From the very beginning of the development of civilization on the planetGeological, meteorological and hydrological emergencies are threatened. However, they often cause significant damage. The magnitude of harm depends on the intensity of catastrophes, the conditions of life of the society, its level of development. Consider further major meteorological emergencies. 
Relevance of the issue
Recently, frequent Geological, meteorological, hydrological and biological emergencies. For example, volcanoes are activated onKamchatka, a growing number of earthquakes in the North Caucasus, Transbaikalia, Sakhalin and the Kuril Islands. The destructive power of catastrophes is also increasing. Recently, floods, landslides, tornadoes, storms, hurricanes, snow drifts, and others have become almost regular. Meteorological and agrometeorological emergencies. Undoubtedly, today humanity is nothelpless as before. Some catastrophes can be successfully predicted, others - to resist effectively. But any response to natural processes requires a deep knowledge of the causes and characters of manifestation.
Regularities
Natural weather meteorological emergencies have a number of things in common:
- Each type of catastrophe has a specific spatial reference.
- The higher the power (intensity) of the phenomenon, the less often it occurs.
- Each phenomenon is preceded by certain signs.
- For all the suddenness of the occurrence of a catastrophe can be predicted.
- Almost always, you can provide active or passive measures to protect against danger.
Causes of meteorological emergencies: examples
Disasters can be caused by different factors. Among the most common are:
- Wind, including tornado, storm, hurricane. Meteorological emergency arise when the speed of air flow from 25 m / s and more.
- Heavy rain - rainfall from 50 mm and more for 12 hours.
- Large hail - particle diameter of 20 mm.
- Heavy snowfall - precipitation from 20 mm in 12 hours.
- Dust storms.
- Strong blizzards with wind speeds of 15 m / s and above.
- Frosts - when the temperature on the soil surface decreases during the growing season below 0 degrees.
- Heatwave.
Squally winds, rains, frost and can cause serious damage to livelihood objects, threaten the life of the population. Natural weather meteorological emergencies can cause disastrous consequences when:
- Occur on the territory of the region (region, region, republic, district).
- Cover several areas.
- Last at least 6 hours.
Air movement
Атмосфера планеты неоднородна и по температуре, и by composition. The temperature difference provides general air circulation. She, in turn, has an impact on climatic conditions on the planet. The movement of air is called the wind. His strength is assessed according to the Beaufort scale in points (from 0 to 12). The movement of air is caused by the presence of anticyclones and cyclones. Wind always goes from high pressure to low. The diameter of a cyclone can reach several thousand kilometers. In the Northern Hemisphere, the wind direction is against, and in the Southern - clockwise.
Hurricanes
They have high speed. It can reach 12 points. Tropical hurricanes, typhoons, arise over the Pacific Ocean. They are considered the most powerful. Meteorological emergency. Hurricanes can have a different size.As a rule, the width of the zone of damage is taken. Often, the storm winds of small force are added to it. In such cases, the width of the hurricane can even reach 1 thousand km. Typhoon damage is usually 15-45 km. The duration of hurricanes is on average 9-12 days. The power of destruction is due to the presence of enormous energy at the epicenter. Its amount released within 1 hour is comparable to the strength of a nuclear explosion of 36 gigatons. Often, along with hurricanes, there are other Meteorological emergency. In particular, the phenomena are accompanied by heavy rains causing landslides and mudflows.
Storms
They are streaming and vortex.The latter are presented in the form of complex formations, the occurrence of which is associated with cyclonic activity. They cover a fairly large area. Streaming storms are local phenomena. They cover a small area. Stream storms are sharply segregated, peculiar and inferior to vortex. They can be jet and drain. In the latter case, the air moves from top to bottom. In jet storms, streams move horizontally and upwards. As a rule, they pass between the mountain ranges connecting the valleys. TO Meteorological emergencies include alsoe dust storms.They cause choking, can carry dangerous parasites, cause significant damage to equipment. As a rule, such phenomena occur in the deserts, with unstable weather, in the zone of atmospheric fronts. Squall storms usually start suddenly. At the same time, they differ in a short character (up to several minutes).
Tornado
It usually occurs in a warm area.cyclone and moves with it at a speed of 10-20 m / s. The length of the path of the tornado can be from 1 to 60 km. In its upper part, a funnel-shaped expansion is formed, which merges with the clouds. In some cases, the lower part increases. This happens when the tornado drops to the ground. Its height can be 800-1500 m. In a tornado, the air rotates and at the same time moves upward in a spiral, drawing water and dust into itself. The speed of such a stream can be 330 m / s. Inside the vortex there is a decrease in pressure. As a result, vapor condensation begins. Visible tornado becomes due to water and dust. Above the sea, its diameter can reach tens, and over land, hundreds of meters. Thunderstorms, hail, rain often occur with the whirlwind. If the streams reach the earth, the objects on it are always destroyed. Tornado tightens all the objects that occur on the way, lifts them and carries over long distances. Such hMeteorological It is very difficult to predict.
Shower
It is an intense precipitation.Especially dangerous are showers, the speed of which is 0.15-0.20 mm / minute. They damage crops, causing their lodging. Prolonged showers cause flooding. In addition, they cause dangerous slope processes (soil liquefaction, landslides, mudflows).
Snowfall
It impedes traffic, substantiallyreduces visibility. In 12 hours, 20 mm and more can fall out. Heavy snowfalls with drifts completely paralyze traffic, causing damage to power lines, buildings (due to high layer pressure). At the same time, snowstorms are not uncommon - the wind carries snow. The lower their intensity, the longer they are.
Frost
During the growing season, a significant decreasetemperature leads to the death of crops. In the northern areas of freezing - a frequent occurrence. Extremely low temperature drops are characteristic of Kamchatka, Chukotka, Yakutia, Magadan Oblast. The magnitude of the damage will depend not so much on the level of deviation from the normal values of t, but on the adaptability of the local population and the economic complex to such phenomena.
Heat
В летний период частым является экстремальное temperature rise. Heat can last for one or several weeks. Emergency mode is announced when the temperature reaches 35 degrees. Heat increases the risk of fires, shallowing rivers, damages agricultural crops. In many cases, it leads to disruptions in the work of transport. Often the heat causes drought. In the vast territory for a long time remains high temperature, combined with the absence of precipitation. If this situation persists for at least a month, the water balance of the plants is disturbed, which leads to their damage and death.
Behavior for meteorological emergencies
There are various recommendations on how to behave when disasters occur. Anyone need to know what to do in case of meteorological emergencybecause not only hislife, but also close. Elementary recommendations are given at school. At the lessons OBZH teacher talks about emergencies and rules of behavior when they occur.
Thunderstorm events
Lightning is dangerous when behind the flashshould be a thunderclap. In such situations it is necessary to take urgent security measures. When staying in the house, it is necessary to close windows, chimneys, doors, ventilation openings. Do not heat the stove, as the gases that will come out of the pipe, have a low resistance. At lightning strikes it is impossible to approach to conducting, drains, the lightning conductor. It is not recommended to be near the window. It is advisable to turn off electrical appliances. If you are in the forest during a thunderstorm, you should choose a short section. It is dangerous to hide under tall trees. From elevations it is better to go down to the lowland. If you are in open space (in the field, steppe) you should not lie down on the ground. You need to select the recess and sit down, clasping his hands.
Measures for hurricane, tornado, storm
При нахождении в здании нужно отойти от окон и take a safe place in the corridor, near the walls, built-in cabinets, under the table, etc. You must first turn off the lights, turn off the taps on the gas equipment, and put out the fire in the stove. In the dark, you should use lamps, candles, lanterns. If the hurricane found on the street, you should try to stay away from light structures, bridges, power lines, ramps, lakes, rivers, masts, trees, industrial facilities. To protect against flying debris, you can use sheets of plywood, boxes, boards and other materials at hand. It is necessary to take shelter in the basement, anti-radiation shelter, cellar, etc., as quickly as possible. Do not enter damaged buildings, since there is a high risk of collapse. In case of a dust storm it is necessary to cover the face with a bandage, a piece of cloth, a scarf If you are in an open area, you should find a road ditch, pit, ditch, any other indentation and lie down into it, pressing tightly to the ground. The head must be closed with clothes or branches. In a car in such a situation it is dangerous to remain.
Snowstorm events
You can leave the buildings only in exceptionalcases. You can only drive in a car on major highways. When exiting the vehicle should not move away from it beyond the zone of visibility. The Ministry of Emergency Situations warns that during the elements the number of thefts and other crimes increases. In this regard, care must be taken when dealing with strangers.
Conclusion
Considering natural emergencies, it should be notedthe value of anthropogenic influence on their occurrence. Human activities often disturb the equilibrium in ecosystems. This, in turn, causes an increase in the intensity and frequency of emergencies. The impact of a disaster can be exposed to any territory of the earth. There is always a connection between emergency situations. Most clearly, it manifests itself in earthquakes and tsunamis. Cyclones in the tropics are almost always followed by floods. Earthquakes often cause fires, dam breaks, etc. When planning protective measures, it is necessary to minimize the size of secondary effects. Through appropriate preparation they can be completely eliminated. For the successful prevention and elimination of emergencies, it is necessary to study their causes and mechanisms. It is possible to predict the occurrence of a phenomenon, knowing its physical essence.
