Dangerous natural phenomena of meteorological origin. Abstract meteorological hazards. The rarest meteorological phenomena
Meteorological phenomena are a natural phenomenon that is dangerous to human life and can cause significant damage to his economy. Today, such climatic anomalies happen every day in different parts of the Earth, so it would be useful to learn more about them and get acquainted with the basic rules of behavior during cataclysms.
Hazardous natural phenomena group 1
This group includes climatic anomalies that can threaten the safety of a person and his property in the event of a long duration or high intensity.
Examples of dangerous meteorological phenomena of category A1:
A1.1 - Extremely strong wind. Its gusts can reach speeds above 25 m/s.
A1.2 - Hurricane. This is a separate type of wind anomaly. Gust speeds can reach up to 50 m/s.
A1.3 - Flurry. A sharp increase in wind (short-term). Gusts can reach up to 30 m/s.
A1.4 - Tornado. This is the most destructive and life-threatening natural phenomenon. A strong wind is localized into a funnel, which is directed from the clouds to the ground.
The following meteorological hazards in this category are associated with precipitation:
A1.5 - Heavy rain. Heavy rain may not stop for a very long time. The amount of precipitation exceeds 30 mm in 1 hour.
A1.6 - Heavy mixed rain. Precipitation falls in the form of showers and sleet. There is a drop in air temperature. The amount of precipitation can reach up to 70 mm in 12 hours.
A1.7 - Extremely heavy snow. These are solid precipitation, the amount of which in 12 hours can exceed 30 mm.
The following meteorological phenomena are included in a separate line:
A1.8 - Continuous downpour. Duration of heavy rain - at least 12 hours (with minor breaks). The amount of precipitation exceeds the threshold of 100 mm.
A1.9 - Big city. Its diameter should be from 20 mm or more.
The second group of hazardous natural phenomena of category A1
This section includes such climatic anomalies as a blizzard, fog, heavy icing, abnormal heat, etc.
Meteorological hazardous natural phenomena of the second group of category A1:
A1.10 - Strong snowstorm. The wind carries snow at a speed of 15 m/s and more. At the same time, the visibility range is about 2 m.
A1.11 - Sandstorm. The wind carries dust and soil particles at a speed of 15 m/s and higher. Visibility range - no more than 3 m.
A1.12 - Fog-haze. There is a serious clouding of the air due to the large accumulation of particles of water, combustion products or dust. The visibility range is less than 1 m.
A1.13 - Heavy frost deposits. Its diameter (on wires) is at least 40 mm.
The following meteorological phenomena of category A1 are associated with temperature changes:
A1.14 - Extremely severe frost. Values vary by geographic location and time of year.
A1.15 - Abnormal cold. In winter, for 1 week, the air temperature is below the meteorological norm by 7 degrees or more.
A1.16 - Extremely hot weather. Maximum temperatures vary by geographic location.
A1.17 - Abnormal heat. In the warm season, for 5 days or more, the temperature is above the norm by at least 7 degrees.
A1.18 - Fire situation. Its indicator belongs to the fifth class of danger.
Hazardous phenomena of nature category A2
This group includes agrometeorological anomalies. Any phenomenon in this category is capable of causing enormous damage to agriculture.
Meteorological natural phenomena related to type A2:
A2.1 - Frost. The temperature of air and soil drops sharply during harvesting or active vegetation of crops.
A2.2 - Waterlogging of the soil. The soil at a depth of 100 mm is visually fluid or sticky (for 2 weeks).
A2.3 - Dry wind. It is characterized by air humidity less than 30%, temperature above 25 degrees and wind from 7 m/s.
A2.4 - Atmospheric drought. Lack of precipitation at an air temperature of 25 degrees for 1 month.
A2.5 - Soil drought. In the upper soil layer (20 cm), the moisture coefficient is less than 10 mm.
A2.6 - Abnormally early appearance of snow cover.
A2.7 - Freezing of the soil (upper layer up to 20 mm). Duration - from 3 days.
A2.8 - in the absence of snow cover.
A2.9 - Slight frost with high snow cover (more than 300 mm). The temperature is not lower than -2 degrees.
A2.10 - Ice cover. Frost crust from 20 mm thick. The duration of soil cover is at least 1 month.
Rules of conduct in case of dangerous meteorological phenomena
During climatic phenomena, it is important to remain calm and reasonable, not to panic.
Wind meteorological natural phenomena (examples: storm, hurricane, tornado) are dangerous for human life only in the immediate vicinity of the source of the anomaly. Therefore, it is highly recommended to hide in specially equipped shelters underground. Do not approach windows, as there is a high risk of injury from broken glass. It is forbidden to be outdoors, on bridges, near power lines.
During abnormal events, movement on the roadway and the countryside should be limited. It is also recommended to stock up on food and water. It is forbidden to stay near power lines and sheer roofs.
In case of flooding, it is necessary to take a safe place on a hill and mark it for subsequent detection by rescuers. It is not recommended to be in one-story rooms, as the water level can rise sharply at any moment.
Record weather anomalies
Over the past 20 years, nature has brought many surprises to mankind. These are all kinds of dangerous meteorological phenomena (examples: huge hail, record-breaking strong winds, etc.) that claimed the lives of people and caused maximum damage to the economy.
In May 1999, the strongest wind gust on the Fedjit scale was recorded. The tornado was categorized F6. The wind speed reached 512 km/h. The tornado demolished hundreds of residential buildings and claimed the lives of dozens of people.
In the summer of 1998, about 30 m of snow fell on the famous Mount Baker in Washington state. Rainfall continued for several months.
The highest temperatures were recorded in Libya in September 1992 (58 degrees Celsius).
The largest hailstorm took place in the summer of 2003 in Nebraska. The diameter of the largest specimen was 178 mm, and its fall speed was about 160 km/h.
The rarest meteorological phenomena
In 2013, the morning after, visitors to the Grand Canyon witnessed a unique natural phenomenon called "inversion". Thick fog descended into the crevices, forming a whole waterfall of clouds.
In the same 2013, the residents of the state of Ohio saw in their yard a huge part of the territory located around their city, right up to the Canadian border. This phenomenon is called superrefraction, when rays of light bend under the pressure of air and reflect objects located far away at great distances.
In 2010, in Stavropol, people could observe multi-colored snow. The city was covered in brown and purple drifts. The snow was not toxic. Scientists have found that the precipitation was colored in the upper atmosphere, mixed with particles of volcanic ash.
Hazardous atmospheric phenomena (signs of approach, damaging factors, preventive measures and protective measures)
Meteorological and agrometeorological hazards
Meteorological and agrometeorological hazards are divided into:
storms (9-11 points):
hurricanes (12-15 points):
tornadoes, tornadoes;
vertical vortices;
large hail;
heavy rain (rainstorm);
heavy snowfall;
heavy ice;
severe frost;
strong blizzard;
heatwave;
heavy fog;
frosts.
Fog is the concentration of small drops of water or ice crystals in the surface layer of the atmosphere from air saturated with water vapor when it cools. In fog, horizontal visibility decreases to 100 m or less. Depending on the horizontal visibility range, heavy fog (visibility up to 50 m), moderate fog (visibility less than 500 m) and light fog (visibility from 500 to 1000 m) are distinguished.
Weak clouding of the air with horizontal visibility from 1 to 10 km is called a veil. The veil can be strong (visibility 1-2 km), moderate (up to 4 km) and weak (up to 10 km). Fogs are distinguished by origin: advective and radiation. The deterioration in visibility complicates the work of transport - flights are interrupted, the schedule and speed of ground transport change. Drops of fog, settling on the surface or ground objects under the influence of gravity or air flow, moisten them. There have been repeated cases of overlapping of insulators of high-voltage power lines as a result of deposition of fog and dew drops on them. Fog drops, like dew drops, are a source of additional moisture for field plants. Settling on them, the drops maintain a high relative humidity around them. On the other hand, drops of fog, settling on plants, contribute to the development of decay.
At night, fogs protect vegetation from excessive cooling as a result of radiation, weaken the harmful effects of frost. During the day, fogs protect the vegetation from solar overheating. Settling of mist drops on the surface of machine parts leads to damage to their coatings and corrosion.
According to the number of days with fog, Russia can be divided into three parts: mountainous areas, the central elevated part and low-lying areas. The frequency of fog increases from south to north. Some increase in the number of days with fog is observed in spring. Fogs of all types can be observed both at negative and at positive temperatures of the soil surface (from 0 to 5°C).
Black ice is an atmospheric phenomenon that is formed as a result of freezing of drops of supercooled rain or fog on the surface of the earth and objects. It is a layer of dense ice, transparent or opaque, which grows on the windward side.
The most significant black ice is observed during the passage of southern cyclones. When cyclones move eastward from the Mediterranean Sea and fill them over the Black Sea, icy patches are observed in southern Russia.
The duration of sleet is different - from parts of an hour to 24 hours or more. Educated icing keeps on objects for a long time. As a rule, black ice forms at night at negative air temperatures (from 0° to - 3°С). Black ice, together with strong winds, causes significant damage to the economy: wires are torn under the weight of icing, telegraph poles fall, trees die, traffic stops, etc.
Hoarfrost is an atmospheric phenomenon, which is the deposition of ice on thin long objects (tree branches, wires). There are two types of frost - crystalline and granular. The conditions for their formation are different. Crystalline hoarfrost is formed during fog as a result of sublimation (the formation of ice crystals immediately from water vapor without its transition to a liquid state or upon rapid cooling below 0 ° C) of water vapor, consists of ice crystals. Their growth occurs on the windward side of objects in light winds and temperatures below -15°C. The length of the crystals, as a rule, does not exceed 1 cm, but can reach several centimeters. Granular hoarfrost - snow-like loose ice that grows on objects in foggy, mostly windy weather.
It has sufficient strength. The thickness of this frost can reach many centimeters. Most often, crystalline hoarfrost occurs in the central part of the anticyclone with high relative humidity below the inversion layer. Grainy hoarfrost, according to the conditions of formation, is close to sleet. Rime frost is observed throughout Russia, but is distributed unevenly, since its formation is influenced by local conditions - the height of the terrain, the shape of the relief, the exposure of slopes, protection from the prevailing moisture-bearing flow, etc.
Due to the low density of hoarfrost (bulk density from 0.01 to 0.4), the latter to a greater extent causes only increased vibration and sagging of power transmission and communication wires, but can also cause them to break. Hoarfrost poses the greatest danger to communication lines during strong winds, as the wind creates an additional load on the wires, which sag under the weight of deposits, and the risk of their breakage increases.
A snowstorm is an atmospheric phenomenon, which is the transfer of snow by the wind over the surface of the earth with a deterioration in visibility. There are such blizzards as a blowing snow, when most of the snowflakes rise a few centimeters above the snow cover; blowing blizzard if snowflakes rise to 2 m or more. These two types of blizzards occur without snow falling from the clouds. And, in the end, a general, or upper, blizzard - snowfall with a strong wind. Blizzards reduce visibility on the roads, interfere with the operation of transport.
A thunderstorm is a complex atmospheric phenomenon in which electrical discharges (lightning) occur in large rain clouds and between clouds and the ground, which are accompanied by a sound phenomenon - thunder, winds and heavy rainfall, often hail. Lightning strikes damage ground objects, power lines and communications. Squalls and downpours, floods and hail accompanying a thunderstorm cause damage to agriculture and some areas of industry. There are intramass thunderstorms and thunderstorms that occur in the zones of atmospheric fronts. Intra-mass thunderstorms, as a rule, are short-term and occupy a smaller area than frontal ones. They arise as a result of strong heating of the underlying surface. Thunderstorms in the atmospheric front zone are distinguished by the fact that they often occur in the form of chains of thunderstorm cells that move parallel to each other, covering a large area.
They occur on cold fronts, fronts of occlusion, as well as on warm fronts in warm, humid, usually tropical air. The zone of frontal thunderstorms has a width of tens of kilometers with a front length of hundreds of kilometers. Approximately 74% of thunderstorms are observed in the front zone, other thunderstorms are intramass.
During a thunderstorm:
in the forest to hide among low trees with dense crowns;
in the mountains and in open areas to hide in a pit, ditch or ravine;
fold all large metal objects 15-20 meters away from you;
having sheltered from a thunderstorm, sit down, bending your legs under you and lowering your head on your legs bent at the knees, connect your feet together;
put under yourself, a plastic bag, branches or spruce branches, stones, clothes, etc. isolating from the soil;
on the way, the group disperse, go one at a time, slowly;
in shelter, change into dry clothes, in extreme cases, carefully squeeze out wet ones.
During a thunderstorm, do not:
take cover near lone trees or trees protruding above others;
lean or touch rocks and sheer walls;
stop at the edges of the forest, large clearings;
walk or stop near bodies of water and in places where water flows;
hide under rocky canopies;
run, fuss, move in a tight group;
be in wet clothes and shoes;
stay on high ground;
be near watercourses, in crevices and cracks.
blizzard
A snow storm is one of the varieties of a hurricane, characterized by significant wind speeds, which contributes to the movement of huge masses of snow through the air, and has a relatively narrow band of action (up to several tens of kilometers). During a storm, visibility deteriorates sharply, and transport communication, both intracity and intercity, may be interrupted. The duration of the storm varies from several hours to several days.
Blizzard, blizzard, blizzard are accompanied by sharp temperature changes and snowfall with strong gusts of wind. The temperature difference, snowfall with rain at low temperatures and strong winds, creates conditions for icing. Power lines, communication lines, roofs of buildings, various supports and structures, roads and bridges are covered with ice or sleet, which often causes their destruction. Ice formations on the roads make it difficult, and sometimes completely hinder the operation of road transport. Pedestrian movement will be difficult.
Snowdrifts occur as a result of heavy snowfalls and snowstorms, which can last from several hours to several days. They cause disruption of transport communication, damage to communication lines and power lines, and negatively affect economic activity. Snow drifts are especially dangerous when snow avalanches come down from the mountains.
The main damaging factor of such natural disasters is the impact of low temperature on the human body, causing frostbite, and sometimes freezing.
In the event of an immediate threat, the population is alerted, the necessary forces and means, road and utility services are put on alert.
A snowstorm, blizzard or blizzard can last for several days, so it is recommended to create a supply of food, water, fuel in the house in advance, and prepare emergency lighting. You can leave the premises only in exceptional cases and not alone. Restrict movement, especially in rural areas.
Vehicles should only be used on main roads. In the event of a sharp increase in wind, it is advisable to wait out the bad weather in the village or near it. If the machine breaks down, do not leave it out of sight. If it is impossible to move further, mark the parking lot, stop (with the engine to the windward side), cover the engine from the side of the radiator. In case of heavy snowfall, make sure that the car is not covered with snow, i.e. shovel snow as needed. The car engine must be periodically warmed up to avoid its “defrosting”, while preventing exhaust gases from entering the cab (body, interior), for this purpose, make sure that the exhaust pipe is not blocked with snow. If there are several cars, it is best to use one car as a shelter, the engines of other cars must be drained of water.
In no case should you leave the shelter (car), in heavy snow, landmarks after a few tens of meters can be lost.
A snowstorm, snowstorm or blizzard can be waited out in a shelter equipped with snow. Shelter is recommended to be built only in open areas, where snow drifts are excluded. Before you take cover, you need to find landmarks on the ground in the direction of the nearest housing and remember their location.
Periodically, it is necessary to control the thickness of the snow cover by piercing the ceiling of the shelter, and to clear the entrance and the ventilation hole.
It is possible to find an elevated, steadily standing object in an open and snowless area, take cover behind it and constantly discard and trample down the arriving snow mass with your feet.
In critical situations, it is permissible to completely bury yourself in dry snow, for which you put on all warm clothes, sit with your back to the wind, cover yourself with plastic wrap or a sleeping bag, pick up a long stick and let the snow sweep you. Constantly clear the ventilation hole with a stick and expand the volume of the formed snow capsule in order to be able to get out of the snow drift. Inside the resulting shelter, a landmark arrow should be laid out.
Remember that a blizzard due to multi-meter snow drifts and snowdrifts can significantly change the appearance of the area.
The main types of work during snow drifts, snowstorms, snowstorms or blizzards are:
search for missing people and providing them with first aid, if necessary;
clearing roads and areas around buildings;
providing technical assistance to stuck drivers;
elimination of accidents on utility and energy networks.
Hail is an atmospheric phenomenon associated with the passage of cold fronts. Occurs with strong ascending air currents during the warm seasons. Droplets of water, falling to a great height with air currents, freeze, and ice crystals begin to grow on them in layers. Drops become heavier and begin to fall down. When falling, they increase in size from merging with drops of supercooled water. Sometimes hail can reach the size of a chicken egg. As a rule, hail falls from large rain clouds during a thunderstorm or a downpour. It can cover the ground with a layer of up to 20-30 cm. The number of days with hail increases in mountainous areas, on hills, in areas with rugged terrain. Hail falls mainly in the second half of the day in relatively small areas of several kilometers. Hail usually lasts from several minutes to a quarter of an hour. The hail causes significant material damage. It destroys crops, vineyards, knocks flowers and fruits from plants. If the size of the hailstones is significant, it can cause the destruction of buildings and death of people. At present, methods have been developed for determining hail clouds, and a hail control service has been created. Dangerous clouds are "shot" with special chemicals.
Dry wind - hot and dry wind with a speed of 3 m/s or more, with high air temperature up to 25°C and low relative humidity up to 30%. Dry winds are observed in partly cloudy weather. Most often they occur in the steppes along the periphery of anticyclones that form over the North Caucasus and Kazakhstan.
The highest dry wind speeds were observed during the day, the lowest - at night. Dry winds cause great damage to agriculture: they raise the water balance of plants, especially when there is a lack of moisture in the soil, since intensive evaporation cannot be compensated by the flow of moisture through the root system. With prolonged action of dry winds, the ground part of the plants turns yellow, the foliage curls, their wilting occurs and even the death of field crops.
Dust, or black, storms are the transfer of large amounts of dust or sand by strong winds. They occur during dry weather due to the winding of sprayed soil over great distances. The occurrence, frequency, and intensity of dust storms are greatly influenced by orography, the nature of soils, forest cover, and other terrain features.
Most often, dust storms occur from March to September. The most intense and dangerous spring dust storms are during a prolonged absence of rain, when the soil dries out, and the plants are still underdeveloped and do not form a continuous cover. At this time, storms blow out the soil over vast areas. Reduced horizontal visibility. S.G. Popruzhenko investigated a dust storm in 1892 in the south of Ukraine. Here is how he described it: “A dry, strong east wind tore the ground for several days and drove masses of sand and dust. The crops, which turned yellow from dry air, were cut under the root, like a sickle, but the roots could not survive. The earth was demolished up to 17 cm deep.Canals filled up to 1.5 m.
Hurricane
A hurricane is a wind of destructive force and considerable duration. A hurricane occurs suddenly in areas with a sharp drop in atmospheric pressure. The speed of a hurricane reaches 30 m/s or more. In terms of its harmful effects, a hurricane can be compared with an earthquake. This is explained by the fact that hurricanes carry colossal energy, its amount released by an average hurricane in one hour can be compared with the energy of a nuclear explosion.
A hurricane can capture an area up to several hundred kilometers in diameter and is capable of moving thousands of kilometers. At the same time, the hurricane wind destroys strong and demolishes light buildings, devastates sown fields, breaks wires and knocks down power lines and communication poles, damages highways and bridges, breaks and uproots trees, damages and sinks ships, causes accidents on utility and energy networks . There were times when hurricane winds threw trains off the rails and knocked down factory chimneys. Often hurricanes are accompanied by heavy rains that cause flooding.
A storm is a type of hurricane. The wind speed during a storm is not much less than the speed of a hurricane (up to 25-30 m/s). Losses and destruction from storms are significantly less than from hurricanes. Sometimes a strong storm is called a storm.
A tornado is a strong small-scale atmospheric vortex with a diameter of up to 1000 m, in which the air rotates at a speed of up to 100 m / s, which has great destructive power (in the USA it is called a tornado).
On the territory of Russia, tornadoes are observed in the Central region, the Volga region, the Urals, Siberia, Transbaikalia, and the Caucasian coast.
A tornado is an ascending vortex consisting of extremely rapidly rotating air mixed with particles and moisture, sand, dust and other suspensions. On the ground, he moves in the form of a dark column of spinning air with a diameter of several tens to several hundred meters.
In the internal cavity of the tornado, the pressure is always reduced, so any objects that are in its path are sucked into it. The average speed of the tornado is 50-60 km / h, when it approaches, a deafening rumble is heard.
Strong tornadoes travel tens of kilometers and tear off roofs, uproot trees, lift cars into the air, scatter telegraph poles, and destroy houses. Threat notification is carried out by giving a signal "Attention to all" by a siren and subsequent voice information.
Actions upon receipt of information about an impending hurricane, storm or tornado - you should carefully listen to the instructions of the civil defense authority, which will report the estimated time, strength of the hurricane and recommendations on the rules of conduct.
Upon receipt of a storm warning, it is necessary to immediately begin to carry out preventive work:
reinforce insufficiently strong structures, close doors, dormer openings and attic spaces, sheathe windows with boards or close them with shields, and glue the glass with strips of paper or cloth, or, if possible, remove it;
in order to balance the external and internal pressure in the building, it is advisable to open the doors and windows on the leeward side and fix them in this position;
from roofs, balconies, loggias and window sills it is necessary to remove things that, if they fall, can cause injury to people. Items located in the yards must be secured or brought into the room;
it is also advisable to take care of emergency lamps - electric lamps, kerosene lamps, candles. It is also recommended to create stocks of water, food and medicines, especially dressings;
put out the fire in the stoves, check the condition of electrical switches, gas and water taps;
take pre-prepared places in buildings and shelters (in case of tornadoes - only in basements and underground structures). Indoors, you need to choose the safest place - in the middle part of the house, in the corridors, on the ground floor. To protect against injury from glass fragments, it is recommended to use built-in wardrobes, durable furniture and mattresses.
The safest places during a storm, hurricane or tornado are shelters, basements and cellars.
If a hurricane or tornado caught you in an open area, it is best to find any natural recess in the ground (ditch, pit, ravine or any recess), lie down on the bottom of the recess and press firmly against the ground. Leave the transport (regardless of whichever one you are in) and take cover in the nearest basement, shelter or recess. Take measures to protect against heavy rainfall and large hail, as hurricanes are often accompanied by them.
be on bridges, as well as in close proximity to objects that use poisonous, potent and flammable substances in their production;
take cover under separate trees, poles, come close to power line supports;
be near buildings from which gusts of wind blow away tiles, slates and other objects;
After receiving a message about the stabilization of the situation, you should leave the house carefully, you need to look around for hanging objects and parts of structures, broken electrical wires. it is possible that they are under voltage.
Without extreme necessity, do not enter damaged buildings, but if such a need arose, then this should be done carefully, making sure that there are no significant damage to stairs, ceilings and walls, fires, breaks in electrical wires, and elevators should not be used.
The fire should not be lit until there is confidence that there was no gas leak. When outdoors, stay away from buildings, poles, high fences, etc.
The main thing in these conditions is not to panic, to act competently, confidently and reasonably, to prevent oneself and keep others from unreasonable acts, to provide assistance to the victims.
The main types of damage to people during hurricanes, storms and tornadoes are closed injuries of various areas of the body, bruises, fractures, concussions, wounds accompanied by bleeding.
Natural disasters.
A natural disaster is a catastrophic natural phenomenon (or process) that can cause numerous casualties, significant material damage and other severe consequences.
Natural disasters include earthquakes, volcanic eruptions, mudflows, landslides, landslides, floods, droughts, cyclones, hurricanes, tornadoes, snow drifts and avalanches, prolonged heavy rains, severe persistent frosts, extensive forest and peat fires. Epidemics, epizootics, epiphytoties, and the mass spread of pests in forestry and agriculture are also classified as natural disasters.
Over the last 20 years of the 20th century, more than 800 million people in the world suffered from natural disasters (over 40 million people a year), more than 140 thousand people died, and the annual material damage amounted to more than 100 billion dollars.
Three natural disasters in 1995 provide clear examples.
1) San Angelo, Texas, USA, May 28, 1995: tornadoes and hail hit a city of 90,000 people; the damage caused is estimated at 120 million US dollars.
2) Accra, Ghana, July 4, 1995: The heaviest rainfall in almost 60 years caused severe flooding. About 200,000 residents lost all their possessions, more than 500,000 more could not get into their homes, and 22 people died.
3) Kobe, Japan, January 17, 1995: An earthquake that lasted only 20 seconds killed thousands of people; tens of thousands were injured and hundreds were left homeless.
Natural emergencies can be classified as follows:
1. Geophysical hazards:
2. Geological hazards:
3. Marine hydrological hazards:
4. Hydrological hazards:
5. Hydrogeological hazards:
6. Natural fires:
7. Infectious incidence of people:
8. Infectious incidence of farm animals:
9. Damage to agricultural plants by diseases and pests.
10. Meteorological and agrometeorological hazards:
storms (9 - 11 points);
hurricanes and storms (12 - 15 points);
tornadoes, tornadoes (a kind of tornado in the form of a part of a thundercloud);
vertical vortices;
large hail;
heavy rain (rainstorm);
heavy snowfall;
heavy ice;
severe frost;
strong blizzard;
heatwave;
heavy fog;
frosts.
Hurricanes and Storms
Storms are long-term movement of wind, usually in one direction at high speed. By their appearance, they are divided into: snowy, sandy. And according to the intensity of the wind along the width of the band: hurricanes, typhoons. Movement and wind speed, intensity is measured on the Beaufort scale in points.
Hurricanes are winds of force 12 on the Beaufort scale, i.e. winds that exceed 32.6 m/s (117.3 km/h).
Storms and hurricanes occur during the passage of deep cyclones and represent the movement of air masses (wind) at great speed. During a hurricane, the air speed exceeds 32.7 m/s (more than 118 km/h). Sweeping over the earth's surface, the hurricane breaks and uproots trees, rips off roofs and destroys houses, power lines and communications, buildings and structures, disables various equipment. As a result of a short circuit in the power grid, fires occur, the supply of electricity is interrupted, the operation of objects stops, and other harmful consequences may occur. People may find themselves under the rubble of destroyed buildings and structures. Fragments of destroyed buildings and structures and other objects flying at high speed can cause serious injuries to people.
Reaching the highest stage, the hurricane goes through 4 stages in its development: tropical cyclone, baric depression, storm, intense hurricane. Hurricanes tend to form over the tropical North Atlantic, often off the west coast of Africa, and gain strength as they move west. A large number of incipient cyclones develop in this manner, but on average only 3.5 percent of them reach the tropical storm stage. Only 1-3 tropical storms, usually over the Caribbean Sea and the Gulf of Mexico, reach the east coast of the United States each year.
Many hurricanes originate off the west coast of Mexico and move northeast, threatening coastal Texas.
Hurricanes usually exist from 1 to 30 days. They develop over overheated areas of the oceans and transform into supertropical cyclones after a long passage over the cooler waters of the North Atlantic Ocean. Once on the underlying land surface, they quickly go out.
The conditions necessary for the birth of a hurricane are not completely known. There is the Storms Project, which is designed by the US government to develop ways to defuse hurricanes at their source. Currently, this set of problems is being studied in depth. The following is known: an intense hurricane is almost correctly rounded in shape, sometimes reaching 800 kilometers in diameter. Inside the pipe of superwarm tropical air is the so-called "eye" - an expanse of clear blue sky with a diameter of about 30 kilometers. It is surrounded by the "wall of the eye" - the most dangerous and restless place. It is here that swirling inward, moisture-saturated air rushes upward. In doing so, it causes condensation and the release of dangerous latent heat - the source of the storm's strength. Rising kilometers above sea level, the energy is released to the peripheral layers. In the place where the wall is located, the upward air currents, mixing with condensation, form a combination of maximum wind force and violent acceleration.
Clouds spiral around this wall parallel to the direction of the wind, thus giving the hurricane its characteristic shape and changing from heavy rain at the center of the hurricane to tropical downpour at the edges.
Hurricanes typically move at 15 kilometers per hour along a westerly path and often pick up speed, usually drifting towards the north pole at a line of 20-30 degrees north latitude. But often they follow a more complex and unpredictable pattern. In any case, hurricanes can cause enormous destruction and tremendous loss of life.
Prior to the approach of a hurricane wind, equipment, individual buildings are fixed, doors and windows are closed in industrial premises and residential buildings, and electricity, gas, and water are turned off. The population takes shelter in protective or buried structures.
Modern methods of weather forecasting allow several hours or even days to warn the population of a city or an entire coastal region about an impending hurricane (storm), and the civil defense service can provide the necessary information about the possible situation and the required actions in the current conditions.
The most reliable protection of the population from hurricanes is the use of protective structures (metro, shelters, underpasses, building basements, etc.). At the same time, in coastal areas, it is necessary to take into account the possible flooding of low-lying areas and choose protective shelters in elevated areas.
A hurricane on land destroys buildings, communication and power lines, damages transport communications and bridges, breaks and uproots trees; when propagating over the sea, it causes huge waves with a height of 10-12 m or more, damages or even leads to the death of the ship.
After a hurricane, the formations, together with the entire able-bodied population of the facility, carry out rescue and emergency recovery work; they rescue people from overwhelmed protective and other structures and provide assistance to them, restore damaged buildings, power and communication lines, gas and water pipes, repair equipment, and carry out other emergency recovery work.
In December 1944, 300 miles east of about. Luzon (Philippines) ships of the US 3rd Fleet were in the area near the center of the typhoon. As a result, 3 destroyers sank, 28 other ships were damaged, 146 aircraft carriers and 19 seaplanes on battleships and cruisers were wrecked, damaged and washed overboard, more than 800 people died.
From hurricane winds of unprecedented strength and gigantic waves that hit the coastal regions of East Pakistan on November 13, 1970, a total of about 10 million people were affected, including about 0.5 million people who died and went missing.
Tornado
A tornado is one of the cruel, destructive phenomena of nature. According to V.V. Kushina, a tornado is not a wind, but a “trunk” of rain twisted into a thin-walled pipe, which rotates around an axis at a speed of 300-500 km / h. Due to centrifugal forces, a vacuum is created inside the pipe, and the pressure drops to 0.3 atm. If the wall of the "trunk" of the funnel breaks, bumping into an obstacle, then outside air rushes into the funnel. Pressure drop 0.5 atm. accelerates the air secondary flow to speeds of 330 m/s (1200 km/h) and more, i.е. to supersonic speeds. Tornadoes are formed in an unstable state of the atmosphere, when the air in the upper layers is very cold, and in the lower layers it is warm. There is an intense air exchange, accompanied by the formation of a vortex of great strength.
Such whirlwinds arise in powerful thunderclouds and are often accompanied by thunderstorms, rain, and hail. Obviously, it cannot be said that tornadoes arise in every thundercloud. As a rule, this happens on the edge of the fronts - in the transition zone between warm and cold air masses. It is not yet possible to predict tornadoes, and therefore their appearance is unexpected.
The tornado does not live long, since rather soon the cold and warm air masses mix, and thus the reason supporting it disappears. However, even in a short period of its life, a tornado can cause enormous damage.
Ministry of Education and Science of the Russian Federation
Stateeducational institution of higher professional building
« Taganrog State Pedagogical Institute »
Abstract on the topic:
Performed:
1st year student of C12 group
Faculty of Social Pedagogy
Volchanskaya Natalya
Taganrog
2011
Content:
- Introduction.
Natural disasters.
Hurricanes, storms, tornadoes.
- Conclusion.
- Introduction.
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, more and more natural disasters have occurred on the planet. Most often, destruction is brought by: storms, hurricanes, tornadoes, tornadoes.
In today's world, this problem is the most relevant. Meteorological hazards bring enormous damage to nature, housing and agriculture.
Natural emergencies (natural disasters) have been on the rise in recent years. Ice, snowdrifts, storms, hurricanes and tornadoes visit Russia every year.
aim my essay is the study of natural emergencies.
The task of my work- consideration of the classification of natural emergencies, the actions of the population during emergencies.
- Natural disasters.
Natural disasters include: hurricanes, tornadoes, tornadoes, snowdrifts and avalanches, prolonged heavy rains, severe persistent frosts.
Over the last 20 years of the 20th century, more than 800 million people in the world suffered from natural disasters (over 40 million people a year), more than 140 thousand people died, and the annual material damage amounted to more than 100 billion dollars.
Two natural disasters in 1995 are good examples.
- San Angelo, Texas, USA, May 28, 1995: tornadoes and hail hit a city of 90,000; the damage caused is estimated at 120 million US dollars.
Accra, Ghana, July 4, 1995: The heaviest rainfall in almost 60 years caused severe flooding. About 200,000 residents lost all their possessions, more than 500,000 more could not get into their homes, and 22 people died.
storms (9 - 11 points);
hurricanes and storms (12 - 15 points);
tornadoes, tornadoes (a kind of tornado in the form of a part of a thundercloud).
- Hurricanes, storms, tornadoes.
Bu? Rya (Who? Rm)- very strong wind , as well as a large excitement at sea . Also, in the course of numerous observations by American scientists, it was found that for areas located in the northern latitudes, a winter hurricane can be considered a snow storm, during which the wind speed reaches 56 kilometers per hour. In this case, the air temperature drops to? 7 ° C. The area of distribution of a snow storm can be arbitrarily vast.
The storm can be observed:
- during the passage of tropical or extratropical cyclone;
during the passage of a tornado (thrombus, then rnado);
during a local or frontal thunderstorm.
Storms include winds with a speed of more than 20 m / s, that is, more than 9 points according to Beaufort scale.
Distinguish:
by intensity:
- strong storm with a speed of 24.5-28.4 m/s (10 points);
severe storm with a speed of 28.5-32.6 m/s (11 points).
- subtropical storm
tropical storm
Hurricane ( Atlantic Ocean)
- Typhoon (Pacific Ocean).
Storms and hurricanes occur during the passage of deep cyclones and represent the movement of air masses (wind) at great speed. During a hurricane, the air speed exceeds 32.7 m/s (more than 118 km/h). Sweeping over the earth's surface, the hurricane breaks and uproots trees, rips off roofs and destroys houses, power lines and communications, buildings and structures, disables various equipment. As a result of a short circuit in the power grid, fires occur, the supply of electricity is interrupted, the operation of objects stops, and other harmful consequences may occur. People may find themselves under the rubble of destroyed buildings and structures. Fragments of destroyed buildings and structures and other objects flying at high speed can cause serious injuries to people.
Hurricanes begin with thunderstorms, collide with trade winds - winds of tropical latitudes.During hurricanes, the width of the zone of catastrophic destruction reaches several hundred kilometers (sometimes thousands of kilometers). The hurricane lasts 9 - 12 days, causing a large number of casualties and destruction. The transverse size of a tropical cyclone is much smaller - only a few hundred kilometers, its height is up to 12-15 km. Pressure in hurricanes falls much lower than in an extratropical cyclone. At the same time, the wind speed reaches 400-600 km/h. In the core of a tornado, the pressure drops very low, so tornadoes "suck" various, sometimes very heavy objects into themselves, which they then carry over long distances. People caught in the center of the tornado die.
Reaching the highest stage, the hurricane goes through 4 stages in its development: tropical cyclone, baric depression, storm, intense hurricane.
Hurricanes tend to form over the tropical North Atlantic, often off the west coast of Africa, and gain strength as they move west. A large number of incipient cyclones develop in this manner, but on average only 3.5 percent of them reach the tropical storm stage. Only 1-3 tropical storms, usually over the Caribbean Sea and the Gulf of Mexico, reach the east coast of the United States each year.
A hurricane is not inferior to earthquakes in terms of its impact on the environment: buildings, masts of power transmission lines and communications, transport routes are destroyed, trees are broken and twisted, ships and vehicles are overturned. Storms and hurricanes are often accompanied by downpours and snowfalls, which further complicates the situation. As a result of strong winds, a wind surge of water occurs at the estuarine section of the rivers, settlements and arable land are flooded, enterprises are forced to stop their production.
Many hurricanes originate off the west coast of Mexico and move northeast, threatening coastal Texas.
The conditions necessary for the birth of a hurricane are not completely known. The following is known: an intense hurricane is almost correctly rounded in shape, sometimes reaching 800 kilometers in diameter. Inside the pipe of superwarm tropical air is the so-called "eye" - an expanse of clear blue sky with a diameter of about 30 kilometers. It is surrounded by the "wall of the eye" - the most dangerous and restless place. It is here that swirling inward, moisture-saturated air rushes upward. In doing so, it causes condensation and the release of dangerous latent heat - the source of the storm's strength. Rising kilometers above sea level, the energy is released to the peripheral layers. In the place where the wall is located, ascending air currents, mixing with condensation, form a combination of maximum wind force and violent acceleration.
Clouds spiral around this wall parallel to the direction of the wind, thus giving the hurricane its characteristic shape and changing from heavy rain at the center of the hurricane to tropical downpour at the edges.
A hurricane on land destroys buildings, communication and power lines, damages transport communications and bridges, breaks and uproots trees; when propagating over the sea.
In December 1944, 300 miles east of about. Luzon (Philippines) ships of the US 3rd Fleet were in the area near the center of the typhoon. As a result, 3 destroyers sank, 28 other ships were damaged, 146 aircraft carriers and 19 seaplanes on battleships and cruisers were wrecked, damaged and washed overboard, over 800 people died.
From hurricane winds of unprecedented strength and gigantic waves that hit the coastal regions of East Pakistan on November 13, 1970, a total of about 10 million people were affected, including about 0.5 million people who died and went missing.
Hurricane Katrina most destructive hurricane in history and usa . It happened at the end of August 2005. The heaviest damage was caused New Orleans in Louisiana , where about 80% of the city's area was under water. As a result of the disaster, 1,836 residents were killed and the economic damage amounted to $125 billion.
The hurricane that hit Bangladesh in 1991 claimed the lives of 135,000 people.
Tornado- one of the cruel, destructive phenomena of nature. According to V.V. Kushina, a tornado is not a wind, but a “trunk” of rain twisted into a thin-walled pipe, which rotates around an axis at a speed of 300-500 km / h. Due to centrifugal forces, a vacuum is created inside the pipe, and the pressure drops to 0.3 atm. If the wall of the "trunk" of the funnel breaks, bumping into an obstacle, then outside air rushes into the funnel. Pressure drop 0.5 atm. accelerates the air secondary flow to speeds of 330 m/s (1200 km/h) and more, i.е. to supersonic speeds. Tornadoes are formed in an unstable state of the atmosphere, when the air in the upper layers is very cold, and in the lower layers it is warm. There is an intense air exchange, accompanied by the formation of a vortex of great strength.
Such whirlwinds arise in powerful thunderclouds and are often accompanied by thunderstorms, rain, and hail. Obviously, it cannot be said that tornadoes arise in every thundercloud. As a rule, this happens on the edge of the fronts - in the transition zone between warm and cold air masses. It is not yet possible to predict tornadoes, and therefore their appearance is unexpected.
The tornado does not live long, since rather soon the cold and warm air masses mix, and thus the reason supporting it disappears. However, even in a short period of its life, a tornado can cause enormous damage.
Until now, the tornado is in no hurry to reveal its other secrets. So, there are no answers to many questions. What is a tornado funnel? What gives its walls a strong rotation and tremendous destructive power? Why is the tornado stable?
It is not only difficult to study a tornado, but also dangerous - upon direct contact, it destroys not only the measuring equipment, but also the observer.
Comparing the descriptions of tornadoes (tornadoes) of the past and present centuries in Russia and other countries, one can see that they develop and live according to the same laws, but these laws have not been fully elucidated and the behavior of a tornado seems unpredictable.
During the passage of tornadoes, of course, everyone hides, runs, and people are not up to observing, and even more so measuring the parameters of tornadoes. The little that we managed to find out about the internal structure of the funnel is due to the fact that the tornado, breaking away from the ground, passed over people's heads, and then it could be seen that the tornado is a huge hollow cylinder, brightly lit inside by the brilliance of lightning. A deafening roar and buzzing is heard from within. It is believed that the wind speed in the walls of the tornado reaches the sound.
A tornado can suck in and lift up a large portion of snow, sand, etc. As soon as the speed of snowflakes or grains of sand reaches a critical value, they will be thrown out through the wall and can form a kind of case or cover around the tornado. A characteristic feature of this case-cover is that the distance from it to the wall of the tornado is approximately the same along the entire height.
Let us consider, as a first approximation, the processes occurring in thunderclouds. Abundant moisture entering the cloud from the lower layers releases a lot of heat, and the cloud becomes unstable. Rapid ascending currents of warm air arise in it, which carry masses of moisture to a height of 12-15 km, and equally rapid cold descending currents that fall down under the weight of the formed masses of rain and hail, strongly cooled in the upper layers of the troposphere. The power of these streams is especially great due to the fact that two streams simultaneously arise: ascending and descending. On the one hand, they do not experience environmental resistance, because the volume of air going up is equal to the volume of air going down. On the other hand, the expenditure of energy by the flow to lift water up is completely replenished when it falls down. Therefore, flows have the ability to accelerate themselves to enormous speeds (100 m/s or more).
In recent years, another possibility has been identified for the rise of large masses of water into the upper troposphere. Often, when air masses collide, vortices are formed, which, for their relatively small size, are called mesocyclones. The mesocyclone captures a layer of air at a height of 1-2 km to 8-10 km, has a diameter of 8-10 km and rotates around a vertical axis at a speed of 40-50 m/s. The existence of mesocyclones has been reliably established, and their structure has been studied in sufficient detail. It has been found that in mesocyclones a powerful thrust arises on the axis, which ejects air to heights of up to 8-10 km and above. Observers have found that it is in the mesocyclone that a tornado sometimes originates.
The most favorable environment for the origin of the funnel is fulfilled when three conditions are met. First, the mesocyclone must be formed from cold, dry masses of air. Secondly, the mesocyclone must enter the area where a lot of moisture has accumulated in the surface layer 1-2 km thick at a high air temperature of 25-35 ° C. The third condition is the ejection of masses of rain and hail. The fulfillment of this condition leads to a decrease in the flow diameter from the initial value of 5–10 km to 1–2 km and an increase in velocity from 30–40 m/s in the upper part of the mesocyclone to 100–120 m/s in the lower part.
In order to have an idea of the consequences of tornadoes, let us consider the description of the Moscow tornado of 1904.
On June 29, 1904, a strong whirlwind swept over the eastern part of Moscow.
On that day, strong thunderstorm activity was noted in four districts of the Moscow region: in Serpukhov, Podolsky, Moskovsky and Dmitrovsky, almost for 200 km. Thunderstorms with hail and storm were observed, in addition, in the Kaluga, Tula and Yaroslavl regions. Starting from the Serpukhov region, the storm turned into a hurricane. The hurricane intensified in the Podolsk region, where 48 villages were affected and there were casualties. The most terrible devastation was brought by a tornado that arose southeast of Moscow in the area of the village of Besedy. The width of the thunderstorm area in the southern part of the Moskovsky region was determined to be 15 km; here the storm moved from south to north, and the tornado arose in the eastern (right) side of the thunderstorm belt.
The tornado caused great destruction on its way. The villages of Ryazantsevo, Kapotnya, Chagino were destroyed; then the hurricane flew into the Lublin grove, uprooted and broke up to 7 hectares of forest, then destroyed the villages of Graivoronovo, Karacharovo and Khokhlovka, entered the eastern part of Moscow, destroyed the Annenhof grove in Lefortovo, planted under Tsaritsa Anna Ioannovna, tore off the roofs of houses in Lefortovo , went to Sokolniki, where he felled a centuries-old forest, headed to Losinoostrovskaya, where he destroyed 120 hectares of large forest, and disintegrated in the Mytishchi region. Further, there was no tornado, and only a strong storm was noted. The length of the tornado's path is about 40 km, the width all the time fluctuated from 100 to 700 m.
In appearance, the vortex was a column, wide at the bottom, gradually narrowing in the form of a cone and expanding again in the clouds; in other places, sometimes it took the form of just a black spinning pillar. Many eyewitnesses mistook it for rising black smoke from a fire. In those places where the tornado passed through the Moskva River, it captured so much water that the channel was exposed.
The torn roofs of buildings flew through the air like shreds of paper. Even stone walls were destroyed. Half of the bell tower in Karacharovo has been demolished. The whirlwind was accompanied by a terrible rumble; its destructive work lasted from 30 s to 1-2 min. The crackling of falling trees was drowned out by the roar of the whirlwind.
When the funnel approached, it became completely dark. The darkness was accompanied by a terrible noise, a roar and a whistle. Electrical phenomena of unusual intensity have been recorded. Ball lightning was observed in Sokolniki. The rain and hail were also of extraordinary intensity. Hailstones with a chicken egg were noted repeatedly. Individual hailstones were star-shaped and weighed 400-600 g.
- Actions of the population under threat and during hurricanes, storms and tornadoes.
On the windward side of buildings, windows, doors, attic hatches and ventilation openings are tightly closed. Glasses of windows are pasted over, windows and show-windows are protected by shutters or boards. In order to equalize the internal pressure, doors and windows on the leeward side of buildings are opened.
It is advisable to fix fragile institutions (country houses, sheds, garages, stacks of firewood, toilets), dig in with earth, remove protruding parts or disassemble, crushing the disassembled fragments with heavy stones, logs. It is necessary to remove all things from balconies, loggias, window sills.
It is necessary to take care of the preparation of electric lamps, kerosene lamps, candles, camping stoves, kerosene stoves and stoves in places of shelter, the creation of stocks of food and drinking water for 2-3 days, medicines, bedding and clothes.
At home, residents should check the placement and condition of electrical panels, gas and water main taps and, if necessary, be able to shut them off. All family members must be taught the rules of self-rescue and first aid for injuries and concussion.
Radios or TVs must be on at all times.
When informed of the imminent approach of a hurricane or severe storm, the inhabitants of the settlements take their previously prepared places in buildings or shelters, preferably in basements and underground structures (but not in the flood zone).
While in the building, you should beware of injuries from broken glass. In case of strong gusts of wind, it is necessary to move away from the windows and take a place in the niches of the walls, doorways or stand close to the wall. For protection, it is also recommended to use built-in wardrobes, durable furniture and mattresses.
When forced to stay in the open air, it is necessary to be away from buildings and occupy ravines, pits, ditches, ditches, road ditches for protection. In this case, you need to lie on the bottom of the shelter and press tightly to the ground, grab the plants with your hands.
Any protective actions reduce the number of injuries caused by the throwing action of hurricanes and storms, and also provide protection from flying fragments of glass, slate, tiles, bricks and various objects. You should also avoid being on bridges, pipelines, in places in close proximity to objects that have highly toxic and flammable substances (chemical, oil refineries and storage bases).
During storms, avoid situations that increase the likelihood of electric shock. Therefore, you can not hide under separate trees, poles, come close to power transmission towers.
During and after a hurricane or storm, it is not recommended to enter susceptible buildings, and if necessary, this should be done with caution, making sure that there are no significant damage to stairs, ceilings and walls, fires, gas leaks, or broken electrical wires.
During snow or dust storms, it is allowed to leave the premises in exceptional cases and only as part of a group. At the same time, relatives or neighbors must be informed of the route and time of return. In such conditions, it is allowed to use only pre-prepared vehicles capable of moving with snow, sand drifts, and sleet. If it is impossible to move further, mark the parking lot, completely close the blinds and cover the engine from the side of the radiator.
When receiving information about the approach of a tornado or detecting it by external signs, you should leave all modes of transport and take refuge in the nearest basement, shelter, ravine, or lie down on the bottom of any recess and cling to the ground. When choosing a place of protection against a tornado, it should be remembered that this natural phenomenon is often accompanied by heavy rainfall and large hail. In such cases, it is necessary to take measures to protect against damage by these hydrometeorological phenomena.
After the end of the active phase of the disaster, rescue and recovery work begins: dismantling the rubble, searching for the living, the wounded and the dead, providing assistance to those who need it, restoring housing, roads, businesses and a gradual return to normal life.
- Conclusion
I have come to the conclusion that there is a wide variety of such natural disasters. But the most dangerous meteorological phenomena are storms, hurricanes, tornadoes.
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 natural disasters has been on the rise. This cannot go unnoticed. The management and bodies of the Ministry of Emergency Situations draw the necessary conclusions from this.
- List of used literature.
etc.................
Emergencies caused by meteorological processes
Emergencies caused by hydrological processes
Emergencies caused by natural fires
Emergencies caused by geological processes
Emergencies caused by space phenomena
Emergencies caused by the temperature and humidity state of the environment
Forecasting natural emergencies
Prevention of natural emergencies
Sources of emergencies can be dangerous phenomena and processes in inanimate nature.
Under natural hazards is understood as an event of natural origin or the result of natural processes, which, by their intensity, scale of distribution and duration, can cause a damaging effect on people, economic facilities and the natural environment.
Every year, the economic damage caused by destruction as a result of natural disasters alone exceeds 200 billion US dollars.
In natural emergencies, the concept of "natural disaster" is often used.
A natural disaster is a destructive natural and (or) natural-anthropogenic phenomenon or process of a significant scale, as a result of which a threat to life and health of people may arise or arise, destruction or destruction of material assets and components of the natural environment may occur.
The peculiarity of natural disasters is that they often occur suddenly, little managed and controlled compared to other emergencies.
They can be a source of other emergencies (hepatitis A outbreaks are frequent after floods).
Emergencies caused by meteorological processes
Hazardous meteorological phenomena are natural processes and phenomena that occur in the atmosphere under the influence of various natural factors or their combinations, which have or may have a damaging effect on people, animals and plants, economic facilities and the natural environment.
Dangerous meteorological phenomena include: dangerous winds, thunderstorms, lightning, hail, droughts, downpours, ice, fog.
Dangerous winds
Winds are the cause of many natural disasters.
Cause of the winds- uneven heating of various regions of the rotating Earth.
The equator heats up more, the poles less. The heated air rises, forming an area of low pressure, and the wind must blow from north or south, but here various physical forces intervene, which change the direction of the wind.
The destructive power of the wind depends on its strength. Strong winds pose a danger to humans, animals and the environment.
A strong wind is the movement of air relative to the surface at a speed of 14 m/s.
With further strengthening of the wind, storms, hurricanes, squalls, tornadoes occur.
Storm- air movement at a speed of 14-33 m / s. Duration from several hours to several days. The width of the front is up to hundreds of kilometers. Communication lines, power lines collapse, tree branches break or are uprooted, the roofs of buildings are demolished, etc.
Hurricane- air speed over 32 km/h. Appears suddenly. It carries colossal energy comparable to the energy of a nuclear explosion with a power of 36 Mt. Accompanied by thunderstorms, downpours, hail.
Whirlwind - atmospheric formation with rotational movement of air around a vertical or inclined axis. Can lift light objects into the air.
Tornado- a strong atmospheric vortex with a diameter of 1000 m, in which the air rotates at a speed of 100 m/s. Has great destructive power. Upon reaching the surface of the earth, the tornado becomes like a funnel. Inside the tornado, the air is highly discharged and the structures that are in its path are destroyed with an explosion. He raises large objects and even entire lakes to a great height.
Flurry - short-term increase in wind speed up to 14 m/s. accompanied by a sharp drop in temperature, occur suddenly in cumulonimbus clouds.
In addition to the listed types of winds, there are also dust and snow storms, which also cause significant material damage.