What are disasters and how to deal with them. What is a cataclysm? Concept and examples Reporting natural disasters

Destructive tsunami in Asia in 2004 and 2011, Hurricane Katrina in the southeastern part of the United States in 2005, landslides in the Philippines in 2006, an earthquake in Haiti in 2010, floods in Thailand in 2011.. This list can be continued for a long time...

Most natural disasters are a consequence of the laws of nature. Hurricanes, typhoons and tornadoes are the result of various weather phenomena. Earthquakes occur as a result of changes in the earth's crust. Tsunamis are caused by underwater earthquakes.

Typhoon - a type of tropical cyclone, which is typical for the northwestern part of the Quiet Ocean. The word comes from Chinese. The zone of typhoon activity, which accounts for a third of the total number of tropical cyclones on Earth, lies between the coast of East Asia in the west, the equator in the south and the date line in the east. Although a considerable part of typhoons occur from May to November, other months are not free from them.

The typhoon season of 1991 was particularly destructive, as a number of typhoons with a pressure of 870-878 bar raged off the coast of Japan. Typhoons are attributed to the shores of the Russian Far East, in most cases, after Korea, Japan and Ryukyu Islands. The Kuril Islands, Sakhalin, Kamchatka and Primorsky territories are more susceptible to typhoons. Many managed to record the typhoon in Novorossiysk using personal photo and video cameras and mobile phones.

Tsunami. Long, high waves generated by a powerful impact on the entire thickness of water in the ocean or other body of water. Most tsunamis are caused by underwater earthquakes, during which a sharp displacement (raising or lowering) of a section of the seabed occurs. Tsunamis are formed during an earthquake of any strength, but those that arise due to strong earthquakes (with a magnitude greater than 7) reach great strength. As a result of an earthquake, several waves are propagated. More than 80% of tsunamis occur on the periphery of the Pacific Ocean.

Note that most recently the Japanese company Hitachi Zosen Corp has developed a tsunami barrier system that automatically responds to a wave strike. At the moment it is known that barriers will be installed at the entrances to the underground parts of buildings. In the normal state, the metal walls lie on the surface of the earth, but when a wave arrives, under the pressure of the advancing water, they rise and take a vertical position. The height of the fence is only one meter, ITAR-TASS reports. The system is completely mechanical and does not require any external power source. Currently, similar barriers are already in place in a number of coastal cities in Japan, but they are powered by electricity.

Tornado (tornado). A hurricane is an extremely fast and strong movement of air, often of great destructive power and considerable duration. A tornado (tornado) is a vortex horizontal movement of air that occurs in a thundercloud and descends to the surface of the earth in the form of an overturned funnel, the diameter of which is up to hundreds of meters. Typically, the transverse diameter of a tornado funnel in the lower section is 300-400 m, although if the tornado touches the surface of the water, this value can be only 20-30 m, and when the funnel passes over land it can reach 1.5-3 km. The development of a tornado from a cloud distinguishes it from some externally similar and also different in nature phenomena, for example, tornado-vortices and dust (sand) whirlwinds.

Very often, tornadoes occur in the United States. Most recently, on May 19, 2013, about 325 people were injured in a devastating tornado in Oklahoma. Eyewitnesses say with one voice: “We thought we were going to die because we were in the basement. The wind tore the door open and pieces of glass and debris began to fly towards us.” "To be honest, we thought we were going to die." The wind speed reached 300 kilometers per hour, more than 1.1 thousand houses were destroyed.

Earthquakes- tremors and vibrations of the Earth's surface caused by natural causes (usually tectonic processes) or artificial processes (explosions, filling of reservoirs, collapse of underground cavities in mine workings). Small tremors can also be caused by the rise of lava during volcanic eruptions. Every year about a million earthquakes occur throughout the Earth, but most of them are so small that they go unnoticed. Strong destructive earthquakes occur on the planet approximately once every two weeks. Most of them occur at the bottom of the oceans and are not accompanied by catastrophic consequences (unless a tsunami occurs).

In our country, Kamchatka is a particularly seismically active zone. The other day, on May 21, 2013, she again found herself at the epicenter of seismic events. Off the southeastern coast of the peninsula, seismologists recorded a series of earthquakes with magnitudes ranging from 4.0 to 6.4. The sources of the earthquakes lay at a depth of 40-60 kilometers under the seabed. At the same time, the most noticeable tremors were in Petropavlovsk-Kamchatsky. In total, according to experts, more than 20 underground disturbances were registered. Fortunately, there was no threat of a tsunami.

What are disasters and how to deal with them

Many complex natural processes, accompanied by energy transformation, serve as the driving force behind the constant change in the appearance of our planet - its geodynamics. The same processes also cause destructive phenomena on the surface and in the atmosphere of the Earth: earthquakes, volcanic eruptions, tsunamis, floods, hurricanes, etc.

Over the past half century, the number of natural disasters has increased fivefold, and material damage from them has increased tenfold. The reasons for this phenomenon are the rapid growth of population and economy and pronounced degradation of the natural environment. The technogenic impact of man on the lithosphere not only activates the development of natural catastrophic processes, but also leads to the emergence of new ones - already technonatural.

Disaster management is an important element of the government's sustainable development strategy. When developing the concept of “fighting disasters,” it is important to understand that a person is not able to stop or change the course of evolutionary transformations of the planet - he can only predict their development with some degree of probability and sometimes influence their dynamics. Therefore, at present, the tasks of timely forecasting natural disasters and mitigating their negative consequences are coming to the fore.

Natural disasters are sources of profound social upheaval, leading to mass suffering, loss of life and enormous material losses. The increase in the number of natural disasters is based on global processes, such as the growth of the population and economy of earthly civilization, degradation of the natural environment and climate change. Disaster management is an important element of the government's sustainable development strategy. It should be based on the principles of reasonable economic use of territories, forecasting threatening dangers and carrying out preventive measures.

Since ancient times, man has experienced fear of the formidable manifestations of the power of nature. As the history of our civilization shows, many natural disasters were accompanied by major social upheavals. The death of Pompeii in Italy as a result of the eruption of Mount Vesuvius (79 AD) is not the only example of how prosperous cities fell into decay as a result of natural disasters, and then completely disappeared. There are cases when economic losses from natural disasters exceeded the gross national product of individual countries, as a result of which their economies found themselves in a critical condition. For example, the direct damage from the Managua earthquake (1972) alone was equal to twice Nicaragua's annual gross product.

An analysis of historical data shows that the number of natural disasters on Earth is steadily growing: over the last half century alone, the frequency of large-scale disasters has increased fivefold. The associated material losses increased almost tenfold, reaching $190 billion in some years. USA. It is expected that by 2050, socio-economic damage from hazardous natural processes (with the current level of protection) will amount to almost half of the increase in global gross product. In Russia, the average damage from natural and technical disasters is currently about 3% of the gross domestic product.

In the overall problem of security, catastrophic events are considered as one of the most important destabilizing factors that impede the sustainable development of mankind.

But what exactly does this concept mean – natural disasters? What is the mechanism of their origin and development? Is it possible to avoid their destructive consequences? And why, despite continuous scientific and technological progress, humanity continues to feel unprotected?

Destructive Energy

According to the outstanding Soviet natural scientist V.I. Vernadsky, the earth's surface shell cannot be considered as a region of only matter, it is also a region of energy.

Indeed, on the surface of the Earth and in the layers of the atmosphere adjacent to it, many complex processes are taking place, accompanied by the transformation of energy. Among them endogenous processes of reorganization of matter inside the Earth and exogenous interaction of the substance of the outer shell of the earth and physical fields, as well as the impact of solar radiation.

All these processes are the driving force behind the constant transformation of the appearance of our planet - its geodynamics. And they also cause destructive phenomena on its surface and in the atmosphere: earthquakes, volcanic eruptions, tsunamis, floods, hurricanes, etc.

Natural disasters are usually divided into types depending on the medium through which the energy impact occurs - through the earth's surface, air or water elements.

The most terrible of them are, perhaps, earthquakes. Powerful shock waves caused by deep-seated processes lead to ground ruptures, which has a horrific destructive effect on the human environment. The amount of energy released in this case sometimes exceeds 1018 J, which corresponds to the explosion of hundreds of atomic bombs, similar to the one dropped on Hiroshima in 1945.

China suffers the most from earthquakes, where they occur almost every year. For example, back in 1556, a series of powerful seismic shocks killed 0.8 million people (about 1% of the country’s population). Over the past decade alone, about 80 thousand people in China have died, and the total economic damage has exceeded 1.4 trillion yuan.

In Russia in last years The most destructive earthquake was in the north of the island. Sakhalin in May 1995, which completely destroyed the village. Neftegorsk and killed more than 2 thousand people.

But still the most powerful source of energy on our planet is volcanoes. The release of energy during a volcanic eruption can be a hundred times greater than the “contribution” of the strongest earthquake. Every year, as a result of volcanic activity, approximately 1.5 billion tons of deep matter are released into the atmosphere and onto the surface of the Earth.

Currently, there are about 550 historically active volcanoes on Earth (every eighth of them is located on Russian soil). Over the course of history, at least 1 million people in the world have died directly as a result of volcanic activity.

IN late XIX V. One of the largest eruptions of the Krakatoa volcano in Southeast Asia occurred. Millions of cubic meters of volcanic ash released into the atmosphere rose to a height of about 80 km. As a result, the “polar night” began - for several months the entire Earth was plunged into twilight. Direct sunlight did not reach the surface of the planet, so it became sharply colder. This situation was later compared to the phenomenon of “nuclear winter” - a potential consequence of the explosion of a super-powerful thermonuclear bomb on the surface of the Earth.

Last spring, the world experienced another natural disaster - a volcanic eruption in Iceland, which affected the economies of many (especially European) countries.

Two earthquakes of similar magnitude in the 1980s. – in Spitak (Armenia) and San Francisco (California, USA) – had very different consequences. The first killed about 40 thousand people, the second - only 40 (!). The reason is differences in the quality of the building structures used and in the organization of preventive measures.

Earthquakes and volcanic eruptions that occur in bodies of water often lead to tsunami. A wave formed in the open ocean during a volcanic explosion or seismic shock can acquire monstrous destructive power near the shore. The biblical flood and the death of Atlantis are attributed to volcanic eruptions in the Mediterranean Sea, accompanied by a tsunami.

In the 20th century only in Pacific Ocean More than two hundred tsunamis were recorded. In December 2004, a series of large waves hit the northeast coast Indian Ocean, carried away more than 200 thousand. human lives, and economic losses amounted to $10 billion.

The biblical legend of the Flood is often remembered by residents of countries that find themselves in the grip of grandiose floods– flooding of the area as a result of a sharp rise in water levels in rivers, lakes, and reservoirs. Floods are dangerous in themselves and also provoke many other natural disasters - landslides, landslides, mudflows.

One of the most terrible floods happened in 1887 in China, when the water in the river. The Yellow River rose to the height of an eight-story building in a matter of hours. As a result, about 1 million inhabitants of this river valley died.

In the last century, according to UNESCO, 4 million people died as a result of floods. One of the last severe floods occurred in the Czech Republic in the summer of 2002. Water flooded the streets of hundreds of settlements and cities, including Prague, where 17 metro stations were flooded.

Similar major catastrophic events occur in Russia. So, during the spring flood of 1994 on the river. Tobol there was an overflow of water over the protective dam of the city of Kurgan. For two weeks, thousands of residential buildings remained flooded to the rooftops. Seven years later, an even more destructive flood occurred on the river. Lena in Yakutia.

Finally, one cannot fail to mention the raging air elements: cyclones, storms, hurricanes, tornadoes... Every year on globe On average, about 80 catastrophic situations associated with these phenomena occur. Ocean coasts often suffer from tropical cyclones, which hit the continents with hurricane-force air currents at speeds of more than 350 km/h, heavy rainfall (up to 1000 mm over several days) and storm waves up to 8 m high.

Thus, three major destructive hurricanes in the fall of 2005 caused damage to the American continent of 156 billion dollars. Against this background, the hurricanes that swept through Western and Northern Europe at the turn of the millennium look more modest - they caused an order of magnitude fewer losses.

Ubiquitous humanity

One of the main reasons for the increase in the number of victims and material losses as a result of natural disasters is the uncontrollable growth of the human population.

In ancient times, the human population changed little, periods of its growth alternated with periods of decline as a result of mortality from epidemics and famine. Up to early XIX V. The Earth's population did not exceed 1 billion people. However, with the advent of the industrial period of social development, the situation changed dramatically: after 100 years, the population doubled, and by 1975 it exceeded 4 billion people.

The growth of human population is accompanied by the process of urbanization. Thus, if in 1830 the urban part of the planet’s population was just over 3%, then at present at least half of humanity lives compactly in cities. Total number The world's population increases annually by an average of 1.7%, but in cities this growth occurs at a much faster pace (4.0%).

The growth of the planet's population leads to the development of areas unsuitable for human habitation: hill slopes, river floodplains, and wetlands. The situation is often aggravated by the lack of advance engineering preparation of the territories being developed and the use of structurally imperfect buildings for development. As a result, cities increasingly find themselves at the center of devastating natural disasters, where suffering and loss of life are widespread.

The industrial and technological revolution led to global human intervention in the most conservative part of the environment - the lithosphere. Back in 1925, V.I. Vernadsky noted that man, with his scientific thought, creates a “new geological force.” Modern geological human activity has become comparable in scale to natural geological processes. For example, during construction and mining, more than 100 billion tons of rocks are moved per year, which is approximately four times the mass of mineral material carried by all the rivers of the world as a result of land erosion.

Technogenic human impact on the lithosphere leads to significant changes in environment, activating the development of natural and initiating the emergence of new ones - already technonatural– processes. The latter include the subsidence of territories as a result of deep mining of minerals, induced seismicity, flooding, karst-suffusion processes, the emergence of various kinds of physical fields, etc.

Thus, in modern economy Two opposing trends are developing: global gross income is growing, and the life-sustaining resources that constitute “natural capital” (water, soil, biomass, ozone layer) are degrading. This happens because industrial development, designed to serve primarily economic progress, came into conflict with the natural environment, since it ceased to take into account the real limits of the stability of the biosphere.

For example, some of the reasons for the increase in the frequency and severity of floods are deforestation, drainage of wetlands, and soil compaction. Indeed, such “reclamation” effects lead to an acceleration of surface runoff from the catchment into the river bed, so during extreme precipitation or snow melting, the water level in rivers rises sharply.

Into hell?

Many people are concerned about the question - what can we expect in the future? According to biblical revelations, human civilization will be destroyed by fire. Judging by global climate changes over the past 150 years, the movement towards such a “doomsday” can already be considered to have begun.

According to the World Meteorological Organization, the global temperature increase was about 0.8 °C. At the regional level, more contrasting changes are observed. For example, in the northern regions of Russia over the past 30 years, the average annual air temperature has increased by 1.0 °C, which is approximately 2.5 times the rate of the global temperature trend. It should be noted that this difference is mainly due to an increase in average winter temperatures, while in the summer seasons the temperature may even drop slightly.

A number of regions of the world have occasionally experienced extreme heat in the summer over the past decade. Thus, in August 2003, the temperature in some countries Western Europe rose to +40 °C, which caused the death of more than 70 thousand people from heatstroke.

Despite the existence of different points of view on the causes of global climate change, the very fact of warming on Earth is undeniable. A further increase in air temperature can have both positive and negative effects on the natural environment, leading to desertification, flooding and destruction of sea coasts, glaciers coming down from mountains, retreat of permafrost, etc.

The most acute humanitarian problem is the shortage drinking water. Severe droughts have been observed in recent years in Latin America, North Africa, India and Pakistan. It is expected that in the near future the area of ​​territories experiencing acute moisture deficiency will expand significantly. The number of “environmental refugees” continues to grow rapidly.

One of the most serious threats associated with global warming is the melting of the Greenland ice sheet and high mountain glaciers. According to satellite observations, since 1978 the area sea ​​ice in Antarctica is decreasing by an average of 0.27% annually. At the same time, the thickness of the ice fields decreases.

Melting glaciers and thermal expansion of water have led to a rise in sea levels by 17 cm over the past 100 years. Sea levels are expected to rise 5 to 10 times faster in the coming years, resulting in significant financial costs to ensure the safety of low-lying coastal areas. Thus, if the level of the World Ocean rises by half a meter, the Netherlands will need about 3 trillion euros to combat flooding, and in the Maldives, protecting just one linear meter of the coast will cost 13 thousand dollars.

Warming will also be accompanied by degradation of permafrost rocks in the permafrost zone, which makes up a significant part of the territory of our country. It was noted that over the past century, the area of ​​distribution of permafrost soils in the Northern Hemisphere has decreased by 7%, and the maximum freezing depth has decreased by an average of 35 cm. If the current climate trend continues, the boundary of continuous permafrost will move northward by 50-80 km over the decade (Osipov , 2001).

Degradation of the permafrost zone will cause the development of such dangerous processes as thermokarst - the subsidence of the territory as a result of melting ice and the formation of ice dams. This will undoubtedly aggravate the problem of safety of gas and oil industry facilities during the development of mineral resources of the North.

Disaster prevention

Until recently, the efforts of many countries to “reduce the risk” of natural disasters were aimed only at eliminating their consequences, providing assistance to victims, organizing technical and medical services, supplying food, etc. However, there is a steady trend towards an increase in the frequency of catastrophic events and the size of the associated with them the damage makes these measures less and less effective.

When developing the concept of “fighting disasters,” it is important to understand that a person is not able to stop or change the course of evolutionary transformations of the planet - he can only predict their development with some degree of probability and sometimes influence their dynamics. Therefore, experts currently consider new tasks a priority: preventing natural disasters and mitigating their negative consequences.

The central place in the strategy to combat disasters is the problem of assessment risk, i.e. the probability of a catastrophic event and the magnitude of expected human casualties and material losses.

The degree of impact of natural hazards on people and infrastructure is assessed by their vulnerabilities. For people, this is a decrease in the ability to perform their functions due to death, loss of health or injury; for technosphere objects – destruction, destruction or partial damage of objects.

Regulating the development of most natural hazards is a very difficult task. Many natural phenomena, such as earthquakes and volcanic eruptions, cannot be directly controlled at all. But there is many years of positive experience of human influence, in particular, on some hydrometeorological phenomena.

So, in scientific organizations Roshydromet developed technologies for introducing active reagents into cloud fields using rocket, aircraft and ground equipment for the purpose of artificially increasing and redistributing atmospheric precipitation, dispersing fog in the vicinity of airports, and preventing hail damage to agricultural crops. It has become possible to regulate precipitation during man-made disasters. Thus, after the explosion at the Chernobyl nuclear power plant in 1986, rain wash-off of products was prevented radiation pollution into the river network.

Much more often, preventive measures are carried out indirectly, by increasing the resilience and security of both people and infrastructure in relation to natural hazards. Among the most important measures to reduce their vulnerability are the rational use of land, careful engineering preparation of infrastructure facilities and the protection of the territories in which they are located, the organization of warning and emergency response means.

Sections of an apparently homogeneous territory with various geomorphological, hydrogeological, landscape and other conditions respond differently to natural influences. For example, in low-lying areas composed of weak water-saturated soils, the intensity of seismic vibrations may be several times higher than in a neighboring area composed of rocks.

It is obvious that in order to reduce vulnerability and increase security, it is necessary to take a strictly justified and responsible approach to the selection of land plots for the construction of settlements, industrial and civil facilities, elements of life-support systems, etc. To solve this problem, engineering-geological zoning territory, which consists in identifying areas with the same or similar geological characteristics and ranking them according to the degree of suitability for economic development and resistance to the effects of natural and man-made hazards.

A map is also drawn up for earthquake-prone areas seismic microzoning. Its main purpose is to identify zones of different seismic hazards (severities) taking into account all factors influencing the propagation of elastic waves in the geological environment. For example, with the participation of the Institute of Geoecology named after. E.M. Sergeev RAS carried out a similar zoning of the Imereti Lowland on the territory of the Adler region, where a complex of structures for the 2014 Olympic Games is being built.

Natural hazard is an extreme phenomenon in the lithosphere, hydrosphere, atmosphere or space. Natural hazard risk, according to UN terminology, is the expected social and material losses in quantitative terms in a given area over a certain period of time.
Risk assessment is carried out on the basis of data on the likelihood of a natural hazard, its physical parameters, as well as the place and time of occurrence.
If a natural hazard appears in urbanized or economically developed areas and directly affects people and material objects, then implementation risk with all the ensuing consequences.
Vulnerability characterizes the inability of people, as well as elements of the social and material sphere, to resist natural phenomena. Expressed in relative units or percentages.
The risk analysis procedure consists of calculating expected losses in the event of a natural hazard based on its quantitative assessment and determining the magnitude of the vulnerability of risk recipients (people and objects).
In the case where the calculated level of risk turns out to be unacceptable (acceptance criteria are still very subjective), carry out risk management, that is, they take measures to reduce it. Some of them directly affect developing natural hazards, others help reduce the vulnerability of the technosphere and increase human safety

Often there is a need to use land that is obviously unsuitable for construction, for example, areas of sea coasts and river valleys, mountain slopes, areas with karst and subsidence soils. In this case, preventive engineering measures are carried out aimed at increasing the stability of the territories and protecting the structures themselves: they erect solid walls and dams, build drainage systems and spillways, raise the territory by filling the soil, strengthen the soil by compacting it, cementing it and reinforcing it.

A recent example of large-scale protective hydraulic engineering is the construction of a protective dam that blocked part of Gulf of Finland and the mouth of the Neva. The need for such a structure was great, since almost every year, due to the wind surge from the Baltic Sea, the waters of the Neva rose above 1.5 m - the level for which St. Petersburg was designed. This led to flooding of certain areas of the city. Completed in 2009, the dam can withstand water rises of over 4 m, which completely relieves residents from the threat of flooding.

However, protecting the territory and even rational selection of a construction site are not sufficient security conditions. The main cause of death in natural disasters is associated with the collapse of residential and industrial buildings. Therefore, it is necessary to improve design solutions, use more durable materials, as well as diagnose the condition of already constructed buildings and structures and periodically strengthen their structures.

Successful management of natural safety cannot exist without a warning and emergency response system, which includes means of monitoring the development of hazardous processes (means monitoring), prompt transmission and processing of received information, warning the population about impending danger.

Monitoring is the most important link in the forecasting and warning system. Predictive monitoring is intended to organize regular observations of anomalous natural phenomena or geo-indicators reflecting their development. Carrying out such monitoring over a long period of time makes it possible to create data banks and time series of observations, the analysis of which makes it possible to clarify the patterns of the dynamics of a dangerous process, model the cause-and-effect relationships of its development and predict the occurrence of extreme situations.

To mitigate the consequences of “instantly” developing catastrophic processes (for example, earthquakes) in the absence of reliable methods for predicting them, it is advisable to use so-called security monitoring. It adjusts to the extreme phase of a catastrophic event and allows, without human intervention, to automatically take urgent measures to minimize the consequences of a dangerous process just seconds before the critical moment occurs.

Most often, a signal from a security monitoring system is used to disconnect a facility from energy supply systems (gas, electricity), notify personnel, etc. Such systems are installed at particularly critical and dangerous facilities, primarily at nuclear power plants, oil refineries, offshore oil production platforms, and chemical pumping stations. product pipelines, etc.

An example of security monitoring is a seismic safety system based on the use of accelerometers(measuring the magnitude of acceleration) strong movements. It was developed at the Institute of Geoecology named after. E. M. Sergeev RAS and installed on oil production platforms located on the shelf of the island. Sakhalin. Analysis of instrument readings using a special algorithm makes it possible to distinguish between object vibrations caused by seismic and other reasons. Therefore, the system only generates an alarm when a preset threshold intensity level is exceeded and does not respond to other shocks. This eliminates the possibility of a “false alarm.”

In recent decades, dangerous trends have emerged in the development of natural processes, largely due to the growth of the population and economy of earthly civilization. The irreversible increase in the number of catastrophic events, including those of techno-natural origin, puts forward the assessment of natural risks and the development of methods to combat them as an important government priority.

Effective risk management is based on the modern level of knowledge about natural phenomena, the systematic organization of observations of hazardous processes, an adequate culture of economic activity and the adoption of responsible management decisions at different levels of government. A risk management strategy should be implemented in all projects and investment programs related to construction, education, social security, and healthcare.

After a rapid breakthrough into space, humanity again turns its gaze to its common home - planet Earth. Planetary problems in the coming century should occupy an important place among the fundamental and practical tasks, because the future of our civilization largely depends on their solution.

Literature

Global Environmental Outlook (Geo-3): past, present and future prospects / Ed. G. N. Golubev. M.: UNEPCOM, 2002. 504 p.

Osipov V.I. Natural disasters at the turn of the 21st century // Bulletin of the Russian Academy of Sciences. 2001. T. 71, No. 4. P. 291-302.

Natural hazards of Russia: in 6 volumes / edited by. ed. V. I. Osipova, S. Shoigu. M.: Publishing company KRUK, 2000-2003: Natural hazards and society / Ed. V. A. Vladimirova, Yu. L. Vorobyova, V. I. Osipova. 2002. 248 pp.; Seismic hazards / Ed. G. A. Soboleva. 2001. 295 pp.; Exogenous geological hazards / Ed. V. M. Kutepova, A. I. Sheko. 2002. 348 p. ; Geocryological hazards / Ed. L. S. Garagulya, E. D. Ershova. 2000. 316 pp.; Hydrometeorological hazards / Ed. G. S. Golitsyna, A. A. Vasilyeva. 2001. 295 pp.; Assessment and management of natural risks / Ed. A. L. Ragozina. 2003. 320 p.

This article uses photographs of volcanoes from the website www.ngdc.noaa.gov/hazard/volcano.shtml of the Department of Commerce, National Administration Oceanic and Atmospheric Research and the National Environmental Satellite Information Service

Classification of natural disasters. Natural disasters are divided into two types according to their origin:

1. endogenous - associated with the internal energy and forces of the Earth (volcanic eruptions, earthquakes, tsunamis);

2. exogenous - caused by solar energy and activity, atmospheric, hydrodynamic and gravitational processes (hurricanes, cyclones, floods, storms).

Causes of natural disasters. One of the causes of natural disasters is a natural disaster, a natural phenomenon that leads to the destruction of material assets, loss of life and other consequences.

Main types of natural disasters:

1. Geological

· Earthquake

Earthquake - underground tremors and vibrations of the earth's surface, resulting from sudden displacements and ruptures in the earth's crust and upper mantle and transmitted over long distances.

· Eruption

A volcanic eruption is a volcanic activity in which volcanic lava and hot gases burst to the surface. In addition to the direct volcanic eruption, the release of volcanic ash and pyroclastic flows (a mixture of volcanic gases, rocks, and ash) cause great damage.

An avalanche is a mass of snow or ice falling or sliding down steep mountain slopes. Particularly destructive avalanches can completely destroy settlements.

Collapse - separation of masses of rocks from the slope and fast travel down. They arise on the banks of rivers, seas, and in the mountains under the influence of precipitation, seismic shocks, and human activity.

· Landslide

Landslide is the separation of earth masses from a slope and their movement along the slope under the influence of gravity.

Mudflow is a powerful mud, mud-stone or water-stone flow that is formed in the beds of mountain rivers due to sudden floods caused by heavy rains, snowmelt and other reasons.

2. Meteorological

Hail is a type of precipitation in the form of dense ice particles (hailstones) irregular shape different sizes.

Drought is prolonged dry weather, often at elevated air temperatures, with no or very little precipitation, leading to depletion of moisture reserves in the soil and a sharp decrease in relative air humidity.

A blizzard is the transport of snow by the wind over the surface of the earth.

A tornado is an extremely strong atmospheric vortex with air circulation closed around a more or less vertical axis.

A cyclone is an atmospheric vortex with low pressure in the middle and air circulation in a spiral.

3. Hydrological

· Flood

Flood - flooding of an area with water.

Tsunamis are sea waves of very long length that occur during strong underwater and coastal earthquakes, as well as during volcanic eruptions or large rock falls from a coastal cliff.

· Limnological catastrophe

Limnological catastrophe is a rare natural phenomenon in which dissolved in deep lakes carbon dioxide is released to the surface, causing suffocation in wild and domestic animals and people.

4. Fires

· Forest fires

Forest fires are spontaneous or human-caused combustion in forest ecosystems

Peat fires

Peat fires are the burning of a layer of peat and tree roots.

A separate group of causes of natural disasters includes the impact space objects to Earth: collision with asteroids, falling meteorites. They pose a great threat to the planet, since even a small celestial body can cause devastating damage when colliding with the Earth.

In this work, we will determine how natural disasters affect the climate of planet Earth, therefore we consider it necessary to define this phenomenon and its main manifestations (types):

The term natural disasters is used to describe two different concepts that, in a sense, overlap. Catastrophe literally means a turn, a restructuring. This meaning corresponds to the most general idea of ​​catastrophes in natural science, where the evolution of the Earth is seen as a series of different catastrophes that cause a change in geological processes and species of living organisms.

Interest in catastrophic events of the past is fueled by the fact that an inevitable part of any forecast is analysis of the past. The older the disaster, the more difficult it is to recognize its traces.

Lack of information always gives rise to fantasies. Some researchers explain the same sharp milestones and turns in the history of the Earth by cosmic reasons - meteorite falls, changes solar activity, the seasons of the galactic year, others - the cyclicality of processes taking place in the bowels of the planet

The second concept - natural disasters - refers only to extreme natural phenomena and processes that result in the death of people. In this understanding, natural disasters are contrasted with man-made disasters, i.e. those caused directly by human activity

Main types of natural disasters

Earthquakes are underground shocks and vibrations of the Earth's surface caused by natural causes (mainly tectonic processes). In some places on Earth, earthquakes occur frequently and sometimes reach great strength, disrupting the integrity of the soil, destroying buildings and causing casualties.

The number of earthquakes recorded annually around the globe amounts to hundreds of thousands. However, the overwhelming majority of them are weak, and only a small proportion reaches the level of catastrophe. Until the 20th century known, for example, are such catastrophic earthquakes as the Lisbon earthquake in 1755, the Vernenskoye earthquake in 1887, which destroyed the city of Verny (now Alma-Ata), the earthquake in Greece in 1870-73, etc.

By its intensity, i.e. According to the manifestation on the Earth's surface, earthquakes are divided, according to the international seismic scale MSK-64, into 12 gradations - points.

The area where an underground shock occurs - the source of an earthquake - is a certain volume in the thickness of the Earth, within which the process of releasing energy that has been accumulating for a long time occurs. In a geological sense, a source is a rupture or a group of ruptures along which almost instantaneous mass movement occurs. In the center of the outbreak there is a point called the hypocenter. The projection of the hypocenter onto the Earth's surface is called the epicenter. Around it there is an area of ​​greatest destruction - the pleistoseist region. Lines connecting points with the same intensity of vibrations (in points) are called isoseists.

Flood - significant flooding of an area with water as a result of a rise in water level in a river, lake or sea caused by for various reasons. Flooding on a river occurs from a sharp increase in the amount of water due to the melting of snow or glaciers located in its basin, as well as as a result of heavy rainfall. Flooding is often caused by an increase in the water level in the river due to blockage of the riverbed with ice during ice drift (jam) or due to clogging of the riverbed under a stationary ice cover with accumulations of inland ice and the formation of an ice plug (jag). Floods often occur under the influence of winds, driving water from the sea and causing an increase in the level due to the retention of water brought by the river at the mouth. Floods of this type were observed in Leningrad (1824, 1924) and the Netherlands (1952).

On sea coasts and islands, floods can occur as a result of flooding of the coastal strip by waves generated by earthquakes or volcanic eruptions in the ocean (tsunami). Similar floods are not uncommon on the shores of Japan and other Pacific islands. Floods can be caused by breaches of dams and protective dams. Floods occur on many rivers in Western Europe - the Danube, Seine, Rhone, Po, etc., as well as on the Yangtze and Yellow Rivers in China, the Mississippi and Ohio in the USA. In the USSR, large N. were observed on the river. Dnieper and Volga.

Hurricane (French ouragan, from Spanish huracan; the word is borrowed from the language of the Caribbean Indians) is a wind of destructive force and significant duration, the speed of which is over 30 m/sec (12 points on the Beaufort scale). Tropical cyclones, especially those that occur in the Caribbean Sea, are also called hurricanes.

Tsunami (Japanese) - marine gravity waves of very long length, resulting from the upward or downward displacement of extended sections of the bottom during strong underwater and coastal earthquakes and, occasionally, as a result of volcanic eruptions and other tectonic processes. Due to the low compressibility of water and the rapid process of deformation of sections of the bottom, the column of water resting on them also shifts without having time to spread, as a result of which some elevation or depression is formed on the surface of the ocean. The resulting disturbance turns into oscillatory movements of the water column - tsunami waves propagating at high speed (from 50 to 1000 km/h). The distance between adjacent wave crests varies from 5 to 1500 km. The height of waves in the area of ​​their occurrence varies between 0.01-5 m. Near the coast it can reach 10 m, and in areas with unfavorable relief (wedge-shaped bays, river valleys, etc.) - over 50 m.

About 1000 cases of tsunamis are known, more than 100 of them with catastrophic consequences, causing complete destruction, washing away of structures and soil and vegetation cover. 80% of tsunamis occur on the periphery of the Pacific Ocean, including the western slope of the Kuril-Kamchatka Trench. Based on the patterns of tsunami occurrence and propagation, the coast is divided into zones according to the degree of threat. Measures for partial protection from tsunamis: creation of artificial coastal structures (breakwaters, breakwaters and embankments), planting forest strips along the ocean shores.

Drought is a prolonged and significant lack of precipitation, often at elevated temperatures and low air humidity, as a result of which moisture reserves in the soil dry up, which leads to a decrease or loss of crops. The onset of drought is usually associated with the establishment of an anticyclone. The abundance of solar heat and dry air create increased evaporation (atmospheric drought), and soil moisture reserves are depleted without replenishment by rain (soil drought). During drought, the flow of water into plants through the root systems is hampered, the moisture consumption for transpiration begins to exceed its influx from the soil, the water saturation of tissues decreases, and the normal conditions of photosynthesis and carbon nutrition are disrupted. Depending on the time of year, spring, summer and autumn droughts are distinguished. Spring droughts are especially dangerous for early grain crops; summer ones cause severe damage to both early and late grain and other annual crops, as well as fruit plants; autumn ones are dangerous for winter crop seedlings. The most destructive are spring-summer and summer-autumn droughts. Most often, droughts are observed in the steppe zone, less often in the forest-steppe zone: 2-3 times a century droughts occur even in the forest zone. The concept of drought is not applicable to areas with rainless summers and extremely low precipitation, where agriculture is possible only with artificial irrigation (for example, the Sahara, Gobi deserts, etc.).

To combat droughts, a set of agrotechnical and reclamation measures are used, aimed at enhancing the water-absorbing and water-retaining properties of the soil and retaining snow in the fields. Of the agrotechnical control measures, the most effective is basic deep plowing, especially in soils with a highly compacted subsoil horizon (chestnut, solonetz, etc.)

Landslides are the sliding movement of rock masses down a slope under the influence of gravity. Landslides occur in any part of a slope or slope due to an imbalance of rocks caused by: an increase in the steepness of the slope as a result of erosion by water; weakening of the strength of rocks due to weathering or waterlogging by precipitation and groundwater; exposure to seismic shocks; construction and economic activities carried out without taking into account the geological conditions of the area (destruction of slopes by road excavations, excessive watering of gardens and vegetable gardens located on slopes, etc.). Most often, landslides occur on slopes composed of alternating water-resistant (clayey) and aquiferous rocks (for example, sand-gravel, fractured limestone). The development of a landslide is facilitated by such occurrence when the layers are inclined towards the slope or are crossed by cracks in the same direction. In highly moist clayey rocks, landslides take the form of a stream. In terms of plan, landslides often have the shape of a semicircle, forming a depression in the slope, called a landslide circus. Landslides cause great damage to agricultural land, industrial enterprises, populated areas, etc. To combat landslides, bank protection and drainage structures are used, slopes are secured with driven piles, planting vegetation, etc.

Volcanic eruptions. Volcanoes are geological formations that arise above channels and cracks in the earth's crust, through which lavas, hot gases and rock fragments erupt onto the earth's surface from deep magmatic sources. Typically, volcanoes represent individual mountains composed of products of eruptions. Volcanoes are divided into active, dormant and extinct. The first include: those that are currently erupting constantly or periodically; about the eruptions of which there is historical data; there is no information about eruptions, but which release hot gases and water (solfatar stage). Dormant volcanoes include those whose eruptions are unknown, but they have retained their shape and local earthquakes occur beneath them. Extinct volcanoes are severely destroyed and eroded without any manifestations of volcanic activity.

Eruptions can be long-term (over several years, decades and centuries) and short-term (measured in hours). Precursors of an eruption include volcanic earthquakes, acoustic phenomena, changes magnetic properties and the composition of fumarolic gases and other phenomena. An eruption usually begins with increased emissions of gases, first along with dark, cold lava fragments, and then with hot ones. These emissions are in some cases accompanied by an outpouring of lava. The height of the rise of gases, water vapor, saturated with ash and lava fragments, depending on the strength of the explosions, ranges from 1 to 5 km (during the Bezymianny eruption in Kamchatka in 1956 it reached 45 km). The ejected material is transported over distances from several to tens of thousands of km. The volume of ejected debris sometimes reaches several km3. The eruption is an alternation of weak and strong explosions and outpourings of lava. Explosions of maximum force are called climactic paroxysms. After them, the force of the explosions decreases and the eruptions gradually cease. The volume of erupted lava is up to tens of km3.

climate natural disaster atmosphere

Natural disasters were also described in the distant past, for example, the “global flood” described in the Bible. Floods occur quite often and can become truly global. For example, a flood in 1931 on the Yangtze River in China flooded an area of ​​300 thousand km², and in some areas the water remained for four months.

The destruction of the cities of Sodom and Gomorrah described in the Bible, according to scientists, resembles a natural phenomenon - an earthquake. Researchers of Atlantis are inclined to believe that the island was also flooded as a result of an earthquake. During the eruption of Mount Vesuvius, the cities of Herculaneum and Pompeii were buried under a layer of ash. The resulting tsunami can be a consequence of earthquakes and volcanic eruptions. The eruption of the Krakatoa volcano in 1833 was accompanied by an earthquake. As a result, a tidal wave was formed that reached the shores of the islands of Java and Sumatra. The death toll was about 300 thousand people.
Natural disasters claim about 50 thousand human lives every year. Since 1970, statistics have been updated with new data. During the 1988 American earthquake, various estimates, between 25 and 50 thousand people died. Nine out of ten natural disasters belong to four types. Floods account for 40%, tropical cyclones - 20%, earthquakes and droughts - 15%. Tropical cyclones take the leading place in the number of victims. Floods cause great material damage. According to R. Cates, the annual damage caused by natural disasters to the global economy is about 30 billion US dollars.

Natural disasters are natural processes that have destructive power, causing injuries and death.
To study natural disasters, it is necessary to know the nature of each of them. Natural disasters in the form of a tropical cyclone carry the danger of extreme action of all its elements: rain, wind, waves, storm surges. Storm surges are the most destructive.
In 1970, a tropical cyclone in the northern Bay of Bengal caused sea levels to rise by six meters. This led to flooding. As a result of the devastating hurricane and the resulting flooding, about 300 thousand people died, and agriculture suffered $63 million in damage. 60% of the population, mostly fishermen, were killed, and 65% of fishing vessels were destroyed. The consequences of the disaster affected the supply of protein food to the entire region.

Tropical cyclones are a seasonal phenomenon. On average, up to 110 incipient hurricanes are tracked by satellites per year over the Atlantic. But only 10-11 of them will grow to gigantic sizes. It is necessary to predict the onset of a tropical cyclone in time to protect people. Hurricanes are first identified and then tracked by satellites. If a hurricane threat is detected, its path and speed are predicted. The speed and direction of a tropical cyclone can be determined at a distance of 300 kilometers by radar. It is important to identify the area of ​​coastline where storm surge may begin, as well as the signs of a tornado. Weather services keep the public informed of the location and characteristics of the cyclone.
Floods are natural disasters that result in inundation of coastal areas. The initial stage of flooding begins with the overflow of the riverbed and water overflowing its banks. Flooding is the most common natural phenomenon. Floods can occur on permanent and temporary watercourses, but even where there have never been rivers or lakes, for example in areas where heavy rainfall occurs.
Floods affect densely populated areas of the Earth: China, India, Bangladesh. Floods in China occur in the valleys of the Yellow and Yangtze rivers. Despite centuries of experience and hundreds of dams, the population of these areas are still victims of floods. Severe floods in the lower reaches of the Yangtze River in the 20th century led to 60 million people suffering from famine. During the flood in 1911, 100 thousand people died.

Floods still pose a big threat today. After heavy rainfall in 1952, the English resort town of Lynmouth was flooded. The flood destroyed buildings, flooded streets, and uprooted trees. A large number of people holidaying in Lynmouth were cut off from solid ground. The next day, the dam broke and 34 people died.

There is an inverse relationship between property damage due to flooding and the number of victims. Countries that have something to lose have all the means to prevent or mitigate the effects of flooding. Conversely, pre-industrial countries suffer more property damage, but do not have the necessary means to prevent a disaster and save people. Flooding may result in outbreaks of infectious diseases. To combat flooding, dams and dams are built, reservoirs are built to collect flood waters, and river beds are deepened.
Earthquakes are natural disasters caused by a sudden release of energy earth's bowels into the form of shock waves and vibrations. An earthquake is dangerous due to direct and secondary effects. Direct manifestations, due to seismic waves and tectonic movements, cause soil displacement. Secondary effects cause subsidence and soil compaction. As a result of secondary effects, cracks form on the earth's surface, tsunamis, avalanches, and fires. A powerful earthquake is always accompanied by a large number of casualties and material losses. According to statistics, greatest number Those affected by this disaster were in China, the USSR, Japan, and Italy. Approximately 14 thousand people die from earthquakes every year. Destruction zones from the epicenter of an earthquake can be several tens or hundreds of kilometers away. For example, the epicenter of the earthquake that occurred in Mexico in 1985 was in the Pacific Ocean, near the city of Acapulco. But despite this, it was so powerful that a significant part of the country was affected, especially the capital of Mexico, Mexico City. On the Richter scale, the force of the tremors reached 7.8. Located 300 kilometers from the epicenter, about 250 buildings were destroyed in Mexico City and 20 thousand people were injured. The devastation zone during the earthquake in Guatemala extended 60 kilometers from the epicenter. The ancient capital of Antigua was completely destroyed, 23 thousand people died, 95% of populated areas were destroyed.

Predicting natural disasters is very difficult. On this moment scientists can predict powerful seismic tremors, but cannot indicate exact time. But there have been cases when scientists were able to accurately predict an earthquake. In the Chinese province of Liaoning in 1974, local residents noticed signs of tectonic activity. The area was under constant monitoring by geologists, who, after the first tremors on February 1, 1975, were able to predict the possibility of a devastating earthquake. The authorities took measures to evacuate the population, and four days later an earthquake began, resulting in damage to 90% of the buildings. According to expert forecasts, the number of victims could reach 3 million people, but thanks to the measures taken big casualties managed to avoid.

Up to 2 billion people continue to live in earthquake-prone areas. A radical measure to preserve the life and health of people is resettlement from seismically active zones.
Volcanic eruptions are natural disasters that have caused the death of 200 thousand people over 500 years. Until now, millions of people live in close proximity to volcanoes. On the island of Martinique in 1902, during a volcanic eruption, the city of Saint-Pierre, which was located 8 kilometers from the Mont Pelee volcano, was destroyed. The death toll was about 28 thousand people. This is almost the entire population of the city of Saint-Pierre. The activity of this volcano was already noted in 1851, but then there were no casualties or destruction. Experts predicted 12 days before the start of the eruption that this eruption would be similar to the previous one, so none of the residents attached great importance to the beginning of the approaching disaster.

In 1985, the Ruiz volcano in Colombia “awakened”. This volcanic eruption resulted in a huge number of casualties and property damage. The city of Amero, which was located 40 kilometers from Ruiz, suffered the most. Molten lava and gases melted the ice and snow on the top of the mountain, thereby causing a mudslide that completely destroyed the city. 15 thousand people, residents of the city of Amero, died. 20 thousand hectares of agricultural plantations, roads were destroyed, and other settlements were destroyed. The total number of deaths was 25 thousand people, about 200 thousand were injured.
Natural disasters in the form of volcanic activity cause as much damage as in previous centuries. However, scientists were able to establish the size of the zones of influence of volcanoes. The lava flow spreads over a distance of up to 30 kilometers when major eruptions. Acidic and hot gases pose a threat within a radius of several kilometers. Acid rain, which spreads over a distance of up to 400-500 kilometers, causes burns in people and poisons vegetation and soil.

Natural disasters must be studied in order to develop a system of measures to protect human health and prevent mass casualties. Engineering-geographical zoning of natural disaster zones is of great importance.