home epics Patterns of the location of geographical zones on the planet. Patterns of distribution of geographical zones and natural zones of the world

Patterns of the location of geographical zones on the planet. Patterns of distribution of geographical zones and natural zones of the world

Planet Earth is a unique source of life within which everything develops naturally. Each continent is a separate biocomplex on which they have adapted to live. different types plants and animals. In geography, separate territories that have a similar climate, soil, vegetation and animal world commonly referred to as natural areas.

Zone types

Zoning is the division of the territories of continents and oceans into separate parts, which are called zones. The easiest way to distinguish them from each other is by the nature of the vegetation, because it depends on it which animals can live in this region.

Rice. 1. Nature on Earth

Into the pattern of placement natural areas There are three types of zoning:

Change of natural zones by latitudes. Moving from the equator to the poles, one can notice how the complexes change one after another in a horizontal position. This pattern is especially clearly seen on the Eurasian continent.
Zonality along meridians. Natural areas also change in longitude. The closer to the ocean, the greater its impact on land. And the farther inland to the continent, the more moderate the climate. Such zonation can be traced in the Northern and South America, Australia.
Vertical zonation. As you know, the change of natural zones occurs in the mountains. The farther from the surface of the earth, the colder it becomes and the nature of the vegetation changes.

Reasons for zoning

The regularity of the location of natural zones is due different amount heat and moisture in different areas. Where there is a lot of rain and high level evaporation - humid equatorial forests appear, where there is a lot of evaporation, and little precipitation - savannahs. Where there is no precipitation at all and the whole year is dry - deserts and so on.

The main reason for zoning is the difference in the amount of heat and moisture in different areas, moving from the equator to the poles.

Rice. 2. Dawn in the steppe

What is the difference between heat and moisture?

The distribution of heat and moisture on Earth depends on the shape of our planet. As you know, it is spherical. The axis of rotation is not straight, but has some inclination. This leads to the fact that the sun heats different parts of the planet in different ways. To better understand this process, consider the figure.

What have we learned?

Natural zones replace each other not only in latitude, but also in longitude. This is due to the remoteness or proximity to the ocean. In the mountains, a change in natural zones can be traced because the higher, the colder the climate. There are two main reasons that affect the pattern of changing natural zones: the spherical shape of the Earth and the rotation of the planet along an inclined axis.

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1. Integrity - is manifested in the fact that a change in one component of the natural complex inevitably causes a change in all the others and the entire system as a whole. Changes that occur in one place of the shell are reflected in the entire shell.

2. Rhythm is the repetition of similar events over time. Rhythms are periodic (have the same duration) and cyclic (have unequal duration). In addition, there are daily, annual, secular, supersecular rhythms. The change of day and night, the change of seasons, the cycles of solar activity (11 years, 22 years, 98 years) are also examples of rhythms. Most rhythms are associated with a change in the position of the Earth in relation to the Sun and Moon. A certain rhythm can also be traced in mountain-building cycles (period of 190-200 million years), glaciations and other phenomena.

3. Zoning - a regular change in all components of the geographic shell and the shell itself from the equator to the poles. Zoning is due to the rotation of the spherical Earth around an inclined axis and the flow of sunlight reaching the earth's surface. Due to the zonal distribution of solar radiation over the earth's surface, there is a regular change in climates, soils, vegetation and other components of the geographic envelope. On Earth, most exogenous phenomena are zonal.

Thus, the processes of frosty physical weathering are most active in subpolar and polar latitudes. Temperature weathering and eolian processes are characteristic of arid regions of the world (deserts and semi-deserts). Glacial processes take place in the polar and high-mountain regions of the Earth. Cryogenic - confined to the polar, subpolar, temperate latitudes of the northern hemisphere. The formation of weathering crusts is also subject to zonality: the lateritic type of weathering crust is characteristic of humid and hot climate zones; montmorillonite - for dry continental; hydromicaceous - for wet cool, etc.

Zoning manifests itself primarily in the existence of geographic zones on Earth, the boundaries of which rarely coincide with parallels, and sometimes their direction is generally close to the meridian (as, for example, in North America). Many zones are broken and are not expressed on the entire continent. Zoning is typical only for flat areas. In the mountains there is altitudinal zonality . In the change of horizontal zones and in the change of altitudinal zones, one can find similarities (but not identity). The mountains of each natural zone are characterized by their own spectrum of altitudinal zonality (a set of belts). The higher the mountains and closer to the equator, the fuller the spectrum of altitudinal zones is. Some scientists (for example, S.V. Kalesnik) believe that altitudinal zonation is a manifestation azonality . Azonality on Earth is subject to phenomena caused by endogenous forces. Azonal phenomena include the sector phenomenon (western, central and eastern parts of the continents). A variety of azonal is considered intrazonal (intrazonal).

Differentiation of the geographic envelope is the division of a single planetary natural complex into objectively existing natural complexes of a different order (rank).

The geographic envelope has never been the same everywhere. As a result of unequal development, it turned out to be composed of many natural complexes. A.G. Isachenko defines natural complex as a natural, historically determined and territorially limited combination of a number of components: rocks with their inherent relief, the surface layer of air with its climatic features, surface and groundwater, soils, groups of plants and animals.

According to the definition of N.A. Solntsev, natural complex - this is a section of the earth's surface (territory), which is a historically determined combination of natural components.

To identify natural complexes existing in nature, physical-geographical zoning is used.

With a huge variety of natural complexes that make up the geographical shell, a system of taxonomic (ordinal) units is needed. Such a unified system does not yet exist. When distinguishing taxonomic units, both zonal and non-zonal (azonal) factors of differentiation of the geographic envelope are taken into account.

Differentiation of the geographic envelope according to azonal characteristics is expressed in the division of the geographic envelope into continents, oceans, physical-geographical countries, physical-geographical regions, provinces, landscapes. However, this approach in no way denies zonality as a general geographical regularity. In other words, all these natural complexes are necessarily zonal.

geographical envelope

geographic zone mainland

zone country

subzone area

provinces

landscape

The differentiation of the geographic envelope according to zonal features is expressed in its division into geographical zones, zones, subzones, and landscapes.

The basic unit of physical-geographical zoning is the landscape. By definition, S.V. Kalesnik, landscape - this is a specific territory, homogeneous in origin and history of development, having a single geological foundation, the same type of relief, common climate, common hydrothermal conditions and soils, and the same biocenosis.

Facies is the smallest unit of physical-geographical zoning, the simplest, elementary natural complex.

Thermal belts

Throughout the geological history of the Earth, the ratio between ocean and land has changed, and this suggests that the heat balance of the planet was not constant. Geographic zonality changed, thermal zones changed. It becomes obvious that modern geographic zoning was once completely unusual for the planet. Scientists believe that neither glaciers nor cold seas simply existed on Earth most of the time, and the climate was much warmer than it is now. The temperature contrasts between the poles and the equator were small, impenetrable forests grew in the Arctic region, and reptiles and amphibians inhabited the entire Earth. First, thermal zoning arose in southern hemisphere, and in northern hemisphere its formation took place later.

The main process of zoning formation took place in Quaternary period of the Cenozoic era, although its first signs appeared $70$ million years ago. With the advent of man, thermal belts were already the same as they are now - one hot zone, two moderate zones, two cold zones. The boundaries between the belts have undergone changes, for example, the border of the cold belt, once passed through the modern Moscow region and the Moscow region was occupied by the tundra zone. The mention of thermal zones can be found in the Greek historian Plibia($204$-$121$ BC). According to his ideas, there were $6 $ thermal belts on Earth - two hot, two moderate, two cold. Travelers' notes also contain such information. These data suggest that people have long been aware of the existence of thermal zones. They explained their presence by the fact that the Sun at different latitudes heats the Earth's surface differently, and associated this with a different angle of inclination of the sun's rays. V northern latitudes The sun is low on the horizon and gives little heat per unit area, so it's colder there. This is how the concept gradually emerges. climate T". This pattern was known as early as $2.5 thousand years ago and remained undeniable until recently. This explanation has been questioned relatively recently.

Observations have shown that Arctic and Antarctic per unit area receives very little solar heat in the summer. But during the long polar day, the total radiation is much greater than at the equator, which means that it should also be warm there. However, summer temperatures rarely rise above +$10$ degrees. This means that the thermal regime cannot be explained by a single difference in the inflow of solar heat. Today, everyone is well aware that character also plays a big role. underlying surface. Albedo snow and ice is very large and reflects up to $90$% of solar radiation, while a surface not covered with snow reflects only $20$%. The albedo of the Arctic surface will decrease if the snow and ice melt, and this will lead to a change in the existing thermal zones of the northern hemisphere. As the water temperature rises in the Arctic basin, forests will replace the modern tundra. After the collapse of Gondwana, the process in the southern hemisphere went something like this.

Definition 1

Thermal belts- These are vast territories located along the parallels around the globe with certain temperature conditions.

It must be said that the formation of thermal belts on the planet depends on how it will be distributed over the Earth's surface and what it will be spent on, and not only on the amount of solar heat entering a particular zone.

Humidification belts

In natural processes, not only certain thermal conditions play a role, but conditions play an even greater role. moisturizing. Humidity is determined by two factors: the amount of precipitation and the intensity of their evaporation.

Definition 2

Moisturizing- this is the ratio between the amount of precipitation in a given area and the amount of evaporated moisture at a given temperature.

Their distribution on the planet, in principle, is also associated with geographic zoning. From the equator to the poles, their average number is reduced, but this pattern is violated by geographical and climatic conditions.

The reasons are as follows:

The free circulation of air is disturbed by the location of the mountains;
Descending and ascending currents of air in different places of the planet;
Variability in cloud distribution.

Mountains can be located both in the latitudinal and in the meridional direction, and most of the precipitation lingers on windward slopes, and with leeward There is very little or no precipitation on the sides. The equatorial region is dominated by ascending air currents - heated light air rises, reaches saturation point and brings an abundance of precipitation. In tropical latitudes, air movement descending, the air moves away from the saturation point and dries up, so very little precipitation flows along the tropics, which contributed to the formation of deserts and dry steppes here. Precipitation zonality recovers north and south of the tropics and persists to the poles. Distribution cloudiness also has its own meaning. Sometimes it happens that different amounts of precipitation fall on the same street.

Evaporation determines the conditions of moistening on the planet and is entirely regulated by the amount of residual radiation. Value evaporation the amount of moisture evaporated at a given temperature.

From the north to the tropics, the moistening of the Earth's surface decreases. In the taiga zone it is close to $1$, in the steppe zone the moisture will be equal to $2$, and in the deserts it will be more than $3$. In the south, the possibility of evaporation is much greater than in the north.

Example 1

Consider an example. The soil in the steppes warms up to $70$ degrees. The air is dry and hot. If the field is irrigated, everything will change, it will be more humid and cool. The earth will revive and turn green. The air here was hot, not because the influx of heat from the Sun is greater than in the north, but because there is very little moisture. Evaporation began from the irrigated field, and part of the heat was spent on this. Thus, the conditions for moistening the Earth's surface depend not only on evaporation, but also from amount of precipitation.

Pressure belts

normal is the atmospheric pressure at sea level at a latitude of $45$ degrees at a temperature of $0$ degrees. Under such conditions, it is $760$ mmHg, but can vary widely. Increased air pressure will be more than normal, and reduced - less than normal with a mark of $ 760 $ mm. rt. Art.

Atmospheric pressure with height going down because the air becomes rarefied. The surface of a planet having different heights will have its own pressure value.

Example 2

for instance, $Perm$ is located at an altitude of $150$ m above sea level and every $10.5$ m the pressure will decrease by $1$ mm. This means that at the height of Perm, the normal atmospheric pressure will not be $760$ mm, but $745$ mmHg. Art.

Due to the fact that during the day there is a change in temperature and air movement, the pressure will be rise twice and fall twice. In the first case, in the morning and in the evening, in the second case, in the afternoon and midnight. On the continents during the year, the maximum pressure will be observed in winter, and the minimum in summer.

On the surface of the Earth, the distribution of pressure is zonal in nature, because the surface heats up unevenly, which leads to a change in pressure.

There are $3$ belts on the planet, where low pressure and $4$ belts dominated by high pressure. Low atmospheric pressure will be in the equatorial latitudes and in temperate latitudes, but here it will change with the seasons of the year. High atmospheric pressure is typical for tropical and polar latitudes.

Remark 1

At the surface of the Earth, the formation of atmospheric pressure belts is influenced by the uneven distribution of solar heat and the rotation of the Earth. In view of the fact that the hemispheres are heated by the sun in different ways, there will be some displacement of the pressure belts: in the summer period - the displacement goes to the north, in the winter period - to the south.

Consider the main zonal-regional patterns of the Earth.

1. geographic zones, due to the spherical figure of the planet and the distribution of solar radiation. The zonal heterogeneity of the geographic envelope is primarily the result of the latitudinal distribution of the energy of geographic and biological processes- solar radiation, the circulation of the atmosphere caused by it and the moisture circulation caused by these processes. Education geographical zones is not associated with endogenous factors, like oceanic and continental rays, but with exogenous ones. Exogenous factors are superimposed on endogenous ones.

On the modern stage of the development of terrestrial nature, the following main planetary belts are distinguished: 1) equatorial hot and humid, 2) tropical hot and dry, 3) moderate; in the northern hemisphere it is warm with a large amplitude of humidity by region, in the southern hemisphere - with an oceanic climate; 4) boreal cool and damp; 5) polar frosty and damp.

2. geographic zones, the features of the nature of which are due to the inclination of the axis of rotation of the Earth to the plane of the ecliptic. For this reason, transitional belts are created - subequatorial, subtropical and subpolar with a pronounced seasonal rhythm of moisture in the subequatorial, heat and moisture in the subtropical, heat in the subpolar.

In each hemisphere, thus, eight belts stand out. In the southern hemisphere, the boundary between the temperate and subpolar zones is indistinct.

The names of geographic zones are associated with their geographic location at certain latitudes of the world.

Belts, thus, cover the Earth in continuous rings, including both continents and oceans.

3. Sector. Clarity is certainly combined with sectoriality. Depending on the intensity and absolute value of the exchange of air masses in the ocean - atmosphere - mainland system, different parts of the land receive more or less heat and moisture and differ in the nature of the seasonal rhythm. Therefore, each belt breaks up into parts, and the same type of parts of different belts on the spherical surface of the Earth form sectors elongated from north to south.

Sector is a taxonomic unit smaller than a ray. On the continents western oceanic, central continental and eastern oceanic sectors. On the oceans, respectively, warm and cold currents - Western and Eastern sectors.

In the distribution of atmospheric moisture, two regularities are equal: a) latitudinal, expressed in the alternation of zones of minimums and maximums of precipitation (Fig. 83), and b) longitudinal, or intrazonal sector.

In low latitudes, which are abundantly provided with heat, differentiation into belts, and then we will see that into zones, is due to the water balance. At high latitudes, heat is of decisive importance, the amount of which here progressively decreases according to the cosine of latitude.

Strictly speaking, belts and sectors, zones and regions are not entirely equal. Rather, they express the general and the specific: the geographical belt and zones appear in each sector and region in their specific forms, the similarities of which give reason to unite them.

There is no known universal hydrothermal indicator, which would correspond to the boundaries of the belts. The versatility of interactions in nature and the multiplicity of landscape components make one look skeptically at the search for such numerical expressions, especially if feedback is taken into account: the vegetation cover not only reacts to soil and climate moisture, but also changes it.

Humidity indicators retain their value - the ratio of precipitation and evaporation.

The leading role of water, together with heat, in the landscape shell system is based not only on the nutrition of plants and the formation of land waters. Moisture cycle determines migration chemical elements and geochemical features of landscapes, for example, the salinity of desert soils and the leaching regime of podzolic soils in the zone of coniferous forests.

4. Zoning. The combination of heat and moisture, or atmospheric humidification in each zone, except for the equatorial zone, is very different. On this basis, inside the belts are formed zones. They are called natural-historical, natural, geographical or landscape; these names can be taken as synonyms.

In geometry, a zone or a spherical belt is called, as is known, a part of the surface of a ball enclosed between two parallel planes intersecting the ball. In accordance with this, sets of homogeneous natural formations, elongated from west to east perpendicular to the axis of rotation of the Earth, have long been called in science zones - climatic, soil, vegetation.

If the zonality of individual components of nature, and primarily climate, vegetation and soils, is known from the experience of people long before geographical generalizations, £o the doctrine of geographical zoning arose only at the turn of the 19th and 20th centuries

Belts and zones are parts and a whole. The combination of zones forms a belt. In the ocean, there are no such narrow bands as land zones.

In the northern hemisphere, the following zones are distinguished: ice, tundra, coniferous forests or taiga, broad-leaved forests, forest-steppe, steppe, temperate desert, subtropical forests, desert tropical, savanna, equatorial forests.

Between the listed zones, transitional zones are distinguished: forest-tundra between tundra and forest, semi-desert between steppe and desert, etc. The concept of "transition zone" is conditional - some researchers consider them to be the main ones, especially forest-steppe.

Each zone is divided into subzones. For example, in the steppe zone they distinguish northern mixed grass steppes on black soil and southern dry fescue-feather grass on dark chestnut soils.

Zones and subzones were named after the vegetation cover of the land, since vegetation is the most striking indicator or indicator of the natural complex. However, vegetation zones should not be confused with geographic ones. So. when they say the steppe zone of vegetation, they mean the predominance of mesoxerophilic herbaceous plants in this area. The concept of "steppe zone" includes flat terrain, semi-arid climate, chernozem or chestnut soils, steppe vegetation, as well as forests and flood meadows in the valleys, and only this zone is characterized by wildlife. In a word, steppes, like forests and swamps, although they are named according to the nature of the vegetation cover, are natural complex. And now, when the steppes are plowed up, the steppe zone still exists, because, although the grassy vegetation has been replaced by cultivated, other features of nature have been preserved.

5. Regionality. Oceanic-continental transfer of heat and moisture differentiates zones into regions or provinces of zones. West-East differentiation is not equally manifested v different latitudes. In the temperate zone, due to western transport, the region of greatest continentality is shifted from the center To east (west-east dissymmetry).

The division into sectors and regions does not mean the limit of differentiation; any subzone and regions can be subdivided into smaller taxonomic units. Regional differences largely due to the history of the development of nature in the region. For example, in Northwestern Europe, which experienced glaciation, conifers are represented only by European spruce. (Picea excelsa) and pine (Pinus silvestris); Siberian spruce (Picea abouata) occupies a small area in the north; Siberian pine or cedar (Pinus Siberia-sa) settled only up to the Pechora basin.

In general, the geographical envelope is zonal-regional.

6. Different form of zones. The configuration of the continents and their macrorelief determines the size and extent of the zones. In North America, the width of the steppe zones turned out to be greater than their length, and they acquired a "meridional strike." V Central Asia the semi-desert zone has the shape of an arc. The essence of zoning does not change.

7. Analogue zones. Each of the continental zones has its counterpart in the oceanic sectors. With excessive and sufficient moisture, two variants of the same zone arise, for example, the Atlantic taiga in Norway and the continental taiga in Siberia. With insufficient moisture, different zones affect the analogues, for example, broad-leaved forests near the ocean correspond to inland steppes.

8. Vertical zonation in mountainous countries.

9. Dissymmetry of geographical zonality. Geographic zonality is dissymmetric with respect to the plane of the equator. Solar radiation is distributed in proportion to cosop and therefore symmetrically in both hemispheres. Therefore, the geographical zones of the hemisphere are generally the same - two polar, two temperate, etc. But the lithogenic basis of zoning is antisymmetric, and the geographical zones of the northern hemisphere are very different from those corresponding to them in the southern. For example, a large forest zone of the northern hemisphere in the southern corresponds to the ocean and only a small region of forests in Chile; in the northern temperate zone, inland deserts occupy large areas, while in the southern they do not exist at all. The dissymmetry increases in the direction from the equator to middle latitudes. The northern and southern temperate belts are so different that each requires an independent description. KK Markov (1963) considers the polar dissymmetry of the geographic envelope to be a structure of the first order, above zoning. This statement is absolutely correct. VB Sochava (1963) believes that it is the tropical and two extratropical belts that act as structures of the first order, against which dissymmetry manifests itself. This author is also right. The fact is that K. K. Markov and V. B. Sochava write about geographical entities different structural levels: the first
about zones, the second about belts. It goes without saying that the geographical zones - tropical and extratropical - are structures of the first order, characteristic of both oceans and continents. The geographical zones on the continents of the northern hemisphere are fundamentally different from the zones in the ocean of the southern hemisphere, and in their formation the continental dissymmetry of the Earth is more significant than zonality.

10. Different rates of variability of nature. Separate areas of the biosphere are characterized by different rates of variability of nature in the process of its development. It is known that the ocean fauna changes relatively more slowly than the terrestrial one. Consequently, the ocean is a more conservative area than the continents.

And on land, the variability of nature is not the same in different zones. And this applies not only to the organic world, but to all geographical conditions. The nature of low latitudes turns out to be more conservative. In the life optimum of the equatorial belt, fluctuations in geographical conditions never fall to the minimum level at which organisms must adapt to new conditions and change. In temperate latitudes, even slight fluctuations in temperature or humidity of the climate, geomorphological or hydrological conditions create a new environment for organisms and necessitate their restructuring; here some species of plants and animals fall out relatively quickly and others are formed.

11. Zones with large and small participation of living matter. Despite the fact that the entire biosphere develops with the continuous and active participation of living matter, it contains zones with both quantitatively large and quantitatively small direct participation of life (Gozhev, 1956). The former include hylaea, savanna, steppe, forest-steppe and forest zones of temperate latitudes; to the second - ice, desert and semi-desert zones. About half of the World Ocean (in water areas remote from the coast) is also biologically unproductive. In the first group of zones of land and ocean areas, living conditions are optimal, in the second, a pessimum is observed.

12. The role of the progress of living matter in the development of the geographical envelope. The qualitative progress of inanimate matter has an upper limit - the transition from inanimate to living. The development of the modern geographical shell - the biosphere is due to the progress of living matter.

The current stage of development of the nature of the Earth's surface - the geographical shell - is the result of the evolution of organic life and its interaction with inert matter. Development was guided by the evolution of living matter according to internal reasons and changing geographical conditions. Therefore, the nature of the earth's surface - inanimate and living can be studied only on the basis of their deepest interaction.

The main role of living matter in the geographic envelope is to increase its energy through the accumulation of solar energy. This is the energy basis for the development of the Earth.

The formation of the earth cosmic body - geological history- emergence of life - evolution organic world- the development of the geographical envelope - the appearance of man - all these are stages of the general progress of matter.

13. Integrity - interaction - development. The most essential features of the geographic shell as a complex natural system, its essence is integrity, interaction of parts and development.