Air is an intangible quantity, it is impossible to feel it, smell it, it is everywhere, but for a person it is invisible, it is not easy to find out how much air weighs, but it is possible. If the surface of the Earth, as in a children's game, is drawn into small squares, 1x1 cm in size, then the weight of each of them will be 1 kg, that is, 1 cm 2 of the atmosphere contains 1 kg of air.

Can it be proven? Quite. If you build a scale from an ordinary pencil and two balloons, fixing the structure on a thread, the pencil will be in balance, since the weight of the two inflated balls is the same. It is worth piercing one of the balls, the advantage will be in the direction of the inflated ball, because the air from the damaged ball has come out. Accordingly, simple physical experience proves that air has a certain weight. But, if we weigh the air on a flat surface and in the mountains, then its mass will be different - the mountain air is much lighter than the one we breathe near the sea. There are several reasons for different weights:

The weight of 1 m 3 of air is 1.29 kg.

• the higher the air rises, the more rarefied it becomes, that is, high in the mountains, the air pressure will not be 1 kg per cm 2, but half as much, but the content of oxygen necessary for breathing also decreases exactly by half, which can cause dizziness, nausea and ear pain;
• water content in the air.

The composition of the air mixture includes:

1. Nitrogen - 75.5%;

2. Oxygen - 23.15%;

3. Argon - 1.292%;

4. Carbon dioxide - 0.046%;

5. Neon - 0.0014%;

6. Methane - 0.000084%;

7. Helium - 0.000073%;

8. Krypton - 0.003%;

9. Hydrogen - 0.00008%;

10. Xenon - 0.00004%.

The number of ingredients in the composition of air can change and, accordingly, the mass of air also undergoes changes in the direction of increase or decrease.

• Air always contains water vapor. The physical pattern is that the higher the air temperature, the more water it contains. This indicator is called air humidity and affects its weight.

How is the weight of air measured? There are several indicators that determine its mass.

How much does a cube of air weigh?

At a temperature equal to 0 ° Celsius, the weight of 1 m 3 of air is 1.29 kg. That is, if you mentally allocate a space in a room with a height, width and length equal to 1 m, then this air cube will contain exactly this amount of air.

If air has weight and weight that is palpable enough, why doesn't a person feel heaviness? Such physical phenomenon, as atmospheric pressure, implies that an air column weighing 250 kg presses on each inhabitant of the planet. The area of ​​the palm of an adult, on average, is 77 cm 2. That is, in accordance with physical laws, each of us holds 77 kg of air in the palm of our hand! This is equivalent to the fact that we constantly carry 5 pound weights in each hand. AT real life even a weightlifter cannot do this, however, each of us can easily cope with such a load, because atmospheric pressure presses from both sides, both outside the human body and from the inside, that is, the difference is ultimately equal to zero.

The properties of air are such that it affects the human body in different ways. High in the mountains, due to lack of oxygen, visual hallucinations occur in people, and at great depths, the combination of oxygen and nitrogen into a special mixture - “laughing gas” can create a feeling of euphoria and a feeling of weightlessness.

Knowing these physical quantities, it is possible to calculate the mass of the Earth's atmosphere - the amount of air that is held in near-Earth space by gravity. The upper boundary of the atmosphere ends at a height of 118 km, that is, knowing the weight of m 3 of air, you can divide the entire borrowed surface into air columns, with a base of 1x1m, and add up the resulting mass of such columns. Ultimately, it will be equal to 5.3 * 10 to the fifteenth degree of tons. The weight of the planet's air armor is quite large, but even it is only one millionth of the total mass. the globe. The Earth's atmosphere serves as a kind of buffer that keeps the Earth from unpleasant cosmic surprises. From solar storms alone that reach the surface of the planet, the atmosphere loses up to 100 thousand tons of its mass per year! Such an invisible and reliable shield is air.

How much does a liter of air weigh?

A person does not notice that he is constantly surrounded by transparent and almost invisible air. Is it possible to see this intangible element of the atmosphere? Clearly, the movement of air masses is broadcast daily on a television screen - a warm or cold front brings long-awaited warming or heavy snowfall.

What else do we know about air? Probably, the fact that it is vital for all living beings living on the planet. Every day a person inhales and exhales about 20 kg of air, a quarter of which is consumed by the brain.

The weight of air can be measured in different physical quantities, including liters. The weight of one liter of air will be equal to 1.2930 grams, at a pressure of 760 mm Hg. column and a temperature of 0°C. In addition to the usual gaseous state, air can also occur in liquid form. For the transition of a substance into a given state of aggregation would require exposure to enormous pressure and very low temperatures. Astronomers suggest that there are planets whose surface is completely covered with liquid air.

The sources of oxygen necessary for human existence are the Amazon forests, which produce up to 20% of this important element on the entire planet.

Forests are truly the “green” lungs of the planet, without which human existence is simply impossible. Therefore, living indoor plants in an apartment are not just an interior item, they purify the air in the room, the pollution of which is ten times higher than on the street.

Clean air has long become a shortage in megacities, the pollution of the atmosphere is so great that people are ready to buy clean air. For the first time, “air sellers” appeared in Japan. They produced and sold clean air in cans, and any Tokyo resident could open a can of clean air for dinner and enjoy its freshest aroma.

Air purity has a significant impact not only on human health, but also on animals. In polluted areas of equatorial waters, near populated areas, dozens of dolphins are dying. The reason for the death of mammals is a polluted atmosphere; in the autopsy of animals, the lungs of dolphins resemble the lungs of miners clogged with coal dust. The inhabitants of Antarctica - penguins - are also very sensitive to air pollution, if the air contains a large amount of harmful impurities, they begin to breathe heavily and intermittently.

For a person, air cleanliness is also very important, so after working in the office, doctors recommend taking daily one-hour walks in the park, forest, and outside the city. After such "air" therapy, the body's vitality is restored and well-being improves significantly. The recipe for this free and effective medicine has been known since ancient times, many scientists and rulers considered daily walks in the fresh air to be a mandatory ritual.

For a modern urban dweller, air treatment is very relevant: a small portion of life-giving air, the weight of which is 1-2 kg, is a panacea for many modern ailments!

A LETTER HAS COME TO THE EDITOR

“WHEN IT RAINS, MY GIRLFRIEND PLACES BUCKETS UNDER THE DRAINERS, BASINS - COLLECTS RAIN WATER. IT WASHES LINEN, WASHES HAIR. BUT THERE IS A LOT OF TALKING ABOUT "ACID RAIN" NOW AND I AM NOT SURE THAT A FRIEND IS DOING RIGHT. SO IS IT POSSIBLE OR NOT TO USE RAIN WATER ON THE HOUSE?”

Sincerely, V. G. Smolko, Donetsk region

An employee of the Research Institute of Hygiene named after F. F. Erisman of the Ministry of Health of the RSFSR, Candidate of Biological Sciences Elena Fedorovna GORSHKOVA, answers the reader’s question:

Let's first understand what rainwater is. Its main source is moisture evaporating from the surface of water bodies and moist soil. The masses of water accumulating in the atmosphere are enormous: one cloud can contain hundreds of tons of water. They continuously move above the earth's surface, redistributing not only heat and moisture, but also solids - various chemical elements, their salts, dust. An ordinary raindrop weighing 50 milligrams, when falling, washes 16 liters of air, and one liter of rainwater absorbs impurities contained in 300,000 liters of air.

Thus, the composition of rainwater also depends on the territory over which the clouds formed, on the pollution of the atmosphere where precipitation falls, on the direction of the wind and other circumstances.

Air, and consequently, rainwater, is polluted primarily by transport, industrial and agricultural enterprises. Motor transport "delivers" to the atmosphere carbon monoxide, oxides of nitrogen and sulfur, and various industrial enterprises - compounds of arsenic, lead, mercury. In agricultural areas, the air is polluted with ammonia, carbon disulfide, pesticides, pesticides. And this list is far from all the substances that from the atmosphere, together with rain, can again fall on the ground.

Sulfur and nitrogen compounds account for the largest percentage of industrial emissions. Reacting with water in the atmosphere, they turn into acids and fall to the ground in the form of so-called acid rain.

The term "acid rain" was introduced about a hundred years ago by the English chemist A. Smith, who discovered the relationship between the level of air pollution and the acidity of precipitation. But their harmful effects began to appear only 10-15 years ago. Today

almost all rain is "acidic" to some degree.

If he caught you on the road - open an umbrella or. put on a raincoat. Repeated exposure to rainwater on the skin can cause redness and flaking due to the acids in the precipitation.

Acid rains also damage the national economy: they accelerate the corrosion of metal structures, destroy sandstone, limestone, marble, acidify the waters of rivers and lakes, the soil, which leads to the death of fish and forests.

In modern conditions, rainwater cannot be used for household purposes: you cannot wash your hair with it, wash your clothes, as was done before, when the air was not so heavily polluted. And even more so, you can’t drink rainwater, wash dishes with it, cook food on it.

Everything is important in science.

Water and life

According to the generally accepted scientific theory life on our planet is, so to speak, a local phenomenon. It originated a long time ago, when favorable conditions developed for this on Earth. And it originated in the ocean, that is, in the water. This process itself was long, taking billions of years. They've gone out of their way to fit chemical compounds, dissolved in the ocean, arose organic matter that laid the foundation for the simplest living beings. New billion years have passed, and life has spread all over the planet. Now she is in various forms and species exist almost everywhere - in water, on land and in the air.

But her organic bond preserved with water. It is impossible to imagine many processes occurring in the body without the participation of water. Take, for example, the food of the living. All nutrients that enter the body in one way or another are necessarily transferred into solution, and this requires water.

Dehydration leads to lethal outcome. This was experimentally shown in pigeons: if one-fifth of the water contained in the body of a bird is lost, it dies, despite the preservation of all other conditions of existence. And it is precisely the lack of water that a person endures most hard of all: for him, thirst is more dangerous and more terrible than hunger. In the human body, water makes up sixty-five percent of the total weight. If for some reason its content drops by ten to twenty percent, the person will certainly die.

In each organ of our body, in each of its cells, various biochemical processes, there are complex transformations of one substance into another. From the food entering the body, substances are produced that are necessary for the normal functioning of all organs, for the life of the body. Water is an indispensable participant in all these biochemical reactions, water is also a kind of sanitary, with its help, unnecessary and harmful metabolic products are removed from the body - a kind of waste of biochemical production.

Numbers are usually boring. But sometimes it is difficult to do without them for the simple reason that in such cases they give visibility to the story.

Here are a few such illustrative examples in numbers.

To grow one kilogram of plant foods - grains, vegetables, an average of two tons of water is required. It takes twenty tons to "grow" one kilogram of meat!

A person consumes an average of sixty tons of life-giving moisture per year only in the process of nutrition. Add to this some three hundred tons of water to satisfy his other vital needs. Total three hundred and sixty tons to one person!

It takes hundreds of cubic meters of water to produce just one ton of steel, synthetic fiber or paper. Even the extraction of coal and oil is not complete without water, on average it is consumed: about five tons per ton of coal, up to one hundred and thirty tons per ton of oil. In other words, the fuel industry consumes as much water in a year as some large river, such as the Dnieper, brings it.

It has been calculated (it must be borne in mind, of course: this calculation is approximate) that our national economy, including the satisfaction of the needs of the population, consumes five hundred to six hundred cubic kilometers (kilometers!) of water per year. Academician A.P. was right. Karpinsky, who called water "the most precious mineral".

Where is this fossil kept? Water is everywhere: in the oceans and seas, in rivers and lakes, springs and swamps, on high mountains and at the poles. Approximately one fifth of the soil is water. A lot of it and below, in the deeper horizons of the earth's crust. Say, at a depth of up to a kilometer in earth's crust over four million cubic kilometers of water is stored.

There is also a lot of it in the atmosphere: on average, about twenty thousand tons “hang” over every square kilometer of the Earth’s surface - in the form of steam.

If you look at our planet from above from space, then it would be more correct to call it not Earth, but Water, because land occupies a much smaller area on its surface than oceans and seas. Scientists say that there are about one billion three hundred and fifty million cubic kilometers of water on our planet. A lot of it? Of course, a lot. But...

Great, vast is the World Ocean, ninety-seven percent of all water reserves on the planet are concentrated in it. However, sea water is not suitable for drinking and cooking - it contains many different salts. It is not suitable for many industries, including primarily agriculture. In order for sea water to be suitable for such use, it must be freed from salts, that is, desalinated. Technically, this problem is not so difficult. All you need is an economically viable source of energy, so that, as they say, the game is worth the candle. Two ways have been outlined here: the first is the creation of industrial desalination plants based on nuclear power plants, the second is the use of "gratuitous" solar energy for the same purposes. In the Caspian Sea, in the city of Shevchenko, a pilot plant based on a nuclear power plant is already operating. The city and all its economy are fully provided with desalinated water.

And where is the other three percent of the world's water supply?

Two of them are the planet's glaciers and polar ice caps, another is atmospheric moisture (0.001 percent of the world's reserves are hardly worth taking into account), groundwater (most of the last, third percent falls on them), and finally , Rivers and lakes. So far they are the main suppliers of water, although their share in the world water balance is no more than one hundredth of a percent! To put it bluntly: not a lot ...

Many cities in the world experience an acute shortage of fresh water - these are Tokyo and Paris, New York and Philadelphia. In a word, there is a lot of water on Earth, and at the same time it is not enough.

Fresh water, this truly unique and universal source of life, in our time is a time of stormy scientific and technological progress, the rapid growth of cities and industry - is becoming an even more valuable fossil of the planet.

Everything is flowing

Water is an eternal traveler. It is in a state of endless circulation. It is not easy to follow her path in all details. But in general it is possible.

The sun's rays heat the surface of the planet and evaporate a huge amount of moisture. Water vapor rises into the air from the surface of the seas, rivers, lakes, from the soil. All plants evaporate water. Its vapors are exhaled by animals.

Water turns into gas at any time of the year, even in winter, when it is very cold. But the higher the temperature, the more its vapors in the atmosphere. In summer, at twenty degrees of heat, each cubic meter of air can contain up to seventeen grams of moisture. If new water vapor enters such saturated air, they will already condense - turn back into water.

In other words, tiny droplets appear in the air. They, as well as ice crystals, if the air is cold, form clouds familiar to everyone. For water vapor to condense, however, it is necessary that there are solid particles of atmospheric dust in the air, which play the role of nuclei that precipitate water vapor molecules. Usually there are a lot of such particles in the atmosphere.

Air currents carry water vapor and clouds across the Earth. Especially a lot of moisture is carried by winds blowing from warm seas. The oceans are the main supplier of moisture to the atmosphere. Saturated with water, air masses, moving over the continents, gradually lose it in the form of rain or snow.

The fate of drops of water that fell from the sky is different. Some of them fall into streams or rivers, into lakes or immediately into the sea, and from there again evaporate into the air over time. Part of the rain water is retained in puddles, in plants, but soon, heated by the sun, it again embarks on a journey across the ocean of air. A lot goes into the ground.

Having traveled in the kingdom of Pluto for days, months, sometimes for many years, the water drop again appears cold and purified, as if it had really been in purgatory, on the surface, in order to then run along with others into the sea or immediately soar up to the clouds.

Why is it raining!

The answer is not so simple at all. And it is very important to get acquainted with the nature of this atmospheric phenomenon, so common for all of us, to know about its features and capabilities. Why?

The better we know the mechanism of rain formation, the sooner and more reliably we can take control of one of the greatest processes of nature - the water cycle.

There are various forms of clouds that form in the blue of the sky. Then they look like large pieces of cotton wool. They look like the feathers of a bird. Sometimes the clouds have a wavy appearance, and sometimes the sky is covered with a solid, monotonous gray veil, in which the rays of the sun go out for a long time.

Clouds, as we have already said, are a collection of water droplets and ice crystals. But they begin to fall to the ground only when they become large enough. While the cloud consists of very small droplets, they are supported by ascending air currents.

What leads to an increase in water droplets in a cloud? The first reason: particles of water vapor from the air are deposited more and more on the smallest drops - in other words, the process of condensation of water vapor continues in the cloud. And the second: individual droplets, moving in a cloud in all directions, often collide with each other and at the same time sometimes merge. However, both of these paths do not always result in rain.

If the cloud consists of only water droplets, then the drops in it grow very slowly. To form just one raindrop, at least a million small cloud drops must join together!

Quite different conditions are created in powerful mixed clouds, which consist of ice crystals in their upper part, and water droplets in their lower part. Here, the formation of a rain cloud is much faster. From such mixed clouds in our latitudes heavy rain can fall, sometimes even a downpour.

Powerful rain clouds usually form on days when there is heat and there is a lot of moisture in the air. Having arisen in a stream of moist air rising from the heated earth, such a cloud grows rapidly. Increasing in size, it rises higher and higher. If the conditions for its growth are favorable, then soon the cloud reaches the high layers, where the cold reigns. At an altitude of eight kilometers, the air temperature often drops to thirty degrees below zero. With such a strong cold, water droplets in the upper part of the cloud begin to turn into crystals. Gradually, the thickness of the cloud formation can reach several kilometers. Its top, illuminated by the sun, becomes like a huge snowy mountain. It hangs like a dark mass above the ground.

When it starts to rain, rising air currents replenish this thundercloud with more and more moisture reserves. This continues until the flow of moist air weakens. In the summer, cumulus clouds sometimes accumulate downright gigantic amounts of water - each cubic kilometer of such a cloud can contain up to a thousand tons of it on average.

Of course, the picture drawn here of the formation of clouds and their transformation into rain or snow clouds is obviously simplified, in reality this whole process (both in general and in “details”) is much more complicated and cannot be said to be studied in all details. But if you look at this picture as an approximate diagram, then it is correct.

By the way, about the word "cloud". Usually in dictionaries, and in colloquial speech, we understand this word as a cloud in general, from which precipitation is already falling or will soon fall. But meteorologists have their own terminology. They refer to rain clouds their most diverse forms - both in origin and in physical properties: cumulonimbus and stratocumulus, as well as stratocumulus, altostratus and stratus. Plus a lot of transitional forms.

We are very often mistaken when we think that the darker the approaching cloud, the more it will rain. “Well, it’s pouring now!” - we say and hurry to get to a safe shelter. Meanwhile, the abundance of rain, and even whether it will fall or not, does not depend on how black the rain cloud is.

Watch and you will see: clouds of a menacing, gloomy appearance often pass without shedding a drop. The fact is that they usually consist of very small droplets and the supply of moisture in them is not so great. But when a dark rain cloud with a leaden tint hangs over us, then expect rain, and not a little.

On the trail of the accused

Summer rain passes quickly. Having rumbled, the thunderstorm leaves, and the sun appears again over the washed, brightened earth. But the rainwater flows continue their destructive work.

A brook, completely imperceptible at first, in a short time leaves behind a deep trace, especially somewhere on a slope with easily eroded soil. These gullies with a narrow bottom and steep walls often become the embryos of a future ravine. Downpour after downpour, stream after stream of meltwater in the spring - and now a small and seemingly harmless ravine has turned into a ravine, one of the most terrible enemies of agriculture. During the year, only melt waters wash away and carry away many tons of fertile soil from fields and arable lands.

Under suitable conditions, the ravine bites deeper into the ground, now it is no longer just a ravine, but a real gorge, along which stormy streams rush in spring and in heavy rains.

Here is a description of such a gorge from the book of the geographer A.P. Nechaev. He saw him near Volsk in Saratov province(It was at the end of the last century).

“Numerous ravines furrowed the area, scattered like dark snakes in all directions. I have never seen real ravines until now, and it is not surprising that they attracted my attention. The next day after my arrival, I went on an excursion and, turning off the road into the first ravine I came across, I was amazed at the picture that unfolded before me. I suddenly found myself in a wild, dark and damp gorge. The sun's rays did not reach its bottom. And the further I went, the higher the walls rose. Above me I could only see a narrow strip of blue sky. In some places the ravine received lateral tributaries, and here the picture became downright majestic... Here and there the walls moved forward in the form of ruined fortresses with towers and battlements. The area took on the appearance of a bizarre mountainous country ...

Suddenly, a distant rumble of thunder was heard, followed by another, a third, more and more clearly. A storm was coming. Several large drops fell on my face. I walked just as carelessly, not thinking about what was happening. Meanwhile, clouds covered the entire narrow gap of the blue sky. A whirlwind swept overhead. Dust swirled over my head. It got completely dark in the ravine. I realized that there would be a downpour and water would rush along the ravine. And it became clear to me that I was in a trap. There is no way to climb straight up these steep, loose cliffs. We must save ourselves... And, stumbling over the stones that covered the bottom of the ravine, I rushed to run. And the rumbles of thunder were heard closer and closer. I ran as far as I could. Suddenly, a dull noise came from somewhere in the distance. There was no doubt that it was water rushing along the ravine in a stormy stream. I doubled my run. The noise was getting closer. And as soon as I ran out onto the road, a muddy stream of water escaped from the ravine. I climbed up to the steep bank of the newly formed river, and, seeing its frantic play, I realized what danger I was exposed to. The water was all churned into foam. Turning stones and cutting off huge blocks of earth from the shores, she rushed furiously forward.

There are many ravines in our country on the Central Russian, Volga and Volyn-Podolsk uplands, in the foothills of the Carpathians, in the Donbass. The reason for this lies in the peculiarities of the climate and soil. Under the top layer of chernozem there are rocks that are also easily eroded by water.

In some places, a very slight crack in the dried soil, a road rut, a furrow is enough for deep gullies to appear here at the first heavy rain - a ravine was born. The formation of such wounds on the soil is also facilitated by the fact that droughts alternate with downpours. Huge masses of water rush into the cracks of the dried-up earth, wash them away, and demolish the top fertile soil layer.

Ravines are dangerous not only because they literally steal from us the land on which we grew bread or grazed cattle. They are still drying it up. After all, what is, in fact, a ravine? This is a naturally dug channel, akin to what reclamators lay through a swamp when they want to drain it. But there is a swamp, and here, let's say, the steppe, already suffering from periodic droughts. And then there is a ravine that sucks out underground moisture, which is why streams, ponds, wells often die, drying up, if this miraculous canal lies not far from them.

Ravines are fought inventively, although not always successfully. Where a ravine has already begun, measures are taken to prevent it from growing; where it has already formed, it is advisable to turn it into a chain of ponds with regulated flow. Great importance they also have regular crop rotations, which lead to the strengthening of the topsoil and prevent its erosion.

What threatens the rain

“... For the fifth day in Honduras, tropical showers have been pouring. Streams of raging water swept away 20 settlements from the face of the earth. On a huge area, the crop of coffee and grain crops was completely destroyed. According to the latest official figures, 126 people died, 20,000 were left homeless.”

This message was circulated by telegraph agencies at the end of May 1982. And two days later, the number of flood victims in this country reached sixty thousand people.

We often read similar reports in newspapers. “A devastating downpour that did not stop for several days,” wrote the Parisian “Humanite” in December 1981, “hit the southwestern regions of France and caused an unprecedented flood in these parts. The wind drove the rain clouds from the Atlantic, where a storm raged for a day. After two days of continuous heavy rains, the elements seemed to have begun to recede, but after a while the showers hit the entire southwestern part of France with renewed vigor. As a result of the flood, a catastrophic situation has developed in this area of ​​​​the country ...

In the department of Landes, many famous pine forests have died: the ground under the trees is completely washed out. In Agen, the capital of the Lot-et-Garonne department, several blocks were flooded, cutting off hundreds of residents from the rest of the city. In Riol-Bas, Saint-Antonin-Noble-Valais, people were rescued by helicopters. Even where the water has subsided, it is almost impossible to move: the streets are covered with a thick layer of mud.”

Floods caused by heavy rains are an eternal disaster that haunts people. Legends associated with it, such as the biblical myth of the Flood, are found in the folklore of many peoples. Sometimes traces of the floods mentioned in the legends are also found during archaeological excavations.

Information about violent floods and high waters is found in Russian chronicles, church and city memorial records, but all this information is scattered, random. Only since 1876, in our country, regular observations began to be made on the rivers, first of all, of course, those that were distinguished by their waywardness and more than once gave free rein to their element.

And where there is an element, there is, as a rule, a disaster.

“In the summer of 6978 (that is, in our chronology - in 1470) ... - we read in the Pskov Chronicle. - That same spring, the water was great and strong, filling the rivers and lakes, for many years the water was not like that; and along the Great River, ice going, the Christians bled a lot in chorus and demolished stocks, and lands, some fields were torn up with ice, and others were washed away with water.

Now, when the Moskva River is regulated, when measures are taken every spring to prevent floods, Muscovites need not fear that they will be taken by surprise by the overflowing river. This has happened before. In 1908, the water in the Moscow River rose by more than ten meters, and a fifth of the city was flooded. The roofs were dotted with residents of flooded houses, tables, benches, logs, carts, hay floated along the river and along the streets ...

One of the most infamous floods in modern times occurred in Italy. It happened in 1951. For several days in a row, heavy rain showers were falling in the Alps. Even the smallest rivers turned into turbulent streams. The Po River overflowed and, breaking through dams and dikes in several places, rushed to houses, gardens, vineyards, flooded dozens of villages. Almost everywhere there were human casualties. Thousands of people were forced to spend several days on the roofs of houses, on trees - without food and warm clothes.

The consequences of this flood were especially severe for Polesina, a typically rural region of northern Italy. According to the writer Carlo Levi, in those days this region was a water desert: it simply did not exist - it disappeared under water.

Floods due to the “fault” of the Po and another river, the Adige, also originating in the Alps, have happened before. The whole history of Polesina is the history of the struggle of many generations of peasants with the elements, the history of efforts to curb water, to protect themselves from it. The flood of 1951 is considered by Carlo Levi to be one of the most destructive in the current century.

So far only statistics

What is happening in heaven? Why do they suddenly begin to pour streams of water onto the ground so mercilessly?

One of the reasons for heavy rains is the especially strong heating of moist soil in the hot summer season. The mass of moisture evaporating from the surface of the earth forms (often this happens right before our eyes) huge heavy clouds. The "thickness" of the cloud layer reaches six - eight, and even ten kilometers. From them, from oversaturated clouds overloaded with water, downpours fall down.

Showers of this origin are especially characteristic of tropical latitudes. In our latitudes, shower clouds are formed, as a rule, in a different way - during the frontal meeting of differently heated air masses, when cold air wedges into warmer air and a complex, rapidly flowing process develops along the entire line of the atmospheric front. Experts call this process convection. physical meaning it is that there is a movement of large air masses with the transfer of heat and other physical factors. It is associated with the formation of cumulonimbus clouds that carry showers and thunderstorms.

Small, far from accurate, but visual model Each of us has seen this process more than once in our lives, opening a window in winter, in severe frost. There is no fog in the yard - clean, frosty air, but, bursting into your window, for some reason it begins to swirl. And it swirls because in our housing the air is warm, saturated with vapors, and they condense in a frosty air stream. The more moisture in the room air, the thicker, more noticeable clubs of frost.

In the spring of 1965, a cold air mass invaded the European part of our country from the north at high speed, the temperature dropped to ten to twelve degrees. And before that, even Kirov region the temperature rose to twenty-five or twenty-eight degrees. Moving to the southeast, the cold air wedged deeper and deeper into the heated, saturated with evaporation. As a result, on a gigantic territory, from Moldova to the Kirov region, a thunderstorm road with showers stretched for thousands of kilometers. In one day, from weather stations located within a radius of two hundred to three hundred kilometers around Moscow, Central Institute Forecasts received sixty warnings of thunderstorms and strong winds.

Rain on time is good. Is always. The same cannot be said about severe downpours, when it seems that the sky itself has opened up and water is pouring onto the earth like a wall. Yes, even if with hail. But they are especially dangerous in the tropics. It is even difficult for residents of a temperate climate to imagine how abundant they are there. With one tropical rain, as much water often pours onto the earth as we have in several years.

In the northeastern part of India, in the Cherrapunji region, near the Himalayan mountains, is the rainiest place on Earth. Here, an average of twelve and a half meters of precipitation falls during the year. This means that if the rainwater that spilled here did not flow into the river and go into the soil, it would cover the surface with a layer of this thickness.

There are many other places in India where rainfall is very plentiful. Therefore, severe floods are very frequent on the rivers of this country.

Autumn 1978. As a result of heavy rains, the waters of the Ganges flooded vast areas. The houses of half the inhabitants of the city of Benares were flooded. There was a threat of an outbreak of epidemics - the bodies of the dead, who did not have time to burn, were carried away by water (the Hindus consider Benares a holy city - they come here to die, they are cremated here). In Uttar Pradesh, India's most populous state, soldiers and emergency workers tried to reach hundreds of thousands of people cut off by the "worst flood in living memory," according to Indian newspapers. One hundred passenger trains were canceled - the railway track in many places turned out to be deep under water, and in other areas it was littered with fragments of rocks, stones, and covered with silt. The flood lasted more than a month and claimed over a thousand lives.

Nature presents similar surprises even to Australia, where almost two-thirds of the territory has a desert or semi-desert climate and where most of the rivers (and there are not so many of them) are channels without water. They are called "screams". But after the showers, you can expect anything from them, even floods. One such flood destroyed the city of Windsor.

Among the largest floods in the world, the culprit of which was a tropical downpour, include the flood in December 1887 in the Chinese province of Henan. It was a real disaster. The overflowing Yellow River broke through a huge dam near the city of Kaifeng, and everything that towered above the ground was ruthlessly washed away. A large territory, equal in area to Holland, turned into a lake for a while. Nine hundred people died...

The Chinese call the Huang He the yellow beast, the river of disasters. And indeed, she often makes devastating raids on the earth. Where its dirty yellow waters raged, only ruins remain.

In general, catastrophic floods in China occur almost regularly. In July 1981, over three days in most of Sichuan, southwest China, more than two hundred, and in some areas almost four hundred and seventy millimeters of rain fell. Streams of water from the mountains rushed into the Yangtze River and its tributaries, and they overflowed their banks. Twenty-five counties were under water, in some places its level reached five meters.

Thousands of dead, hundreds of thousands left homeless - this is the result of this next atmospheric cataclysm.

It seems that such catastrophes in the distant past could not but give rise to myths and legends about the flood, which were then interpreted by various religions in the spirit of their teachings.

global flood

The Bible did not pass by his attention either. Here is how she substantiates both the flood itself and its terrible consequences: “And the Lord said: I will destroy from the face of the earth the people whom I created, from man to cattle, and I will destroy creeping things and birds of the air: for I repented that I created them.”

Only Noah and his family were pleasing to God. By God's command, the righteous man built an ark, into which he was allowed to take "two of every flesh."

The Bible goes on to say that it rained for forty days and nights. A flood began, and "the high mountains that are under the whole sky were covered." All living things perished, except, of course, those who were in the ark. One hundred and fifty days passed, and the water began to recede. Noah's Ark rested on the mountains of Ararat...

Historians have established that the biblical flood myth is, in fact, a retelling of more ancient sources. Almost the same legend, for example, is contained in one of the Assyrian legends written on clay tablets that were kept in the library of the Assyrian king Ashurbanipal (7th century BC). The Assyrians, in turn, retell the legend of the Sumerians, ancient people Mesopotamia, which created the first written language here.

The Sumerian flood myth is part of the Epic of Gilgamesh, famous traveler, "who has seen everything, to the end of the world, who has known the seas, who has crossed all the mountains."

The hero of the flood myth in the Sumerian legend is the sage Ziusudra, referred to in a later manuscript as Utnapishtim. Both names mean the same thing: "He passed through a life of long days."

One day, the legend says, the god of fresh waters and wisdom, Za, visits Utnapishtim at night and informs him of the decision of the gods to drown mankind. God recommends that he make an ark and load all his possessions and living creatures on it. He builds an ark of rectangular shape and huge size, which is hardly launched into the water. The ark had six tiers and was divided into seven parts, and its bottom into nine compartments. Utnapishtim loaded it with his gold, silver and domestic animals, as well as steppe cattle and animals, took all his family and relatives and, when it began to rain, closed and pitched all the doors of the ark.

The flood is described below. Wind, storm and rain continued for six days and seven nights. On the seventh day, the storm subsided, the waters calmed down, and Utnapishtim saw: all around, as far as the eye could see, was water. After twelve fields (which is probably from eighty-four to one hundred and twenty kilometers), an island appeared, on which the ark landed. It was Mount Nitsir, now Pir Omar Gudrun, in the west of the Iranian Highlands, four hundred and fifty kilometers north of Shuruppak, within the southern Mesopotamia.

Utnapishtim released a dove, then a swallow, but they returned, not finding a dry place. The raven released later saw that the water had subsided and never returned. Then Utnapishtim came out of the ark and offered a sacrifice to the gods.

The Sumerian myth is almost no different from the biblical one. A small difference in details is quite legitimate, given that the Bible is separated from the Epic of Gilgamesh by at least one and a half millennia. During this period, much has fallen out of people's memory, something has been added, conjectured by later retellers.

So, the widely known biblical legend today is just a retelling of much more ancient folk tales. But was there really such a global flood? Is there any convincing confirmation of the main thing in this legend - the fact that once heavy rains flooded all the land on the globe?

Alas, there is no such evidence. The opposite has been scientifically proven: there has never been such a global flood. Even in the most remote geological epochs, when a warm climate reigned on the planet and many parts of modern land were covered by shallow seas (by the way, then there was still no modern animal world, including, of course, humans), still not all continents were flooded.

Another question is interesting here: are there any legends underlying the legend? real events which were then implausibly exaggerated by religious fantasy and written down in sacred books?

Recall that the Sumerians lived along the middle and lower reaches of the high-water rivers of the Tigris and Euphrates. Here, in Mesopotamia, in Mesopotamia, long before Ancient Greece and especially ancient rome arose ancient civilizations with high culture for that time. Many records have been preserved from them, made with special cuneiform signs on clay tablets. And when the information contained in them about the “world flood” was studied in detail, some important details were revealed that are not in the biblical version of this legend.

Even in the last century, the Austrian geologist E. Suess drew attention to the fact that the Sumerian description of the flood mentions cracks that appeared in the earth. Later, historians found here information about a huge black cloud that moved in from the south before unprecedented downpours began. These and other data gleaned from cuneiform sources have allowed scientists to more clearly present the real picture of what happened here in Mesopotamia several thousand years ago.

Obviously, the flood occurred in the lower reaches of the Euphrates. It was a devastating flood, caused simultaneously by a tropical cyclone and an earthquake, or rather, a seaquake - its center was at the bottom of the sea. During such earthquakes, huge waves are formed - tsunamis, which, having reached the low shores in these places, could cause terrible destruction (we will talk about this later) and flood a large area on the plain. And then there was “the earth opened up” (cracks), which sometimes accompanies earthquakes. All this apparently led to such huge sacrifices that it left a long memory in the history of mankind.

But for all that, the catastrophe was not a “global flood”, but a phenomenon, an event of a local nature, although for the inhabitants of Mesopotamia it could seem like the end of the world. Indeed, according to the ideas of those who lived here then, Mesopotamia was both the beginning and the end of the whole world, the whole world.

By the way, the Sumerian myth speaks of only one flood. It is quite possible that there were several such floods in these places. But in the minds of the people of that time, who did not know and did not understand the causal relationships in nature, they merged into one - as a punishment sent down to them from above for disobedience to the gods. In later religions, this idea of ​​retribution for sins, for unbelief and disobedience received further development. Hence, apparently, the borrowing of the Sumerian myth by the ancient Jews and its inclusion in the Bible - in Old Testament, which later became a holy book for Christians.

Supporters of the biblical version of the global flood, in order to prove its reality, refer to that.

that the legends of other peoples who lived by no means in Mesopotamia speak of such an event. Even more than that - away from her, on another continent. Indeed, the tradition of the Indians of the Quiche tribe speaks of something similar ( South America, Guatemala). According to this legend, the god of fear Hurakan (hence the word "hurricane" came from) decided to destroy all life on earth with water and fire. A big wave rose and overtook people - because they forgot their creator and did not thank him, they were killed and drowned. Resin and tar from the sky. The earth was plunged into darkness, heavy rains fell day and night. People climbed the houses, but the houses were destroyed and buried them; they climbed trees, but the trees threw them off their branches; they tried to hide in the caves, but the caves closed. All died.

The tribes that inhabited Mexico in ancient times had a legend about how God destroyed the giants who lived there by flooding the land with water. The natives of Canada also talk about a terrible flood, when the water rose to the mountain peaks...

Well, maybe the Flood is really not a fairy tale? Not! Traditions about catastrophes, when many people died in water and fire, only say that floods - but by no means global, but local - happened repeatedly at different times and in different places. And here one thing is certain: their causes were not supernatural, but quite natural - earthquakes and seaquakes, strongest hurricanes and tsunamis.

"The same summer there was a bucket ..."

In the list of disasters associated with the life of the atmosphere, there is a kind of antipode to high water - unprecedented severe droughts. In the chronicles of past centuries, one can find many mournful records about this. “The same summer,” a Russian chronicler wrote in 1162, “there was a bucket and great heat through the summer and all life and all abundance burned, and the lakes and rivers dried up, the swamps burned out, and forests and lands burned.”

Such droughts were accompanied by famine.

When dry years followed one after another, death mowed down entire nations, in many countries all life froze. And this was not only the case in the past. In our time, reports of severe droughts, of the innumerable disasters that they bring to people, are not so rare. The peoples of a number of regions in Africa and Asia are especially hard hit by them.

In 1972-1974, a drought hit the countries along the southern border of the Sahara. In Senegal, Niger, Mali, Guinea-Bissau, Upper Volta, hundreds of thousands of people died of hunger and thirst. More than three million head of cattle died. Less than ten years passed, and trouble came again: for two years - 1980 and 1981 - not a drop of rain fell in the sub-Saharan countries. The water from the wells has gone, the springs have dried up, the lakes have become shallow.

These years turned out to be just as difficult because of the drought in the countries East Africa. All the way from Djibouti and Ethiopia to Uganda and Sudan, the earth is cracked with thirst and turned white. “This human tragedy is stunning,” newspapers wrote in 1980. - It's even scary to think how many people die... The fate of individual people no longer touches anyone. Starvation threatens everyone and everyone.

Such a tragedy befell twenty-five African countries...

Downpours, rains, droughts... How much they mean for life on Earth, what a huge role they played in the fate of mankind in the past and continue to play even now. It cannot be said that the dependence of people and their economic activity on the vagaries of the weather is now the same as it was before. But it is there, and quite significant. But people from time immemorial dreamed of getting rid of it. Too much water is bad, not enough too. The farmer, having sowed grain, wanted it to be well born, not to get wet, watered by endless rains, or not to burn out under the scorching rays of the sun. And he prayed for this to the sky, hoping for the mercy of the Almighty. Sometimes it seemed to him that the prayer had reached its goal: a fertile rain suddenly fell on the field languishing under the heat. If the Almighty remained deaf and did not want to help, the farmer dutifully blamed himself - apparently, he angered God with something ... One lucky coincidence, that is, when the rain would have passed anyway and without prayer, spurred both thoughts and feelings of believers. The clergy made good use of this.

And somewhere aside from the religious worldview, and even often in spite of it, gradually, from century to century, observations were accumulated - the basis of experimental knowledge, which took the form of signs. Practical people trusted more omens than prayers.

In fact, a sign is the same forecast, only made intuitively, "not according to science." It may or may not come true. And not only because it was compiled "not according to science", but mainly because nature is not immune from accidents. Therefore, even today, making a forecast is not an easy task, although the scientific and technical equipment of a modern specialist working in this field cannot be compared with what people had in the past. It is necessary to take into account many factors, and many of them have not yet been studied, not identified, not all relationships in nature have been discovered. It is necessary to process a gigantic amount of scientific information - it is so gigantic that it is almost impossible to cope with it without the help of electronic computers. And as a result, get a forecast, the reliability of which is not always, or rather, not 100% guaranteed. This is especially true for long-term forecasts.

Increasing the reliability of the forecast is such a task facing the complex of sciences studying global geophysical processes. Along with it, scientists hope to solve another, more radical one - to learn how to control the weather. Isn't this a baseless fantasy? “We live in an era when the distances from the craziest fantasies to completely real reality are shrinking with incredible speed,” these words of M. Gorky are confirmed by the entire course of the modern scientific and technological revolution. At first, this task will apparently be solved on a limited scale - within the limits of a particular locality or region. A number of successful experiments allow us to hope that this is quite achievable. So, by scattering special substances in the atmosphere, it was possible, if necessary, to clear the sky (above the airport), or make a cloud rain, or accelerate and intensify the condensation of water vapor in the atmosphere with the formation of clouds ...

What will be the solution of the problem in fact, the future will show.

Interesting facts about water.

The human body contains about 47 liters of water. It turns out that many of our organs contain a surprising amount of water. For example, muscles are 75% water, the liver is 70%, the brain is 79%, and the kidneys are 83%! But this body fluid is not pure water. In fact, it is a saline solution.

MYSTERIES

1. I will look out the window; long Antoshka is coming

(Rain)

2. In the yard, in the cold - with a mountain, and in the hut - with water

(Snow)

3. The eagle flies across the blue sky.

Wings spread out

The sun covered

(Cloud)

4.Teklo, inferno and easily under glass

(Ice on the river)

We are so accustomed to calling the planet on which we live, the Earth, the globe, that we don’t even think: did the one who first came up with this name made a mistake? But it's worth thinking about, really! What kind of globe is this if its surface is not more than 30%, and everything else is water: rivers, lakes, seas, oceans, swamps. And if the Earth could be straightened, made flat, like a table, then it would not be visible at all - all of it would be hidden by a 150-meter layer of water. The globe ... It would be more correct to call it water, not earth!

Water pollution.

Among such a huge amount of water, a person worries about its lack! Is it legal?

The waters of the Pacific Ocean alone will be enough for the needs of mankind for many years!

(Children may object that the water in the oceans and seas is salty, it is not suitable for human needs. A person needs fresh water.)

Is all fresh water safe for human health?

Tell us how a person, without hesitation, pollutes the waters of rivers and lakes, seas and oceans.

The waters of the oceans are gradually polluted by the waste of human activity. According to the World Organization for Environmental Protection, humanity “produces” 20 billion tons of waste, and 85% of it is dumped into water basins.

It is a shame to admit it, but mankind has long included rivers, seas and oceans in the sewerage system. Wastewater most often merge even without preliminary cleaning.

The most amazing thing is that cleaning up human waste is not difficult - there are excellent technologies for this. But recycling is worth the money! Therefore, say, not too rich countries consider the construction of waste processing plants an unaffordable luxury.

Industrial and municipal waste is carried into the oceans mainly by rivers (Explain why) For example, hundreds of millions of tons of zinc, lead, copper, cadmium, mercury, arsenic enter the Arctic Ocean. All these poisons are deposited in the tissues of marine life. For example, North Sea cod in one mass sometimes contains up to 0.8 grams of mercury, which has been sucked into it from polluted water. It is estimated that by eating 5-8 of these fish, a person receives as much deadly mercury as it is contained in a medical thermometer.

Oil ship accidents have become a real scourge of the oceans. For example, in 1981, an English tanker crashed in the Lithuanian port of Klaipeda. 16,000 tons of fuel oil spilled into the sea. Thickets of special algae decreased by 10 times in the disaster area

The main spawning grounds for herring. But it was an “ordinary” accident by world standards!

At the end of World War II, 170 thousand tons of poisonous substances were flooded in the Norwegian fjords, and the burial coordinates were ... lost. The Norwegian authorities still cannot determine this place, but the poison can break out at any moment!

Water in the oceans and seas, rivers and lakes, underground and in the soil. On high mountains, in the Arctic, Antarctica, water is in the form of snow and ice. This is the water in solid state. Ice can be seen on our rivers and lakes when they freeze in winter. A lot in the atmosphere: these are clouds, fog, steam, rain, snow. On the surface of the land is not all the water available on Earth. There are underground rivers and lakes deep in the ground.

Plants in the absence of water wither and may die. Animals, if deprived of water, quickly die: for example, a well-fed dog can live without food for up to 100 days, and without water for at least 10.

Water loss is more dangerous for the body than starvation: a person can live without food for more than a month, and without water - only a few days.

A person's need for water, which he uses with food and drink, depending on the climate, is 3-6 liters per day.

WATER - a good friend and helper of a person. She is - comfortable road: ships sail on the seas and oceans. Water conquers drought, revitalizes deserts, increases the yield of fields and orchards. She obediently rotates turbines at hydroelectric power plants. The water of mineral springs has a healing effect.

Rivers and lakes live thanks to their ability to self-purify. So, for example, in 12 days all the water in the river is renewed, and in the lake, mollusks and other smallest creatures pass the entire volume of water through themselves 6-8 times a year, thereby purifying it. But even here there is a limit beyond which a living system loses its ability to self-repair.

And here are some facts of pollution of very large reservoirs and their consequences.

1. Thermal pollution is characteristic of major rivers, on the banks of which steel-smelting or machine-building machines, heat and power plants are built. These enterprises use cold speech water to cool industrial plants. They pour water back into the river, fairly heated, almost hot. Thus, the temperature balance of the reservoir is disturbed, tropical viral diseases are spreading, valuable fish - salmon, trout, sturgeon - are dying. In muddy, green-smelling water, only certain types of fish survive - chub, roach. The Volga (show on the map) is one of the rivers subject to thermal pollution.

2. About 150 million people live on the shores of the Baltic (show on the map). Thousands of industrial enterprises work for their needs. As usual, they dump their waste into the sea. As a result, due to pollution, it is no longer possible to distinguish where there is fresh water and where there is salt water - all of them have become poisonous. Baltic fishermen often come across cylinders with poisonous gas in their nets. They have been floating in the sea since the Second World War, many of them are damaged, which means that the deadly gas has dissolved in sea water and has had a destructive effect on environment. In the Baltic, it is already possible to catch fish with a mutilated spine, two heads or tails, with tumors on the body.

3. The Mediterranean Sea (show on the map) stretches between Africa and Europe. Until recently, coastal countries did not know the end of tourists. Now the situation has changed. Sewage polluted the Mediterranean Sea so much that instead of a good rest, people began to suffer from gastrointestinal diseases here.

4. The destructive activity of man has not bypassed the Black Sea (show on the map). Due to accidents on ships, the share of oil products in it in the region of Tuapse (map) and Novorossiysk (map) is 9 times higher than the permissible norm.

Properties of water, Three states of water

Due to its fluidity, water can penetrate everywhere. Indeed, water is found almost everywhere on earth. There is a lot of it in the oceans and seas, less, but also a lot, in lakes, rivers, ponds and swamps. There is also water underground. If you start digging a well, then at a depth of 7-12 meters (somewhere less, somewhere more) you will find groundwater.

Moreover, the entire soil is saturated with water. Digging a hole or digging up a vegetable garden, you find that the ground is wet. It is not for nothing that in fairy tales and poems the earth is often called damp: “mother is damp earth”.

An ordinary stone in the smallest cracks contains a microscopic amount of water. In living organisms - plants, animals and humans - contains a lot of water. You may have heard that the human body is 8/10 water. Plants are 9/10 water. Water is essential for life. Without it, all living things die. For example, a person can go without food for several months.

Pure water is transparent. If the water is not transparent, then it contains some impurities, such as silt. But some solids break down in water into such small particles that the resulting mixture remains transparent. In this case, the substance is said to have dissolved in water, and the mixture is called a solution. Water can be said to have a solvent solution. A filter is used to purify water (and not only water, but also other liquids). A filter is a device for purifying liquids. Water is odorless and tasteless. If the water has a taste, then it contains some impurities.

The water is colorless. You ask: “But what about the sea? Is it deep? The fact is that there is another property of water: it can, like a mirror, reflect what it is in front of it (or, more precisely, above it). The sea is blue because the sky is reflected in it. Experience at home. Remind yourself of a large bowl or basin with water and try to see in it the reflection of surrounding objects and your own. It is better to look at the surface of the water not from above, but from the side, at an angle. Please note that the reflection does not prevent you from seeing the walls and bottom of the dishes behind it.

Water expands when heated and contracts when cooled. An alcohol thermometer is based on this property. The fact is that some part of the alcohol is water.

Water may evaporate. If water is heated to a temperature of 100 degrees, it boils and quickly turns into steam. But water can also evaporate at lower temperatures. For example, if we put a saucer of water on the window of a room, after a few days all the water will disappear. We see that at room temperature, water also evaporates, but much longer. Very cold water also evaporates, though even longer. When cooled, the water vapor turns back into water.

Water may freeze. If the water is cooled to a temperature of 0 degrees, it quickly turns into ice.

If the ice is heated to a temperature above 0 degrees, it will melt, that is, it will turn into water.

So, water in nature can be in three states: liquid, gaseous (steam) and solid (ice). Water can change from one state to another.

1. Many fairy tales mention living and dead water. Does this really happen? There are different types of water in nature. plain water is made up of oxygen and hydrogen. But if hydrogen is replaced by a heavier substance, deuterium, the so-called heavy water is obtained. In large doses, it is called the death of the body. You can call her dead. Heavy water is an obligatory companion of ordinary water, but there is very little of it in natural water. Drinking water in natural water is almost 7000 times more than heavy water, so you can drink it without fear. And what kind of water can be called living? Taluyu. It contains less heavy water than water from a river or a well. In addition, water formed from melted ice or snow, for some time, has a structure that favors the vital activity of the organism. Animals and plants that receive melt water grow and develop faster than others. But there is one important condition! Melt water must be clean.

In the old days, people were interested in the question: “Where does the rain come from?” What do you think?

Maybe there is also a sea, a lake or a river in the sky? People used to think that way. But we know that nothing like this can be there. Where does the water that falls from the sky come from? Before answering this question, let's ask ourselves one more. You already know that water evaporates. Why hasn't all the water disappeared from the earth yet? There is only one answer to these questions: because there is a water cycle in nature. The water that falls from the sky as rain is the same water that has previously evaporated from earth's surface. You know that water can change from one state to another. It can turn into steam - evaporate or ice - freeze. Ice can become water again - melt. Water vapor, when cooled, turns into water. The ability of water to move from one state to another underlies the water cycle in nature. From the surface of the oceans, seas, lakes, rivers and land, water evaporates and rises to the top. Water vapor cools in the air, turns into the smallest droplets of water, snowflakes or into the smallest pieces of ice, while gathering into clouds. In the clouds, these tiny droplets, snowflakes and ice floes combine and fall to the ground in the form of rain, snow and hail. Rain water, as well as water formed as a result of the melting of snow and ice, again finds its way into rivers, swamps, lakes, seas and oceans. That's why they don't disappear. Water is always moving. First upwards, from the earth to the sky, in the form of water vapor, then downwards, from the sky to the earth, in the form of rain, snow or hail. And therefore up again, and down again, and so on for many millions of years.

What happens to water after it returns to earth as precipitation?

If rain fell, for example, over the sea or lake, it simply increased the amount of water in the sea or lake. What if it's above ground? Some of the rainwater evaporates from the surface of the earth, but most of it is absorbed into the ground. What happens to this water? In order to answer this question, we must first know what the top layer of the earth is made of. And it consists of soil, sand and clay. The soil is located at the very surface. Below the soil is usually a layer of sand, even lower - a layer of clay.

What happens to the rain melt waters soaked into the ground? They easily seep through soil and sand, but clay delays them. Water accumulates here and, if there is a slope, flows down. Sooner or later, on its way, there will be a sharp decrease in terrain, for example, a ravine or a deep depression. Underground water will then be on the surface of the earth. The place of the natural outlet of groundwater to the earth's surface is called a spring, or a key. The water flowing from the spring gives rise to a new stream. Streams merge together and form a river. Large full-flowing rivers have a very modest beginning - small streams running from springs.

Puzzles

He has no arms, he has no legs

I was able to get out of the ground.

He us in the summer in the heat

Icy drink water

(Spring)

Where the roots curl

On the forest path

small saucer

Hidden in the grass.

Everyone who passes

Fits, bends -

And again, strength will be gained on the road.

(Spring)

The pulse of our land

pure, pure,

He hurries on his eternal journey,

To save the earth from thirst.

(Spring)

RIVERS

Streams flow from higher places to lower ones. At the same time, they are interconnected, forming a large full-flowing stream. The more streams are connected into one, the wider and deeper the resulting stream. So streams form a river. A river is a large stream of water. A river differs from a stream in its greater width and depth of water flow. It is impossible to say exactly where the stream ends and the river begins. Sometimes it is difficult to determine whether we have a wide stream in front of us, or a narrow river. But when the river becomes full enough, no doubts arise. The river flows along the course. A channel is a depression in the earth's surface along which a river flows. The channel is of natural origin and is usually made by the river itself. If you become facing in the direction of the river, then the right bank will be on the right, and the left bank will be on the left.

Both the river and the stream have a source. The source is the place where the water flow (river, stream) begins. The source of the stream is the spring from which it flows. What is considered the source of the river? After all, the river is often formed by several streams? In which case they are the source of the river. In some cases, it is possible to say exactly from which spring the river originates. Then this spring will be called the source of the river.

Each river has its own name (Moscow, Volga, Oka, Yenisei). Sometimes names can have streams. For example, Rattlesnake Creek, Cold Creek, Runner Creek.

It often happens that two rivers merge into one. In this case, one river is said to flow into another. The river that flows into is called a tributary, and the one into which it flows is called the main river. How to determine which of the two rivers is a tributary, and which is the main one? Usually the tributary is shorter than the main river. It is often narrow. What is the name of the river, obtained after the confluence of two rivers? Sometimes it is new, but most often the name of the main river is preserved. But the main river can meet a longer river in its path and become a tributary itself. The place where a river flows into another river, lake or sea is called a mouth. The mouth is the end of the river.

The river can be short, only a few tens of kilometers long, or it can stretch up to several thousand kilometers. If the river flows through flat terrain, its course is smooth, calm, rather slow. In mountainous areas, the flow of rivers is stormy, sometimes very fast.

In order for the river not to disappear, water must flow into it all the time. Both in summer and winter, the rivers are fed by groundwater coming from springs. These springs are located at its source and along the entire channel. In summer, a lot of water enters the rivers due to rains, in spring - due to melting snow.

So, a river is a large water stream that flows in a natural channel and has a source and a mouth. A stream is a small stream of water.

PUZZLES

No matter how winding, where to wander -

Everything comes to the blue sea.

Let the road be far

But don't get lost

(River)

Slightly shaking in the breeze

Ribbon in space.

The narrow tip is in the spring,

And wide - in the pore.

(River)

Hiding in the winter

I appear in the spring

I have fun in the summer

I go to bed in autumn

(River)

Which road do they drive for six months,

do they go for six months?

(River)

Lakes, ponds, swamps

Do you know what a lake is and what a pond is?

Lakes are large natural depressions on the surface of the land filled with water. Unlike rivers, lakes have neither source nor mouth; water does not flow anywhere in them. But this does not mean that the same water will always remain in the lakes.

As in a river, the water in the lake is constantly changing, one water leaves, another comes to replace it. Only in the river does this change occur quickly, and therefore we notice it. Then we say, "The river is flowing." In a lake, the water changes more slowly than in a river. We do not notice this change, so it seems to us that the water in the lake is still. In fact, part of the water gradually evaporates from the surface, part is absorbed into the ground. The old water either evaporates from the surface of the lake or soaks into the ground. New water is brought by rivers and streams flowing into the lake, as well as rains and melting snow.

Lakes are of natural origin, that is, they were created by nature, not people. There are many natural depressions on the surface of the earth (natural means not dug by people). Some of these depressions are filled with Vova from rivers, streams and springs, rain and melt water. This is how a river is formed. Lakes are wastewater and drainless. Waste lakes - those from which rivers flow; do not flow out of drainless rivers. In sewage lakes, water is always fresh (non-salty), and in endorheic lakes, with rare exceptions, it is salty. Water in a waste lake is completely replaced in several decades, and in a drainless lake in 200-300 years.

Lakes are our wealth. It is unacceptable to pollute the water in lakes, to drain poorly purified water from plants and factories into it, to wash cars in lakes. But, unfortunately, many lakes (as well as other water bodies) are already polluted with harmful harmful substances. In addition, there may be pathogenic microbes. Therefore, you can not drink water from reservoirs. (At home on the landscape sheet there is a poster “Beware of the lake!”.)

It often happens that people dig a large enough hole and fill it with water. This is how a pond is made. Sometimes people fill existing natural depressions with water. In this case, it also turns out a pond. It is important that the pond is always created artificially. There is a third way to create a third pond - to block the river with a dam. This is called "damming up the river". In this case, the pond is called a dam.

So - lakes are formed naturally, they are created by nature, ponds are created by people artificially.

PUZZLES

in the middle of the field

The mirror lies

blue glass,

Frame green

(Lake)

Young children look at him,

Colored their own using kerchiefs.

Young birch trees look into it,

Straightening her hair in front of him.

And the month, and the stars - everything is reflected in it.

What is this mirror called?

(Pond)

Not water, not land -

Don't sail on a boat

You can't walk with your feet.

(Swamp)

top duckweed,

And to come - it is viscous.

You will not pass, you will not swim -

You go to the side.

And you won't drink water

With blue film.

(Swamp)

Everyone bypasses this place.

Here the land is

Like a dough

There are sedges, tussocks, mosses….

No leg support

(Swamp)

Oceans and seas

There are huge natural depressions filled with water. They are called oceans and seas. Open the physical map of the world. It is dominated by Blue colour are all oceans. Oceans are vast expanses of water, very deep. The usual depth of the ocean is several kilometers. In total, four oceans are distinguished - several kilometers. In total, four oceans are distinguished - the Pacific, Atlantic, Indian and Arctic. The sea is the part of the ocean that extends into the land, sometimes very far. Such are the Mediterranean Seas, which protrude less into the land, for example, the Barents and East Siberian Seas in the north of our country.

How is a sea different from a lake? First, seas tend to be much larger than lakes. True, there are lakes that are larger than some seas. For example, Lake Baikal is larger than the Sea of ​​Marmara, African Lake Victoria is larger than the Sea of ​​Azov. Secondly, in the seas the water is always salty, and in the lakes it is usually fresh. Although there are lakes in which the water is salty. The main difference between a sea and a lake is that the sea is connected to the ocean, either directly or through other seas. If we sail on a ship, we can always get from any sea to the ocean. Strictly speaking, being in the sea, we are already in the ocean, since the sea is always part of the ocean. The lake has nothing to do with the ocean. The shores of the lake are closed. The only way to sail from the lake to the ocean is if a river flows out of the lake. For example, the Neva River flows out of Lake Ladoga and flows into the Baltic Sea. But this does not make Lake Ladoga a sea. Even if a lake is connected to the ocean of a river, it remains a lake. Find on the map the Mediterranean, Aegean, Adriatic, Ionian, Tyrrhenian, Marmara, Black and Azov seas. The Mediterranean Sea is called because it connects directly to the Atlantic Ocean through the Strait of Gibraltar. A strait is not a river, it is part of the sea, part of the ocean. If this strait did not exist, the Mediterranean Sea would be considered a lake. The Aegean Sea is connected to the ocean through the Mediterranean Sea. The Adriatic, Ionian, Tyrrhenian seas are also connected to them. Calculate how many seas you have to swim through to get from Sea of ​​Azov to the Atlantic Ocean? Our country has the Caspian Sea. It is very large, the water in it is salty, so it was called the sea. However, this is a lake. Yes, yes, in fact, the Caspian Sea is just a lake, because it is not directly connected to any ocean. The Aral Sea is also a lake. They are called so - the lake of the Caspian Sea, the lake of the Aral Sea. You ask, why is the “sea” kept in their name? Traditionally. Everyone is so used to these names that they don't want to change them.

PUZZLES

Nobody salted, but salty

(sea)

The blue, the green

Now meek, now indignant,

Spread out to the ground.

Yachts and ships are friends with him.

And we are with you and him in the summer heat

Do not mind talking day-to-day.

(sea)

wide wide,

deep deep,

Day and night beats on the shore,

It does not drink water

Because it's tasteless

And bitter and salty.

(sea)

OCEANS AND SEA

There are four oceans on Earth. The largest of them is the Pacific Ocean. “Quiet” is just a name. In fact, the Pacific Ocean is often very rough. Why is it called the Quiet? It is said that when the first European travelers saw him, he was indeed very calm. This ocean occupies more than 1/3 of the earth's surface! It is also the deepest. It has the so-called Mariana Trench, the depth of which is 11022 meters. The next largest and deepest is the Atlantic Ocean. It is half the size of the Pacific and occupies more than approximately 1/6 of the earth's surface. Its greatest depth is 8742 meters. The third largest and deepest is the Indian Ocean. It occupies about 1/7 of the earth's surface. Its greatest depth is 7209 meters. And finally, the smallest and shallowest ocean is the Arctic Ocean. It is so named because it is located around North Pole of our planet and most of it is covered with ice. The Arctic Ocean occupies approximately 1/34 of the earth's surface. It is 12 times smaller than the Pacific, 6 times smaller than the Atlantic, and 5 times smaller Indian Oceans. Its greatest depth is 5527 meters.

Each ocean has several seas. The sea is a part of the oceans, which partially or completely (like the Mediterranean) protrudes into the land. To Pacific Ocean 13 seas belong to the Atlantic - 9, to the Indian - 5, to the Arctic - 10 seas.

Glossary of terms

A drainless lake is a lake from which no river flows. The water in almost all drainless lakes is salty.

A swamp is an area with excessively moistened soil, but without a continuous mirror of water on the surface.

Riding swamp - a swamp covered with a layer of mhasfagnum. Vegetation is poor, occasionally there are dwarf pines, lingonberries. Raised bog peat is an excellent fuel, but poor fertilizer.

A waterfall is a stream of water falling rapidly from a height.

To flow in - to flow in, to pour in (about the river).

Main river - a river into which another river flows (tributary)

Frost is a thin layer of snow that forms on a cooling surface from water vapor.

Source - the place where the water flow begins (river, stream).

Source (key, spring) - the place where groundwater comes out to the surface.

The key (spring, source) is the place where groundwater comes out to the surface.

The water cycle in nature is the evaporation of water from the surface of the Earth, the transfer of water vapor by winds, the condensation of water vapor and the formation of vapor and the formation of clouds, precipitation (rain, snow, hail.) And their runoff into rivers, lakes, seas and oceans.

Glacier - ice cover up to several tens of meters thick.

Forest swamp is one of the types of swamps. Covered with basic or birch forest, with a layer of moss and grass.

The sea is a part of the ocean that partially or completely protrudes into the land, a body of water with bitter salt water. If the sea goes completely into the land, it is connected to the ocean through the strait and other seas.

Lowland swamp - a swamp, the surface of which is covered with a thick layer of grass. Here sometimes there are birches, willow bushes; little moss. Peat from the fens is a good fertilizer, but a poor fuel (leaves too much ash - clogs the topics).

Lake - a natural reservoir located in the recesses of the land; feeds on ground and surface waters.

The ocean is huge deep space. There are 4 oceans on Earth - Pacific, Atlantic, Indian, Arctic.

A tributary is a river that flows into another (main) river.

A pond is an artificial (that is, man-made) body of water in a natural or excavated depression, as well as a ponded place in a river. (A dammed place in a river is otherwise called a dam).

A river is a water stream of significant size, flowing in a natural channel and having a source and mouth.

A spring is a place where groundwater comes to the surface

Dew is atmospheric moisture that precipitates as small water droplets when cooled.

A channel is a depression in the earth's surface along which a river flows. The channel has a natural origin, usually it is done by the river itself.

A stream is a small stream.

A wastewater lake is a lake from which at least one river flows. The water in these lakes is never salty.

The bog is the most dangerous place in the swamp; a place where a swamp sucks a person or animal into it.

Fog is opaque air containing a lot of water vapor.

A mouth is a place where a river flows into a sea, lake, or another river.

A filter is a device for purifying a liquid.

FOR INQUIRY

For the curious

1. What property of water do you think mom uses when she washes dishes or does laundry? Water is a universal solvent. It can dissolve many substances.
2. What is mineral water? Groundwater dissolves the salts that are in the ground. Therefore, mineral water is water that contains a solution of mineral salts. Such waters are often curative.
3. Suppose we have a mixture of sand, salt and sawdust. How to separate them from each other with water? We pour the whole mixture into the water, sawdust floats to the surface, salt and sand settle. We will remove the sawdust and stir the water until the salt is completely dissolved. Then we pass through the filter, sand will settle on it. We boil the resulting saline solution and keep it on until all the water has evaporated. Since the salt does not evaporate, it will remain at the bottom of the vessel.
4. Despite the fact that there is a lot of water on Earth, it is distributed extremely evenly. In Africa and Asia there are vast expanses devoid of water - deserts. A whole country - Algeria - lives on imported water. Fresh water is also delivered by ship to some of the islands of Greece. About 3 billion people around the world lack clean drinking water.
5. A person consumes 60 tons of water in a year only in the process of eating. And 300 tons of output goes to meet his other vital needs. Even the extraction of coal and oil is not complete without water: for 1 ton of coal - 5 tons of water, for 1 ton of oil - 130 tons.

FOR INQUIRY

1. Rain cools the air and cleans it of dust. Therefore, in the summer after rain it is easier to breathe.
2. If you open a window in a cold room, then white puffs of fog appear in a warm room. What's this? These are the smallest droplets of water. There is a lot of steam in a warm room. When we open the window, the air in the room will cool and the steam will turn into tiny droplets of water, forming fog. Then we closed the window. The water droplets turned into steam again, and the mist disappeared.
3. If we bring a dry cold object into a warm room, then droplets of water will appear on it. What a miracle The air contains steam. The steam comes into contact with a cold object, cools down and turns into water droplets.
4. Almost all solar energy falling on the earth is spent on the evaporation of water from the surface of water bodies: oceans, seas, rivers, lakes. Thousands of cubic kilometers of water rise into the atmosphere every year. Approximately 1/3 of atmospheric water returns as precipitation to the ocean, and 2/3 falls on land.
5. If all the water vapor contained in the atmosphere fell to the ground in the form of rain, then a layer of water 1 meter thick would form on land. But, fortunately, not all atmospheric water vapor falls to the ground in the form of rain and snow.
6. Academician A.P. Karpinsky called water "the most precious fossil". Where is this fossil kept? Water is everywhere: in reservoirs, on high mountains, at the poles. Approximately 1/5 of the soil is water. At a depth of up to 1 km. More than 4 million square kilometers of water are stored in the earth's crust. And over every square kilometer of the Earth's surface hangs an average of about 20 thousand tons of water in the form of steam.

FOR INQUIRY

1. From some source flows hot water. Typically, such sources are found in the vicinity of mountains, especially volcanoes. How is water heated? On the surface of the earth it is difficult to feel the inner warmth of our planet. But at a depth of 2-3 thousand meters the temperature rocks reaches 100 degrees. Water at such a depth is very hot, expands through cracks and cracks flows to the surface.
2. The moisture contained in the soil is completely renewed in 1 year.
3. The average residence time of water in the atmosphere is 10 days on average. However, in different areas it can reach 15 days, and in the central regions of Russia - 7.

FOR INQUIRY

1. There is a village in Altai - Raspberry Lake. This settlement arose in the neighborhood of a lake, the water in which seems to be raspberries. The water casts a crimson color because crimson-colored crustaceans live in abundance in it. In the Kuril Islands, on the island of Kumanshir, there is a lake with milky white water due to the presence of acid - hydrochloric and sulfuric. In Indonesia, on top of one of the active volcanoes, there are three small lakes: one is filled with bright red water, the other is blue, and the third is milky white. Red Lake owes its color to the presence of iron in its water. In two other lakes, hydrochloric and sulfuric acid. There is Lake Gokcha in the Caucasus. Near its banks, the water is yellowish, further away it is blue, and in the middle it is dark blue. Many lakes of the southern Andes play the most different colors: either blue and green, or steel and pearl. There is an ink lake in Algiers. The quality of its ink water can be tested even on paper. Two rivers flow into this lake. The water of one of them brings a lot of iron salts. In water, there are many substances that are formed in the soil during the decomposition of plants. These substances mix and form an inky liquid.
2. On the island of Java there is a lake that blows bubbles. Steam and gases rising from its surface blow out bubbles up to one and a half meters wide. They fly into the air like balloons and burst with a loud crack.
3. The United States has the Great Salt Lake. It's unbearably hot in here. In summer, even boating is not fun. Water skiing is also risky: a fall threatens to break bones. After all, the water in this lake is ¼ of petrified salt.
4. in the Urals Chelyabinsk region there is a sweet lake. The water here is really unusual. You can wash clothes in it, and oil stains are washed off even without soap. Studies have shown that a lot of soda is dissolved in the water of the “sweet” lake. It helps in washing and leaves a sweet aftertaste.
5. One frightening, though infrequent, phenomenon is observed in the swamps. From the depths, a column of water 20-30 meters high rises with noise. It was methane that escaped from under the bottom silt - a swamp gas formed during the decay of plant sediments. Emissions of marsh gas are sometimes accompanied by powerful eruptions of mud. A description of a powerful swamp eruption in Ireland in 1896 has been preserved. The Great New Wrathmore Swamp threw out a stream of mud, several kilometers long, which flooded everything in its path. One house was flooded with mud along with people. In our country, a large eruption was observed in the century before last, not far from Lake Onega. On one of the swampy water meadows, a fountain of mud, silt and sand 4 meters high beat for several days. And then a spring appeared at this place.

FOR INQUIRY

1. The word "ocean" comes from the Greek "okeanos" - "a great river flowing around the whole earth."
2. The world ocean is the water shell of the globe, covering most of its surface. The waters of the world's oceans are completely renewed on average for 3 thousand years.
3. Sargasso Sea. Not a single navigator has yet managed to land on the shores of this boundless mysterious sea. Christopher Columbus was the first to discover this sea, completely covered with floating algae - Sargasso. The strong currents of the Atlantic Ocean are conditionally considered the shores of this sea. The Sargasso Sea is rich in wildlife diversity. In calm weather, small crabs and shrimps scurry along the unsteady Sargassum “islands”. Tunas, mackerels, and swordtails circle above them. This sea also holds many secrets. Many ships and planes hit bermuda triangle located in this sea.

Guess the crossword.

Water condition

Horizontally:

1. In the morning the beads sparkled,

All the grass was tucked in.

And let's go look for them during the day -

We are looking for, we are looking for - we will not find.

2) Grows upside down.

It does not grow in summer, but in winter.

A little sun will bake it -

She will cry and die.

3) When all the flowers withered,

We flew from above.

We are like silver bees

Sat on a thorny tree.

Vertically:

3) In the yard by a mountain,

and in the hut with water.

5) Does not burn in fire,

does not sink in water.

6) Milk floated over the river,

Nothing was visible.

Dissolved milk -

It became visible far away.

7) Spread the golden bridge

For seven villages, for seven miles.

In addition to lakes and ponds, another type of water bodies can be found on the surface of the land - a swamp. A swamp is an area with excessively moistened soil, but without a continuous mirror of water on the surface. Wetlands usually form in lowlands where clay soil is poorly water-permeable. The swamps are very swampy, walking in the swamp is life-threatening. You can fall into a quagmire - the most swampy place in the swamp. The quagmire sucks in a person or animal that has got there and it is very difficult, and sometimes simply impossible, to get out of it without outside help. Sometimes the bog seems like a flat meadow, absolutely safe. But walking on it can lead to death. Cranberries grow in many swamps. People often go to the swamps for cranberries. But you can go on such a trip only with a person who knows the area well. In addition, poisonous snakes are often found there. Therefore, you can go there in high boots so that the snake does not bite your leg.

Guess the crossword.

Water condition

Horizontally:

1. In the morning the beads sparkled,

All the grass was tucked in.

And let's go look for them during the day -

We are looking for, we are looking for - we will not find.

2) Grows upside down.

It does not grow in summer, but in winter.

A little sun will bake it -

She will cry and die.

3) When all the flowers withered,

We flew from above.

We are like silver bees

Sat on a thorny tree.

Vertically:

3) In the yard by a mountain,

and in the hut with water.

5) Does not burn in fire,

does not sink in water.

6) Milk floated over the river,

Nothing was visible.

Dissolved milk -

It became visible far away.

7) Spread the golden bridge

For seven villages, for seven miles.

The game "Water will not spill"

Russian has a lot of educated expressions related to water. For example, “how to sink into the water” - to disappear without a trace; “as if lowered into the water” - having a dull look, etc. Remember which expressions correspond to the following values.

1. Keep silence (Take water in your mouth).

2. This is how to say, it is not known what the outcome will be. (Written with a pitchfork on the water)

3. Guessed, correctly predicted (As he looked into the water)

4. Take advantage of other people's difficulties. (Catch fish in troubled waters)

5. Confuse others, deliberately bring confusion to any issue. (Turn up the water)

6. Be ready for any act in the name of affection, ideas. (Into fire and water)

7. About complete similarity. (The same)

8. You can’t get through anything, you don’t care. (Like water off a goose)

9. Avoid well-deserved punishment. (Come out dry from water)

10. Distant relative. (Seventh water on jelly)

11. A lot of superfluous, unnecessary. (Much water)

12. Do some useless work. (Drag water in a mortar)

13. Live from hand to mouth, live in poverty. (Sit on bread and water.)

14. Hide all traces of an unseemly deed. (And ends in the water)

15. A lot of time has come. (A lot of water has flowed under the bridge)