Dangerous weather events. Abstract: Meteorological phenomena What relates to dangerous meteorological phenomena

natural weather atmospheric

• - heavy rains. Most often (probability 95-100%) they fall in the Carpathians and predetermine mudflows, avalanches and shifts;
• - heavy blizzards, snowfalls. Blizzards are associated with the movement of cyclones from the south and southwest. Poor visibility during blizzards and heavy snow drifts create many difficulties, both in operation different types transport, and in work at construction sites;
• - strong wind maximum speed over 25 m/s), squalls, tornadoes. Most often, such a wind is observed in mountainous regions, as well as in the Donetsk, Volyn and Podolsk uplands;
• Fog is an accumulation of water droplets or ice crystals suspended in the surface layer of the atmosphere, which impairs horizontal visibility at a distance of up to 1 km. According to the intensity, fogs are very strong (visibility is less than 50 m), strong (50-200 m), moderate (201-500 m) and weak (501-1000 m);
• - A thunderstorm is a complex atmospheric phenomenon that is accompanied by electrical discharges, significant precipitation and often hail. A thunderstorm belongs to dangerous phenomena, the action of which can cause significant losses to activities and even threaten human life;
• - Grad - rounded or irregular shape ice particles that fall mostly during the warm season from powerful cumulonimbus clouds with significant vertical movement and high moisture content. Hail causes significant losses to agriculture: it damages crops, vineyards, fruit trees, over large areas. The amount of losses depends on the size of the hailstones, their density and intensity of precipitation;
• - A squall is a short-term sharp increase in wind speed, which is formed in cumulonimbus clouds, is accompanied by a change in wind direction and is observed during thunderstorms and showers. During a squall, trees are broken, crops are destroyed, buildings are destroyed, sometimes even human casualties are possible;
• - A tornado is a vortex of a complex structure with a vertical axis, which descends from the lower limit of powerful cumulonimbus clouds to the earth's surface. In the form of a light or dark funnel that rotates and is characterized by significant wind speeds, powerful downdrafts and updrafts, a significant difference atmospheric pressure, from the center of the funnel to the periphery, which together creates an extraordinary tornado energy;
• - A dust or black storm is a phenomenon that is caused by transferring a large number dust or sand by strong winds and is accompanied by a deterioration in visibility. A dust storm occurs during dry weather and during an increase in wind speed to values ​​at which parts of dust or sand are blown out of the underlying surface.

Meteorological emergencies are dangerous 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, farm animals and plants, economic facilities and the natural environment.

Meteorological emergencies include:

• meteorological phenomena associated with the movement of air in the atmosphere;
• meteorological phenomena associated with high and low temperatures;
• meteorological phenomena associated with precipitation;
• meteorological phenomena associated with the deposition of ice and sticking of wet snow on electrical wires;
• meteorological phenomena associated with the formation of ice on the roads;
• fog.

Meteorological phenomena associated with the movement of air in the atmosphere include:

• strong wind- movement of air relative to the earth's surface with a speed or horizontal component of more than 14 m/s;
• vortex – atmospheric education With rotational movement air around a vertical or inclined axis;
• Hurricane- wind of destructive force and considerable duration, the speed of which exceeds 32 m/s. Hurricane Katrina began forming on August 23, 2005 in the Bahamas. The wind speed during the hurricane reached 280 km/h. On August 27, 2005, the hurricane passed over the coast of Florida near Miami and turned towards the Gulf of Mexico. The most severe damage was caused to New Orleans in Louisiana, where about 80% of the city's area was under water. The disaster killed 1,836 people;
• cyclone- an atmospheric disturbance with low air pressure and hurricane wind speeds that occurs in tropical latitudes and causes great destruction and death of people. Local name tropical cyclone- typhoon;
• storm - prolonged very strong wind with a speed of more than 20 m/s, causing severe waves at sea and destruction on land;
• tornado - 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 (Fig. 8.8). A tornado is the most dangerous natural phenomenon associated with the movement of air in the atmosphere;
• flurry - a sharp short-term wind force up to 20–30 m/s and higher, accompanied by a change in its direction and associated with convective processes;
• dust storm- the transfer of large amounts of dust or sand by strong winds, accompanied by a deterioration in visibility, blowing the topsoil along with seeds and young plants, falling asleep crops and highways. In case of a dust storm, you should cover your face with a gauze bandage, a scarf, a piece of cloth, and your eyes with glasses.

Rice. 8.8.

Meteorological phenomena associated with high and low temperatures include:

• hard frost is a meteorological phenomenon when expected and observed negative anomalies average daily temperatures air in November - March is for at least 5 days from -10 to -25 ° C and more, or the minimum air temperature is close to extreme values;
• heatwave is a meteorological phenomenon when the expected and observed positive anomalies of average daily air temperatures in May-August for at least 5 days are +27°C or more or the maximum air temperature is close to extreme values.

AT summer time a dangerous agrometeorological phenomenon, drought, may occur. Drought- this is a complex of meteorological factors in the form of a prolonged lack of precipitation, combined with high temperature and a decrease in air humidity, leading to a violation of the water balance of plants and causing their inhibition or death.

Severe frost and heat are dangerous for the life and health of people, adversely affect their ability to work, and damage agriculture and industry. Also during such periods, the fire hazard increases. Long-term and extreme low temperatures pose a particular danger to public utilities due to freezing of water supply pipes in the streets and indoors, which leads to a lack of water supply and water heating in people's homes.

High and low temperatures can be accompanied by strong winds. AT winter time blizzards are dangerous. heavy blizzard- this is the transfer of snow above the ground by wind at a speed of more than 15 m / s and visibility of less than 500 m. A snowstorm is possible in combination with snowfall, which leads to a deterioration in visibility and skidding of transport routes.

In winter, the effect of the cooling force of the wind on the human body should be taken into account (Table 8.3).

During heavy blizzards and low temperatures it is undesirable to move outside settlements. You can lose your bearings and freeze. The car can only move on major roads and highways. When leaving the car, do not leave it out of sight.

Table 8.3

The influence of the cooling force of the wind on the human body

Meteorological phenomena associated with precipitation include the following.

Grad - atmospheric precipitation falling in the warm season in the form of particles of dense ice with a diameter of 5 mm to 15 cm, usually together with heavy rain during a thunderstorm. Large hail is considered to be ice particles with a diameter of more than 20 mm. strong hail dangerous to human life and health, can destroy crops, cause damage to the roofs of buildings, Vehicle.

Downpour (heavy rain)- this is short-term precipitation of great intensity, usually in the form of rain (rain with snow). Heavy rain is considered to be precipitation of 50 mm or more in 12 hours or 30 mm or more in 1 hour. Prolonged heavy showers are precipitation of 100 mm or more in 2 days. heavy rains can cause floods, flooding of streets, mudflows, impede traffic.

Heavy snowfall - this is a prolonged intensive snowfall (20 mm of precipitation or more in 12 hours), leading to a significant deterioration in visibility and difficulty in traffic.

Meteorological phenomena associated with the formation of ice and wet snow sticking to electrical wires pose a danger to power supply, which can lead to wire breaks and disruption of power supply to settlements and regions. Such cases occur in Russia, in particular on the Black Sea coast of the Caucasus, in Stavropol Territory etc. Broken wires pose a danger to human life.

Ice- this is a layer of dense ice that forms on the earth's surface and on objects when supercooled drops of rain or fog (melted and then refrozen snow) freeze. Ice is dangerous for pedestrians and vehicles.

If the weather forecast indicates ice or icy conditions, measures should be taken to reduce the likelihood of injury, prepare low-slip shoes, attach metal heels or foam rubber to the heels, and stick adhesive plaster on dry soles, you can rub the soles of shoes with sandpaper.

You should move carefully, slowly, stepping on the entire sole. In this case, the legs should be slightly relaxed, hands free. If you slip, you should

crouch to reduce the height of the fall. At the time of the fall, it is necessary to group up, and, rolling, soften the blow to the ground.

Fog - meteorological phenomenon, the accumulation of condensation products in the form of drops or crystals suspended in the air directly above the earth's surface, accompanied by a significant deterioration in visibility. Heavy fog is fog with a visibility of less than 100 m. Due to heavy fog, car accidents can occur, and airplanes cannot land at airports.

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.

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.

Hurricanes, storms, tornadoes.

during the passage of tropical or extratropical cyclone;
during the passage of a tornado (thrombus, then rnado);
during a local or frontal thunderstorm.

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).

Actions of the population under threat and during hurricanes, storms and tornadoes.

Conclusion

List of used literature.

Ministry of Education of the PMR

Transnistrian State University them. T. G. Shevchenko

Department of Life Safety and Fundamentals of Medical Knowledge

Topic: "Meteorological and agrometeorological hazards"

Supervisor:

Dyagovets E.V.

Executor:

Student 208 group

Rudenko Evgeny

Tiraspol

PLAN

Introduction

Chapter 1. Metrological and agrometrological hazards

1. Strong fogs

Blizzards and snowdrifts

Tender and icy crusts

Rules of behavior of the population in case of snow drifts and actions to eliminate their consequences

Chapter 2

Conclusion

Bibliography

fog blizzard snow drift liquidation

Introduction

The spontaneous actions of the forces of nature, which are not yet fully subject to man, cause enormous damage to the economy of the state and the population.

Natural disasters are such natural phenomena that cause extreme situations, disrupt the normal life of people and the operation of objects.

Natural disasters usually include earthquakes, floods, mudflows, landslides, snowdrifts, volcanic eruptions, landslides, droughts, hurricanes, storms, fires, especially massive, forest and peat. Dangerous disasters are, in addition, industrial accidents. Of particular danger are accidents at oil, gas and chemical industry. . Natural disasters occur suddenly and are of an extreme nature. They can destroy buildings and structures, destroy valuables, disrupt production processes, and cause death of people and animals.

By the nature of their impact on objects, individual natural phenomena can be similar to the impact of some damaging factors nuclear explosion and other means of attacking the enemy.

Each natural disaster has its own characteristics, the nature of damage, the volume and scale of destruction, the magnitude of disasters and human casualties. Each leaves its mark on the environment in its own way.

Advance information makes it possible to carry out preventive work, to alert forces and means, to explain to people the rules of conduct.

The entire population should be ready to act in extreme situations, to participate in the elimination of natural disasters, to be able to master the methods of providing first aid. medical care injured.

Natural disasters are dangerous natural phenomena or processes of geophysical, geological, hydrological, atmospheric and other origin of such magnitude that cause catastrophic situations characterized by a sudden disruption of the life of the population, defeat and destruction material assets, defeat and death of people and animals.

Natural disasters can occur both independently of each other and in interconnection: one of them can lead to another. Some of them often arise as a result of not always reasonable human activity (for example, forest and peat fires, industrial explosions in highlands, during the construction of dams, laying (development) of quarries, which often leads to landslides, snow avalanches, glacial collapses, etc.).

Earthquakes, floods, extensive forest and peat fires, mudflows and landslides, storms and hurricanes, tornadoes, snow drifts, and icing are the real scourge of mankind. 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.

Good examples are three natural disasters in 1995. 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.

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.

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:

.Marine hydrological hazards:

.Hydrological hazards:

.Hydrogeological hazards:

.Natural fires:

.Infectious morbidity in humans:

.Infectious incidence of farm animals:

.The defeat of agricultural plants by diseases and pests.

.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.

CHAPTER 1. Metrological and agrometrological hazards

A dangerous hydrometeorological event (HH) is understood as a phenomenon that, by its intensity, duration or time of occurrence, poses a threat to people's safety, and can also cause significant damage to sectors of the economy. At the same time, hydrometeorological phenomena are assessed as OH when critical values ​​of hydrometeorological values ​​are reached. Hazardous hydrometeorological phenomena have an adverse impact on the production economic activity society. According to the UN, in last decade 1991-2000 more than 90% of the people who became victims of natural hazards died from severe meteorological and hydrological events.

1. Strong fogs

Fog is generally an aerosol with a droplet-liquid dispersed phase. It is formed from supersaturated vapors as a result of condensation. Atmospheric fog is a suspension of small water droplets or even ice crystals in the surface layer. The prevailing droplet sizes are 5-15 microns. Such droplets can be kept in suspension by ascending air currents at a speed of 0.6 m/s. When the number of such droplets in 1 dm3 of air reaches 500 or more, the horizontal visibility in the surface layer of the atmosphere drops to 1 km or less. That's when meteorologists talk about fog. The mass of water drops in 1 m3 (this value is called water content) is small - hundredths of a gram. A denser fog, of course, is characterized by a higher water content - up to 1.5 and 2 g per 1 m.

Mist Characteristics . The water content of fog is used to characterize fogs, it indicates the total mass of water droplets per unit volume of fog. The water content of fogs usually does not exceed 0.05-0.1 g/m3, but in some dense fogs it can reach 1-1.5 g/m3. In addition to water content, the transparency of the fog is affected by the size of the particles forming it. The radius of fog droplets usually ranges from 1 to 60 µm. Most of the drops have a radius of 5-15 microns at a positive air temperature and 2-5 microns at a negative temperature.

Fog is a more frequent occurrence in the coastal regions of the seas and oceans, especially on elevated shores.

Where do water droplets come from in the air? They are formed from water vapor. When earth's surface cooled due to thermal radiation (thermal radiation), the air layer adjacent to it is also cooled. The content of water vapor in the air in this case may be higher than the limit for a given temperature. In other words, relative humidity becomes equal to 100%, and excess moisture condenses in the form of drops. Fog formed by this (by the way, the most common) mechanism is called radiation. Radiation fog is formed most often in the second half of the night; in the first half of the day it dissipates, and sometimes passes into a thin layer of low stratus clouds, the height of which does not exceed 100-200 m. Radiation fogs especially often occur in lowlands and wetlands.

Advective fog is formed by the horizontal movement (advection) of warm, moist air over a cooled surface. Such fogs are frequent in oceanic regions with cold currents, for example, near Vancouver Island, as well as off the coast of Peru and Chile; you the Bering Strait and along the Aleutian Islands; off the western coast of South Africa "over the cold Bengal current and in the Newfoundland region, where the Gulf Stream meets the cold Labrador current; on the east coast of Kamchatka over the cold Kamchatka current and northeast of Japan, where the cold Kuril current and the warm Kuroshio current meet. Similar fogs are often observed on land, when warm and humid oceanic or sea ​​air invades the chilled territory of a continent or a large island.

The fogs of the ascent appear in the warm and humid air when it rises along the slopes of the mountains. (As you know, in the mountains - the higher, the colder.) An example is the island of Madeira. There is practically no fog here at sea level. The higher the mountains, the greater the average annual number of foggy days. At an altitude of 1610 m above sea level, there are already 233 such days. True, in the mountains, fogs are practically inseparable from low clouds. Therefore, at mountain weather stations, on average, there is much more fog than on the plains. At El Paso Station in Colombia, at 3,624 meters above sea level, there are an average of 359 foggy days per year. On Elbrus at an altitude of 4250 m, on average, there are 234 days with fog a year, on the top of Mount Taganay on Southern Urals- 237 days. Among stations close to sea level, the largest average number of days with fog per year (251) is observed in US state Washington - on the island of Tatush, and in our country - on the Sakhalin Cape Patience (121) and on the Kamchatka Cape Lopatka (115). One of the largest centers of fog formation is located in the Republic of Zaire. There are many swamps on its territory, the equatorial-tropical climate prevailing here differs high temperatures and air humidity, the country is located in a vast basin with weakened air circulation in the surface layers of the atmosphere. Due to such conditions, 200 or more foggy days are observed annually in the southwestern part of the republic. Of course, when we talk about a foggy day, this does not mean that the fog lasts around the clock. The longest average duration of fog is observed in our country at Cape Patience and is 11.5 hours. But if we introduce another indicator of "nebula" - the average annual number of hours with fog, then the Fichtelberg mountain weather station (GDR) holds the record here - 3881 hours. This is slightly less than half the number of hours per year. The longest was a three-month dry fog over Europe in 1783, caused by the intense activity of Icelandic volcanoes. In 1932, humid fog at the American Cincinnati airport at an altitude of 170 m above sea level lasted 38 days. Fogs can become more frequent in certain months of the year. In July, all Patience can be up to 29 days with fog, in August on the Kuril Islands. - up to 28 days, in January-February on the mountain peaks of the Crimea and the Urals - up to 24 days.

Fog significantly complicates transport communication due to a decrease in horizontal visibility, so this atmospheric phenomenon is of particular concern to airport dispatchers, workers in sea and river ports, pilots, ship captains, and car drivers. Over the past 50 years, 7,000 people have died on Earth from the activity of fogs.

Difficulties associated with aviation and flights.

The wind speed during radiation fog does not exceed 3 m/sec. The vertical thickness of the fog can vary from a few meters to several tens of meters; rivers, large landmarks and lights are clearly visible through it. Visibility near the ground can deteriorate to 100 or less. Flight visibility deteriorates sharply when entering the fog layer on landing. Flight above the radiation fog does not present any particular difficulties, since in most cases it is located in spots and makes it possible to conduct a visual orientation. However, in the cold season, such fogs can occupy large areas and, merging with the overlying stratus clouds, persist for several days. In this case, fog can be a serious obstacle to flight operations.

Flying at low altitudes across a foggy front is quite difficult, especially if the fog layer merges with: the overlying frontal cloud and the fog zone is wide. In the presence of fog at the front, it is more expedient to fly above the upper limit of the fog.

Fog in mountainous areas occurs when air rises and cools along windward slopes, or when clouds formed in another area move in and obscure the hills. In the absence of clouds over the ridge, flying above such fog presents no serious difficulties.

frosty mists - a frequent occurrence at airfields, where they occur during takeoff and landing, while taxiing aircraft, during vehicle operation. In these cases, the visibility on the runway may deteriorate to several hundred meters, while around the airfield at this time, excellent visibility is maintained.

It is customary to call fog when the range of horizontal visibility does not exceed 1 km. With a visibility range of 1 to 10 km, the accumulation of the smallest drops of water or ice crystals in the surface layer of air should not be called fog, but haze. When flying over a layer of darkness, the pilot may not see the ground, while the aircraft is clearly visible from the ground. With a thinner layer of haze, the pilot will see the ground directly below him, but when descending and entering the haze layer, he may not see the airfield, especially when flying against the sun. In light winds, landing is best done in such a direction that the sun remains behind. The upper boundary of haze in the presence of a delaying layer (inversion, isotherm) is usually sharply defined and can sometimes be perceived as a second horizon.

Cancellation of flights due to heavy fog. In Moscow on November 22, 2006 there was an unprecedented fog. Sheremetyevo and Vnukovo airports were in such a dense veil that the dispatchers had to redirect two dozen aircraft to alternate airfields.

Difficulties encountered on the roads.

Fogs, as you know, when they arise, create a thick veil over the surface of the earth, interfering with road and rail traffic. In this case, there is a difficulty in movement, a slowdown in movement, as well as car accidents in which many people die.

Examples of road accidents. A major traffic accident occurred on September 11, 2006 at the entrance to Krasnodar. Due to heavy fog at the entrance to the city from Rostov-on-Don, 62 cars collided. As a result of a car accident, one person died, 42 people were hospitalized with injuries of varying severity.

In Istanbul on November 17, 2006, more than a hundred cars collided due to fog. 33 people were injured, doctors fear for the lives of at least two of the victims. A major accident happened on the highway leading from Istanbul to the city of Edirne, which is located near the Bulgarian border.

Difficulties associated with maritime navigation.

With light fog, visibility is reduced to 1 km, with moderate fog - up to hundreds of meters, and with heavy fog - up to several tens of meters. And then the ships temporarily anchor, the sirens of the lighthouses turn on. Sometimes, due to fog, ships stumble upon rocks, or icebergs. Yes, maybe

Example. The Turkish sea straits Bosphorus and Dardanelles are closed for navigation due to thickened fog, visibility in the straits has decreased to 200 meters.

The most famous tragedy at sea associated with fog. tita ́ nick is an English Olympic-class liner, the largest passenger steamship in the world at the time of its construction, owned by the White Star Line. During the first voyage on April 14, 1912, she collided with an iceberg due to thick fog and sank after 2 hours and 40 minutes. Of the 2223 passengers and crew members, 706 survived. The Titanic disaster became legendary and was one of the largest shipwrecks in history.

Fog protection at sea. The navigation system for small craft is intended for navigation of small-tonnage craft in conditions of limited optical visibility (night, fog, snow, rain, high smoke, etc.) or its absence, when control and navigation is carried out by visual control, or according to other optical or IR data. -sensors, difficult or impossible.

Harm to agriculture.

Fogs adversely affect the development of crops. With fog, relative humidity reaches 100%, so frequent fogs in the warm season favor the reproduction of plant pests, the appearance of bacteria, fungal diseases, etc. When harvesting grain, fog contributes to the accumulation of moisture in grain and straw; damp straw is wound on the working parts of the combine, the grain is poorly threshed and a significant part of it goes into the chaff. Wet grain needs to dry longer, otherwise it may germinate. Frequent fogs in late summer and autumn make it difficult to harvest potatoes, as the tubers dry slowly. In winter, fogs “eat up” the snow, and if after that a sharp cooling occurs, an ice crust forms.

. Blizzards and snowdrifts

A snowstorm (blizzard) is the transfer of snow by a strong wind over the surface of the earth. The amount of snow carried is determined by the wind speed, and the areas of snow accumulation are determined by its direction. In the process of snow drifting, snow moves parallel to the ground. At the same time, most of it is transported in a layer with a height of less than 1.5 m. Loose snow rises and is carried by the wind at a speed of 3-5 m/s or more (at a height of 0.2 m).

There are ground (in the absence of snowfall), riding (with wind only in a free atmosphere) and general blizzards, as well as saturated blizzards, i.e., carrying the maximum amount of snow possible at a given wind speed, and unsaturated. The latter are observed with a lack of snow or with a high strength of the snow cover. The solid discharge of a saturated blowing blizzard is proportional to the third power of the wind speed, and that of a riding blizzard is proportional to its first power. At a wind speed of up to 20 m/s, blizzards are classified as weak and ordinary, at a speed of 20-30 m/s - as strong, at high speed- to very strong and super-strong (in fact, these are already storms and hurricanes). Weak and ordinary blizzards last up to several days, stronger ones - up to several hours.

Snow accumulation during blizzard transport is many times greater than the accumulation of snow, which is observed as a result of snowfalls in calm weather.

Snow deposition occurs as a result of a decrease in wind speed near ground obstacles. The shape and size of the reserves are determined by the shape and size of the obstacles and their orientation with respect to the direction of the wind.

In Russia, snowy regions of the Arctic, Siberia, the Urals, the Far East and the North of the European part are primarily subject to heavy snow drifts. In the Arctic, snow cover lasts up to 240 days a year and reaches 60 cm; in Siberia, up to 240 days and 90 cm, respectively; in the Urals, up to 200 days and 90 cm; Far East- up to 240 days and 50 cm, in the north of the European part of Russia - up to 160 days and 50 cm.

Additional negative effect during snow drifts, it occurs due to severe frost, strong wind during snowstorms and icing. The consequences of snow drifts can be quite severe. They are able to paralyze the work of most modes of transport, suspending the transportation of people and goods. Wheeled vehicles cannot normally drive on level snowy roads, if the thickness of the snow cover exceeds half the diameter of the wheel. People who find themselves on the ground in isolation due to snow drifts are at risk of frostbite and death, and in the conditions of snowstorms they lose their bearings. With heavy drifts, small settlements can be completely cut off from supply lines. The work of utilities and energy enterprises is becoming more difficult. If drifts are accompanied by severe frosts and winds, power supply, heat supply, and communications systems may fail. The accumulation of snow on the roofs of buildings and structures in excess of excessive loads leads to their collapse.

In snowy areas, the design and construction of buildings, structures and communications, especially roads, should be carried out taking into account the reduction of their snow penetration.

To prevent drifts, snow protection fences are used from structures prepared in advance or in the form of snow walls, shafts, etc. Fences are built in snow-prone directions, especially along railways and important highways. At the same time, they are installed at a distance of at least 20 m from the edge of the road.

A preventive measure is to notify authorities, organizations and the public about the forecast of snowfalls and snowstorms.

For orientation of pedestrians and drivers of vehicles caught in a blizzard, milestones and other signs are installed along the roads. In mountainous and northern regions, stretching of ropes is practiced on dangerous sections of trails, roads, from building to building. Holding on to them, in a storm, people navigate the route.

In anticipation of a snowstorm, at construction and industrial sites, crane booms and other structures that are not protected from the effects of the wind are fastened. Stop working in open areas and heights. Strengthen the mooring of ships in ports. Minimize the exit of vehicles on the routes.

Upon receipt of a threatening forecast, the forces and means intended to combat drifts and carry out emergency recovery work are alerted.

The main measure to combat snow drifts is the clearing of roads and territories. First of all, they clear the railway and motorways, runways of airfields, station tracks of railway stations from drifts, and also provide assistance to vehicles caught in a disaster on the way.

In the most severe cases, paralyzing the life of entire settlements, the entire able-bodied population is involved in clearing snow.

Simultaneously with the clearing of drifts, they organize continuous meteorological monitoring, search for and release of people and vehicles from snow captivity, assistance to victims, traffic control and transport wiring, protection and restoration of life support systems, delivery of emergency cargo by special snow-travelable vehicles to blockaded settlements, protection of livestock facilities . If necessary, they carry out a partial evacuation of the population and organize special public transport routes in columns, as well as stop the work of educational institutions and institutions.

Blizzards and the snow drifts they create are possible in the subtropics of Asia every few decades, North Africa, United States, but are especially common in areas of stable snow cover. Here, the volume of snow transport during the winter through one meter of a blizzard front is usually measured in tens, and in some places in thousands of cubic meters; the thickness of drifts on the roads of Scandinavia, Canada, the north of the USA exceeds 5 m.

In the European part of Russia, the average number of days with a snowstorm is 30-40, the average duration of a snowstorm is 6-9 hours. Dangerous snowstorms make up about 25%, especially dangerous snowstorms, about 10% of their total number. Every year on the territory of the whole country there are on average 5-6 strongest snowstorms that can paralyze railways and roads, cut off communication and power lines, etc.

3. Snow and ice crusts

Snow and ice crusts are formed when snow sticks and water drops freeze on various surfaces. Wet snow sticking, which is the most dangerous for communication lines and power transmission lines, occurs during snowfalls and air temperatures in the range from 0° to +3°C, especially at a temperature of +1 -3°C and wind of 10-20 m/s. The diameter of snow deposits on wires reaches 20 cm, weight is 2-4 kg per 1 m. Wires are torn not so much under the weight of snow as from wind load. On the roadway under such conditions, a slippery snow run-up forms, paralyzing traffic almost in the same way as an icy crust. Such phenomena are characteristic of coastal regions with mild, wet winters (western Europe, Japan, Sakhalin, etc.), but are also common in inland regions at the beginning and end of winter.

When rain falls on frozen ground and when the surface of the snow cover gets wet and then freezes, ice crusts are formed, called icing. It is dangerous for grazing animals, for example, in Chukotka in the early 80s, sleet caused mass death deer. The type of ice cover includes the phenomenon of icing of berths, offshore platforms, vessels due to freezing water spray during a storm. Icing is especially dangerous for small vessels, the deck and superstructures of which are not raised high above the water. Such a vessel can gain a critical ice load in a matter of hours. Every year, about ten fishing vessels perish in the world from this, hundreds are in a precarious position. Spatter ice on the shores of the Sea of ​​Okhotsk and the Sea of ​​Japan reaches a thickness of 3-4 m, greatly hindering economic activity in the coastal strip.

When supercooled fog drops freeze on various objects, ice and frost crusts form, the first - at an air temperature range of 0 to -5 ° C, less often up to -20 ° C, the second - at a temperature of -10-30 ° C, less often up to -40 °C.

The weight of ice crusts can exceed 10 kg/m (up to 35 kg/m in Sakhalin, up to 86 kg/m in the Urals). Such a load is devastating for most wire lines and for many masts. Glaze recurrence is highest where fogs are frequent at air temperatures from 0 to -5°C. On the territory of Russia, it sometimes reaches tens of days a year.

The impact of ice on the economy is most noticeable in Western Europe, the USA, Canada, Japan, in the southern regions of the former USSR and is mainly of a depressing nature. Occasionally emergencies are created. For example, in February 1984, in the Stavropol Territory, ice and wind paralyzed roads and caused accidents on 175 high-voltage lines; their normal work resumed only after 4 days. When there is ice in Moscow, the number of car accidents triples.

4. Rules for the behavior of the population in case of snow drifts and actions to eliminate their consequences

The winter manifestation of the elemental forces of nature is often expressed by snow drifts as a result of snowfalls and snowstorms.

Snowfalls, the duration of which can be from 16 to 24 hours, strongly affect the economic activity of the population, especially in countryside. The negative impact of this phenomenon is exacerbated by snowstorms (blizzards, snowstorms) in which visibility deteriorates sharply, transport communication is interrupted, as well as intercity. Snowfall with rain at low temperatures and hurricane winds creates conditions for icing of power lines, communications, contact networks, electric transport, roofs of buildings, various types of supports and structures, causing their destruction.

With the announcement of a storm warning - a warning about possible snow drifts - it is necessary to limit movement, especially in rural areas, to create the necessary supply of food, water and fuel at home. In some areas, with the onset of the winter period, it is necessary to stretch ropes along the streets, between houses, helping pedestrians navigate in a strong snowstorm and overcome strong winds.

Snow drifts are especially dangerous for people caught on the way, far from human habitation. Snow-covered roads, loss of visibility cause complete disorientation on the ground. When driving by road, you should not try to overcome snow drifts, you must stop, completely close the blinds of the car, cover the engine from the side of the radiator. If possible, the car should be installed with the engine in the windy direction. Periodically, you need to get out of the car, shovel the snow so as not to be buried under it. In addition, a car not covered with snow is a good guide for the search party. The car engine must be periodically warmed up in order to avoid its "freezing". When warming up the car, it is important to prevent exhaust gases from flowing into the cab (body, interior), for this purpose it is important to ensure that the exhaust pipe does not fill up with snow. If there are several people on the road together (in several cars), it is advisable to get everyone together and use one car as a shelter; water must be drained from the engines of other vehicles. In no case should you leave the shelter-car: in a heavy snowfall (blizzard), landmarks at first glance, seemingly reliable, can be lost after a few tens of meters. In rural areas, with the receipt of a storm warning, it is necessary to prepare the required amount of food and water for animals kept on farms. Cattle kept on remote pastures are urgently driven to the nearest shelters, previously equipped in the folds of the terrain or to stationary camps.

With the formation of ice, the scale of the disaster increases. Ice formations on the roads make it difficult, and on very rough terrain they completely stop the operation of road transport. Pedestrian movement is hampered and collapses various designs and objects under load become real danger. Under these conditions, it is necessary to avoid being in dilapidated buildings, under power and communication lines and near their supports, under trees.

In mountainous areas, after heavy snowfalls, the risk of avalanches increases. The population is informed about this danger by various warning signals installed in places of possible avalanches and possible snow falls. These warnings should not be neglected, their recommendations should be strictly followed. To combat snow drifts and icing, civil defense formations and services are involved, as well as the entire able-bodied population of the given region, and, if necessary, neighboring regions. Snow removal works in cities are primarily carried out on the main transport routes, the work of life-supporting energy, heat, and water supply facilities is being restored. Snow is removed from the roadway to the leeward side. They widely use engineering equipment, which is on the equipment of formations, as well as snow-removing equipment of objects. All available transport, loading equipment and the population are involved in the work.

CHAPTER 2. Description of icing in Kamensky, Rybnitsa and Dubossary regions

Over three thousand settlements of Ukraine, especially the Vinitsa region, as well as northern Pridnestrovie, suddenly lost light, heat and communications as a result of the violence of the elements on the night of November 26-27. Trees, poles, wires, wet from prolonged rains, as a result of a sudden cold snap, were instantly overgrown with a thick layer of ice and collapsed from gravity and gusts of wind of 18-20 meters per second. Even some antenna masts of the Pridnestrovian television and radio center "Mayak" did not survive.

According to preliminary estimates, about 25% of all forests of the PMR, which had been grown for decades, perished. The raging elements spared the city of Dubossary itself. Literally a few meters from the head station, which feeds the entire city, it froze, otherwise Dubossary would have lost heat and light for a long time.

Otherwise, the picture is regional. 370 towers of high-voltage power lines and 80 low-voltage ones were destroyed. Damaged 12 transformers. According to preliminary data, the damage inflicted only on the enterprises of regional power networks amounted to 826 billion rubles. The material losses of Telecom TG are estimated at 72.7 billion rubles. Total - almost 900 billion rubles.

Kamensky district, as the northernmost, suffered the most from the natural disaster. The elements damaged about 2.5 thousand hectares of the state forest fund. This makes up 50% to 70% of forested areas. More than 150 km have been put out of action. power lines, 2880 electrical pylons were blocked. Gardens were badly damaged. For several days, the regional center was left without heat and light. A day and a half without water.

In the Mayak village of the Grigoriopol region, the elements swept away the concrete poles of power lines like matches. radio antenna, which cloudy weather propped up the clouds, collapsed. For its repair, approximately 400 thousand USD will be needed.

The village of Mayak, the villages of Gyrton, Glinnoe, Kamarovo, Kolosovo, Makarovka, Kotovka, Pobeda, Krasnaya, Bessarabia, Frunzovka, Veseloye, Kipka were left without electricity.

A heavy anticyclone left the elements on the outskirts of Tiraspol.

CONCLUSION

There are serious reasons to believe that the scale of the impact of disasters and catastrophes on the social, economic, political and other processes of modern society and their drama have already exceeded the level that allowed them to be treated as local failures in the measured functioning of state and public structures. That threshold of systemic adaptation, which allows the system (in this case, society) to absorb deviations from the permissible parameters of life and at the same time maintain its qualitative content, apparently, was passed in the 20th century.

Before the individual and society in the XXI century. becoming more and more clear new goal- global security. Achieving this goal requires a change in a person's worldview, value system, individual and public culture. New postulates are needed in the preservation of civilization, ensuring its sustainable development, fundamentally new approaches to achieving integrated security. At the same time, it is very important that there should not be dominant problems in ensuring security, since their consistent solution cannot lead to success. Security problems can only be solved comprehensively.

The surface of the Earth will continuously change under the influence of natural processes. Landslides will occur on unstable mountain slopes, high and low water in the rivers will continue to alternate, and storm surges will flood the sea coasts from time to time, and there will be fires. Man is powerless to prevent the natural processes themselves, but it is in his power to avoid casualties and damage.

It is not enough to know the patterns of development of catastrophic processes, to predict crises, to create disaster prevention mechanisms. It is necessary to ensure that these measures are understood by the people, that they are in demand, that they become everyday life, being reflected in politics, production, psychological attitudes of a person. Otherwise, the state and society will face the “Cassandra effect”, which is almost always mentioned by eyewitnesses of major disasters: many people do not follow warnings, ignore danger warnings, do not take steps to save (or make erroneous actions).

BIBLIOGRAPHY

1.Kryuchek N.A., Latchuk V.N., Mironov S.K. Security and protection of the population in emergency situations. M.: NTs EIAS, 2000

.S.P. Khromov "Meteorology and climatology": - St. Petersburg, Gidrometeoizdat, 1983

.Shilov I.A. Ecology M.: graduate School, 2000.

.Newspaper "Pridnestrovie". Issue from 30.10.00 - 30.12.00

Similar jobs to - Meteorological and agrometeorological hazards

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 refers to an event of natural origin or the result of natural processes that, due to 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).

1. 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.