The water shell of the Earth is the hydrosphere.
Didactic goal: create conditions for the primary assimilation, comprehension and comprehension of new educational information using developmental learning technology.
Content goals.
Educational : contribute to the formation of knowledge about the hydrosphere, how
the shell of the Earth, its components, the world cycle
Water in nature.
Educational: create conditions for the development of cognitive activity,
intellectual and creative abilities of students;
promote the development of skills to identify, describe and
explain the essential features of the main concepts of the topic;
promote the development of independent work skills
geographical texts, textbook, geographical map, with
multimedia presentation materials, diagrams, making
generalizations and conclusions.
Educational : contribute to the education of geographical culture,
culture of educational work, sense of responsibility, careful
attitude towards the environment, promote development
communication skills; develop interest in what is being studied
subject.
Planned results.
Personal : awareness of the value of geographical knowledge as an essential component of the scientific picture of the world.
Metasubject: the ability to organize one’s activities, determine its goals and objectives, the ability to conduct independent search, analysis, selection of information, the ability to interact with people and work in a team; express judgments, confirming them with facts; mastering practical skills in working with a textbook.
Subject: knowledge and explanation of the essential features of concepts, their use to solve educational problems.
Universal learning activities (UAL).
Personal : realize the need to study the topic.
Regulatory: plan your activities under the guidance of a teacher, evaluate the work of classmates, work in accordance with the assigned task, compare the results obtained with the expected ones.
Cognitive: extract, select and analyze information, obtain new knowledge from ESM sources, process information to obtain the required result.
Communicative: be able to communicate and interact with each other (in a small group and in a team).
Lesson type– a lesson in learning new knowledge.
Forms of organizing student activities– group (the class is divided into 5 working groups), individual.
Teacher Equipment:- multimedia presentation;
Video film "Hydrosphere of the Earth";
Computer, projector;
Physical map of the hemispheres.
Equipment for students: a computer and a file folder with tasks on the table of each group; textbook by A. A. Letyagin “Geography. Beginning course: 5th grade" - M.: Ventana - Graf, 2012; atlas on geography; dictionaries and encyclopedias; EOR; equipment needed for experiments: measuring cup, raw chicken egg, two 0.5 liter bottles of drinking water, two bottles of mineral water (one chilled, the other at room temperature), 4-5 tbsp. spoons of table salt, a tablespoon, a glass, 2 plates, edible ice cubes.
During the classes.
1. Organizational stage.
Target: emotionally – a positive attitude towards the lesson, creating an atmosphere of success and trust.
Teacher: I'm glad to see you at the geography lesson. Today we work in groups.
Everything you need
each group for the lesson (computer, file folder with forms
assignments, textbooks, dictionaries, encyclopedias) is on your desks.
Coordinators help me organize the work of each group:
Anufrieva Varya
Zhidkova Lera Stepanova Katya
Ciobanu Grisha Saleev Sergei
We continue our acquaintance with the geospheres of the Earth.
---Slide 1. Geospheres of the Earth: lithosphere - let’s get acquainted
atmosphere - got to know each other
hydrosphere
biosphere
Find in the table of contents of the textbook the topic that we studied in the last lesson.
(Man and atmosphere).
---Slide 2. The water shell of the Earth is the hydrosphere (from the Greek “water” and “ball”)
Viewing text of paragraph 15 , name the main questions that we will consider in today's lesson (subheadings highlighted in the text ).
Highlight key concepts of the topic (highlighted in boxes and in the text).
On the board under the name of the topic, signs are hung one by one, formulating the main points of the lesson.
HYDROSPHERE
- meaning As you master the topic according to this plan, there will be
- properties to move the cursor indicating the stage on
- the composition of which we will be in a certain
- World moment of the lesson.
cycle
water
Group assignment: using various sources of information (dictionaries, encyclopedias, the Internet), formulate additions to the definition of the hydrosphere on the slide.
On the board around the concept of "hydrosphere" cards are posted with information from different sources of information components of this term:
Oceans seas underground water ice and snow rivers lakes
Swamps reservoirs cycle more than 70% of the earth's surface
4 billion years liquid state solid state gaseous state
2. Updating knowledge. Goal setting.
Target: Based on the students’ basic knowledge on the specified topic, formulate tasks for this lesson.
Teacher: Let's remember what you already know about water?
Where on Earth can you find water?
Give examples of reservoirs.
In what three states does water exist in nature? (Fig. 56, p. 85)
3. The stage of joint discovery and assimilation of new knowledge.
Target: To acquaint students during research and problem-search work with the meaning of water, its properties, the composition of the hydrosphere and the World water cycle in nature.
- Statement of a problematic question.
Teacher: speaking about the meaning of water, I suggest you listen to an excerpt from the story of the French writer, pilot, participant in World War II Antoine de Saint-Exupéry “Planet of Humans”.
--- Slide 3. Statement by Exupery: “Water!” You are not just necessary for life, you are life. ……you give us infinitely simple happiness.”
You have no taste, no color, no smell, you cannot be described, you are enjoyed without understanding what you are. You are not just necessary for life, you are life. With you, bliss spreads throughout your entire being, which cannot be explained only by our five senses. You are returning to us the strength and properties that we had already given up on. By your mercy the dry springs of the heart are opened again.
You are the greatest wealth in the world, but also the most fragile - you, so pure in the depths of the Earth...... You do not tolerate impurities, you cannot tolerate anything alien, you are a deity who is so easily frightened...
But you give us infinitely simple happiness.”
Students speak out about the importance of water.
Teacher: To formulate the basic properties of water, I invite each group to conduct small studies.
(3 min.) (* - properties)
Detailed instructions for the experiments are in the section “School of the Geographer-Pathfinder” to paragraph 15.
1 group– studies the taste, color, smell of water; and also turns ice into liquid and then into water vapor.
2nd group– finds out information about the processes associated with the transition of water from one state to another.
Exercise: establish a correspondence (performed using cards with concepts and wording from the file folder).
1. Evaporation. A. The transition of water from liquid to solid.
2. Freezing (crystallization) B. The transition of water from a gaseous state to a liquid state.
3. Condensation. B. The transition of water from liquid to gaseous state.
4. Melting (melting) D. The transition of water from solid to liquid.
Answers: 1 – B; 2 – A; 3 – B; 4 – G.
3 group– explores the density of fresh and salt water (an experiment with a chicken egg in a glass of fresh and salt water).
4 group– explores the property of water to dissolve gases (an experiment with chilled and warm bottles of mineral water).
5 group– working with the text of paragraph 15 (p. 84), formulates the basic properties of water.
In the process of work, each group fills out its technological maps and reports the results of its research.
--- Slide 4 . Three states of water. (after the performance of 1 group).
Checking the work of group 2 (the concepts selected for each term are spoken out). EVAPORATION
FREEZING (crystallization)
CONDENSATION
MELTING (melting)
--- Slide 5 . Study of the density of fresh and salt water (group 3).
1. The density of fresh (drinking) water is less than the density of an egg,
therefore the egg sinks in fresh water.
2. The density of salt water is greater than the density of an egg, so the egg
does not sink in salt water.
---Slide 6. Study of the properties of water to dissolve gases (group 4).
A lot of gases were released from the cooled mineral water, so
More gases can be dissolved in chilled water than in
mineral water at room temperature.
--- Slide 7 . Properties of water: (to the answer of group 5).
- has no smell, taste and color;
- dissolves more substances than any other liquid;
- destroys hard rocks;
- oxidizes metals;
- expands when frozen;
- absorbs a large amount of heat;
- conducts electricity well.
HOME TASK: write down conclusions based on the results of experiments in the DGS.
(* - compound)
(*-World cycle
Water)
It will help answer questions related to the composition of the hydrosphere and the global water cycle in nature. a video fragment that is viewed with pauses, so that the guys have time to catch the main points. During the viewing process, the children are invited do some work with an individual card , in the text of which you need to fill in the gaps using words for selection.
---Slides 8 – 11.
Video fragment “Why. Hydrosphere". (5 minutes.)
Card - task .
1. The Earth’s hydrosphere includes the World Ocean, ____________ and water in the atmosphere.
2. The world's _________ occupies 96% of the Earth's surface.
3. The World Ocean includes several oceans: the Pacific, _________, Indian, Arctic and Southern.
4. The largest of them is the _____________ ocean.
5. Fresh water plays a more important role in human life, concentrated in rivers, lakes, _________ and underground.
6. All parts of the hydrosphere participate in the World ___________water in nature.
Words for selection: Atlantic, glaciers, land water, Pacific, gyre, ocean.
After viewing, students' attention is drawn to water cycle diagram Earth - fig. 57, p.86.
--- Slide 12. Text with the completed task.
Self-test (test using sample ).
A text appears on the screen with the blanks filled in, students check their work and evaluate themselves (give themselves a + for each correct answer).
Guys, are there anyone among you who chose 4 answers correctly? You did a good job!
Do we have anyone who has chosen 5 correct answers? You did a good job!
Raise your hands if you have 6 answers found. Well done! You did a great job!
---Slides 13, 14, 15 Physical education minute.
We fly like seagulls: And the seagulls are circling over the sea,
Let's fly after them together.
Splashes of foam, sound of the surf,
And above the sea - you and I.
Swimming movements with arms : We are now sailing on the sea
And we frolic in the open space.
Have fun raking
And catch up with the dolphins.
Walking in place : Look: seagulls are important
They walk along the sea beach.
Sit down, children, on the sand,
Let's continue our lesson.
---Slide 16. “A person does not value water until the source dries up”
(Mongolian proverb).
? What idea does this Mongolian wisdom suggest to you?
? How can we help nature? (do not pollute water, save money, etc.)
Test and self-test (performed in groups on computers, each answer is immediately checked).
Let's go back to the lesson plan. All points of the plan have been completed.
--- Slide 17. Homework .
- Reflection.
Students are asked to fill out an individual card in which they need to highlight phrases that characterize the student’s work in the lesson in three areas (cards for each are in the file folder of each group).
And also give yourself a grade for your work in class, including test results.
| I'M AT CLASS | ||
| Interesting. Doesn't matter. | Helped others. | I understand the material. I learned more than I knew. Didn't understand the material. |
Hands up, who was interested. What would you like to tell your parents about what you learned in class?
Hands up, who worked in the lesson. What new things did you learn about yourself today?
Hands up, who understood today's material. What was the most difficult thing for you today?
There are some in the class who didn't understand material?
In the last file, the folders of each group contain balloons in light blue and dark colors. Everyone in the group is asked to choose and inflate matching ball. If a person was interested, he worked and understood the material, then he can inflate a blue balloon; and if a person was bored, indifferent and rested during the lesson, then the color of his ball will be dark. Each group forms a wave from their balls. Based on the color of the waves formed, one can draw a conclusion about the results of the lesson.
The hydrosphere is the water shell of the Earth, which includes all non-chemically bound water. Water is present on Earth in three phase states: solid, liquid and gas. Of the almost 1.5 billion km3 of the total volume of water in the hydrosphere, about 94% comes from the World Ocean, 4% from groundwater (most of which are deep brines), 1.6% from glaciers and permanent snow, about 0.25% - on land surface waters (rivers, lakes, swamps), most of which are located in lakes. Water is present in the atmosphere and living organisms.
The unity of the hydrosphere is due water cycle- the process of its continuous movement under the influence of solar energy and gravity, covering the hydrosphere, atmosphere, lithosphere and living organisms (Fig. 8.3). The water cycle consists of evaporation from the surface of the ocean, the transfer of moisture in the atmosphere, precipitation on the ocean and land, its infiltration, and surface and underground runoff from land to the ocean. In the process of the global water cycle, its gradual renewal occurs in all parts of the hydrosphere. Moreover, groundwater is renewed over hundreds, thousands and millions of years; polar glaciers - for 8-15 thousand years; waters of the World Ocean - for 2.5-3 thousand years; closed, drainless lakes - for 200-300 years; flow-through - for several years; rivers - 11-20 days; atmospheric water vapor - for 8 days; water in organisms - in a few hours. It is known that the slower the water exchange, the higher the mineralization (salinity) of water in the hydrosphere element. That is why the waters of the underground hydrosphere are the most highly mineralized, and river waters serve as the beginning of almost all sources of fresh water.
An important element of the hydrosphere is World Ocean, the average depth of which is 3700 m, the greatest - 11,022 m (Mariana Trench). Almost all substances known on Earth are dissolved in sea water in varying quantities. The main part of the salts dissolved in sea water are chlorides (88.7%) and sulfates (10.8%), carbonates (0.3%). Each kilogram of water contains on average about 35 g of salts. The salinity of ocean water depends on the ratio of precipitation and evaporation. Its salinity is reduced by river waters and melting ice waters. In the open ocean, the distribution of salinity in the surface layers of water (up to 1500 m) has a zonal character: in the equatorial belt, where there is a lot of precipitation, it is low, in tropical latitudes it is high, and in temperate and polar latitudes, salinity decreases again. The world's oceans absorb and release
Rice. 8.3.
I - evaporation from the surface of the oceans; 2 - evaporation from river basins; 3 - precipitation falling on the surface of the oceans; 4 - precipitation falling on the surface of river basins; 5 - global moisture turnover between the ocean and
by land; b-infiltration of water into soils and its flow into rivers; 7-river flow; .U-infiltration of water into deep underground horizons; 9- the flow of groundwater into the oceans through the sides of their basins; 10- endorheic reservoir (closed area);
II - movement of water in the oceans; 12 - small water cycle; 13 - intra-continental moisture circulation; 14 - glaciers;
15 - icebergs
§8.3. The hydrosphere and atmosphere of the Earth contain a huge amount of gases (oxygen, nitrogen, carbon dioxide, hydrogen sulfide, ammonia, etc.).
The water surface temperature of the World Ocean is also characterized by zonality, which is disrupted by currents, the influence of land, and constant winds. The highest average annual temperatures (27-28 °C) are observed in equatorial latitudes. With increasing latitude, the temperature of the waters of the World Ocean drops to 0 °C and even lower in the polar regions (the freezing point of water with average salinity is 1.8 °C below zero). The average temperature of the surface layer of water is + 17.5 °C, and the average water temperature of the entire World Ocean is +4 °C. The thickness of perennial ice reaches a thickness of 3-5 m. Continental ice in the ocean forms floating mountains - icebergs. Ice covers about 15% of the entire water area of the World Ocean.
The water of the World Ocean is not at rest, but undergoes oscillatory (waves) and translational movements (currents). Waves on the surface of the ocean are formed mainly by wind; their height is usually no more than 4-6 m, maximum up to 30 m; wave length from 100-250 m to 500 m. The excitement caused by the wind fades with depth: at a depth of 200 m, even strong excitement is unnoticeable. When approaching the shore, friction with the bottom reduces the speed of the wave base, and the wave crest overturns - a surf appears. On steep shores, where the wave energy is not absorbed by the bottom, the force of their impact reaches 30-38 tons per 1 m2. Unrest throughout the entire thickness of ocean waters causes earthquakes, volcanic eruptions, and tidal forces. Thus, underwater earthquakes and volcanic eruptions cause tsunamis that travel at speeds of more than 700 km/h. In the open ocean, the length of a tsunami is estimated at 200-300 km with a height of about 1 m, which is usually imperceptible to ships. Off the coast, the height of the tsunami wave increases to 30 m, which causes catastrophic destruction.
Under the influence of the gravitational forces of the Moon and the Sun, ebbs and flows occur. Tides caused by the Moon are especially noticeable. Due to the rotation of the Earth, tidal waves move towards its movement - from east to west. Where the crest of a tidal wave passes, a high tide occurs, followed by an ebb. Depending on the conditions, the tides can be semidiurnal (two high tides and two low tides per lunar day), diurnal (one high tide and one low tide per day) and mixed (diurnal and semidiurnal tides replace each other). Solar tides are 2.17 times less than lunar tides. Lunar and solar tides can be added and subtracted. The magnitude and nature of sea tides depend on the relative positions of the Earth, Moon and Sun, on geographic latitude, sea depth, and the shape of the coastline. In the open ocean, the tide height is no more than 1 m, in narrow bays - up to 18 m. The tidal wave penetrates some rivers (Amazon, Thames) and, quickly moving upstream, forms a water shaft up to 5 m high.
Ocean currents are caused by wind, changes in water level and density. The main cause of surface currents is wind. In colder waters there are warm currents, in less cold waters there are cold currents. Warm currents are directed from lower latitudes towards higher latitudes, cold currents - vice versa. The direction of the current is influenced by the rotation of the Earth, which explains their deviation to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. Systems of surface currents in the oceans depend on the direction of the prevailing winds and on the position and configuration of the oceans. In tropical latitudes, stable air currents over the oceans (trade winds) cause northern and southern trade wind currents, pushing water to the eastern shores of the continents. An inter-trade countercurrent arises between them. Along the eastern coasts, warm currents flow north and south into temperate latitudes. In temperate latitudes, westerly winds cause currents to cross the oceans from west to east. The causes of currents at depth are different densities of water, which can be caused by the pressure of the mass of water from above (for example, in places of surge or driven by the wind), changes in temperature and salinity. Changes in the density of water are the reason for its vertical movements: the lowering of cold (or more salty) and the rise of warm (or less salty).
The movement of water is associated with the supply of depths with oxygen and other gases from the atmosphere and the removal of nutrients for organisms from the depths to the surface layers. Places of intense water mixing are richest in life. The World Ocean is home to about 160 thousand species of animals and more than 10 thousand species of algae. There are three groups of marine organisms: 1) plankton - passively moving unicellular algae and animals, crustaceans, jellyfish, etc.; 2) nekton - actively moving animals (fish, cetaceans, turtles, cephalopods, etc.); 3) benthos - organisms living on the bottom (brown and red algae, mollusks, crustaceans, etc.). The distribution of life in the surface layer of water is zonal.
Land waters, which include groundwater, rivers, lakes, swamps, and glaciers, play a significant role in the existence of life on Earth.
The groundwater are located in the rock mass of the upper part of the earth's crust. The bulk of them is formed due to the seepage of rain, melt and river water from the surface. The depth, direction and intensity of movement of groundwater depend on the permeability of rocks. According to the conditions of occurrence, groundwater is divided into soil; soil, lying on the first permanent waterproof layer from the surface; interstratal, located between two impermeable layers. Groundwater feeds rivers and lakes.
Rivers - constant water flows on the land surface. The main river and its tributaries form a river system. The area from which a river collects surface and groundwater is called a river basin. The basins of neighboring rivers are separated by watersheds. The speed of the river flow is directly dependent on the slope of the channel - the ratio of the difference in the height of the section to its length. In lowland rivers the flow speed rarely exceeds 1 m/s, and in mountain rivers it is usually more than 5 m/s. The most important characteristic of rivers is their nutrition - snow, rain, glaciers and underground. Most rivers have mixed feeding. Rain feeding is typical for rivers in equatorial, tropical and monsoon regions. Rivers of temperate climates with cold, snowy winters are fed by the waters of melting snow. Rivers that begin in high, glacier-covered mountains are fed by glaciers. Groundwater feeds many rivers, thanks to which they do not dry out in the summer and do not dry up under the ice. The regime of rivers largely depends on nutrition - changes in water flow according to the seasons of the year, fluctuations in its level and changes in temperature. The most abundant river in the world is the Amazon (220,000 m 3 /s per year). In our country, the most abundant river is the Yenisei (19,800 m 3 /s per year).
Lakes- reservoirs of slow water exchange. They occupy about 1.8% of the land surface. The largest of them is the Caspian Sea, the deepest is Baikal. Lakes can be drainage (rivers flow from them) or drainless (devoid of flow); the latter are often salty. In lakes with very high mineralization, salts can precipitate (self-sedimented lakes Elton and Baskunchak). Zoning is observed in the distribution of lakes across the earth's surface. There are especially many lakes in the tundra and forest zones. In areas with insufficient moisture, mainly temporary reservoirs appear.
Swamps- excessively moist land areas with moisture-loving vegetation and a peat layer of at least 0.3 m (with a smaller layer - wetlands). Swamps are formed as a result of overgrowth of lakes or swamping of land and are divided into lowland, fed mainly by groundwater and having a concave or flat surface, transitional and upland, the main nutrition of which is precipitation, their surface is convex. The total area occupied by swamps is about 2% of the land area.
Glaciers- moving masses of ice that arise on land as a result of the accumulation and gradual transformation of solid atmospheric precipitation. They form where more solid precipitation falls during the year than has time to melt and evaporate. The limit above which snow accumulation is possible is called the snow line. In the polar regions it is located low (in Antarctica - at sea level), at the equator - at an altitude of about 5 km, and in tropical latitudes - above 6 km. Glaciation is of two types: cover (Antarctica, Greenland) and mountain (Alaska, Himalayas, Hindu Kush, Pamir, Tien Shan). A glacier has areas of feeding (where ice accumulates) and drainage (where its mass decreases due to melting, evaporation, and mechanical calving). Once accumulated, the ice begins to move under the influence of gravity. The glacier can advance and retreat. Now glaciers occupy about 11% of the total land area; during the era of maximum glaciation they covered about 30% of its area. Glaciers contain almost 70% of the fresh water on Earth.
Earth is the 3rd planet from the Sun, located between Venus and Mars. It is the densest planet in the solar system, the largest of the four, and the only astronomical object known to host life. According to radiometric dating and other research methods, our planet formed about 4.54 billion years ago. The Earth gravitationally interacts with other objects in space, especially the Sun and Moon.
The Earth consists of four main spheres or shells, which depend on each other and are the biological and physical components of our planet. They are scientifically called biophysical elements, namely the hydrosphere ("hydro" for water), the biosphere ("bio" for living things), the lithosphere ("litho" for land or earth's surface), and the atmosphere ("atmo" for air). These main spheres of our planet are further divided into various sub-spheres.
Let's look at all four shells of the Earth in more detail to understand their functions and meaning.
Lithosphere - the hard shell of the Earth
According to scientists, there are more than 1386 million km³ of water on our planet.
The oceans contain more than 97% of the Earth's water. The rest is fresh water, two-thirds of which is frozen in the planet's polar regions and on snowy mountain peaks. It is interesting to note that although water covers most of the planet's surface, it makes up only 0.023% of the Earth's total mass.
The biosphere is the living shell of the Earth
The biosphere is sometimes considered one big one - a complex community of living and nonliving components functioning as a single whole. However, most often the biosphere is described as a collection of many ecological systems.
Atmosphere - the air envelope of the Earth
The atmosphere is the collection of gases surrounding our planet, held in place by the Earth's gravity. Most of our atmosphere is located near the earth's surface, where it is densest. The Earth's air is 79% nitrogen and just under 21% oxygen, as well as argon, carbon dioxide and other gases. Water vapor and dust are also part of the Earth's atmosphere. Other planets and the Moon have very different atmospheres, and some have no atmosphere at all. There is no atmosphere in space.
The atmosphere is so widespread that it is almost invisible, but its weight is equal to the layer of water more than 10 meters deep that covers our entire planet. The lower 30 kilometers of the atmosphere contain about 98% of its total mass.
Scientists say many of the gases in our atmosphere were released into the air by early volcanoes. At that time there was little or no free oxygen around the Earth. Free oxygen consists of oxygen molecules not bonded to another element, such as carbon (to form carbon dioxide) or hydrogen (to form water).
Free oxygen may have been added to the atmosphere by primitive organisms, probably bacteria, during . Later, more complex forms added more oxygen to the atmosphere. The oxygen in today's atmosphere likely took millions of years to accumulate.
The atmosphere acts like a giant filter, absorbing most of the ultraviolet radiation and allowing the sun's rays to penetrate. Ultraviolet radiation is harmful to living things and can cause burns. However, solar energy is essential for all life on Earth.
The Earth's atmosphere has. The following layers extend from the surface of the planet to the sky: troposphere, stratosphere, mesosphere, thermosphere and exosphere. Another layer, called the ionosphere, extends from the mesosphere to the exosphere. Outside the exosphere is space. The boundaries between atmospheric layers are not clearly defined and vary depending on latitude and time of year.
Interrelation of the Earth's shells
All four spheres can be present in one place. For example, a piece of soil will contain minerals from the lithosphere. In addition, there will be elements of the hydrosphere, which is moisture in the soil, the biosphere, which is insects and plants, and even the atmosphere, which is soil air.
All spheres are interconnected and depend on each other, like a single organism. Changes in one area will lead to changes in another. Therefore, everything we do on our planet affects other processes within its boundaries (even if we cannot see it with our own eyes).
For people dealing with problems, it is very important to understand the interconnection of all the layers of the Earth.
Hydrosphere – the water shell of the Earth, including oceans, seas, rivers, lakes, groundwater and glaciers, snow cover, as well as water vapor in the atmosphere. The Earth's hydrosphere is 94% represented by salty waters of the oceans and seas, more than 75% of all fresh water is conserved in the polar caps of the Arctic and Antarctica (Table 1).
Table 1 – Distribution of water masses in the Earth’s hydrosphere
|
Part of the hydrosphere |
Volume of water, thousand km 3 |
Share in the total volume of water, % |
|
World Ocean |
1 370 000 |
94,1 |
|
The groundwater |
60 000 |
|
|
Glaciers |
24 000 |
|
|
Lakes |
0,02 |
|
|
Water in the soil |
0,01 |
|
|
Atmospheric vapors |
0,001 |
|
|
Rivers |
0,0001 |
Water on Earth is present in all three states of aggregation, but the largest volume is in the liquid phase, which is very significant for the formation of other features of the planet. The entire natural water complex functions as
a single whole, being in a state of continuous movement, development and renewal. The surface of the World Ocean, which occupies about 71% of the earth's surface, is located between the atmosphere and the lithosphere. The diameter of the Earth, i.e. its equatorial diameter is 12,760 km, and the average depth of the ocean in its modern bed– 3.7 km. Consequently, the thickness of the layer of liquid water is on average only 0.03% of the Earth's diameter. In essence, it is the thinnest film of water on the surface of the Earth, but, like an ozone protective layer, it plays an extremely important role in the biosphere system.
Without water there could not be humans, animals and plants, since most plants and animals consist mainly of water. In addition, life requires temperatures in the range from 0 to 100 ° C, which corresponds to the temperature limits of the liquid phase of water. For many living creatures, water serves as a habitat. Thus, the main feature of the hydrosphere is the abundance of life in it.
The role of the hydrosphere in maintaining a relatively constant climate on the planet is great, since, on the one hand, it acts as a heat accumulator, ensuring the constancy of the average planetary temperature of the atmosphere, and on the other–Due to phytoplankton, it produces almost half of all oxygen in the atmosphere.
The aquatic environment is used for fishing and other seafood, collecting plants, mining underwater deposits of ore (manganese, nickel, cobalt) and oil, transporting goods and passengers. In production and economic activities, people use water for cleaning, washing, cooling equipment and materials, watering plants, hydrotransportation, and ensuring specific processes, such as generating electricity
and so on.
An important circumstance inherent in the aquatic environment is that infectious diseases are mainly transmitted through it (approximately 80% of all diseases). The simplicity of the flooding process compared to other types of burial, the inaccessibility of the depths for humans and the apparent isolation of water have led to the fact that humanity actively uses the aquatic environment to dump production and consumption waste. Intense anthropogenic pollution of the hydrosphere leads to serious changes in its geophysical parameters, destroys aquatic ecosystems and is potentially dangerous to humans.
The environmental threat to the hydrosphere has confronted the international community with the task of taking urgent measures to save the human habitat. Their peculiarity is that not a single state, even with the help of strict measures, is able to cope with the environmental threat. Therefore, international cooperation in this area is necessary, the adoption of an optimal environmental strategy that includes a concept and program of joint actions of all countries. These measures must comply with the principles of modern international law.
2. ECOLOGICAL – ECONOMIC ANALYSIS OF HYDROSPHERE
Analysis of the bioeconomy of seas and oceans includes several methodological aspects of determining the quantitative and qualitative characteristics of biological resources, the conditions for their use in the national economic complex. The results of this analysis are the basis for developing or improving the economic and organizational system for managing the rational use of biological resources. The controlled bioeconomic system of the oceans includes many determining and resulting ecological and economic indicators, parameters of their relationships and interdependencies. The level of controllability of a bioeconomic system is determined mainly by the knowledge of processes and phenomena at each hierarchical level (international, interstate and regional), the presence of interstate agreements on the rational use of sea and ocean resources and their protection.
The rational use of hydrosphere biological resources in general can be considered as a system of social measures of a legal, economic, economic and scientific-standardized nature, determined by the need for the systematic maintenance and reproduction of commercial biological resources, as well as the reliable protection of natural conditions and their aquatic habitat.
Over the past century-long history of economic management, humanity has developed an understanding of the need for careful use of natural resources. In recent decades, various assessment approaches have been intensively developed to create a system of program measures for the protection of land, water, forests and other resources.
Bioeconomic assessment of hydrosphere resources is sometimes carried out using an inventory. However, it should be noted that there is a fundamental difference between the use of the bioeconomic cadastre in the Russian Federation and its use in some other countries. In our country, the adopted land legislation contains a special section “State Land Cadastre”, which states that in order to ensure the rational use of land resources, the cadastre must contain a set of necessary information about the natural, economic and legal status of lands, soil classification and economic valuation of lands.
A distinctive feature of the bioeconomic cadastre from the land cadastre is that its compilation, processing of hydrological, physicochemical characteristics, as well as the species composition of living resources of the hydrosphere are more strictly centralized in official documents. The formation and use of the bioeconomic cadastre of the hydrosphere is at a high level, allowing the widespread use of information systems for data processing and the creation of data banks.
In a general sense, under bioeconomic cadastre implied a significant set of documents in which the necessary information about specific types of aquatic biological resources and their habitat, natural, legal and economic-organizational conditions for their economic use is systematized in an orderly form at a national or regional level.
The main objectives of the bioeconomic cadastre are to generalize and bring closer to objectivity the available information on the distribution, habitat conditions and reserves of specific species of the hydrosphere, on the conditions of economic activity and exploitation in the interests of maximizing the satisfaction of society's needs for food and non-food products. The bioeconomic cadastre acts as an advisory and sometimes as a directive document that provides the functions of national economic management related to the development, use, protection and reproduction of aquatic biological resources.
The bioeconomic cadastre of seas and oceans functionally provides the following main activities:
1) accounting and environmental - economic forecasting of reserves, distribution and condition of specific types of biological resources in national and international waters;
3) comprehensive planning of the activities of other sectors of the national economy that have a certain impact on the state and dynamics of the number of biological resources of the hydrosphere;
5) development and implementation of long-term programs of environmental and reproductive measures at the regional, national and international levels;
6) implementation of measures for economic and mathematical modeling of bioeconomic processes of the hydrosphere;
7) determination of the amount of mutual settlements for the use of biological resources by national and foreign organizations;
8) determination of the amount of damage, as well as compensation by sectors of the national economy for biological resources of the hydrosphere;
9) development of integrated environmental - economic programs for the long-term use of resources by region and individual economic tasks related to the development of the World Ocean, etc.
The practical needs of the development and implementation of bioeconomic inventories require their implementation and classification according to certain criteria depending on the spatial and geographical distribution of the aquatic environment and biological resources and depending on their international legal status. Under these conditions, objective social needs arise for the development of environmental— economic assessment of natural resources in general and biological resources in particular.
In the studied object of hydrosphere biological resources there must certainly be an initial supply of them that is not equal to zero, while for artificially created resources (seaculture, etc.) this rule is not so necessary.
With regard to stocks of biological resources, two approaches to constructing a bioeconomic cadastre are possible. They are associated with the minimum or maximum state of stocks at the time of making a decision on the reproduction of resources of the seas and oceans and their protection.
Of great importance for constructing a bioeconomic inventory of the hydrosphere is the study of the properties of these reserves, taking into account persistence, mobility, renewability, inclusion in consumption, reactivity and uniqueness.
Storability manifests itself in the fact that the reserves of biological resources of the hydrosphere in terms of volume or composition can only exist for a certain time, after which they either break up into smaller reserves, or are completely lost for use, or require some kind of cost to increase, etc.
Mobility manifests itself in the possibility of redistributing reserves or concentrating the production of biological resources hydrosphere.
Recoverability - This is a complete or limited bringing of the stock to the desired level. Under certain environmental conditions, the supply of biological resources may not be restored at all.
Inclusion in consumption as a property is manifested in the ability of biological resources to be used without certain conditions or in the presence of such conditions, for example, appropriate environmental conditions, the level of development of fishing technology, etc.
Reactivity involves studying the reaction of the influence of individual factors on the reserves of biological resources in quantitative and qualitative terms.
Uniqueness or ordinaryness is expressed in varying degrees of dispersion and availability of hydrosphere bioresources.
Modern data on the mineral, energy and chemical resources of the World Ocean are of significant practical interest for the national economy, especially the mineral wealth of the shelf subsoil - oil, natural gas, sodium, etc. Therefore, the marine environment can be considered as a “nature - production” object where processes take place creation of material resources for society and their reproduction.
Under shelf of seas and oceans should be understood underwater extensions of the continent towards the sea with a depth of 20 to 600 m. The width of the shelf can be on average about 40-1000 km, and the area - about 28 million km 2 (19% sushi).
For example, industrial oil production in the Caspian Sea began back in 1922, and now more than 18 million tons of oil are produced here annually. In 1949, offshore drilling began off the coast of Brazil in the Gulf of Makapkan, and now more than 60 countries are drilling the seabed and 25 of them are extracting oil and natural gas from the depths of the sea. World oil production in 1972 amounted to 2.6 billion tons, and according to forecasts in 2000 it will be 7.4 billion tons. About 40 billion tons of oil were extracted from the bowels of the earth throughout the history of mankind, and until 2000 150 billion tons will be produced.
In 1975, international oil concerns produced products worth approximately $40 billion, and the total value of marine mineral raw materials extracted in 1976 was estimated at $60–70 billion. For decades, coal has been extracted from land-based mines. subsoil of the seabed in England, Japan, Canada, Chile. Significant coal deposits are hidden in the depths of the shelf off the coast of Turkey, China, and. Taiwan, off the coast of Australia. The largest iron ore deposits on the seabed are concentrated off the eastern coast of the island. Newfoundland, where total ore reserves reach 2 billion tons. The marine placers of Australia, where gold, platinum, rutile, ilmenite, zircon, and mangancite were discovered, are world famous. In the USA, more than 900 kg of platinum are mined annually from sea placers, and in South-West Africa - about 200 thousand carats of diamonds. Currently, 1/3 of the world's salt production, 61% of magnesium metal, and 70% of bromine are obtained from sea water. Fresh drinking water is becoming increasingly important.
Nowadays, more than 500 million people get sick every year from the consumption of poor-quality water by the population of some areas of the globe. In the near future, freshwater resources on land will increasingly need to be replenished by desalinating seawater. However, water desalination is a very energy-intensive production, so it becomes necessary to find ways to use additional marine resources for this purpose. With the exception of oil and natural gas production, the energy resources of the seas are underutilized. Therefore, the relatively high cost of desalinated water is sometimes the main reason for the introduction of scientific and technological progress. According to preliminary estimates, the cost of desalinated water when using electrical energy from tidal and other conventional power plants is 6-20 thousand den. units/m3, and when using nuclear power plants - 1-4 thousand den. units/m3.
The total tidal energy capacity is just over 1 billion kW. Since 1968, the Kislogubskaya tidal power plant with a capacity of 1 thousand kW has been operating; in France, a similar station was built on the Cotentin Peninsula with a capacity of 33 million kW. The intensification of the development of the resources of the World Ocean and the development of energy do not occur without causing damage to it. Complex biological and other natural processes take place in the World Ocean, for example, more than half of all earth's oxygen is produced, and a violation of the ecological balance leads to a decrease in the productivity of phytoplankton, which, in turn, leads to a decrease in oxygen content and an increase in carbon dioxide in the atmosphere. Currently, the fauna and flora of the World Ocean are seriously threatened by pollution: municipal, industrial, agricultural and other wastewater is a source of bacterial and radioactive pollution; emergency discharges; oil leaks from tankers; pollutants coming from the air, etc. Every year, about 2 million tons of oil fall from tankers and offshore drilling rigs to the surface of the ocean. Not only offshore drilling is dangerous for the seas and oceans, but also seismic methods of oil exploration, since explosions kill eggs, larvae, juveniles and adult fish.
Thus, the problem of protecting the World Ocean is of national and international significance, and its successful solution will contribute to progress in the field of protecting the biosphere within an individual state and the entire planet. The country cooperates in protecting the marine environment from pollution with Germany, the USA, Canada, France, Japan, Sweden, Finland, and actively participates in the activities of the International Union for the Conservation of Nature and Natural Resources and other international organizations. To protect water resources, our country has adopted a number of resolutions “On measures to prevent pollution of the Caspian Sea”, “On measures to prevent pollution of the Volga and Ural river basins with untreated wastewater”, “On measures to preserve and rationally use the natural complexes of the lake. Baikal" and others.
The multifaceted use of the ocean creates problems and contradictions in the development of many industries. For example, oil production in coastal waters causes damage to fisheries and resorts. Hydrosphere pollution has a negative impact on biological resources and on humans, and causes enormous damage to the economy.
Available methods make it possible to determine the amount of economic and social damage caused to nature by sectors of the national economic complex of our country. The further task of increasing the environmental and economic efficiency of nature management is to improve the economic mechanism that allows the transfer of environmental measures from the state budget to economic accounting. Under these conditions, it will be possible to rationally use and protect resources and the hydrosphere, i.e. the World Ocean will be able to ensure the progress of mankind only by taking into account the reasonable interaction of society and nature.
3. ECOLOGICAL AND ECONOMIC ASSESSMENT OF THE CONSEQUENCES OF HYDROSPHERE POLLUTION
The growth in the possibilities of industrial, agricultural production and non-production spheres complicates the relationship between society and nature, resulting in the need to preserve and improve the life support system on a global and regional scale. External environment hydrosphere, atmosphere and metasphere becomes a direct participant in the production of a social product. Therefore, here, as in basic production, systematic accounting, control and planning for the rational use of natural resources and environmental protection are required. The effectiveness of these measures is closely related to determining the amount of economic and social damage caused to society and nature by negative anthropogenic impacts. Under economic and social damage
should be understood losses in the national economy and society, directly or indirectly resulting from negative anthropogenic impacts leading to environmental pollution with aggressive substances, noise, electromagnetic or other wave effects.
In the general interpreted understanding, specific damage is the amount of reduction in national income per unit of emitted aggressive substances in hydrosphere, lithosphere, atmosphere. It can be calculated for 1 km 2 of sea, 1 hectare of agricultural land, 1 hectare of forests, per 1000 people, 1 million den. units fixed assets, etc.
Using the calculated characteristics of changes in the amount of damage from the concentration of an aggressive substance in the environment and the duration of its impact on a subject or object, it is possible to develop a pollution assessment monogram hydrosphere, lithosphere or atmosphere, in which zones are distinguished according to the degree of danger. When determining the danger zone of water pollution, the directions of use of water resources should be taken into account. For example, the requirements for water quality are different when people use it for cooking or for cultural and domestic needs. The absolute and comparative effectiveness of environmental protection measures is closely related to the requirements for maintaining the quality of water and other natural resources. The criteria for the comparative effectiveness of environmental protection measures can be the achievement of growth in national income by preventing economic damage with minimal costs for environmental protection measures. It follows from this that the amount of economic damage can act as a general measure when optimizing the relationship between society and nature. The need to optimize resource-saving and environmental measures is of particular importance, since their implementation requires expenditures of more than 20% of all capital investments in the national economic complex. At the same time, comparative indicators ecological—
Lecture 3.
Hydrosphere is the watery shell of the earth.
Hydrosphere pollution.
Sources of hydrosphere pollution.
Methods for monitoring water quality.
Water protection measures.
Wastewater treatment methods.
Hydrosphere is the watery shell of the Earth.
Hydrosphere- the water shell of the Earth, including all waters in liquid, solid and gaseous states.
The hydrosphere includes the waters of the oceans, seas, groundwater and surface waters of the land. Some water is found in the atmosphere and in living organisms.
Water occupies the predominant part of the Earth's biosphere (71% of the total area of the earth's surface).
The hydrosphere already 4 billion years ago was represented by the following three components: terrestrial (the World Ocean, river, soil, lake waters, glaciers), underground (water of the lithosphere), air (vapor water of the atmosphere). The hydrosphere includes the following types of water (in parentheses the share of the total volume of water in the hydrosphere, %, according to M.I. Lvovich, 1974):
World Ocean (94.0);
groundwater (4.3);
glaciers (1.7);
land waters (lakes, river waters, soil moisture) (0.03);
atmospheric vapor (0.001).
Water is an essential component of living matter (70–99%). In essence, living matter is an aqueous solution of “living” molecules. It is water that ensures their life. Terrestrial life originated in an aquatic environment, and therefore can be considered a derivative of water.
Fundamental properties of water:
1. First property hydrosphere – unity and "omnipresence""(according to V.I. Vernadsky) natural waters. All waters are interconnected and represent a single whole. This unity of natural waters is determined by:
a) easy transition of water from one phase state to another. Within the limits of earthly temperatures, three states are known: liquid, solid, vapor. The plasma state of water exists at high temperatures and pressures in the deep parts of the subsurface;
b) the constant presence of gas components in water. Natural water is an aqueous solution (gas, suspended solids, minerals).
2. Second property hydrosphere is determined special structure of the water molecule. The structure and properties of water provide the most favorable conditions for the development of life on Earth. From physics we know that all bodies expand when heated and contract when cooled. Water behaves differently. If it were to compress when turning into ice (cooling), the ice would be heavier than water and would sink to the bottom of rivers and lakes. The rivers would be frozen to the bottom, and life in these bodies of water would be impossible. Ice is an insulator that keeps the water underneath the ice from freezing, which protects all underwater life. If it were not for this property, the Earth would turn into an ice-bound planet.
The special structure of the water molecule provides variety of structure it when external factors change (temperature, pressure, chemical composition). In winter we had to observe the variety and beauty of ice patterns on the windows, snowflakes, frost on the trees. Just as no two drops of water are exactly alike, no two types of water are identical in structure.
3. Third property hydrosphere is expressed in geologically its eternal mobility. The movement of water is very diverse and manifests itself in numerous cycles. The main movement of water is the geological cycle of matter. Every second, under the influence of the sun's heat, millions of cubic meters of water rise up and form clouds. The wind sets the clouds in motion. When conditions are right, moisture falls in the form of rain or snow. Raindrops have a favorable size for everything on earth and fall quietly and softly. Are all favorable coincidences in life random? Thus, water participates in peculiar cycles of matter and energy. This system was established on Earth with the advent of free water and continues to this day.
Why is the movement happening? Movement can occur under the influence of: a) gravity; b) solar (thermal) energy; c) molecular movement when changing phase state.
4. Fourth property hydrosphere is determined by high chemical activity of water. Under the conditions of the earth's crust, there are no natural bodies that, to one degree or another, would not dissolve in natural waters. Water in the biosphere acts as a universal solvent, because, interacting with all substances, as a rule, it does not enter into chemical reactions with them. This ensures the exchange of substances between land and ocean, organisms and the environment.
The most important abiotic factors of the aquatic environment are the following:
1. Density and viscosity.
The density of water is 800 times, and the viscosity is approximately 55 times greater than air.
2. Heat capacity.
Water has a high heat capacity, so the ocean is the main receiver and accumulator of solar energy.
3. Mobility.
The constant movement of water masses helps maintain the relative homogeneity of physical and chemical properties.
4. Temperature stratification.
A change in water temperature is observed along the depth of the water body.
5. Periodic (annual, daily, seasonal) temperature changes
The lowest water temperature is considered to be - 2 ° C, the highest + 35-37 ° C. The dynamics of fluctuations in water temperature are less than those of air.
6. Transparency and turbidity of water.
Determines the light regime below the surface of the water. The photosynthesis of green bacteria, phytoplankton, higher plants, and, consequently, the accumulation of organic matter depends on transparency (and its inverse characteristic - turbidity).
Turbidity and transparency depend on the content of suspended substances in water, including those entering water bodies along with industrial discharges. In this regard, transparency and suspended solids content are the most important characteristics of natural and waste waters that are subject to control at an industrial enterprise.
7. Salinity of water.
According to the degree of salinity, all reservoirs are conventionally divided into
fresh with salinity less than 0.5 0 / 00,
brackish water - salinity ranges from 0.5 - 16 0 / 00,
salty - more than 16 0 / 00.
The salinity of oceanic water bodies is 32 - 38 0/00,
The highest salt content is in salt lakes, where the concentration of electrolytes reaches 370 0/00.
Main difference sea water from river salt is that the overwhelming majority of sea salt is chlorides, and in river water prevail carbonic salts. A person uses only fresh water to ensure life. Of the total water resources on earth, share of fresh water have to no more than 3%.
8. Dissolved oxygen and carbon dioxide.
Excessive consumption of oxygen for the respiration of living organisms and for the oxidation of organic and mineral substances entering the water with industrial discharges leads to the impoverishment of the living population to the point where aerobic organisms cannot live in such water.
9. Hydrogen ion concentration (pH).
All aquatic organisms have adapted to a certain pH level: some prefer an acidic environment, others prefer an alkaline environment, and others prefer a neutral one. A change in these characteristics can lead to the death of aquatic organisms.