted a 17-point system for dividing wind speeds and gives approximate damage that occurs at different wind strengths.

A strong wind is considered to have a speed of more than 12 m/s; a storm (storm) has a speed of 18.3-29 m/s; hurricane - 29 m/s and more.

At a wind speed of about 23 m / s, tree branches break, roofs of houses are torn off. At a wind speed of about 26 m/s, large destruction of buildings occurs.

Hurricane- this is a wind of great destructive power and considerable duration, the speed of which is approximately equal to 32 m / s. and more (12 points on the Beaufort scale).

The average duration of a hurricane is 9-12 days. The width of a hurricane is assumed to be the width of the zone of catastrophic destruction (up to several hundred kilometers) and can sometimes reach up to 1000 km. Typhoons (tropical hurricanes) Pacific Ocean) the destruction zone is usually 15-45 km.

Storm- this is a wind whose speed is less than the speed of a hurricane and can reach 15-20 m/s. A violent storm is sometimes called storm.

Storm when air masses move over the surface of the sea (ocean), it causes strong excitement. The wave height reaches 10-12 m or more, which leads to damage and loss of ships.

The most reliable protection against hurricanes and storms is the shelter of people in protective structures (shelters), as well as in the subway, underground passages, basements, etc.

Tornado (tornado)- vortex air movement that occurs in a thundercloud, and then propagates in the form of a black sleeve to the ground. When a tornado descends to the ground, its base resembles a funnel, several tens of meters in diameter. The movement of air in the funnel is counterclockwise at speeds up to 100 m/s (360 km/h). The air pressure inside the funnel is sharply lowered, so everything that the vortex can tear off the ground and lift upwards in a spiral is sucked in there, transferring it over considerable distances. Moving over the terrain, the tornado destroys buildings, transmission lines, bridges, etc.

Blizzards, snowstorms, blizzard, blizzard, snowdrifts characterized by the movement of huge masses of snow at high speed (50-100 km / h) for several hours to several days.

Hydrological emergencies

floods- this is a significant flooding of the area as a result of a rise in the water level in a river, lake, reservoir, caused by the influx of water during periods of snowmelt or heavy rains, wind surges of water, ice jams on rivers, breakthrough of dams and enclosing dams, blockages of rivers during earthquakes, mountain landslides or mudflows. In terms of the number of human casualties and material damage, floods are second only to earthquakes.

Tsunami is a dangerous natural phenomenon, which is sea ​​waves, resulting mainly from the up or down shift of the seabed during submarine and coastal earthquakes. The tsunami-prone areas of our country are the Kuril Islands, Kamchatka, Sakhalin, and the Pacific coast. Having formed in any place, a tsunami can propagate at high speed (up to 1000 km/h) for several thousand kilometers, while the height of the tsunami in the area of ​​origin is from 0.1 to 5 meters, and when it reaches the shore, the wave height increases sharply, reaching heights from 10 to 50 meters. Huge masses of water thrown ashore lead to flooding of the area, destruction of buildings and structures, power transmission and communication lines, roads, bridges, piers, as well as to the death of people and animals. Air is propagated in front of the water shaft. shock wave. It acts similarly to a blast wave, destroying buildings and structures. The tsunami wave may not be the only one. Very often it is a series of waves approaching the shore with an interval of 1 hour or more. The possible scale of destruction is determined by the range of the tsunami: weak (1-2 points); average (3 points); strong (4 points); destructive (5 points).

natural fires

Fire- this is an uncontrolled combustion process, accompanied by the destruction of valuables and endangering the life and health of people, animals and plants.

landscape fires are caused by careless handling of fire, violation of fire safety rules, lightning strikes, as well as spontaneous combustion of peat and dry vegetation. According to statistics, up to 90% of fires are caused by human faults and only 8-10% by lightning.

Forest fires according to the intensity of burning, they are divided into weak, medium and strong, and according to the nature of burning - into low and high, fluent and stable.

Forest ground fires are characterized by burning of forest litter, ground cover and undergrowth without capturing tree crowns. The speed of the ground fire front is 0.3-1 m/min. The height of the flame does not exceed 1-2 m.

Forest crown fires are characterized by burning tree crowns. Speed ​​up to 25 km/h. With a stable crown fire, not only the crowns, but also the trunks of trees are covered by fire. The flame covers the entire forest from the ground cover to the tops of the trees and spreads at a speed of 5-8 km/h.

underground fires sometimes arise as a continuation of the forest. The deepening of the fire begins at the trunks of trees and spreads at a speed of several centimeters to several meters per day.

Peat fires can arise independently, without connection with forest ones. Such fires often cover vast areas and are difficult to extinguish. Their danger is that after burning, voids remain in the ground, into which people, animals, and equipment can fall.

Steppe (field) fires occur in open areas in the presence of dry grass or ripened bread. They are seasonal in nature and occur more often in summer, less often in spring and are practically absent in winter. Their propagation speed reaches 20-30 km/h.

biological emergency

The cause of a biological emergency can be a natural disaster, a major accident or catastrophe, the destruction of an object associated with research in the field of infectious diseases, as well as the introduction of pathogens from neighboring territories into the country (terrorist act, military operations).

The mass spread of infectious diseases among people, farm animals and plants often leads to emergency situations (epizootics, epiphytoties and epidemics).

Epizootic- simultaneous, progressing in time and space within a certain region, the spread of an infectious disease among a large number one or more species of animals, significantly exceeding the level of disease usually recorded in the area.

Epiphytoty- a massive infectious disease of agricultural plants progressing in time and space and (or) a sharp increase in the number of plant pests, accompanied by mass death of agricultural crops and a decrease in their effectiveness.

The main measures to protect plants from epiphytotics are: breeding and growing disease-resistant crops, observing the rules of agricultural technology, destroying foci of infection, chemical treatment of crops, seed and planting material, quarantine measures.

Epidemic- mass, progressing in time and space within a certain region, the spread of an infectious disease of people, significantly exceeding the incidence rate usually recorded in this territory. The emergence and expansion of the epidemic process is possible if there is a source of infection, the mechanism of infection transmission, and human susceptibility. Infected people and animals are called sources of infection.

Pathogenic bacteria, viruses, rickettsiae, fungi, plants and toxins can become the causative agents of infectious diseases in humans and animals.

Space emergencies

Space emergencies are the dangers that threaten man from outer space. First of all, they are dangerous space objects and cosmic rays. These are asteroids and comets approaching the Earth, solar radiation.

The meeting of our planet with celestial bodies poses a serious threat to the entire biosphere. Calculations show that the impact of an asteroid with a diameter of about 1 km is accompanied by the release of energy ten times greater than the entire nuclear potential available on Earth.

Many dangerous natural phenomena are closely related. So an earthquake can cause collapses, landslides, mudflows, floods, tsunamis, avalanches, activation of volcanic activity. Many storms, hurricanes, tornadoes are accompanied by showers, thunderstorms, hail. Intense heat is accompanied by drought, a decrease in the level of groundwater, fires, epidemics, and pest invasions.

Scheme of "chain" interaction of natural phenomena

Not every dangerous natural phenomenon leads to an emergency, especially if there is no threat to human life at the place of its occurrence.

So, for example, an annual flood is not counted as a flood if it does not threaten anyone. There is no reason to consider storms, storms, avalanches, freeze-ups, volcanic eruptions in those places where a person does not live and does not carry out any work as an emergency.

An emergency emerges only when, as a result of a dangerous natural phenomenon, a real threat arises to a person and his environment.

Natural emergencies, depending on the type, scale and consequences, are conditionally divided into natural disasters (large in scale and with severe consequences) and dangerous natural phenomena.

AT recent times more and more hazards lead to serious consequences and are regarded as emergencies. For example, frost and icing at the beginning of the last century did not cause serious harm, while in the winter of 2001 several regions of Ukraine were left without electricity, which, of course, caused enormous material and economic damage.

Natural disasters- these are dangerous processes of lithospheric, atmospheric, hydrological, biospheric or other origin of such scales that lead to catastrophic situations with sudden disruption of the life systems of the population, destruction and destruction of material values, objects of the national economy

Types of natural disasters:

- Meteorological:

o significant increase or decrease in temperature.

- Tectonic:

o earthquake,

o volcanic eruption,

- Topological:

o flood,

o mudflow,

o rockfall,

o snowdrifts,

- Space:

o increased radioactive radiation,

o the fall of a large cosmic body.

- Biological:

o abnormal increase in the number of macrobiological objects,

o diseases and damage to plants and animals,

o epidemic.

Dangerous natural phenomena - are processes that can lead to negative consequences in a small area and become the causes of emergencies of natural or man-made origin.

Types of natural hazards:

o lightning strike,

o ice

o strong wind.

Global natural and, in some cases, man-made emergencies, the environmental consequences of which extend to the entire or most of the planet, are called cataclysms.

The consequences of some of the largest natural disasters that have occurred on Earth are shown in Table 2.2.

Table 2.2

The largest natural disasters and the number of their victims

Type of disaster	Description and number of casualties	The possible number of victims in a disaster of the same scale in modern conditions
river floods	In June 1931, a flood on the river. Huang-se in China. The number of victims is from 1 to 2 million people.	2-3 million people
earthquakes	On 01/24/1556, as a result of a strong earthquake in China (Shen-si province), 830 thousand people died.	1.0 - 1.5 million people
Winter eruption<я вулка-нов	The eruption of Mount Etna in 1669. The town of Catania and other settlements were destroyed. 100 thousand people died.	1 - 2 million people
Typhoons		0.5 - 1.0 million people
Tsunami	On August 27, 1883, the tsunami that arose as a result of the eruption of the Krakatoa volcano led to the death of 36.4 thousand people.	100 - 200 thousand people
Landslides		0.5 million people

All natural hazards are characterized general rules:

Each type of danger is preceded by some specific signs;

With all the unexpectedness of natural danger, its appearance can be foreseen;

The greater the intensity of a dangerous phenomenon, the less often it happens;

Each type of hazard is characterized by a certain spatial conditionality;

To prevent natural emergencies, passive and active protective measures can be used. Active protection against natural hazards involves the construction of engineering structures, intervention in the mechanism of the phenomenon, the reconstruction of natural objects, etc., passive - the use of protective structures. In most cases, passive and active protection methods are combined.

Natural phenomena are ordinary, sometimes even supernatural climatic and meteorological events that occur naturally in all corners of the planet. It can be snow or rain familiar from childhood, or it can be incredible destructive or earthquakes. If such events take place away from a person and do not cause material damage to him, they are considered unimportant. No one will draw attention to this. Otherwise, dangerous natural phenomena are considered by mankind as natural disasters.

Research and observation

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

Weather phenomena of nature

Natural phenomena characterize the weather with its seasonal changes. Each season has its own set of events. So, for example, in the spring the following snowmelt, flood, thunderstorms, clouds, wind, rains are observed. In summer, the sun gives the planet an abundance of heat, natural processes at this time are most favorable: clouds, warm wind, rain and, of course, a rainbow; but can also be severe: thunderstorms, hail. In autumn they change, the temperature drops, the days become cloudy, with rain. During this period, the following phenomena prevail: fogs, leaf fall, hoarfrost, first snow. In winter, the plant world falls asleep, some animals hibernate. The most frequent natural phenomena are: freezing, snowstorm, blizzard, snow, on the windows appear

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

Dangerous natural phenomena

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

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

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

Drought

The main reason for this cataclysm is the lack of rainfall. Drought is very different from other natural disasters in its slow development, often hidden by various factors. There are even recorded cases in world history when this disaster lasted for many years. Drought often has devastating consequences: First, water sources (streams, rivers, lakes, springs) dry up, many crops stop growing, then animals die, and ill health and malnutrition become widespread.

Tropical cyclones

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

Air pollution

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

desert locust

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

Flash floods and flash floods

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

Other natural hazards

1. Debris (mud) flow or landslide.

5. Lightning.

6. Extreme temperatures.

7. Tornado.

10. Fires on undeveloped lands or in forests.

11. Heavy snow and rain.

12. Strong winds.

Topic: General concepts of dangerous and emergency situations of a natural nature.

Lesson topic: Natural phenomena and their classification.

The purpose of the lesson: To acquaint students with natural phenomena and their diversity.

Lesson objectives:

I. Educational tasks:

• Recall and consolidate knowledge about the shells of the Earth.
• To form students' knowledge that the formation of any natural phenomenon is associated with the processes occurring in the Earth's shells.
• To give a general idea to students about the types of natural phenomena at the place of their occurrence.

II. development tasks.

• To develop in students the ability and ability to foresee the natural phenomena of their area, which can lead to serious consequences, as well as ways to protect against them.

III. educational tasks.

• To instill in students the belief that any natural phenomenon of destructive power brings huge damage to the state of various types, primarily material and loss of life. Therefore, the state needs to send funds to scientific institutions so that they deal with this problem and be able to predict them in the future.

During the classes

Teacher: Today, children, we will talk about natural phenomena and their diversity. Of course, you know some, some you learned from the course of natural history and geography, and if someone is interested in the media, then from there. If you turn on the TV, radio or use the Internet, then we can say with confidence that natural phenomena of destructive power are occurring more and more often, and their strength is becoming greater. Therefore, we need to know what natural phenomena occur, where they occur most often and how to protect ourselves from them.

Teacher: And so let's remember from the course of geography what shells of the Earth exist.

In total, 4 shells of the Earth are distinguished:

1. Lithosphere - it includes the earth's crust and the upper part of the mantle.
2. The hydrosphere is a water shell, it includes all water in different states.
3. The atmosphere is a gas shell, the lightest and most mobile.
4. The biosphere is the sphere of life, it is the area of ​​existence of all living organisms.

Teacher: In all these shells, certain processes take place, as a result of which natural phenomena arise. Therefore, various natural phenomena can be divided according to the place of their occurrence:

Teacher: From this diagram, we see how many natural phenomena exist. Now let's look at each of them and find out what they are. (Children should take an active part in this part.)

Geological.

1. An earthquake is a natural phenomenon associated with geological processes occurring in the Earth's lithosphere, it manifests itself in the form of tremors and vibrations of the earth's surface resulting from sudden displacements and ruptures in the earth's crust or in the upper part of the mantle.

Picture 1.

2. A volcano is a conical mountain, from which an incandescent substance, magma, erupts from time to time.

A volcanic eruption is the release of molten matter from the earth's crust and mantle, which is called magma, to the surface of the planet.

Figure 2.

3. A landslide is a downward displacement of soil masses under the action of gravity, which occurs on slopes when the stability of the soil or rocks is disturbed.

The formation of landslides depends on various factors such as:

• what rocks make up this slope;
• slope steepness;
• ground water, etc.

Landslides can occur both naturally (eg earthquake, heavy rainfall) and man-made (eg human activities: deforestation, excavation).

Figure 3

4. A collapse is a detachment and fall of large masses of rocks, their overturning, crushing and rolling on steep and steep slopes.

Causes of landslides in the mountains can be:

• the rocks that make up the mountains are layered or broken by cracks;
• water activity;
• geological processes (earthquake), etc.

Causes of collapses on the coast of seas and rivers are the washing and dissolution of the underlying rocks.

Figure 4

5. An avalanche is a collapse of a mass of snow on mountain slopes, the slope angle must be at least 15 °.

The causes of an avalanche are:

• earthquake;
• intensive snow melting;
• prolonged snowfall;
• human activity.

Figure 5

Meteorological.

1. A hurricane is a wind whose speed exceeds 30 m/s, resulting in huge destruction.

Figure 6

2. A storm is a wind, but with a lower speed than in a hurricane and is no more than 20 m/s.

Figure 7

3. A tornado is an atmospheric vortex that forms in a thundercloud and descends, has a funnel or sleeve head start.

A tornado consists of a core and a wall. Around the core there is an upward movement of air, the speed of which can reach 200 m / s.

Figure 8

Hydrological.

1. Flooding is a significant flooding of the area as a result of a rise in the water level in a lake, river, etc.

Reasons for the flood:

• intensive snowmelt in spring;
• heavy rainfall;
• blockage of the river bed with rocks during an earthquake, collapse, etc., as well as ice during traffic jams;
• wind activity (water surge from the sea, bay at the mouth of the river).

Types of floods:

Figure 9

2. Mudflow is a stormy stream in the mountains of a temporary nature, consisting of water and a large number of rock fragments.

The formation of mudflows is associated with abundant precipitation in the form of rain or intense snowmelt. As a result, loose rocks are washed away and move along the riverbed at high speed, which picks up everything in its path: boulders, trees, etc.

Figure 10.

3. Tsunami is a type of sea waves resulting from the vertical shift of large areas of the seabed.

A tsunami occurs as a result of:

• earthquakes;
• underwater volcano eruptions;
• landslides, etc.

Figure 11.

Biological.

1. A forest fire is an uncontrolled burning of vegetation, spontaneously spreading through a forest area.

Forest fire can be: grassroots and riding.

An underground fire is the burning of peat in marshy and swampy soils.

Figure 12.

2. An epidemic is the spread of an infectious disease among a large number of the population and significantly exceeds the incidence rate usually recorded in the area.

Figure 13.

3. An epizootic is a widespread infectious disease among animals (for example: foot-and-mouth disease, swine fever, bovine brucellosis).

Figure 14.

4. Epiphytotics is a mass spread of an infectious disease among plants (for example: late blight, wheat rust).

Figure 15.

Teacher: As you can see, in the world there are a huge number of phenomena that surround us. So let's remember them and be extremely careful at the time of their occurrence.

Some of you may say: “Why do we need to know all of them if they are not typical for our region?”. From one point of view you are right, but from the other you are wrong. Each of you tomorrow, the day after tomorrow or in the future will surely go on a trip to other parts of the Motherland and the country. And there, as you know, there can be completely different phenomena that are not typical for our area. And then your knowledge will help you survive in a critical situation and avoid negative consequences. As the saying goes: "God saves the safe."

Literature.

1. Smirnov A.T. Fundamentals of life safety. 7th grade.
2. Shemanaev V.A. Pedagogical practice in the system of modern teacher training.
3. Smirnov A.T. The program of educational institutions of the basics of life safety grades 5-11.

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 path length 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 a large number of particles of soil and sand. 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. FROM 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 - on average, 10 - 12 cases are recorded annually.

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.