People living on the planet in different eras have repeatedly encountered various disasters, not last place among which are tornadoes and their derivatives. Wind is a very powerful element, it's hard to argue with that. His strength is enough to demolish almost any structure built by man, lift into the air and carry cars, objects and people over long distances. Large-scale catastrophes of this kind happen relatively infrequently, so any hurricane, tornado, typhoon or tornado is an extraordinary event that attracts world attention.
Hurricanes: Causes of Natural Disasters
What is a hurricane? This phenomenon is caused by the wind of great speed. The occurrence of hurricanes is explained simply: the wind appears due to the difference in atmospheric pressure. Moreover, the more expressive the pressure amplitude, the greater the direction of the air flow - from the area of high pressure to a place with lower rates.
As a rule, the causes of hurricanes are cyclones and anticyclones, which move quickly from place to place. Cyclones are characterized by low pressure, anticyclones, on the contrary, are high. Winds in such huge air masses ah blow in different directions, depending on the hemisphere.
Relatively speaking, any hurricane is an air whirlpool. The causes of hurricanes come down to the appearance of an area low pressure, into which air rushes at a frantic speed. Such phenomena occur throughout any season, but in Russia they most often appear in the summer.
Tornado, storm, hurricane: differences
Strong winds can be called differently: typhoons, hurricanes, storms, tornadoes or storms. They differ not only in name, but also in speed, method of formation and duration. For example, a storm is the weakest windy incarnation. The wind during a storm blows at a speed of about 20 m/s. The phenomenon lasts up to a maximum of several days in a row, and the coverage area is more than a hundred kilometers, while a hurricane can rage for about 12 days, bringing chaos and destruction. In this case, the hurricane whirlwind flies at a speed of 30 m/s.
The tornado, which the long-suffering Americans call a tornado, deserves special mention. This is a mesocyclone, an air vortex, the pressure in the center of which drops to record low levels. A funnel in the form of a trunk or whip increases during movement and, sucking in earth and objects, changes color to a darker one. exceeds 50 m/s, possessing enormous destructive power. The diameter of the vortex column is sometimes hundreds of meters. A column descending from a thundercloud draws objects, cars and buildings into itself with truly gigantic force. A tornado sometimes captures hundreds of kilometers, destroying everything that is on the road.
Hurricanes, storms, tornadoes are sometimes observed on Russian territory. In particular, hurricanes most often occur in the northern regions: in Kamchatka, in the Khabarovsk Territory, in Chukotka, on Sakhalin Island. But tornadoes in Russia are an infrequent phenomenon. One of the first mentions of such a phenomenon dates back to the 15th century. The tornado of 1984 in the city of Ivanovo also brought significant damage. And in 2004 and 2009, the hurricane vortex did not bring serious damage.
Strong winds in Russia
Although tornadoes are rare in Russia, hurricanes and storms, of course, do happen. In terms of strength, fortunately, they are not as significant as the famous "Camilla" or "Katrina", but they also lead to destruction and casualties. In addition to those mentioned, it is worth noting the most noticeable hurricanes in Russia.
the date | Region | Damage |
8 people were killed, 157 people were injured. More than 2,000 buildings and power lines were damaged. The wind speed was 31 m/s. |
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Perm region | Residential buildings in Perm and the region were damaged, water supply was disrupted, power lines were destroyed. |
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Kemerovo region | The hail massively destroyed vast areas of agricultural land. Roofs were blown away from many residential buildings. The damage amounted to more than 50 million rubles. |
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2001 September | One person died and 25 were injured. Trees uprooted, some broken. Roofs damaged. |
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Novosibirsk region | Windows shattered, roofs torn off. The wind exceeded the speed of 28 m/s. Power pylons were destroyed, wheat crops were damaged. |
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The wind knocked down shields, 3 people lost their lives. In general, the area of the hurricane spread over central regions Russia. In Moscow, even the airport stopped its work. In the Tula region, a bus was overturned, trees were knocked down, and houses were damaged. |
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Irkutsk region | Six people died, 58 people were seriously injured. More than 200 pillars were knocked down, leaving thousands of people without electricity. |
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Northern Europe | The hurricane also touched Russia: residential buildings were damaged in Moscow, the Neva River overflowed its banks in St. Petersburg, and a whirlwind knocked down in Kaliningrad Christmas tree. The Pskov region was almost completely de-energized. |
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March 2006 | South of Russia | The impact of the elements fell on Vladikavkaz: many buildings were destroyed, a lot of trees were knocked down, 7 people suffered from the hurricane. Also, the wind flying at a speed of more than 30 m / s, and abundant sleet de-energized the Kuban, Rostov region, Dagestan, Adygea, Stavropol and Kalmykia (in Elista it was necessary to introduce |
May 2006 | A crazy whirlwind, rushing at a speed of up to 40 m / s, led to the death of 2 people and massively damaged power lines. |
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2006 August | Chita region | The cyclone from Lake Baikal brought with it a downpour and strong squalls. People lost power supply, collectors on two streets were flooded, roofs were torn off houses. A teenager died from electric shock. |
May 2007 | Krasnoyarsk region | Cars were damaged, communication was interrupted for some time. |
June 2007 | Volga and Ural | 52 people were injured, three were killed. The wind tore off wires and roofs. Falling trees damaged power lines. |
Tomsk region | The squall demolished the roofs of houses, there are dead (woman), 11 people were injured. An emergency regime has been introduced. |
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July 2007 | Tatarstan | More than 40 settlements were affected by the storm, residential and administrative buildings were damaged. |
Russian size
Based on the above information, we can conclude that there are hurricanes in Russia, but their scale is incomparable with those that rage in other parts of the world. Why is nature so merciful to Russian expanses? The consequences of hurricanes in Russian territories are, of course, painful for the victims, but still not as fatal and voluminous as in the United States or Australia.
The fact is that for the occurrence of a hurricane, it is necessary that the air filled with heat and water particles come into contact with the cold. And this should certainly happen over a cool surface. Therefore, most often tornadoes and hurricanes occur in the coastal areas of the southern seas. Russia does not fit into such a scheme.
"When the ocean rages..."
A hurricane at sea is called a storm. At the beginning of the 19th century, an admiral of the English fleet named Beaufort developed a special scale, which is used to measure the strength of the wind to this day. This grading system operates both at sea and on land. The scale has a 12-point gradation. Already from 4 points, waves up to one and a half meters high rise, then with the wind it is no longer possible to speak, and it is very difficult to go against the air flow. In a 9-point storm, the wind grows stronger up to 24 m/s, and the waves reach a height of 10 meters. The maximum, 12-point hurricane destroys everything in its path. Small and medium-sized vessels are the first to be hit, for which there is almost no chance of surviving in such a wind. The sea wildly foams and rages. The hurricane rushes at a speed of over 32 m/s.
The typhoon is also related to the oceans. This is a cyclone that occurs over the surface of the Atlantic, and it got its name in Asia. In translation, the word means too strong a wind. The Sakhalin region is hit by up to eight typhoons during the year. There are also Pacific typhoon hurricanes. This type of element has the most catastrophic consequences.
Some tropical cyclones are called supertyphoons because of their eccentricity and terrible strength. Typhoon Georgia is an example of such a hurricane. He suddenly collapsed in 1970 in the south of Sakhalin and mercilessly demolished everything that was possible. Unfortunately, it was not possible to avoid casualties.
The deadliest hurricanes in the world
Examples of hurricanes, even over the past 20 years, we can often observe. The ten most destructive elements included such elements as:
- Pauline, which raged in Mexico in 1997.
- "Mitch", in 1998, destroyed the countries of Central America; the force of the hurricane sometimes reached 320 km / h, human casualties numbered in the tens of thousands.
- Category 5 hurricane Kenna devastated the city of Nayarit; the wind uprooted trees, destroyed buildings and roads, and only by a lucky chance people did not die.
- Typhoon Ivan hit the United States in 2004 and caused billions in damage.
- Wilma destroyed the coasts of Cuba and the United States in 2005; it claimed 62 human lives.
- A huge whirlwind 900 km long swept over the expanses of the United States in 2008; for 14 hours of rampant elements, enormous damage was caused; the wind of such strength was called "Hayk".
- "Charlie" in 2004 took a walk in Jamaica, Cuba and the USA; wind force reached 240 km / h.
- In 2012, Hurricane Sandy killed 113 people; the element raged in the east of the United States, especially the state of New York.
Tornado with a female character
Interestingly, the most devastating effects of hurricanes are observed from those elements that are named after women.
These are the most capricious and unpredictable hurricanes, reminiscent of a lady in a fit of hysterics. Maybe this is a prejudice, but judge for yourself:
- Katrina is one of the worst hurricanes in history. This deadly wind hit the US in 2005. Massive floods, about 2,000 human lives, hundreds of missing people - this is the tribute collected by the elements in that fateful year.
- An earlier but no less terrible hurricane hit India and Bangladesh in 1970. They called him strange - "Flea". More than 500 thousand people died from floods provoked by an unprecedented storm.
- The Chinese typhoon, romantically named Nina, devastated the great Bankiao Dam, causing flooding that killed an estimated 230,000 people.
- The Camille swept over the Mississippi in 1969. Meteorologists could not measure the strength of the wind, as the instruments were destroyed by the violent elements. It is believed that hurricane gusts reached 340 km / h. Hundreds of bridges were damaged, many houses were damaged, 113 people drowned, thousands were injured.
In fairness, it should be noted that the most terrible hurricane, named San Calixto, has nothing to do with female names. Nevertheless, it became the deadliest recorded. Tens of thousands of people died, almost all the buildings were destroyed, the wind tore the bark from the trees before uprooting them. A huge tsunami washed away everything that blocked her path. Modern experts believe that the force of the hurricane was at least 350 km/h. This terrible event happened in 1780 in the Caribbean.
Storm! The storm is coming soon! Or how to measure the strength of a tornado
In order to measure the strength of the wind, the Beaufort scale is again used, somewhat modified, refined and supplemented. An instrument called an anemometer measures the speed of air currents. For example, the last hurricane Patricia, recorded in Texas, had a force of 325 km / h. This was enough to demolish a large train into the water.
The destructive force of the wind starts at 8 points. This corresponds to an air speed of 60 km/h. With such a wind, thick trees break. Further, the wind increases to 70-90 km/h and begins to demolish fences and small buildings. A 10-point storm uproots trees and destroys capital buildings. The wind force reaches 100-110 km/h. Strengthening, the element drops iron wagons like matchboxes, knocks down poles. A hurricane with a power of 12 produces total destruction, sweeping at a speed of over 130 km / h. Such deadly hurricanes in Russia, fortunately, are extremely rare.
catastrophic consequences
A hurricane is a serious element, so immediately after the wind stops you should not leave the shelter, you have to wait a few hours before coming out into the light. The consequences of tornadoes, hurricanes, storms are very impressive. These are fallen trees, ripped roofs, flooded sewers, destroyed roads, damaged power pylons. In addition, the waves caused by the wind can turn into a tsunami, sweeping away everything that is alive and built by people. With the destruction of dams, global floods are inevitable, and if wastewater get into tanks with drinking water, it often provokes an uncontrolled growth of infectious diseases and even epidemics.
But life will gradually begin to recover, because emergency rescue units will take over the work, which ordinary residents can also help. In order to minimize the consequences as much as possible, and at least avoid human casualties, there are rules of conduct before, during and after the rampage of the elements.
Rules of conduct in emergency natural conditions
Correct and thoughtful actions during a hurricane are not capable of saving the life of both the person himself and his loved ones. After meteorologists detect a hurricane and calculate its trajectory, this information is necessarily reported to the public. Usually the standard signal "Attention!" on all channels of television, radio broadcasting and the necessary public information is transmitted.
The preparatory stage includes the following steps:
- sources of information remain included so as not to miss important points;
- students must be sent home without fail;
- if the hurricane is already beginning to rage, then the students take refuge in the basement;
- it is necessary to prepare supplies of water, food and medicine for about 3 days;
- lanterns, lamps, candles, portable stoves must be available;
- glasses are glued crosswise or in the shape of a star;
- shop windows are protected by large shields;
- balconies are cleared of objects and rubbish that can be blown away by the wind;
- window sills must be empty;
- in the villages, cattle are driven into a fortified barn, equipped with a supply of food and water; summer buildings are fixed as far as possible;
- windows on the windward side are tightly closed, and on the opposite side, on the contrary, remain open.
What actions should be taken during a hurricane upon hearing of its approach? First, turn off electrical appliances and gas stoves, fix the taps. Secondly, take a suitcase with the most necessary things and documents. Further, stocks of food, medicines, water should be transferred to a safe shelter and take refuge there with the family. If there is no such shelter, then in the house you need to hide under reliable furniture, in niches, doorways. In no case should you approach windows that must first be curtained.
In the event that the elements caught in an open area, any ravine or depression can serve as a refuge. Bridges, or rather places under them, can become an excellent shelter. Keep away from billboards, torn wires, narrow passages (danger of crowds), lowlands, as there is a possibility of flooding. Before the hurricane, it is imperative to agree with loved ones about the meeting place in case of various unforeseen circumstances.
After the end of the element:
- do not light matches, as gas leakage is not ruled out;
- untreated water should not be used, as it may be heavily polluted;
- you should find out if your neighbors need first aid.
Hurricanes in Russia happen infrequently, but it is still necessary to know these rules, because natural disasters, due to climate change, tend to change their localization.
As I already wrote, the emergence of large-scale, stable and fairly long-lived atmospheric vortices is a very common phenomenon. It is very natural and follows from the fundamental laws of hydrodynamics, and does not even require any special temperature conditions or energy influx. But not every whirlwind becomes a serious hurricane. This requires energy "recharge" in the form of very warm water on the surface of the ocean, leading to abundant evaporation and convection into the upper layers of the troposphere.
The first experimental attempts to fight hurricanes were made back in the 40s and 50s and were rather naive, due to insufficient understanding of the physics of the processes. The technology was similar to cloud-seeding guns: the idea was to destroy the walls of the "eye" of a hurricane with the help of a seed for water droplets (usually iodine salts) that would fall in the form of rain. But it did not work: the walls of the "eye" were constantly being restored.
To understand why such methods do not work, one must keep in mind that although the central convective cell (the "eye" of a hurricane) plays a crucial role in its dynamics, it contains only a small fraction of its energy. If the central cell is destroyed, the rapid rotation of the surrounding air will continue. As the rotating air rubs against the ocean's surface, the Coriolis force (due to the Earth's rotation) will push the lower layers of air towards the center of rotation. If there is warm water in the ocean, this will be accompanied by intense evaporation, and will quickly lead to the restoration of the convective cell.
For the same reasons, a large explosion in the center of a hurricane will not work either: it will, of course, temporarily disrupt convection, but it will quickly recover for the reasons described above.
Some of the methods being considered now are based on a different idea: to create artificial small hurricanes that would "suck" energy from the atmosphere and the upper layer of water. One of the more exotic ways is a kind of "star wars" to heat the top layer of water or a column of air using microwave radiation from space, creating a "seed" for a moderately sized atmospheric vortex. But this, of course, is rather frivolous.
Another version was proposed by Moshe Alamaro from the Department of Earth, Atmopspheric and Planetary Sciences (Massachusetts Institute of Technology), in collaboration with Russian and German scientists. Once I myself worked at this faculty (and also defended my Ph.D. there). Recently on this topic was. The idea is to put a lot of old aircraft engines on the barge and blow their exhaust jet up. This should initiate the convective cell of a small hurricane, preventing it from becoming a very intense one like Katrina.
I am very skeptical about this. This is reminiscent of the idea that lies in the artificial, controlled burning of forest areas, so as not to leave dry land for a big fire. But if there is only a certain and limited amount of combustible material in the forest, then incomparably more thermal energy is contained in the upper layer of the tropical ocean than in all hurricanes combined for the entire season. Trying to reduce this amount with small vortices is unproductive. On the contrary, small vortices can merge with their own kind and form large ones. Such a procedure would be reminiscent of an uncontrolled burning of a forest area, but making large fires on the territory of an oil storage facility is a dubious undertaking.
There is another problem with such an undertaking: for the formation of a hurricane, a very large-scale initial heating is needed, which is unlikely to be created by several dozen aircraft turbines. It is necessary that the convective cell "pierce" through the entire troposphere, and the outer contours of the hurricane be in the so-called "geostrophic regime" (when the pressure gradient is balanced by the Coriolis force, then a stable rotation occurs). This is achieved at distances of at least many tens of kilometers - this should be the diameter of the initial "seed" for a hurricane.
In fact, there were precedents when such a regime was caused by artificial heating: during the massive bombing of Dresden and Hamburg by Allied aircraft in 1945. Then the burning cities turned into a kind of hurricane, where intense convection took place in the center to the very stratosphere, and a self-sustaining vortex arose along the edges like an ocean hurricane. But spending so much energy in the middle of the ocean is still problematic.
However, not bad at all for some opportunistic considerations: for example, in Russia there is a lot of aviation fuel and a lot of old decommissioned turbojet engines. To imagine thousands of turbines constantly blowing into the sky in the middle of the ocean is a pretty good way to cut down on the American budget. Hurricanes will not be prevented, but less money will be left for some new adventures like Iraq - again, the benefit to all mankind.
The third group of potential methods of dealing with hurricanes is to deprive them of recharge - to dramatically reduce the evaporation of water from the surface of the ocean. For this, various methods are considered. One is a thin layer of organic material (something like an oil slick) on the surface of the water that would hold up well in stormy weather but self-destruct without any trace a few days later. A similar idea is being explored by renowned hurricane specialist Kerry Emmanuel from the same department (during my time at MIT, my office was a few doors away from his):
http://www.unknowncountry.com/news/?id=4849
So far, experiments with surface films are at the very initial stage, and also cause skepticism. Another idea, while rather amorphous, is to induce "anti-convection" (upwelling) in the ocean so that deep, cold layers rise to the surface of the ocean at the site of the hurricane and weaken it. In my opinion, this is a generally more sensible direction, which may turn out to be quite reasonable in terms of energy costs and does not contradict any laws of physics or our knowledge of hurricanes, and does not have long-term consequences on environment. But how this can be done in practice remains very vague.
A natural disaster is a natural phenomenon that is of an emergency nature and leads to disruption of the normal activities of the population, death of people, destruction and destruction of material values.
Descriptions of the greatest natural disasters of the distant past are explicitly or implicitly recorded in the memory of people, in myths and legends, ancient books, and historical manuscripts. In the Bible, for example, a "global flood" is described, which in fact was, of course, not "global", i.e. global, but for a community of people whose sphere of life was limited to the valley of a large river or a vast intermountain basin, a severe flood undoubtedly seemed to be the death of the whole world. Floods occur quite often, but some of them become truly catastrophic. So, in 1931, a grandiose flood on the Yangtze River in China flooded 300 thousand square meters. km of territory. In some areas, including in the city of Hankou, the water subsided for four months. The Bible also tells about the destruction of the cities of Sodom and Gomorrah and the destruction of the city of Jericho. Experts believe that the biblical description quite accurately reproduces the picture of the earthquake. Many researchers of the legendary Atlantis believe that it was a large island that sank to the bottom as a result of an earthquake. The cities of Herculaneum and Pompeii were destroyed and buried under a layer of ash, pumice and mud as a result of the eruption of Vesuvius. Sometimes volcanic eruptions and earthquakes lead to the formation of a giant tidal wave - a tsunami. In 1833, Krakatau erupted, accompanied by an earthquake, which in turn caused a huge tidal wave. It reached the neighboring densely populated islands of Java and Sumatra and claimed about 300 thousand human lives.
A lot of publications are devoted to the characteristics of various natural disasters in the past and present. We will name only some of them, mainly those that are most widely used in this section. In 1976, the XXIII International Geographical Congress took place in Moscow, where the section "Study of natural disasters" worked. The materials of this section were published in the collection of abstracts of reports and messages "Man and Environment" (M., 1976). Of particular interest to the topic under consideration is the work of R. Cates "Natural Disaster and economic development". Huge factual material is also contained in the monographs: R. Cates "Natural disasters: study and methods of struggle" (M., 1978); S.V. Polyakov "Consequences of strong earthquakes" (M., 1978); S.S. Ginko "Disasters on the banks of rivers" (L., 1963), A.A. Grigoriev "Ecological lessons of the past and present" (1991) and others. The following works of his were published: "Craters on Fire" (M., 1958), "Meetings with the Devil" (M., 1961), "Volcanoes" (1963), etc. A large section "Natural Hazards and Risk Assessment" is included in the monograph "The Changing World: A Geographical Approach to Study" (M., 1991). For specialists in human ecology, the most important aspect of natural disasters is their consequences for human life. According to the disaster department of the Smithsonian Institution (USA), the number of victims on the planet, caused by natural disasters during the period from 1947 to 1970, there were exactly as follows:
Cyclones, typhoons, storms on the coast - 760 thousand dead
Earthquakes - 190 thousand dead
Floods - 180 thousand dead
Thunderstorms, tsunamis, volcanic eruptions, etc. - 62 thousand dead
Total - 1192 thousand dead
Thus, for almost a quarter of a century, about 50,000 people per year on average died from natural disasters. After 1970, the statistics were supplemented by an extensive list of natural disasters. Let us recall only the earthquake in America in 1988. Then, according to various estimates, from 25 to 50 thousand people died. It is estimated that 9/10 of the world's natural disasters are of four types: floods (40%), tropical cyclones (20%), earthquakes (15%), droughts (15%). In terms of the number of victims, tropical cyclones rank first, while floods are more frequent and cause great material damage. R. Cates believes that the damage caused to the world economy by natural disasters is about 30 billion US dollars annually. 20 billion of them are net damages, and the remaining 10 billion are expenses for preventive actions and measures to mitigate the consequences of the rampant disaster.
In the anthropological aspect, the definition of natural disasters can be formulated as follows: natural disasters are destructive natural processes that cause death of people as a result of exposure to poisonous hot gases and lava during volcanic eruptions, tidal waves during tsunamis and typhoons, water and mud flows during mudflows etc., as well as as a result of injuries in the destruction of residential and public buildings, production facilities and technical structures; destruction of agricultural products in fields and plantations, in storage facilities and warehouses; death of farm animals; destruction of communal and sanitary infrastructure, including electrical networks, communication systems, water supply and sewerage. The latter circumstance often leads to massive outbreaks of infectious diseases after natural disasters. E.Yu. White (1978) notes: “As the population grows, the spread of scientific and technological achievements and the complexity of the structure of society, a person becomes more and more vulnerable to extreme natural phenomena, the damage from which is associated not only with their spread, but also with the uncertainty of their occurrence. The cost to society from avalanches, earthquakes, tropical cyclones, and many other natural disasters is on the rise. This is happening despite increasing scientific research into the causes of extreme events and the proliferation of new ways to deal with natural disasters, reducing losses in some areas. Man endangers new material values, and also increases the danger of some natural phenomena. Sophisticated ways to help when disaster strikes are better designed than ways to prevent it."
The danger of a tropical cyclone consists in the extreme action of one or all of its elements (wind, rain, storm surges and waves). Storm surges represent the most destructive factor. On November 12, 1970, a tropical cyclone in the northern Bay of Bengal caused a 6-meter rise in sea level, which coincided with high tide. This storm and resulting flooding killed an estimated 300,000 people, and crop losses alone are estimated at $63 million, but these numbers do not reflect the full impact of the storm. Approximately 60% of the coastal fishing population was killed and 65% of fishing boats in the coastal region were destroyed, which significantly affected the supply of protein food for the entire region.
Tropical cyclones - seasonal phenomena, the frequency of which in different areas varies on average from one to 20 hurricanes per year. Up to 110 hurricanes originating over the Atlantic can be traced from satellites per year. But only 10-11 of them grow to such a size that they can be called hurricanes or tropical storms. An important measure of protecting people from hurricanes is their forecasting. Tropical cyclones are usually identified initially and then tracked by satellite imagery. If a hurricane is found to be intensifying, a forecast of its path and speed is made, which is then refined as new information becomes available. When Hurricane approaches the coast at a distance of 300 km, its speed and direction of movement can be determined by radar. Forecasts typically seek to identify the stretch of coastline threatened by the hurricane, the location of the expected maximum storm surge, areas of heavy rainfall and flooding, and signs of tornadoes at least 36 hours before the tropical cyclone makes landfall. The US Weather Service issues 24-, 12-, and 6-hour forecasts to the public that contain information about the location and characteristics of the cyclone, and if necessary, hourly bulletins are issued. In Australia, warnings are issued every 6 hours when the hurricane is more than 100 miles offshore and every 3 hours when it is making landfall.
In order to protect people's lives and their property, the administration and the population itself in hurricane-prone areas take various measures. Attempts are being made to influence the hurricane itself. To do this, for example, clouds in the hurricane zone are seeded with silver iodide. Protective coastal dams are being built, protective ramparts are being poured, dunes are fixed with vegetation, forest plantations are being made. Shelters are being built. Great importance is attached to strict observance of the rules of zoning of the territory, compliance with building codes. Buildings are strengthened, their wind and hydroprotection is made. Stocks of water, food and building materials are being stockpiled in case of disaster. The most important role belongs to the hurricane warning system. Equally important is the well-organized evacuation of people from the danger zone. American researchers very succinctly formulate protection measures directly during a hurricane: "Evacuation. Search for shelter. Prayer." Concise and recommendations on what to do immediately after the hurricane:
- Submit insurance claims.
- Provide the necessary financial assistance to the victims and restore normal life.
- Accept losses.
Everyone understands that tropical cyclones pose a great threat to life and property in many parts of the world, but most people are surprisingly nonchalant about this threat. In the city of Miami on the coast of Florida, only 20% of the population spends money on preventive measures. In Bangladesh, during the catastrophic hurricane of 1970, 90% of the inhabitants of the area knew about its approach, but only 1% took shelter from the hurricane.
In a hydrological sense, flooding means the inundation of coastal areas with river flow that exceeds the full capacity of the channel. In arid areas, at the time of high flow, the channel itself, usually not filled with water, “floods *. The flood stage begins when the channel overflows, when the water overflows the banks. The flood level is usually set, critical in terms of damage to property and interference with human activity. Flood- a significantly more common natural disaster compared to other extreme natural events. Flooding can occur on both permanent and temporary streams, as well as in areas where there are no rivers and lakes at all, for example, in dry areas with heavy rainfall. The problem of human adaptation to floods is becoming especially complex, because floods, along with a negative impact on the population and on its habitat, have positive sides. In flood-prone areas, there is no shortage of water and fertile floodplain lands. Attempts to resolve the conflict between the need to develop coastal lands and the inevitable losses from floods have been made throughout human history. Even in the more primitively organized pre-industrial societies, people adapted to floods. So, special forms of land use developed among farmers in the lower reaches of the Nile, in the lower reaches of the Mekong. The people of the Barotse Plain in northwest Zambia are responding to the annual seasonal flooding of coastal areas by general migration to higher ground.
AT industrial societies In the 20th century, the concept of multi-purpose river basin management was widely entrenched, according to which the reduction of damage from floods should be combined with planning for rational water use. Densely populated areas of the Earth are especially affected by floods on rivers: India, Bangladesh, China. In China, devastating floods most often occur in the lowlands, in the valleys of the Huang He and Yangtze rivers. Despite many hundreds of dams, centuries of experience in flood control, the inhabitants of these places still become victims of floods. Floods occur here almost every year, and once every 20-30 years they are catastrophic. Many large cities are confined to the river valleys, and the main agricultural areas are located on their banks. In the XX century. especially severe floods on the Yangtze occurred in 1911, 1931, 1954. In 1931, 60 million people suffered from a famine caused by a flood. During the flood of 1911, 100 thousand people died.
There is usually an inverse relationship between property damage from floods and the number of victims. Societies that have something to lose in terms of building structures, engineering networks, Vehicle etc., usually have scientific and technical means to ensure monitoring, warning, evacuation of the population and repair and restoration work, and all this helps to reduce the number of victims. On the contrary, pre-industrial societies, especially those with a high rural population density, suffer less significant property losses, but do not have the necessary funds to implement preventive measures and save people. Population casualties are the most tragic and by far the most easily identified direct result of the flood. In rural areas, losses are especially high due to the death of farm animals and flooding of land, accompanied by soil erosion and the destruction of crops. Water damages agricultural equipment, seeds, fertilizers, feed stored in warehouses, disables irrigation systems and other sources of water supply, and destroys roads. Floods cause damage to city property, including buildings of all types, engineering structures and communications, transport, and river management. Indirect losses are usually associated with impacts on human health and general well-being, although values such as scenic beauty, recreational opportunities and the preservation of wilderness areas should also be taken into account. The normal functioning of health services is greatly complicated by damage to vehicles and engineering networks, especially water pipes. As a result of flooding, there is a danger of infection and pollution of the area, outbreaks of epizootics, which can lead to an increase in the incidence of the population.
In mitigation negative consequences floods the role of forecasts is great. The lead time for forecasting the maximum rise in the water level or overflowing the channel can vary from several minutes during heavy rainfall to several hours in small watersheds in the upper reaches of rivers and several days in the lower reaches of large rivers.
The lead time and reliability of warnings increase as you move down the river, if you have the necessary information about the course of the flood in the upstream sections. Most developing countries have to rely on far scarcer data than is needed for forecasting and warning purposes. With the floods caused by floods on the rivers, a person is actively fighting. For this, dams and dams are being built, channels are being deepened and straightened, reservoirs are being built to collect flood waters, and measures are being taken to manage land use in the river basin.
Many examples can be given of how in our country the damage from floods was significantly reduced by preventive measures. In May and June 1987, a very severe flood occurred in the Tyumen region. On the rivers Irtysh, Tobol, Tura, Vaga and Iset, the water overflowed its banks and formed a vast spill. Some areas of Tobolsk, Tyumen, Khanty-Mansiysk and a number of smaller settlements were under the threat of flooding and destruction. As a result of the flood, five railway bridges were damaged, more than 300 km of roads were destroyed or damaged. More than 500 thousand hectares of agricultural land were flooded and devastated. The damage would have been much greater if they had not begun to prepare for the flood in advance, back in March. In particular, Tyumen was saved from flooding as a result of the urgent construction of a 27 km long dam. An artificial earthen rampart helped protect the river and a significant area of the lower part of Tobolsk from flooding. In those places of the Tyumen region, where preparations for meeting with the flood were carried out technically and ecologically illiterate, the damage from the elements was more tangible. Many villages were flooded here. In total, more than 1 thousand houses, 80 villages and villages were cut off from the regional centers by the flood. In some places, urgent evacuation of people was needed. Many small dams, built without taking into account the size of the natural disaster, were also destroyed.
The willingness to bear the losses continues to be the main mode of adaptation to floods for most residents of potentially flooded areas in developing countries, and often developed ones. Obviously, special measures are needed in order to encourage the population and administration to act and develop a common management strategy for these natural disasters.
An earthquake is a sudden release of the potential energy of the earth's interior, which takes the form of shock waves and elastic vibrations (seismic wave) propagating in all directions. An earthquake is a complex disaster due to its many direct and secondary manifestations on earth's surface. Among the direct consequences is the displacement of the soil from seismic waves or tectonic surface movements. Secondary effects include subsidence and compaction, landslides, cracks, tsunamis, fires and snow avalanches. This many-sided disaster entails a huge number of victims and great material losses. The total number of victims from earthquakes from 1980 to 1989 is, according to A.A. Grigoriev (1991), about 1.2 million people. The largest number of earthquake victims (82% of all victims) falls on 6 countries of the world: China - 550 thousand people, the USSR - 135 thousand (taking into account the victims of only the Ashgabat and Spitak earthquakes), Japan - 111 thousand, Italy - 97 thousand ., Peru - 69 thousand, Iran - 67 thousand people. On average, about 14 thousand people die every year from earthquakes on Earth. Danger zones around the epicenters of destructive earthquakes reach large sizes. The boundaries of the devastation zone can be tens or even hundreds of kilometers away from the epicenter. So, in particular, it happened in 1985 during the earthquake in Mexico. Its epicenter was in the Pacific Ocean, not far from the resort town of Acapulco. However earthquake was so strong that it caused damage to a large part of the country. Its capital, Mexico City, was especially hard hit. The force of the push reached 7.8 points on the Richter scale. In Mexico City, which was located 300 km from the epicenter, over 250 buildings were completely destroyed, 20 thousand people were injured. During the earthquake in Guatemala in 1976, the devastation zone extended to 60 km from the epicenter. 95% of settlements were destroyed in it, including the ancient capital of the country, Antigua, was completely destroyed. 23 thousand people died.
Despite 4,000 years of experience in studying earthquakes, it is very difficult to predict this phenomenon. The most that modern science can do is predict a major seismic shock without specifying the exact time. True, there are individual cases of accurate prediction of earthquakes, as, for example, in China in 1975 in the province of Liaoning. The first signs of a revival of tectonic activity in the area were seen local residents in December 1974. They were carefully studied by specialists. The area was under constant surveillance. And already after the first small shocks on February 1, 1975, geologists came to a firm conclusion about the possibility of a devastating earthquake in the very near future. On the same day, the local authorities carried out an urgent evacuation of the population. Three days later, on February 4, a strong earthquake began. In some areas of the province, 90% of the buildings were damaged. However, there were few casualties. According to experts, the deaths of 3 million people were avoided. Earthquakes continue to be formidable enemies of mankind. About 2 billion people currently live in seismically active regions of the world. Among the densely populated areas, China, Japan, Indonesia, Central America, the western United States and the south of Central Asia.
The most radical means of protecting the health and life of people from earthquakes is the relocation of the population to seismically safe areas. However, examples of this kind are extremely rare, among them is the relocation of the city of Valdez in Alaska. In 1964, seismic shocks here destroyed the port and most of residential and commercial areas. Under the pressure of the administration in 1967, the city was moved to a safe place.
As a result of volcanic activity, thousands of people die, and huge damage is caused to the economy and property of the population. In the last 500 years alone, 200,000 people have died from volcanic eruptions. Their death is the result of both the direct impact of volcanoes (lava, ash, poisoned hot gases) and indirect consequences (including famine, loss of livestock). Despite the negative experience of mankind, modern knowledge about volcanoes, many millions of people live in their immediate vicinity. In the 20th century alone, several tens of thousands of people died from eruptions. In 1902, on the island of Martinique, during a volcanic eruption, the entire city of Saint-Pierre, located 8 km from the crater of the active volcano Mont Pele, was destroyed. Almost the entire population died (about 28 thousand). The eruption of Mont Pele was noted in 1851, but then there were no casualties or destruction. In 1902, 12 days before the eruption, experts predicted that it would be similar in nature to the previous one, and thereby reassured the inhabitants. The largest volcanic eruption in terms of the number of victims and material damage occurred in 1985 in Colombia. Ruiz Volcano woke up, which had not erupted since 1595. The main disaster occurred in the city of Amero, located 40 km from the Ruiz crater. Hot gases ejected from the crater of the volcano and pouring lava melted the snow and ice on its top. The resulting mudflow completely destroyed Amero, in which 21 thousand inhabitants lived. At the same time, about 15 thousand people died. Several other settlements were also destroyed. Great damage was caused to 20 thousand hectares of agricultural plantations, roads, communication lines. About 25 thousand people died, the total number of victims exceeded 200 thousand.
Today, volcanic activity does no less harm to mankind than in previous centuries. And this is very surprising, since through observations it was possible to quite accurately establish the dimensions of the zones of dangerous impact of volcanoes. The lava flow during large eruptions extends to a distance of up to 30 km. Incandescent as well as acidic gases are dangerous within a radius of several kilometers. For a much longer distance, up to 400-500 km, acid rainfall zones spread, which cause burns in people, poisoning of vegetation, crops, and soil. Mud-stone flows that arise on the tops of volcanoes during the sudden melting of snow during the eruption, spread over a distance of several tens of kilometers, often up to 80-100 km.
A.A. Grigoriev (1991) notes: “It would seem that the colossal experience accumulated by mankind in the fight against natural disasters should have long ago convinced people to leave areas dangerous to their livelihoods. However, in practice, something completely different is observed. Moreover, it turned out that many people do not consider dangerous some phenomena of the elements that really threaten their lives. Quite indicative are the assessments of the behavior of people living in the eastern part of the island of Pune, which belongs to the Hawaiian Islands. Here is the Kilauza volcano, at a distance of 30 miles from which there are several settlements. This active volcano erupted 50 times after 1750, and 20 times after 1955. During eruptions, lava flows repeatedly directed towards settlements, destroying houses, roads, crops, and agricultural land. But the inhabitants, although they sometimes move the villages to other places, do not think of leaving this dangerous region. At the same time, 57% of the residents surveyed believe that the Kilauz eruption is dangerous for the land, property, but not for the people themselves. Over 90% of respondents believe that living near a volcano has more advantages than disadvantages.
For many centuries, humanity has developed a fairly coherent system of measures to protect against natural disasters, the implementation of which in various parts of the world could significantly reduce the number of human casualties and the amount of material damage. But until today, unfortunately, we can only talk about individual examples of successful opposition to the elements. Nevertheless, it is advisable to once again list the main principles of protection against natural disasters and compensation for their consequences. A clear and timely forecast of the time, place and intensity of a natural disaster is necessary. This makes it possible to timely notify the population about the expected impact of the elements. A properly understood warning allows people to prepare for a dangerous event by either temporary evacuation, or building protective engineering structures, or strengthening their own homes, livestock buildings, etc. The experience of the past must be taken into account, and its hard lessons must be brought to the attention of the population with the explanation that such a disaster may happen again. In some countries, the state is buying up land in areas of potential natural disasters and organizing subsidized transfers from hazardous areas. Insurance is essential to reduce losses from natural disasters. AT former USSR state insurance was established for personal and collective-farm-state-farm property and people's lives against the following natural disasters: earthquakes, floods, lightning strikes, hurricanes, mudflows, snow avalanches, landslides, landslides, droughts, mud flows, downpours, hail, early autumn and late spring frosts. Agricultural lands were insured not only against these phenomena, but also against soil silting, hoarfrost, calm weather during the period of plant pollination; animals in the far north and south of the country were insured against ice, deep snow, snow crust, and low temperatures. The state paid compensation to collective farms and state farms for all types of damage associated with the loss of livestock, crop failure or the destruction of buildings that were caused by natural processes unusual for the area. At present, in Russia, due to the emergence of private insurance companies and changes in the forms of ownership, the principles of insurance are changing. An important role in the prevention of damage from natural disasters belongs to the engineering-geographical zoning of zones of possible natural disasters, as well as the development of building codes and regulations that strictly regulate the type and nature of construction. Quite flexible legislation on economic activity in areas of natural disasters has been developed in various countries. If a natural disaster occurred in a populated area and the population was not evacuated in advance, emergency rescue operations are carried out, followed by repair and restoration.
Protection of the population during hurricanes, storms, tornadoes
Hurricanes, storms and tornadoes are related to wind meteorological phenomena, in their destructive effect they are often comparable to earthquakes. The main indicator that determines the destructive effect of hurricanes, storms and tornadoes is the velocity pressure of air masses, which determines the force of dynamic impact and has a propelling effect.
In terms of the speed of the spread of danger, hurricanes, storms and tornadoes, given in most cases the forecast of these phenomena (storm warnings), can be classified as emergency events with a moderate speed of propagation. This makes it possible to carry out a wide range of preventive measures both in the period preceding the immediate threat of occurrence, and after their occurrence - until the moment of direct impact.
These time measures are divided into two groups: advance (preventive) measures and work; operational protective measures taken after the announcement of an unfavorable forecast, immediately before this hurricane (storm, tornado).
Early (prevention) measures and work are carried out to prevent significant damage long before the onset of the impact of a hurricane, storm and tornado and can cover a long period of time.
Early measures include: restriction of land use in areas of frequent passage of hurricanes, storms and tornadoes; restriction in the placement of facilities with hazardous industries; dismantling of some obsolete or fragile buildings and structures; strengthening industrial, residential and other buildings and structures; carrying out engineering and technical measures to reduce the risk of hazardous industries in strong wind conditions, incl. increasing the physical stability of storage facilities and equipment with flammable and other hazardous substances; creation of material and technical reserves; training of the population and personnel of rescue services.
Protective measures taken after receiving a storm warning include:
forecasting the path of passage and time of approach to various areas of the hurricane (storm, tornado), as well as its consequences;
operational increase in the size of the material and technical reserve necessary to eliminate the consequences of a hurricane (storm, tornado);
partial evacuation of the population;
preparation of shelters, basements and other underground facilities for the protection of the population;
moving unique and especially valuable property to solid or buried premises;
preparation for restoration work and measures for the life support of the population.
Measures to reduce possible damage from hurricanes, storms and tornadoes are taken taking into account the ratio of the degree of risk and the possible extent of damage to the required costs.
Particular attention in carrying out early and prompt measures to reduce damage is paid to the prevention of those destructions that can lead to the emergence of secondary factors of damage, exceeding in severity the impact of the natural disaster itself.
An important area of work to reduce damage is the struggle for the stability of communication lines, power supply networks, urban and intercity transport. The main way to improve stability in this case is their duplication by temporary and more reliable means in strong wind conditions.
Hurricanes, storms and tornadoes are one of the most powerful forces of the elements. They cause significant destruction, cause great damage to the population, and lead to human casualties. In terms of their destructive impact, they are compared with earthquakes and floods.
The destructive effect of hurricanes, storms and tornadoes depends on the velocity pressure of air masses, which determines the force of dynamic impact and has a propelling effect.
Often storms and hurricanes are accompanied by thunderstorms and hail.
A hurricane, originating in the ocean, comes to land, bringing catastrophic destruction. As a result of the combined action of water and wind, strong buildings are damaged and light structures are demolished, wires of power transmission and communication lines are cut off, fields are devastated, trees are broken and uprooted, roads are destroyed, animals and people are killed, ships are sinking.
How terrible is a hurricane?
First, hurricane waves crashing on the coast. The hurricane, as it were, squeezes huge waves (several meters high) onto the shore in front of it. They destroy everything in their path and lead to severe flooding in coastal areas. The terrible consequences of hurricane waves are observed when a hurricane coincides with the tide. Rarely do eyewitnesses of these terrible and powerful waves survive.
Secondly, catastrophic downpours and floods. The fact is that a hurricane at its inception absorbs a huge amount of water vapor, which, condensing, turns into powerful thunderclouds that serve as a source of catastrophic downpours and cause floods not only in coastal areas, but also in large areas remote from the coast. Heavy rainfall that accompanies hurricanes is also the cause of mudflows and landslides.
In winter conditions, instead of rain, a huge amount of snow falls, causing unexpected avalanches. In the spring, when such masses of snow melt, floods occur.
Thirdly, the propelling action of the velocity pressure of a hurricane is manifested in the separation of people from the ground, their transfer through the air and impact on the ground or structures. At the same time, various solid objects are rapidly sweeping through the air, which hit people. As a result, people die or receive injuries of varying severity and concussion.
A secondary consequence of the hurricane is fires resulting from lightning strikes, accidents on power lines, gas communications, and leakage of flammable substances.
Storms are far less devastating than hurricanes. However, they, accompanied by the transfer of sand, dust or snow, cause significant damage. agriculture, transport and other sectors of the economy.
Dust storms cover fields, settlements and roads with a layer of dust (sometimes reaching several tens of centimeters) over areas of hundreds of thousands of square kilometers. Under such conditions, the harvest is significantly reduced or completely lost, and large expenditures of effort and money are required to clean up settlements, roads and restore agricultural land.
Snow storms in our country often reach great strength over vast areas. They lead to the cessation of traffic in cities and rural areas, the death of farm animals and even people.
Thus, hurricanes and storms, being dangerous in themselves, in combination with the phenomena accompanying them, create a difficult situation, bring destruction and casualties.
A tornado, in contact with the earth's surface, often leads to destruction of the same degree as with strong hurricane winds, but on much smaller areas.
These destructions are associated with the action of rapidly rotating air and a sharp rise of air masses upwards. As a result of these phenomena, some objects (cars, light houses, building roofs, people and animals) can lift off the ground and be transported hundreds of meters. Such an action of a tornado often causes the destruction of lifted objects, and inflicts injuries and contusions on people, which can lead to death.
Measures to protect and reduce the consequences of hurricanes, storms, tornadoes. Algorithm of actions in case of hurricanes, storms and tornadoes
Protection of the population from the consequences of hurricanes and storms is carried out within the framework of the functioning of the Unified state system prevention and liquidation of emergency situations (RSChS).
The state of the atmosphere is continuously monitored from artificial earth satellites. For this, a network of meteorological stations has been created. The received data is processed by weather forecasters, on the basis of which forecasts are made.
Forecast of the occurrence of cyclones, their movement and possible consequences allows to carry out preventive measures to protect the population from the consequences of hurricanes and storms. These activities can be divided into two groups according to the time of their implementation: early and operational-protective, carried out directly in the event of a threat of natural disaster.
Early measures include: restrictions on the placement of facilities with hazardous industries in areas prone to the effects of hurricanes and storms; dismantling of some obsolete or fragile buildings and structures; strengthening industrial and residential buildings and structures. Preparations are being made for action in a natural disaster.
Operational and protective measures are carried out after receiving a storm warning about the approach of a natural disaster. Operational and protective measures include: forecasting the path of passage and the time of approach of a hurricane (storm) to various regions of the region and its possible consequences; strengthening supervision over the implementation of permanent safety rules; transition of various objects of the economy to a safe mode of operation in conditions of strong wind. A partial evacuation of the population from the areas of the expected natural disaster can be carried out; shelters and basements are being prepared to protect the population.
Notification of the population about the threat of hurricanes and storms is carried out in advance according to the established notification scheme of the RSChS: people are informed about the time of the approach of a natural disaster to a particular area and are given recommendations on actions in a particular situation.
Particular attention is paid to the prevention of those destructions that can lead to the emergence of secondary factors of damage (fires, accidents at hazardous industries, dam breaks, etc.), exceeding in severity the impact of the natural disaster itself.
Measures are taken to prevent the spill of hazardous liquids.
An important area of work to reduce damage is the struggle for the stability of communication lines, power supply networks, wired urban and intercity transport, vulnerable to hurricanes, storms and tornadoes.
When carrying out operational measures in rural areas, along with generally accepted measures, they organize the delivery of feed to farms and complexes, the pumping of water into towers and additional tanks, and the preparation of backup energy sources. Farm animals located in forests are taken to open areas or sheltered in ground structures and natural shelters.
To effectively protect the population from hurricanes, storms and tornadoes, preparations are being made for the use of shelters, basements and other buried structures.
Information about the threat of hurricanes, storms and tornadoes is carried out in advance.
Remember!
Anyone who lives in areas prone to hurricanes and storms needs to be aware of the signs of their approach. This is an increase in wind speed and a sharp drop in atmospheric pressure; heavy rainfall and storm surge from the sea; heavy snowfall and ground dust.
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