What is latitudinal zonation? What is latitudinal zonality and altitudinal zonality, how they are expressed, examples.

The primary cause of zoning is the uneven distribution of solar energy over latitude due to the spherical shape of the Earth and changes in the angle of incidence of sunlight on the earth's surface. In addition, latitudinal zonality also depends on the distance to the Sun, and the mass of the Earth affects the ability to hold the atmosphere, which serves as a transformer and redistributor of energy.

Of great importance is the inclination of the axis to the plane of the ecliptic, this determines the irregularity of the flow of solar heat over the seasons, and the daily rotation of the planet determines the deviation of air masses. The result of the difference in the distribution of the radiant energy of the Sun is the zonal radiation balance of the earth's surface. Uneven heat input affects the location of air masses, moisture circulation and atmospheric circulation.

Zoning is expressed not only in the average annual amount of heat and moisture, but also in intra-annual changes. Climatic zoning is reflected in the runoff and hydrological regime, the formation of a weathering crust, and waterlogging. Big influence renders on the organic world, specific landforms. Homogeneous composition and high air mobility smooth out zonal differences with height.

In each hemisphere, 7 circulation zones are distinguished. Latitudinal zonality also manifests itself in the World Ocean.

The surface of our planet is heterogeneous and is conditionally divided into several belts, which are also called latitudinal zones. They naturally replace each other from the equator to the poles. What is latitudinal zonation? Why does it depend and how does it manifest itself? We will talk about all this.

What is latitudinal zoning?

In various parts of our planet, natural complexes and components differ. They are unevenly distributed, and may appear to be chaotic. However, they have certain patterns, and they divide the surface of the Earth into so-called zones.

What is latitudinal zonation? This is the distribution of natural components and physical and geographical processes in belts parallel to the equator line. It is manifested by differences in the average annual amount of heat and precipitation, change of seasons, vegetation and soil cover, as well as representatives of the animal world.

In each hemisphere, the zones replace each other from the equator to the poles. In areas where there are mountains, this rule changes. Here, natural conditions and landscapes change from top to bottom, relative to the absolute height.

Both latitudinal and altitudinal zoning are not always expressed in the same way. Sometimes they are more noticeable, sometimes less. Features of the vertical change of zones largely depend on the remoteness of the mountains from the ocean, the location of the slopes in relation to the passing air currents. The most pronounced altitudinal zonality is expressed in the Andes and the Himalayas. What is latitudinal zonality is best seen in the flat regions.

What does zoning depend on?

The main reason for all the climatic and natural features of our planet is the Sun and the position of the Earth relative to it. Due to the fact that the planet has a spherical shape, the solar heat is distributed unevenly over it, heating some areas more, others less. This, in turn, contributes to uneven heating of the air, which is why winds arise, which also participate in climate formation.

The natural features of individual parts of the Earth are also affected by development on the ground. river system and its regime, distance from the ocean, the level of salinity of its waters, sea currents, the nature of the relief and other factors.

Manifestation on the continents

On land, latitudinal zonality is more pronounced than in the ocean. It appears in the form natural areas and climatic zones. In the northern and southern hemispheres, such belts are distinguished: equatorial, subequatorial, tropical, subtropical, temperate, subarctic, arctic. Each of them has its own natural zones (deserts, semi-deserts, arctic deserts, tundra, taiga, evergreen forest, etc.), which are much more.

Which continents have the most pronounced latitudinal zonality? It is best observed in Africa. It can be traced quite well on the plains of North America and Eurasia (Russian Plain). In Africa, latitudinal zonality is clearly visible due to the small number high mountains. They do not create a natural barrier for air masses, so climatic zones replace each other without breaking the pattern.

The equator line crosses the African continent in the middle, so its natural zones are distributed almost symmetrically. Thus, humid equatorial forests turn into savannahs and woodlands of the subequatorial belt. This is followed by tropical deserts and semi-deserts, which are replaced by subtropical forests and shrubs.

Interesting zonality is manifested in North America. In the north, it is standardly distributed in latitude and is expressed by the tundra of the arctic and taiga of the subarctic belts. But below the Great Lakes, the zones are distributed parallel to the meridians. The high Cordilleras in the west block the winds from the Pacific Ocean. Therefore, natural conditions change from west to east.

Zoning in the ocean

The change of natural zones and belts also exists in the waters of the World Ocean. It is visible at a depth of up to 2000 meters, but is very clearly visible at a depth of up to 100-150 meters. It manifests itself in a different component of the organic world, the salinity of water, as well as its chemical composition, in the temperature difference.

The belts of the oceans are almost the same as on land. Only instead of arctic and subarctic, there is subpolar and polar, since the ocean reaches right to North Pole. In the lower layers of the ocean, the boundaries between the belts are stable, while in the upper layers they can shift depending on the season.

Landscape zoning- a regular change in physical and geographical processes, components and geosystems from the equator to the poles.

Reason: uneven distribution of short-wave solar radiation due to the sphericity of the Earth and the inclination of its orbit. Zonality is most pronounced in changes in climate, vegetation, wildlife, and soils. These changes in groundwater and lithogenic base are less contrasting.

It is expressed primarily in the average annual amount of heat and moisture at different latitudes. First, this is a different distribution of the radiation balance of the earth's surface. The maximum is at 20 and 30 latitudes, since there is the least cloudiness in contrast to the equator. This implies an uneven latitudinal distribution of air masses, atmospheric circulation and moisture circulation.

Zonal landscape types are landscapes formed under autonomous conditions (upland, eluvial), that is, under the influence of atmospheric moisture and zonal temperature conditions.

Drain Zones:

equatorial zone of abundant runoff.

tropical zones

Subtropical

Moderate

Subpolar

Polar

20. Geographic sector and its impact on regional landscape structures.

Sector Law(otherwise azonal law , or provinciality , or meridionality ) - the pattern of differentiation of the Earth's vegetation cover under the influence of the following reasons: the distribution of land and sea, the relief of the green surface and the composition of rocks.

The sector law is an addition to the law of geographic zoning, which considers the patterns of distribution of vegetation (landscapes) under the influence of the distribution of solar energy over the Earth's surface, depending on the incoming solar radiation, depending on latitude. The law of azonality considers the influence of the redistribution of the incoming solar energy in the form of changes in climatic factors when moving deeper into the continents (the so-called increase in continental climate) or oceans - the nature and distribution of precipitation, the number of sunny days, average monthly temperatures, etc.

Sector of the oceans. Expressed in distribution:

River runoff (desalination of ocean waters).

Receipts of suspended solids, nutrients.

Salinity of waters caused by evaporation from the surface of the oceans.

and other indicators. In general, there is a significant depletion of ocean waters in the depths of the oceans, the so-called oceanic deserts.

On the continents, the sector law is expressed in:

Circumoceanic zonality, which can be of several types:

but) symmetrical - oceanic impact is manifested with the same strength and extent from all sides of the mainland (Australia);

b) asymmetric - where the influence of the Atlantic Ocean prevails (as a result of western transport), as in the north of Eurasia;

in) mixed.

The growth of continentality as you move deeper into the mainland.

21. Altitudinal zonality as a factor of landscape differentiation.

Altitudinal zonality - part of the vertical zonality of natural processes and phenomena, related only to mountains. Change of natural zones in the mountains from the foot to the top.

The reason is the change in heat balance with height. The amount of solar radiation increases with height, but the radiation of the earth's surface grows even faster, as a result, the radiation balance drops, and the temperature also drops. The gradient here is higher than in the latitudinal zonality.

As the temperature drops, the humidity also drops. A barrier effect is observed: rain clouds approach the windward slopes, rise, condense and precipitate. As a result, already dry and non-humid air rolls over the mountain (to the leeward slope).

Each flat zone has its own type of altitudinal zonation. But this is only outwardly and not always, there are analogues - alpine meadows, cold deserts of Tibet and the Pamirs. As we approach the equator, the possible number of these types increases.

Examples: Ural - tundra and the Goltsov belt. Himalayas - subtropical forest, coniferous forest, boreal coniferous forest, tundra. + Eternal snow is possible.

Differences from zones: rarefaction of air, atmospheric circulation, seasonal fluctuations in temperature and pressure, geomorphological processes.

Latitudinal zonality (landscape, geographical) is understood as a regular change in physical and geographical processes, components and complexes (geosystems) from the equator to the poles.

The reason for zoning is the uneven distribution of solar radiation over latitude.

The uneven distribution of solar radiation is due to the spherical shape of the Earth and the change in the angle of incidence of the sun's rays on the earth's surface. Along with this, the latitudinal distribution of solar energy also depends on a number of other factors - the distance from the Sun to the Earth and the mass of the Earth. As the Earth moves away from the Sun, the amount of solar radiation coming to the Earth decreases, and as it approaches, it increases. The mass of the Earth influences zoning indirectly. It holds the atmosphere, and the atmosphere contributes to the transformation and redistribution of solar energy. The inclination of the earth's axis at an angle of 66.5° determines the uneven seasonal supply of solar radiation, which complicates the zonal distribution of heat and moisture and enhances the zonal contrast. The deviation of moving masses, including air masses, to the right in the northern hemisphere and to the left in the southern hemisphere introduce additional complication into zoning.

The heterogeneity of the surface of the globe - the presence of continents and oceans, a variety of landforms further complicate the distribution of solar energy, and hence zonality. Physical, chemical, biological processes proceed under the influence of solar energy, and hence it follows that they have a zonal character.

The mechanism of geographic zoning is very complex, so it manifests itself in various components, processes, separate parts epigeosphere is far from clear.

The results of the zonal distribution of radiant energy - the zoning of the radiation balance of the earth's surface.

The maximum total radiation falls not on the equator, but on the space between the 20th and 30th parallels, since the atmosphere here is more transparent to the sun's rays.

Radiant energy in the form of heat is spent on evaporation and heat transfer. The heat consumption on them is quite difficult to change with latitude. An important consequence of the uneven latitudinal transformation of heat is the zonality of air masses, atmospheric circulation and moisture circulation. Under influence uneven heating, evaporation of moisture from the underlying surface, zonal types of air masses with different temperatures, moisture content, and density are formed. Zonal types of air masses include equatorial (warm, humid), tropical (warm, dry), temperate boreal (cool and humid), arctic and southern hemisphere antarctic (cold and relatively dry) air masses. Unequal heating, and consequently, different density of air masses (different atmospheric pressure) cause a violation of thermodynamic equilibrium in the troposphere and the movement of air masses. If the earth did not rotate, then the air would rise within the equatorial latitudes and spread to the poles, and from them would return to the equator in the surface part of the troposphere. The circulation would have a meridional character. However, the rotation of the Earth introduces a serious deviation from this pattern, and several circulation patterns are formed in the troposphere. They correspond to 4 zonal types of air masses. In this regard, in each hemisphere there are 4 of them: equatorial, common for the northern and southern hemispheres (low pressure, calm, ascending air currents), tropical (high pressure, easterly winds), moderate (low pressure, western winds) and polar (low pressure, easterly winds). There are also 3 transition zones - subarctic, subtropical, subequatorial, in which the types of circulation and air masses change seasonally.

Atmospheric circulation is a mover, a mechanism for the transformation of heat and moisture. It smooths out temperature differences on the earth's surface. The distribution of heat determines the allocation of the following thermal zones: hot (average annual temperature above 20°C); two moderate (between the annual isotherm of 20°С and the isotherm of the warmest month of 10°С); two cold ones (the temperature of the warmest month is below 10°C). Inside the cold belts, sometimes, “areas of eternal frost” are distinguished (the temperature of the warmest month is below 0 ° C).

The zonality of atmospheric circulation is closely related to the zonality of moisture circulation and humidification. The amount of precipitation and the amount of evaporation determine the conditions for moistening and moisture supply for landscapes as a whole. Moisture coefficient (determined by the ratio Q / Use, where Q is the annual rainfall, and Use.

- annual evapotranspiration) is an indicator of climatic humidification. The boundaries of landscape zones coincide with certain values ​​of the moisture coefficient: in the taiga - 1.33; forest-steppe - 1–0.6; steppes - 0.6–0.3; semi-desert - 0.3–0.12.

When the moisture coefficient is close to 1, the humidification conditions are optimal, and when the moisture coefficient is less than 1, the humidification is insufficient.

An indicator of heat and moisture supply is the index of dryness M.I. Budyko R / Lr, where R is the radiation balance, Lr is the amount of heat required to evaporate the annual amount of precipitation.

Zoning is expressed not only in the average annual amount of heat and moisture, but also in their mode - intra-annual changes. The equatorial zone is characterized by a flat temperature regime, temperate latitudes are characterized by four seasons. Climatic zoning is manifested in all geographical phenomena - in the processes of runoff, hydrological regime.

Geographic zonality is very well traced in the organic world. Due to this circumstance, the landscape zones got their names according to the characteristic types of vegetation: arctic, tundra, taiga, forest-steppe, steppe, dry-steppe, semi-desert, desert.

The zoning of the soil cover is no less clearly expressed, which anticipated the development of V.V. Dokuchaev the doctrine of the zones of nature. In the European part of Russia, from north to south, there is a successive procession of soil zones: arctic soils, tundra-gley, podzolic soils of the taiga zone, gray forest and chernozems of the forest-steppe zone, chernozems of the steppe zone, chestnut soils of the dry steppe, brown semi-desert and gray-brown desert soils.

Zoning is manifested both in the relief of the earth's surface and in the geological foundation of the landscape. The relief is formed under the influence of endogenous factors of azonal nature, and exogenous, developing with the direct or indirect participation of solar energy, which has a zonal character. So, the Arctic zone is characterized by: upland glacial plains, glacial flows; for the tundra - thermokarst depressions, heaving mounds, peat mounds; for the steppe - ravines, beams, subsidence depressions, and for the desert - eolian landforms.

In the structure of the earth's crust, zonal and azonal features appear. If the igneous rocks are of azonal origin, then the sedimentary rocks are formed with the direct participation of climate, soil formation, runoff, and have pronounced zonality features.

In the World Ocean, zonality is most clearly traced in the surface layer; it also manifests itself in its underlying part, but less contrastingly. At the bottom of the oceans and seas, it indirectly manifests itself in the nature of bottom sediments (silts), which are mostly of organic origin.

From the foregoing, it follows that zoning is a universal geographical regularity, which manifests itself in all landscape-forming processes and in the location of geosystems on the earth's surface.

Zoning is a derivative not only of the modern climate. Zoning has its own age and its own history of development. Modern zoning developed mainly in the Cenazoic. Kainazoi (era of new life) is the fifth era in the history of the earth. It follows the Mesozoic and is divided into two periods - Tertiary and Quaternary. Significant changes in landscape zones are associated with continental glaciations. The maximum glaciation extended over more than 40 million km2, while the dynamics of glaciation determined the displacement of the boundaries of individual zones. Rhythmic displacements of the boundaries of individual zones can be traced in recent times. At certain stages of the evolution of the taiga zone, it extended to the shores of the Arctic Ocean; the tundra zone within its present boundaries exists only in the last millennia.

The main reason for the displacement of zones are macroclimatic changes. They are closely related to astronomical factors (fluctuations in solar activity, changes in the Earth's axis of rotation, changes in tidal forces).

The components of geosystems are rebuilt at different rates. So, L.S. Berg noted that the vegetation and soils do not have time to rebuild, so relic soils and vegetation can remain in the territory of the “new zone” for a long time. An example can be considered: podzolic soils on the coast of the Arctic Ocean, gray forest soils with a second humus horizon in the place of the former dry steppes. The relief and geological structure are very conservatistic.