Subject: General concepts of dangerous and emergency situations of a natural nature.
Lesson topic: Natural phenomena and their classification.
The purpose of the lesson: To acquaint students with natural phenomena and their diversity.
Lesson objectives:
I. Educational tasks:
- Recall and consolidate knowledge about the shells of the Earth.
- To form students' knowledge that the formation of any natural phenomenon is associated with the processes occurring in the Earth's shells.
- To give a general idea to students about the types of natural phenomena at the place of their occurrence.
II. development tasks.
- To develop in students the ability and ability to foresee the natural phenomena of their area, which can lead to serious consequences, as well as ways to protect against them.
III. educational tasks.
- To instill in students the belief that any natural phenomenon of destructive power brings huge damage to the state of various types, primarily material and loss of life. Therefore, the state needs to send funds to scientific institutions so that they deal with this problem and be able to predict them in the future.
During the classes
Teacher: Today, children, we will talk about natural phenomena and their diversity. Of course, you know some, some you learned from the course of natural history and geography, and if someone is interested in the media, then from there. If you turn on the TV, radio or use the Internet, then we can say with confidence that natural phenomena of destructive power are occurring more and more often, and their strength is becoming greater. Therefore, we need to know what natural phenomena occur, where they occur most often and how to protect ourselves from them.
Teacher: And so let's remember from the course of geography what shells of the Earth exist.
In total, 4 shells of the Earth are distinguished:
- Lithosphere - it includes the earth's crust and the upper part of the mantle.
- The hydrosphere is a water shell, it includes all water in different states.
- The atmosphere is a gas shell, the lightest and most mobile.
- The biosphere is the sphere of life, it is the area of existence of all living organisms.
Teacher: In all these shells, certain processes take place, as a result of which natural phenomena arise. Therefore, various natural phenomena can be divided according to the place of their occurrence:
Teacher: From this diagram, we see how many natural phenomena exist. Now let's look at each of them and find out what they are. (Children should take an active part in this part.)
Geological.
1. An earthquake is a natural phenomenon associated with geological processes occurring in the Earth's lithosphere, it manifests itself in the form of tremors and vibrations of the earth's surface resulting from sudden displacements and ruptures in the earth's crust or in the upper part of the mantle.
Picture 1.
2. A volcano is a conical mountain, from which an incandescent substance, magma, erupts from time to time.
A volcanic eruption is the release of molten matter from the earth's crust and mantle, which is called magma, to the surface of the planet.
Figure 2.
3. A landslide is a downward displacement of soil masses under the action of gravity, which occurs on slopes when the stability of the soil or rocks is disturbed.
The formation of landslides depends on various factors such as:
- what rocks make up this slope;
- slope steepness;
- ground water, etc.
Landslides can occur both naturally (eg earthquake, heavy rainfall) and man-made (eg human activities: deforestation, excavation).
Figure 3
4. Collapse is the separation and fall of large masses of rocks, their overturning, crushing and rolling on steep and steep slopes.
Causes of landslides in the mountains can be:
- the rocks that make up the mountains are layered or broken by cracks;
- water activity;
- geological processes (earthquake), etc.
Causes of collapses on the coast of seas and rivers are the washing and dissolution of the underlying rocks.
Figure 4
5. An avalanche is a collapse of a mass of snow on mountain slopes, the slope angle must be at least 15 °.
The causes of an avalanche are:
- earthquake;
- intensive snow melting;
- prolonged snowfall;
- human activity.
Figure 5
Meteorological.
1. A hurricane is a wind whose speed exceeds 30 m/s, resulting in huge destruction.
Figure 6
2. A storm is a wind, but with a lower speed than in a hurricane and is no more than 20 m/s.
Figure 7
3. A tornado is an atmospheric vortex that forms in a thundercloud and descends, has a funnel or sleeve head start.
A tornado consists of a core and a wall. Around the core there is an upward movement of air, the speed of which can reach 200 m / s.
Figure 8
Hydrological.
1. Flooding is a significant flooding of the area as a result of a rise in the water level in a lake, river, etc.
Reasons for the flood:
- intensive snowmelt in spring;
- heavy rainfall;
- blockage of the river bed with rocks during an earthquake, collapse, etc., as well as ice during traffic jams;
- wind activity (water surge from the sea, bay at the mouth of the river).
Types of floods:
Figure 9
2. Mudflow is a turbulent stream in the mountains of a temporary nature, consisting of water and a large number of rock fragments.
The formation of mudflows is associated with abundant precipitation in the form of rain or intense snowmelt. As a result, loose rocks are washed away and move along the river bed at high speed, which picks up everything in its path: boulders, trees, etc.
Figure 10.
3. Tsunami is a type of sea waves resulting from the vertical shift of large areas of the seabed.
A tsunami occurs as a result of:
- earthquakes;
- underwater volcano eruptions;
- landslides, etc.
Figure 11.
Biological.
1. A forest fire is an uncontrolled burning of vegetation, spontaneously spreading through a forest area.
Forest fire can be: grassroots and riding.
An underground fire is the burning of peat in marshy and swampy soils.
Figure 12.
2. An epidemic is the spread of an infectious disease among a large number of the population and significantly exceeds the incidence rate usually recorded in the area.
Figure 13.
3. An epizootic is a widespread infectious disease among animals (for example: foot-and-mouth disease, swine fever, bovine brucellosis).
Figure 14.
4. Epiphytotics is a mass spread of an infectious disease among plants (for example: late blight, wheat rust).
Figure 15.
Teacher: As you can see, in the world there are a huge number of phenomena that surround us. So let's remember them and be extremely careful at the time of their occurrence.
Some of you may say: “Why do we need to know all of them if they are not typical for our region?”. From one point of view you are right, but from another point you are wrong. Each of you tomorrow, the day after tomorrow or in the future will surely go on a trip to other parts of the Motherland and the country. And there, as you know, there can be completely different phenomena that are not typical for our area. And then your knowledge will help you survive in a critical situation and avoid negative consequences. As the saying goes: "God saves the safe."
Literature.
- Smirnov A.T. Fundamentals of life safety. 7th grade.
- Shemanaev V.A. Pedagogical practice in the system of modern teacher training.
- Smirnov A.T. The program of educational institutions of the basics of life safety grades 5-11.
natural catastrophic danger emergency
On the territory of Russia there are more than 30 natural hazards and processes, among which the most destructive are floods, storm winds, downpours, hurricanes, tornadoes, earthquakes, forest fires, landslides, mudflows, snow avalanches. Most of the social and economic losses are associated with the destruction of buildings and structures due to insufficient reliability and protection from natural hazards. The most frequent on the territory of Russia are natural catastrophic atmospheric phenomena - storms, hurricanes, tornadoes, squalls (28%), followed by earthquakes (24%) and floods (19%). Dangerous geological processes, such as landslides and collapses account for 4%. The remaining natural disasters, among which forest fires have the highest frequency, total 25%. The total annual economic damage from the development of the 19 most dangerous processes in urban areas in Russia is 10-12 billion rubles. in year.
Of the geophysical extreme events, earthquakes are one of the most powerful, terrible and destructive natural phenomena. They arise suddenly, it is extremely difficult, and most often impossible, to predict the time and place of their appearance, and even more so to prevent their development. In Russia, zones of increased seismic hazard occupy about 40% of the total area, including 9% of the territory belong to 8-9-point zones. More than 20 million people (14% of the country's population) live in seismically active zones.
Within the seismically dangerous regions of Russia, there are 330 settlements, including 103 cities (Vladikavkaz, Irkutsk, Ulan-Ude, Petropavlovsk-Kamchatsky, etc.). The most dangerous consequences of earthquakes are the destruction of buildings and structures; fires; releases of radioactive and emergency chemically hazardous substances due to the destruction (damage) of radiation and chemically hazardous facilities; transport accidents and disasters; defeat and loss of life.
A striking example of the socio-economic consequences of strong seismic events is the Spitak earthquake in Northern Armenia, which occurred on December 7, 1988. This earthquake (magnitude 7.0) affected 21 cities and 342 villages; 277 schools and 250 healthcare facilities were destroyed or were in emergency condition; more than 170 industrial enterprises ceased to function; about 25 thousand people died, 19 thousand received various degrees of mutilation and injury. The total economic losses amounted to $14 billion.
Of the geological emergency events, landslides and mudflows are of great danger due to the massive nature of the distribution. The development of landslides is associated with the displacement of large masses of rocks along the slopes under the influence of gravitational forces. Precipitation and earthquakes contribute to the formation of landslides. In the Russian Federation, from 6 to 15 emergencies associated with the development of landslides are created annually. Landslides are widespread in the Volga region, Transbaikalia, the Caucasus and Ciscaucasia, Sakhalin and other regions. Urbanized areas are especially hard hit: 725 Russian cities are subject to landslides. Mudflows are powerful streams, saturated with solid materials, descending through mountain valleys at great speed. Mudflows are formed with rainfall in the mountains, intensive melting of snow and glaciers, as well as breakthrough of dammed lakes. Mudflow processes are manifested in 8% of the territory of Russia and develop in the mountainous regions of the North Caucasus, in Kamchatka, the Northern Urals and the Kola Peninsula. Under the direct threat of mudflows in Russia there are 13 cities and 42 more cities are located in potentially mudflow-prone areas. The unexpected nature of the development of landslides and mudflows often leads to the complete destruction of buildings and structures, accompanied by casualties and large material losses. Of the hydrological extreme events, floods can be one of the most common and dangerous natural phenomena. In Russia, floods rank first among natural disasters in terms of frequency, distribution area, material damage, and second after earthquakes in terms of the number of victims and specific material damage (damage per unit area affected). One severe flood covers an area of the river basin of about 200 thousand km2. On average, up to 20 cities are flooded every year and up to 1 million inhabitants are affected, and in 20 years almost the entire territory of the country is covered by serious floods.
On the territory of Russia, from 40 to 68 crisis floods occur annually. The threat of floods exists for 700 cities and tens of thousands of settlements, a large number of economic facilities.
Floods are associated with significant material losses every year. In recent years, two major floods have occurred in Yakutia on the river. Lena. In 1998, 172 settlements were flooded here, 160 bridges, 133 dams, 760 km of roads were destroyed. The total damage amounted to 1.3 billion rubles.
Even more devastating was the flood in 2001. During this flood, the water in the river. Lene rose to 17 m and flooded 10 administrative districts of Yakutia. Lensk was completely flooded. About 10,000 houses were under water, about 700 agricultural and more than 4,000 industrial facilities were damaged, and 43,000 people were resettled. The total economic damage amounted to 5.9 billion rubles.
A significant role in increasing the frequency and destructive power of floods is played by anthropogenic factors - deforestation, irrational agriculture and economic development of floodplains. The formation of floods can be caused by improper implementation of flood protection measures, leading to the breakthrough of dams; destruction of artificial dams; emergency discharges of reservoirs. The aggravation of the problem of floods in Russia is also associated with the progressive aging of fixed assets of the water sector, the placement of economic facilities and housing in flood-prone areas. In this regard, the development and implementation of effective flood prevention and protection measures may be an urgent task.
Among the atmospheric hazardous processes occurring on the territory of Russia, the most destructive are hurricanes, cyclones, hail, tornadoes, heavy rains, snowfalls.
Traditional in Russia is such a disaster as a forest fire. Every year, from 10 to 30 thousand forest fires occur in the country on an area of 0.5 to 2 million hectares.
Hazardous natural phenomena include all those that deviate the state of the natural environment from the range that is optimal for human life and for their economy. They represent catastrophic processes of endogenous and exogenous origin: earthquakes, volcanic eruptions, floods, avalanches and mudflows, as well as landslides, soil subsidence.
In terms of the size of the one-time damage of the impact, hazardous natural phenomena vary from minor to those that create natural disasters.
A natural disaster is any unavoidable terribly destructive natural phenomenon that causes economic damage and poses a threat to the health and life of people. When it comes to measuring losses, the term is used - an emergency situation (ES). In emergencies, first of all, absolute losses are measured - for a quick response, to decide on the necessary external assistance to the affected area, etc.
Catastrophic earthquakes (9 points or more) cover the areas of Kamchatka, the Kuril Islands, Transcaucasia and a number of other mountainous regions. In such areas, engineering construction, as a rule, is not carried out.
Strong (from 7 to 9 points) earthquakes occur in a territory stretching in a wide strip from Kamchatka to, including the Baikal region, etc. Only earthquake-resistant construction should be carried out here.
Most of the territory of Russia belongs to the zone in which earthquakes of small magnitude are extremely rare. So, in 1977, shocks of magnitude 4 were registered in Moscow, although the epicenter of the earthquake itself was in the Carpathians.
Despite the great work done by scientists in seismic hazard prediction, earthquake prediction is a very difficult problem. To solve it, special maps, mathematical models are built, a system of regular observations is organized using seismic instruments, a description of past earthquakes is compiled based on a study of a complex of factors, including the behavior of living organisms, analyzing their geographical distribution.
The most effective ways to deal with floods are flow regulation, as well as the construction of protective dams and dams. So, the length of dams and dikes is more than 1800 miles. Without this protection, 2/3 of its territory would be flooded every day by the tide. A dam was built to protect against floods. The peculiarity of this implemented project lies in the fact that it requires high-quality wastewater treatment of the city and the normal functioning of culverts in the dam itself, which was not provided for in the dam design in due measure. The construction and operation of such engineering facilities also require an assessment of possible environmental consequences.
Floods - an annual recurring seasonal long and significant increase in the water content of rivers, which are accompanied by an increase in the water level in the channel and flooding of the floodplain - one of the main causes of floods.
Large floodplain floods during floods are observed in most of the territory of the CIS, and in Eastern Europe.
sat down — mud or mud-stone streams that suddenly appear in the channels of mountain rivers and are characterized by a sharp short-term (1-3 hours) rise in the water level in the rivers, undulating movement and the absence of a complete periodicity. Mudflow can occur when heavy rains fall, intense melting of snow and ice, less often as a result of volcanic eruptions, breakthroughs of mountain lakes, as well as as a result of human economic activity (blasting, etc.). The prerequisites for the formation are: a cover of slope deposits, significant slopes of mountain slopes, increased soil moisture. According to the composition, mud-stone, water-stone, mud and water-grown mudflows are distinguished, in which the content of solid material ranges from 10-15 to 75%. Separate fragments carried by mudflows weigh more than 100-200 tons. The speed of mudflows reaches 10 m/s, and the volume is hundreds of thousands, and sometimes even millions of cubic meters. Having a large mass and speed of movement, mudflows often bring destruction, acquiring the nature of a natural disaster in the most catastrophic cases. So, in 1921, a catastrophic mudflow destroyed Alma-Ata, killing about 500 people. At present, this city is reliably protected by an anti-mudflow dam and a complex of special engineering structures. The main measures to combat mudflows are associated with fixing the vegetation cover on the mountain slopes, with the preventive descent of mountains that threaten to break through, with the construction of dams and various mudflow protection structures.
Avalanches — masses of snow falling down steep mountain slopes. Especially often avalanches descend in cases where snow masses form ramparts or snow cornices hanging over the underlying slope. Avalanches occur when snow stability is disturbed on a slope under the influence of heavy snowfalls, intense snowmelt, rain, non-crystallization of the snow mass with the formation of a weakly connected deep horizon. Depending on the nature of the movement of snow along the slopes, there are: axial - snow landslides sliding along the entire surface of the slope; flume avalanches - moving along hollows, logs and erosion furrows, jumping from ledges. When leaving the dry snow, a destructive air wave propagates ahead. Avalanches themselves also have enormous destructive power, since their volume can reach 2 million m 3, and the impact force is 60-100 t/m2. Usually, avalanches, although with varying degrees of constancy, are confined year after year to the same places - foci of different sizes and configurations.
To combat avalanches, protection systems have been developed and are being created that provide for the placement of snow shields, the prohibition of felling and forest planting on avalanche-prone slopes, the shelling of dangerous slopes with artillery, the construction of avalanche ramparts and ditches. The fight against avalanches is very difficult and requires large material costs.
In addition to the catastrophic processes described above, there are also such as collapse, landslide, sinking, subsidence, destruction of coasts, etc. All these processes lead to the movement of matter, often on a large scale. The fight against these phenomena should be aimed at weakening and preventing (where possible) the processes that cause a negative impact on the stability of engineering structures that endanger people's lives.
Natural disasters by nature of origin are very diverse. Despite this, natural disasters have some common patterns. Here are some of them.
The first pattern of natural hazards is that they can never be completely eliminated. This is due to the fact that mankind constantly uses the environment as a source of its existence and development.
The second pattern of natural hazards is revealed when analyzing the development of a geographical system: the total number of extreme events leading to the occurrence of natural disasters is constantly increasing (for example, the increase in natural disasters in the Russian Federation in 1997 compared to 1996 was 29.7%) . At the same time, the destructive power and intensity of most natural disasters are growing, as well as the number of victims, the moral and material damage caused by them (Table 3.1). As can be seen from the table, in the north of Eurasia, the greatest danger is
floods (746 cities affected), landslides and collapses (725), earthquakes (103), tornadoes (500).
The total annual socio-economic damage from the development of the 21 most dangerous processes in Russia, according to expert estimates, is about 15-19 billion rubles.
The third regularity is connected with the second and is manifested in the ever-increasing general sensitivity of the world community to natural disasters. Increasing “sensitivity” means that the community is devoting more and more resources to the preparation and implementation of various global organizational and technical measures, as well as to the manufacture of protective devices and the construction of protective structures.
The fourth regularity makes it possible to identify the main general factors, without which it is impossible to reliably predict material damage and the number of victims in any natural disasters. These include the historical and social conditions in society that have developed by the time of the forecast; level of economic development and geographic location of disaster areas; determining the conditions of land landscaping and their prospects; the possibility of a negative combination with other natural processes, etc.
The fifth pattern is that for any type of natural disasters, spatial confinement can be established.
The sixth regularity makes it possible to link the strength and intensity of a natural disaster with its frequency and recurrence: the greater the intensity of a natural disaster, the less often it recurs with the same force.
These patterns are confirmed by the growth dynamics of hazardous natural phenomena over the past 5 years (Table 3.29.
As can be seen from the table, with fluctuations in the number of natural hazards characteristic of the territory of Russia, ranging from 300 to 500 per year, there has been a steady increase in the number of emergencies (from 123 to 360) resulting from natural hazards over the past five years. .
A hazardous natural phenomenon should be understood as a spontaneous event of natural origin, which, due to its intensity, scale of distribution and duration, can cause negative consequences for the life of people, as well as the economy and the natural environment.
A natural disaster is a catastrophic natural phenomenon (or process) that can cause numerous casualties, significant material damage and other severe consequences.
3.2, Classification of natural emergencies
Depending on the mechanism and nature of origin, hazardous natural phenomena are divided into the following groups (classes):
Geophysical hazards:
E) earthquakes;
E) volcanic eruptions;
E) tsunami.
Geological hazards (exogenous geological phenomena):
E) landslides, axes; E) avalanches;
c prone to flushing;
ts subsidence (failure) of the earth's surface as a result of the carriage;
c abrasion, erosion;
c kurum;
dust storms.
Meteorological and agrometeorological hazards:
ci storms (9-11 points);
c hurricanes (12-15 points);
c tornadoes (tornadoes);
c squalls;
u vertical vortices (flows);
Еi large hail;
c heavy rain (rainstorm);
c heavy snowfall;
c heavy ice;
O severe frost;
About a strong blizzard;
O intense heat;
O strong fog;
O drought;
About dry winds;
freezing.
Marine hydrological hazards:
c tropical cyclones (typhoon);
C strong excitement (5 points or more);
C strong fluctuations in sea level;
c strong traction in ports;
О early ice cover or fast ice;
О pressure of ice, intense drift of ice;
O impassable (hard to pass) ice;
About icing of ships;
ts detachment of coastal ice.
Hydrological hazards:
c high water level:
About the flood;
About rain floods;
O low water level;
rising groundwater levels (flooding).
Natural fires:
О extreme fire danger;
About forest fires;
About the fires of the steppe and grain massifs;
About peat fires;
About underground fires of fossil fuels.
Not every dangerous natural phenomenon leads to an emergency, especially if there is no threat to human life at the place of its occurrence. So, for example, an annual flood is not counted as a flood if it does not threaten anyone. There is no reason to consider storms, storms, avalanches, freezing, volcanic eruptions as emergency situations in those places where a person does not live and does not carry out any work. An emergency emerges only when, as a result of a dangerous natural phenomenon, a real threat arises to a person and his environment.
Many natural hazards are closely related. Earthquake
can cause collapses, landslides, mudflows, floods, tsunamis, avalanches, activation of volcanic activity. Many storms, hurricanes, tornadoes are accompanied by showers, thunderstorms, hail. Intense heat is accompanied by drought, lowering of groundwater, fires, epidemics, and pest infestations. Try to trace these connections and the mechanisms of their formation in the study of individual topics.
About congestion and congestion; About wind surge;
e early freezing and the appearance of ice on navigable reservoirs and rivers;
