The most terrible natural phenomena. Presentation on the topic “Hazardous Weather Phenomena” Hazardous Weather Phenomena and Human Safety Project

Slide 2

Weather is a major factor

Weather is the main factor on which human safety in natural conditions depends.
Some weather conditions significantly complicate human stay in the natural environment.
When going on a hike, you need to find out how the weather changes in the places of your planned vacation in different times of the year.

Slide 3

We know that...

From the organization's experience active rest It has been established in nature that for any area and each type of tourist trip (hiking, mountain, water, skiing) the most favorable and unfavorable seasons can be distinguished in terms of weather conditions.

We know that...

Slide 4

For mountain and ski trips

Thus, for amateur mountain hikes, the second half of summer (July - August) is considered the most favorable season in almost all regions of the country.
For ski tourism in middle lane March is preferable, and in northern regions- March, April.

Slide 5

In bad weather

Experienced tourists advise that in case of short-term intense precipitation (heavy rain), stop in the first convenient place and wait out the bad weather in a shelter, under an awning or a cape.

In bad weather

Slide 6

Transitions in snow and rain

You can continue driving in rain and snow on a technically simple section, along trails, on flat terrain, covered with a cape. Immediately after crossing in the rain (or snow), it is necessary to organize a bivouac, preferably in a shelter where you can make a fire, change clothes, and dry wet clothes and shoes.

Transitions in snow and rain

Slide 7

What to do during a thunderstorm

Particular care must be taken during thunderstorms. This weather phenomenon is associated with the development of cumulonimbus clouds and the accumulation of large electric charges. The greatest danger to humans is a direct lightning strike.

What to do during a thunderstorm

Slide 8

Lightning

Lightning is a giant electrical discharge that occurs between thunderclouds or between clouds and the ground. Currents generated in the ground when lightning strikes the earth's surface are also dangerous.

Slide 9

Harbingers

The harbingers of a thunderstorm are powerful cumulonimbus clouds, multiple flashes of lightning, and rumbles of thunder. Immediately before the start of a thunderstorm, there is usually a lull or the wind changes direction, then the wind suddenly increases sharply (squall) and the rain begins.

Harbingers

Slide 10

First measures

If you are on a hill (on a ridge, hill, steep slope) when a thunderstorm approaches, you need to get down as quickly as possible to avoid being struck by lightning.

If you are in the water, you need to quickly get to shore.

In the forest, it is best to hide among low trees with dense undergrowth.

Remember that among trees, birch and maple are less susceptible to direct lightning strikes, while oak and poplar are the most susceptible.

First measures

Slide 11

Taking cover

In open areas, you should choose sandy or rocky areas; you can hide in a dry hole, ditch, or ravine.

In the mountains, it is undesirable to seek shelter from a thunderstorm in small grottoes (shallow caves with a wide entrance), rock holes, or depressions, as there is a danger of being struck by currents formed in the ground after a lightning strike.

Taking cover

Slide 12

In a cave

If you still had to take refuge in a cave, grotto, or large depression, you cannot be at the entrance or in the far corner of such a place; a person’s position is safe when the distance between him and the walls is at least 1 m.

Slide 13

Remember!

During a thunderstorm you cannot:

be located next to the railway track, near a body of water, near a tall object (tree);
lean your head, back or other parts of your body against the surface of rocks or tree trunks;
stop at the edges of the forest and forest clearings.

Slide 14

What to do during a blizzard

In a snowstorm, with strong wind and cold, a person’s normal breathing is disrupted, the heat-protective properties of clothing are reduced, due to poor visibility, he loses orientation, can get lost, run out of strength and die.

Slide 15

What to do during a blizzard

A blizzard does not come suddenly. Before it begins, there is an increase in air temperature and a gradual increase in wind speed. A harbinger of a blizzard is the appearance of a dark gray or black cloud growing on the horizon with changing outlines. The wind gradually intensifies and becomes gusty, which lifts the snow and disperses the drifting snow. A cloud covers the entire sky, and a blizzard begins.

Slide 16

What to do during a blizzard

It is best to wait out the snowstorm in a bivouac camp. If a group is moving along the route when a blizzard approaches, it is necessary to immediately stop, set up camp and wait for it to end.

Slide 17

What to do during a blizzard

The primary task facing a group of tourists before or after the onset of a blizzard is setting up a bivouac. When setting up a tent, you should find at least partial shelter from the wind. The tent is installed with the entrance on the leeward side, its guy ropes are secured by sticking them into the snow with skis or ski poles. After setting up the tent, backpacks are brought in and placed at the back windward wall and in the corners of the tent.

Slide 18

What to do during a blizzard

When setting up bivouac in a snowstorm, you cannot move away from the tent. A tourist who has moved away from the tent and lost sight of the camp must retrace his steps. If the tracks are covered up, you should stop and take all measures to independently arrange a temporary shelter.

Slide 19

Signs of worsening weather

If it is clear during the day, but clouds thicken in the evening, then rain or a change in weather should be expected.
Wavy (altocumulus) clouds that resemble ripples or wave crests are a sure sign of severe weather within a few hours. Air temperature in winter time increases slightly, warming sets in. In summer, the difference between air temperature day and night decreases; the evening is warmer than the day.
The wind intensifies, especially in the evening, and the regular daily changes in local winds are disrupted.
Cloudiness increases, clouds move in the opposite direction or across the direction in which the wind blows at the earth's surface.
The sun sets in a cloud, the evening dawn has a bright red color.

Slide 20

Questions and tasks

Why do you need to know the weather forecast before going outdoors?
How can you ensure your protection from atmospheric precipitation in natural conditions?
How dangerous is a thunderstorm for a person in natural conditions?
How can you ensure your safety if a thunderstorm finds you outdoors?
What precautions should you take to protect yourself from a snowstorm?

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

Research and observations

People began to study characteristic natural phenomena in ancient times. However, it was possible to systematize these observations only in the 17th century; even a separate branch of science (natural science) was formed that studied these events. However, despite many scientific discoveries, and to this day some natural phenomena and processes remain poorly understood. Most often, we see the consequence of this or that event, but we can only guess about the root causes and build various theories. Researchers in many countries are working to make forecasts of their occurrence, and most importantly, to prevent their possible occurrence or at least reduce 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 and sublime in this. What natural phenomenon is most fascinating? They could be listed for a long time, but perhaps 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. For example, in the spring the following snowmelt, floods, thunderstorms, clouds, wind, and rain are observed. IN summer period the sun gives the planet an abundance of heat, natural processes at this time are most favorable: clouds, warm winds, rains and, of course, rainbows; but they can also be severe: thunderstorms, hail. In autumn the temperature changes, the days become cloudy and rainy. During this period, the following phenomena prevail: fog, leaf fall, frost, first snow. in winter vegetable world falls asleep, some animals hibernate. The most common natural phenomena are: freeze-up, blizzard, blizzard, snow, which appear on the windows

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

Natural hazards

These are extreme and severe climate and meteorological events that occur in all parts of the world, but some regions are considered more vulnerable to certain types of events compared to others. Natural hazards become disasters when infrastructure is destroyed and people die. These losses represent major obstacles to human development. It is almost 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 occur on different scales and in different time. In fact, each of them is unique in its own way, and therefore it is very difficult to predict it. For example, flash floods and tornadoes are destructive but short-lived events that affect relatively small areas. Other dangerous disasters, such as droughts, can develop very slowly but affect entire continents and entire populations. Such disasters last for several months and sometimes years. In order to monitor and predict these events, some national hydrological and meteorological services and special specialized centers are tasked with 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 precipitation. Drought is very different from others natural Disasters its slow development, its beginning is often hidden various factors. There are even recorded cases in world history when this disaster lasted for many years. Drought often has dire consequences: first, water sources (streams, rivers, lakes, springs) dry up, many crops stop growing, then animals die, becoming widespread realities. poor health and malnutrition.

Tropical cyclones

These natural phenomena represent 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. Interaction low pressure and wind-driven waves often result in a coastal storm surge - a huge volume of water thrown ashore with tremendous force and high speed, which wash away everything in their path.

Air pollution

These natural phenomena arise as a result of the accumulation in the air of harmful gases or particles of substances formed as a result of disasters (volcanic eruptions, fires) and human activities (the work of industrial enterprises, vehicles, etc.). Haze and smoke result from fires in undeveloped lands and forested areas, as well as the burning of crop residues and logging; in addition, due to the formation volcanic ash. These air pollutants have very serious consequences for the human body. As a result of such disasters, visibility is reduced and interruptions in the operation of road and air transport occur.

Desert Locust

Similar natural phenomena cause serious damage in Asia, the Middle East, Africa and southern European continent. When environmental and weather favor the reproduction of these insects; they concentrate, as a rule, in small areas. However, as their numbers increase, the locust ceases to be an individual creature and turns into a single living organism. Small groups form huge flocks that move in search of food. The length of such a school can reach tens of kilometers. In a day, it can cover distances of up to two hundred kilometers, sweeping away all vegetation in its path. Thus, one ton of locusts (this is a small part of the swarm) can eat as much food in a day as ten elephants or 2,500 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. All floodplains are vulnerable to flooding, and severe storms cause flash floods. In addition, short-term floods sometimes even occur after periods of drought, when very heavy rain falls on a hard and dry surface through which 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 may be increased by exposure to warm weather). El Niño currents), melting snow and ice jams. In coastal areas, storm surges often lead to flooding as a result of a tsunami, cyclone, or rising river levels due to unusually high tides. The reason for the flooding of vast areas located below the barrier dams is often high water on rivers, which is caused by melting snow.

Other natural hazards

1. Mud flow or landslide.

5. Lightning.

6. Extreme temperatures.

7. Tornado.

10. Fires on undeveloped lands or forests.

11. Heavy snow and rain.

12. Strong winds.

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

1. Earthquakes

Among all natural hazards, earthquakes should take first place. In places of ruptures earth's crust tremors occur that cause vibrations of the earth's surface with the release of gigantic energy. The resulting seismic waves are transmitted over very long distances, although these waves have the greatest destructive power at the epicenter of the earthquake. Due to strong vibrations of the earth's surface, massive destruction of buildings occurs.
Since quite a lot of earthquakes occur, and the surface of the earth is quite densely built up, then total people throughout history who died as a result of earthquakes exceed the number of all other victims natural disasters and numbers in many millions. For example, over the past decade, about 700 thousand people have died from earthquakes around the world. Entire settlements instantly collapsed from the most destructive shocks. Japan is the country most affected by earthquakes, and one of the most catastrophic earthquakes occurred there in 2011. The epicenter of this earthquake was in the ocean near the island of Honshu; on the Richter scale, the force of the tremors reached 9.1. Powerful aftershocks and the subsequent destructive tsunami disabled the Fukushima nuclear power plant, destroying three out of four power units. Radiation covered a significant area around the station, making densely populated areas, so valuable in Japanese conditions, uninhabitable. The colossal tsunami wave turned into mush what the earthquake could not destroy. Only officially over 16 thousand people died, to which we can safely include another 2.5 thousand who are considered missing. Only in this century destructive earthquakes took place in Indian Ocean, Iran, Chile, Haiti, Italy, Nepal.

2. Tsunami waves

A specific water disaster in the form of tsunami waves often results in numerous casualties and catastrophic destruction. As a result of underwater earthquakes or shifts of tectonic plates in the ocean, very fast but subtle waves arise, which grow into huge ones as they approach the shores and reach shallow waters. Most often, tsunamis occur in areas with high seismic activity. A huge mass of water, quickly approaching the shore, destroys everything in its path, picks it up and carries it deep into the coast, and then carries it into the ocean with a reverse current. People, unable to sense danger like animals, often do not notice the approach of a deadly wave, and when they notice, it is too late.
Usually killed by a tsunami more people than from the earthquake that caused it (the latest case in Japan). In 1971, the most powerful tsunami ever observed occurred there, the wave of which rose 85 meters at a speed of about 700 km/h. But the most catastrophic tsunami was observed in the Indian Ocean in 2004, the source of which was an earthquake off the coast of Indonesia, which claimed the lives of about 300 thousand people along a large part of the Indian Ocean coast.

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

3. Volcanic eruption

Throughout its history, humanity has remembered many catastrophic volcanic eruptions. When the pressure of magma exceeds the strength of the earth's crust at the most weak points, which is what volcanoes are, it ends in an explosion and outpouring of lava. But the lava itself, from which you can simply walk away, is not so dangerous as the hot pyroclastic gases rushing from the mountain, penetrated here and there by lightning, as well as the noticeable influence of the strongest eruptions on the climate.
Volcanologists count about half a thousand dangerous active volcanoes, several dormant supervolcanoes, not counting thousands of extinct ones. Thus, during the eruption of Mount Tambora in Indonesia, the surrounding lands were plunged into darkness for two days, 92 thousand inhabitants died, and cold temperatures were felt even in Europe and America.
List of some major volcanic eruptions:

Volcano Laki (Iceland, 1783). As a result of that eruption, a third of the island's population died - 20 thousand inhabitants. The eruption lasted for 8 months, during which streams of lava and liquid mud erupted from volcanic fissures. Geysers have become more active than ever. Living on the island at this time was almost impossible. The crops were destroyed and even the fish disappeared, so the survivors starved and suffered from unbearable living conditions. This may be the longest eruption in human history.
Volcano Tambora (Indonesia, Sumbawa Island, 1815). When the volcano exploded, the sound of the explosion spread over 2 thousand kilometers. Even the remote islands of the archipelago were covered with ash, and 70 thousand people died from the eruption. But even today Tambora is one of the highest mountains in Indonesia, which remain volcanically active.
Volcano Krakatoa (Indonesia, 1883). 100 years after Tambora, another catastrophic eruption occurred in Indonesia, this time “blowing the roof off” (literally) the Krakatoa volcano. After the catastrophic explosion that destroyed the volcano itself, frightening rumbles were heard for another two months. A huge amount was released into the atmosphere rocks, ash and hot gases. The eruption was followed by a powerful tsunami with wave heights of up to 40 meters. These two natural disasters together destroyed 34 thousand islanders along with the island itself.
Volcano Santa Maria (Guatemala, 1902). After a 500-year hibernation, this volcano woke up again in 1902, beginning the 20th century with the most catastrophic eruption, which resulted in the formation of a one and a half kilometer crater. In 1922, Santa Maria reminded itself again - this time the eruption itself was not too strong, but the cloud of hot gases and ash brought the death of 5 thousand people.

4. Tornadoes

On our planet there are a wide variety of dangerous places, which in Lately began to attract special category extreme tourists looking for...

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

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

5. Sandstorms

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

Throughout human history, strong earthquakes have repeatedly caused colossal damage to people and caused huge number casualties among the population...

6. Avalanches

They periodically descend from snow-capped mountain peaks snow avalanches. Climbers especially often suffer from them. During the First World War, up to 80 thousand people died from avalanches in the Tyrolean Alps. In 1679, half a thousand people died from snow melting in Norway. In 1886, a major disaster occurred, as a result of which “ White death"claimed 161 lives. The records of Bulgarian monasteries also mention human casualties from avalanches.

7. Hurricanes

In the Atlantic they are called hurricanes, and in Pacific Ocean typhoons. These are huge atmospheric vortices, in the center of which the strongest winds and sharply reduced pressure are observed. In 2005, the devastating Hurricane Katrina swept over the United States, which particularly affected the state of Louisiana and the densely populated city of New Orleans, located at the mouth of the Mississippi. 80% of the city's territory was flooded, and 1,836 people died. Other famous destructive hurricanes include:

Hurricane Ike (2008). The diameter of the vortex was over 900 km, and in its center the wind blew at a speed of 135 km/h. In the 14 hours that the cyclone moved across the United States, it managed to cause $30 billion worth of destruction.
Hurricane Wilma (2005). This is the largest Atlantic cyclone in the entire history of weather observations. The cyclone, which originated in the Atlantic, made landfall several times. The damage it caused amounted to $20 billion, killing 62 people.
Typhoon Nina (1975). This typhoon was able to breach China's Bangqiao Dam, causing the destruction of the dams below and causing catastrophic flooding. The typhoon killed up to 230 thousand Chinese.

8. Tropical cyclones

These are the same hurricanes, but in tropical and subtropical waters, representing huge low-pressure atmospheric systems with winds and thunderstorms, often exceeding a thousand kilometers in diameter. Near the surface of the earth, winds at the center of the cyclone can reach speeds of more than 200 km/h. Low pressure and winds cause a coastal storm surge to form - when ashore with high speed Colossal masses of water are released, washing away everything in its path.

It is difficult to scare a Russian person with anything, especially bad roads. Even safe routes claim thousands of lives a year, let alone those...

9. Landslide

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

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

10. Ball lightning

We are accustomed to ordinary linear lightning accompanied by thunder, but much more rare and mysterious are ball lightning. The nature of this phenomenon is electrical, but scientists cannot yet give a more accurate description of ball lightning. It is known that she can have different sizes and shape, most often yellowish or reddish luminous spheres. For unknown reasons, ball lightning often defies the laws of mechanics. Most often they occur before a thunderstorm, although they can also appear in absolutely clear weather, as well as indoors or in an airplane cabin. The luminous ball hovers in the air with a slight hiss, then can begin to move in any direction. Over time, it seems to shrink until it disappears completely or explodes with a roar.

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phenomena

Dangerous weather

Weather is a major factor

Weather is the main factor that determines

human safety in natural conditions.

Some weather events significantly complicate

human presence in the natural environment.

When going on a hike, you need to find out how the

weather in the places of planned vacation at different times of the year.

We know that...

From the experience of organizing active recreation in nature, it has been established that for any area and each type of tourist trip (hiking, mountain, water, skiing), the most favorable and unfavorable seasons in terms of weather conditions can be identified.

For mountain and ski trips

Thus, for amateur mountain hikes, the second half of summer (July - August) is considered the most favorable season in almost all regions of the country.

For ski tourism in the middle zone, March is preferable, and in the northern regions - March - April.

In bad weather

Experienced tourists advise that in case of short-term intense precipitation (heavy rain), stop in the first convenient place and wait out the bad weather in a shelter, under an awning or a cape.

Transitions in snow and rain

What to do during a thunderstorm

Particular care must be taken during thunderstorms. This weather phenomenon is associated with the development of cumulonimbus clouds and the accumulation of large electrical charges in them. The greatest danger to humans is a direct lightning strike.

Lightning

Harbingers

First measures

If you are on a hill (on a ridge, hill, steep slope) when a thunderstorm approaches, you need to get down as quickly as possible to avoid being struck by lightning.

If you are in the water, you need to quickly get to shore.

In the forest, it is best to hide among low trees with dense undergrowth.

Remember that among trees, birch and maple are less susceptible to direct lightning strikes, while oak and poplar are the most susceptible.

Taking cover

In open areas, you should choose sandy or rocky areas; you can hide in a dry hole, ditch, or ravine.

In a cave

Remember!

During a thunderstorm you cannot:

be located next to the railway track, near a body of water, near a tall object (tree);

lean your head, back or other parts of your body against the surface of rocks or tree trunks;

stop at the edges of the forest and forest clearings.

What to do during a blizzard

It is best to wait out the snowstorm in a bivouac camp. If a group is moving along the route when a blizzard approaches, it is necessary to immediately stop, set up camp and wait for it to end.

What to do during a blizzard

Signs of worsening weather

If it is clear during the day, but clouds thicken in the evening, then rain or a change in weather should be expected.

Wavy (altocumulus) clouds that resemble ripples or wave crests are a sure sign of severe weather within a few hours. The air temperature rises slightly in winter and warming sets in. In summer, the difference between air temperature day and night decreases; the evening is warmer than the day.

The wind intensifies, especially in the evening, and the regular daily changes in local winds are disrupted.

Cloudiness increases, clouds move in the opposite direction or across the direction in which the wind blows at the earth's surface.

The sun sets in a cloud, the evening dawn has a bright red color.

To predict hazardous phenomena, Roshydromet has developed criteria - using them, experts determine the degree of danger of an impending or already occurring disaster. A total of 19 weather phenomena have been identified that may pose a serious threat.

Element No. 1: wind

Very strong wind(at sea there is a storm). The speed of the element exceeds 20 meters per second, and with gusts it increases by a quarter. For high-altitude and coastal areas, where winds are more frequent and intense, the standard is 30 and 35 meters per second, respectively.

In Russia, Primorye suffers from storms more often than other regions, North Caucasus and Baikal region. The strongest winds blow in the archipelago New Earth, the islands of the Sea of Okhotsk and in the city of Anadyr on the edge of Chukotka: the air flow speed often exceeds 60 meters per second.

Hurricane- the same as a strong wind, but even more intense - with gusts the speed reaches 33 meters per second. During a hurricane, it is better to be at home - the wind is so strong that it can knock a person off his feet and cause injury.

The hurricane on May 29 of this year in Moscow became the largest in terms of the number of victims in the last hundred years. During the hurricane on May 29, wind speeds in some areas of the capital reached 25 m/s. More than 10 people were killed, more than a hundred were injured.

Squall- wind speed of 25 meters per second, not weakening for at least a minute. It poses a threat to life and health and can damage infrastructure, cars and houses.

Tornado- a vortex in the form of a pillar or cone, moving from the clouds to the surface of the Earth. On July 31, 2011, in Blagoveshchensk, Amur Region, a tornado knocked over three trucks, damaged more than 50 support pillars, roofs of houses, non-residential buildings and broke 150 trees.

An encounter with a vortex may be the last in your life: inside its funnel, the speed of air flows can reach 320 meters per second, approaching the speed of sound (340.29 meters per second), and the pressure can drop to 500 millimeters mercury(norm 760 mm Hg). Objects within the range of action of this powerful “vacuum cleaner” rise into the air and rush through it at great speed.

frosts called a temporary decrease in soil or air temperature near the ground to zero (against the background of positive average daily temperatures).

Severe frost recorded when the temperature reaches dangerous value. Each region, as a rule, has its own.

If in the period from October to March the average daily temperature is seven degrees below the long-term norm, it means that the abnormal cold. Such weather leads to accidents in housing and communal services, as well as to the freezing of agricultural crops and green spaces.

Element No. 2: water

Heavy rain. If more than 30 millimeters of precipitation falls in an hour, such weather is classified as heavy rain. It is dangerous because the water does not have time to sink into the ground and flow into the rain drain. Heavy rainfall forms powerful streams that paralyze traffic on the roads. Erasing the soil water masses metal structures are brought down to the ground. In hilly areas or areas dissected by ravines, heavy rainfall increases the risk of mudflows.

If at least 50 millimeters of precipitation falls in 12 hours, meteorologists classify this phenomenon as "Very heavy rain", which can also lead to the formation of mudflows. For mountainous areas, the critical indicator is 30 millimeters, since the probability catastrophic consequences higher there.

Powerful mud flow with fragments of stones represents mortal danger: its speed can reach six meters per second, and the “head of the elements” Front edge mudflow - 25 meters in height.

In July 2000, powerful mudflow hit the city of Tyrnyanz in Karachay-Cherkessia. 40 people were missing, eight died, and another eight were hospitalized. Residential buildings and city infrastructure were damaged.

Continuous heavy rain. Precipitation that falls over half or a whole day should exceed 100 millimeters, or 120 millimeters in two days. For rain-prone areas, the norm is 60 millimeters.

Probability of flooding, washout and mudflows during prolonged heavy rain increases sharply.

Very heavy snow. This type of dangerous phenomenon means heavy snowfall, resulting in over 20 millimeters of precipitation in 12 hours. This amount of snow blocks roads and makes it difficult for cars to move.

hail It is considered large if the diameter of the ice balls exceeds 20 millimeters. This weather phenomenon poses a serious risk to property and human health. Hailstones falling from the sky can damage cars, break windows, destroy vegetation and destroy crops.

In August 2015, hail struck the Stavropol region, accompanied by heavy rain and wind. Eyewitnesses filmed hailstones the size of egg and a diameter of five centimeters!

Heavy snowstorm is a weather phenomenon in which for half a day the visibility of flying snow is up to 500 meters, and the wind speed does not drop below 15 meters per second. When disaster strikes, driving cars becomes dangerous and flights are cancelled.

Heavy fog or haze, are conditions under which for 12 hours or more visibility is from five to zero meters. The reason for this may be a suspension of tiny drops of water with a moisture content of up to one and a half grams of water per cubic meter of air, soot particles and tiny ice crystals.

Meteorologists determine atmospheric visibility using a special technique or using a transmissometer device.

Severe icy conditions. This weather phenomenon is recorded by a special device - an ice machine. Among characteristic features this bad weather - ice 20 millimeters thick, wet, non-melting snow 35 millimeters high, or frost half a centimeter thick.

Ice provokes many accidents and leads to casualties.

Element No. 3: earth

Dust storm recorded by meteorologists when, for 12 hours, dust and sand, carried by winds at a speed of at least 15 meters per second, impair visibility at a distance of up to half a kilometer.

Element No. 4: fire

Abnormal heat is recorded by meteorologists when, during the period from April to September, for five days, the average daily temperature is seven degrees higher than the climatic norm of the region.

The UN Office for Disaster Risk Reduction noted that from 2005 to 2014, more than 7,000 people died from the effects of heat waves.

Heatwave— the temperature exceeds the established dangerous threshold in the period from May to August (the critical value is different for each territory).

This leads to droughts, increased fire danger and heat strokes.

Extreme fire hazard. This type of dangerous phenomenon is declared when high temperature air associated with a lack of precipitation.