Many centuries ago, there were science, studying the planet, its foreign surface. These include geodesy, topography, cartography, and others. But most of all phenomena that always touches people studying science topography. It studies the Earth's surface and all sorts of ways of depicting it on paper. The word "topography" is derived from two Greek words: "topos" — which means "place" and "The Count" — "write", "topography" — "description of the terrain."
In more recent times, this science has attracted the attention of the military. The fact is that for combat operations on land and sea required maps depicting the Earth's surface and waters. With the card you can see the terrain, study it, seeing and being on the drink. There was a special science — military topography, which studies the properties of the so-called tactical areas with a direct impact on the conduct of hostilities. This includes properties such areas as throughput, safety and camouflage properties, conditions for orientation, observation, fire, etc.
But not only the military study the topography and any professional should know some of the basics of the science. This information is necessary for everyone who wants to make a tourist trip, tour, travel, choose a place for recreation, construction, or even familiar with the terrain, its lakes and rivers, vegetation, roads, settlements, etc.
In our century — the century of civilization to travel is becoming easier and more and more people in need of basic knowledge on the topographic map and its symbols, in guiding her to the ground using a compass and without him, day and night, summer and winter.
In hikes and often found the need to determine the distance to an object, the steepness of the slope, the width of the river or lake. And it must be able to do quickly.
Let's start the study of the basic features of the terrain.
Before considering these basic properties, we dwell on its varieties and the terminology used in science — the topography.
The terrain is usually called a surface area of the earth, with all its bumps and things (objects) that are on it.
From this definition, it appears that the area is made up of two elements: the actual surface of the earth, with all its bumps — it surveyors called relief, and all that is in it, call the local objects. The latter can be very different. Natural origin (rivers, lakes, forests, bushes, swamps, etc.) and man-made, that is created by the hands of man, his work (railways, towns, industrial, agricultural and cultural facilities, etc.).
The main element is the local topography. He has the greatest impact on water supplies, and especially land cover, and on the roads, and the location, the layout of settlements, and even the climate.
Relief, depending on the natural conditions of the area may be the most diverse forms. But if the
look closely to all the earth deformations, it is still possible to see the so-called basic (standard) forms of relief: a mountain, ridge, valley, valley and saddle (Fig. 1). They are found in pure form and in combination with each other and, in turn, have their own versions. For example, instead of the mountain you can often see her kind — a hill or mound, instead of hollow — beam, ravine, valley, ravine.
Depending on the height of elevation it is called a mountain, hill, mound. In the mountain (hill, mound) always distinguish top, sole and rays (slopes), that is, the side surfaces. The angle formed by the inclined surface slope with an imaginary horizontal plane, called the steep slope. This is a very important characteristic of the slope, because of its size is often dependent permeability, preodolevaemost slope. Therefore, depending on the steepness of the slope (angle), they are divided into shallow (dp 8 °), average slope (8 to 20 °), cool (20 to 35 °) and very steep, steep (over 65 °). These angles and determine the possibility of overcoming the rays technology and people.
So, gentle slopes are available to all types of equipment and vehicles. Ramps average slope can overcome wheeled all-terrain vehicles. Steep slopes is available only tracked vehicles (tanks, tractors, trucks). Very steep slopes can cover only the people and the restraining hand of the vegetation and the projections on the ground (Fig. 2).
In rainy weather and off-road values overcome slopes significantly reduced.
Ramps differ from each other not only steep, but also the shape of its incline. They are
flat, convex, concave and wavy (Fig. 3). It is not just their classification, the form is essential. Judge: smooth and concave slopes can be easily seen from the top of a hill (topographic ridge) to the sole. Now imagine a convex slope. With its top part of the area at the foot of the review and close a so-called field of invisibility ("dead" space.) On such a slope is always a bend, from which the whole area visible to the sole. This inflection slope called battle crest, it is usually located slightly below the topographic ridge (Fig. 3).
Undulating slope called a ramp, which consistently alternated all skates: flat, convex and concave.
The second model is a form of relief ridge. This elevation, extending in a certain direction. It distinguishes watershed line (ridge) extending along the ridge, from which diverge in opposite its slopes.
The basin is a closed cavity. Depending on the size it is sometimes called depression, and sometimes pit. If the walls are steep and smooth, then the pit is called a funnel.
Dell — is deepening, going down in one lied lenii. Line along the bottom of the valley, is a kind of bed for the water flow, in this regard, it is called the overflow line or a weir. Most valley with gentle slopes and is usually slightly tilted down is called the valley. Its size can be huge.
Many of you have seen, or just as heavy rain streams erode the land of deep, narrow slit with almost vertical walls — gullies. So, if these hollow ravines reaches more than 5 meters, they are called gullies. A gully overgrown with bushes, gullies.
Saddle — the space between two adjacent hills (Fig. 1) who is a combination of two ravines, which diverge in opposite directions. In mountainous areas, roads and trails through the impassable mountain ranges, usually pass through the saddle, in which case they are called passes.
We have discussed the main, the main element of terrain — terrain, its basic forms and varieties. The second important element of the area are local objects. They are even more varied than the relief, but split them into separate species is still possible. Thus, depending on their external form and function, they are divided into the following groups:
— Settlements (cities, towns and country type, village, villages, individual households);
— Industrial, agricultural and cultural facilities (factories, power plants, mines, grain elevators, cultural centers, cinemas, etc.);
— Road network (railways, motorways, highways, country roads and dirt, field and forest roads, trails);
— Land cover (forest, shrubs, gardens, meadows, fields, gardens, marshes, sand, etc.);
— Hydrography (rivers, lakes, canals and other structures in their dams, ports, marinas, ferries, etc.);
— Power lines and communication (radio, postal, telegraph stations, transmission lines, etc.).
Local objects may greatly affect the general character of the country. People have learned to create ponds and even the sea, make fertile land, where once were impassable swamps, reforest, build dams, roads, build cities, to change the land.
All this is done to improve the lives of people. But sometimes it happens that such activities bring irreparable harm. Here, for example, the valley Sioaris in southern Italy, which was once famous for its extraordinary productivity, and surrounded on three sides by its hills were covered with dense thickets of evergreen. Gradually, these forests were cut down and bared hills rains demolished land to the coastal valley. A few years turned into the fertile valley of malarial swamp.
All this suggests that the use of nature must be very careful and reasonable.
By definition, surveyors, terrain is of two types: open or closed.
Open country — is plain with some groves, scrub, with occasional settlements. It allows you to view from the heights available on it, at least 75% of its area. This area has favorable conditions for observation, a broad overview (up to 4-5 km) in all directions.
By type of open areas include desert areas Kazakh, Uzbek, Turkmen republics steppes of the Lower Volga region, some areas of the Left-Bank Ukraine, the Don, Western Siberia and Kuban (Fig. 4).
The closed area is characterized by a large number of local subjects on it and pronounced relief. It is usually covered in forest, shrubs, gardens (Fig. 5).
Enclosed ground you can view from the heights, located on it, no more than 25% of its area.
By type of closed areas include forest areas of Belarus, the Republic of Karelia, the Carpathians, the Far East and the entire band of the taiga.
Naturally, there is no sharp boundary between the open and closed areas, so in the classification of a so-called intermediate stage — semiclosed terrain, allowing you to view from the heights, located on it, up to 50% of its area.
In terms of cross-country, that is, the presence of obstacles on its rivers, lakes, marshes, ditches, gullies, ravines, facilities, etc., it is divided at the intersection and non-intersection.
Terrain — it is such, at which more than 20% of the area occupied by obstacles. It includes all the mountain and high mountain areas, areas of Right-Bank Ukraine with many ravines, many areas of the Karelian ASSR with numerous lakes (Fig. 6), the areas of the Estonian SSR and the Kaliningrad region dominated by hills.
Terrain can be open or closed, that is, have different conditions for its review.
Terrain with little or sometimes encounters obstacles, most of which are overcome both wheeled and tracked vehicles, refers to maloperesechennoy areas. To distinguish it from the rough sometimes indicate that it is not more than 10% of the area can be occupied passable
obstacles. If there are no obstacles or they make up less than 10%, consider this area of non-intersection.
General character of the country, as stated above, the topography. Based on the nature of the relief, the area is divided into plains, hilly and mountainous.
Terrain, which surface in sight horizon (up to 4 — £ miles) flat or slightly hilly, with very gentle slopes (up to 2-3 °) and minor variations of height (20-30 m) refer to the plains (Figure 7 ). In most cases, flat terrain is open and sometimes, if it is covered by forest, shrubs or her are many settlements, it refers to the closed. If on it has a large number of rivers, lakes, wetlands, ravines and other obstacles, it becomes rough.
Hilly area (Figure 8) has a lot of hills, gullies, ravines, gullies, but the steepness of the slopes of the average range of about 5 °, that is, it allows for movement on all types of equipment and vehicles. It can also be both open and closed as a cross, and not crossing.
By hilly terrain can be attributed most
Central Russian regions, the Volga, in the Volyn-Podolsk, Stavropol Upland, some areas in the foothills of the Carpathians, the Caucasus, the Urals, etc.
Highlands (Fig. 9) is characterized by alternating ridges above the valleys, saddles and canyons. In Wei dominated steep slopes, often passing into the cliffs and rocks. Depending on the height of the mountain is divided into low (500 to 1000 m) 1 medium-altitude (1,000 to 2,000 m) and high (2000 m).
To include the low mountains of the Middle Urals Mountains, the northern Caucasus mountain ranges, the mountains of the Kola Peninsula. They are usually completely covered with forests.
By type of medium mountains are mountains of Crimea, the Carpathians, the Southern Urals, the backbone, the Sikhote-Alin. They are also covered by forests, but they are often treeless vershipy — "Goltz". Passes through these ridges are usually to a height of 700 m and more.
High mountains (the so-called Alpine type) are characterized by snow and glaciers on grebpyah ridges and peaks. Their tops are usually devoid of vegetation.
By type of mountains are mountains of the Caucasus Mountains of the Pamirs, Tien Shan Mountains, passes through the ridges of the mountains lying! at an altitude of 1500-3000 m
For mountainous terrain is characterized by sharp changes in the weather, snow, fog, avalanches (streams of snow from the mountains), rockslides, mudslides (streams of water with stones and mud).
The mountainous terrain is a closed and rugged. It is difficult to pass, and the thin air increases fatigue and even cause altitude sickness.
In the mountains you can move only in the valleys, and along roads and rivers.
The soil and vegetation of our planet is very diverse, and describe in detail all its varieties is impossible.
Consider just some of the variety and properties of soil and vegetation. Let's start with the soil.
The soil surface is called the fertile layer of the earth's crust, carrying a vegetative cover.
The soils in the world under the influence of climate differ from each other, and their types are arranged in a sequence, that is, bands (stripes) from the poles to the equator.
In the most northern areas with wet and very cold climates are tundra soils. They are usually full of water, waterlogging and at a certain depth — permafrost.
In temperate regions, where rainfall is more than evaporates, formed under forest podzolic soils.
They contain a lot of upper quartz, which gives them a whitish color, resembling ash. The lower layers of podzols are high in clay particles, solid and trudnopronitsaemyh water, which promotes the formation of these places swamps.
Black soils, which are located further south, black, have high fertility. During the thaw, they form mud and impassable at this time.
Further south chernozem — brown soil, they are close to their cross-chernozem.
Ground for the deserts and semi-deserts are usually gray soils — loam and sandy soils. In addition, in a desert salt flats are often found in the upper layers of which there are up to 1% of the soluble salts.
Soils should not be confused with the ground. Ground — those of terrestrial rocks, which come into contact in the construction and road case. They are rocky, poluskalnyh and friable.
If we consider the overall land cover, the area can be divided into four types: wooded, swampy, steppe and desert.
Woodland called Earth surface, entirely or more than half covered with woody vegetation. Forest area can be varied according to the density and species of trees and their age.
The forest is dense if its crown of trees or intertwined between them there is no more than a diameter of the crown. If the distance between the crowns of more than 5 or 6 diameters of the trees, then a forest called rare.
Depending on the height and thickness of the forest trees are divided into young, height is 4.6 m and the thickness of the trees at the base of the trunk 8-15 cm, mean (middle-aged), height Trees 6-15 m, and the thickness of the trunk 15 — 25 cm, and, finally, ripe (that is overgrown forest) Trees more than 15 meters, and the thickness of the trunk 25 cm or more.
Woodland can be heterogeneous in age, that is, it is and ripe, and the young forest and underbrush.
In this case, the forest is divided by the number of storeys: single storey with no undergrowth, and multilevel (Fig. 10), in which the crown of large trees and shrubs form two, three, or even four tiers. Multi-storey wood affects the visibility in the woods.
But the forest tree species divided by coniferous (spruce, pine, fir, cedar, larch) and deciduous (birch, aspen, basswood, oak, beech). Most often found mixed forest, one in which the trees of various species.
Woodland refers to the closed and broken.
Depending on the age and density of the forest from the trees may not be able to move in it equipment and motor vehicles. In addition, in a wooded area difficult observation, orientation and exposure of a given direction.
Moorland — is the earth's surface, entirely or largely occupied excessively wet soils. This area consists of marshes and wetlands.
Swamp is excessively wet land area with a layer of peat 30 cm
Wetlands, where the peat layer of 30 cm of peat Sometimes in such a region at all.
Depending on where the water comes into the swamp, and what it vegetation, wetlands are divided into lowland, upland and transitional. Fens are fed mainly by groundwater. Upland replenished by rainfall and water flows in the transitional and both ways.
Under the terms of cross-classified into impassable bogs, impassable and impenetrable, which is always very marked on the map. But the degree of patency of the marshes can be determined by various
nym signs, and primarily by vegetation cover.
So, moss bogs, flooded by the old (dead) layer of peat moss or are generally passable for people. Swamps with lots of bumps (The earth), with sedges are often impassable, and swamp with floating on the surface vegetation (Quagmirran) or covered with reeds (reeds), usually impassable. True, the surface of the marsh and is deceptive. Often a thin surface layer of the water is shallow and, in fact, rests on a solid base, a swamp passable. Conversely, apparent on the face of a solid surface swamp easily falls under the weight of a person is swamp is impassable.
Note that the small green patches on the treeless swamp — Solid islands usually are signs of very viscous and Carr, and these swamps have to be unlocked.
But also do not forget that almost every swamp can be found passages, though it might seem narrow. Such places can be identified by Krotov and ant mounds, in the thick grass, interspersed with sedges and areas where there is growth pine forest.
Steppe terrain is plain covered by vegetation. In most cases it is open. Sometimes steppe is indented
deep ravines and gullies, then it belongs to the rough terrain.
Deserted place (Fig. 11) is generally flat or slightly hilly surface, covered with sand, which by the wind or sand dunes form a ridge.
For desert, dry and typical continental climate, with large annual (from +50 ° to — 40 °) and daily (up to 30-40 °) temperature changes, strong winds (day 7-8 points). On the little desert settlements, roads, water sources and there is almost no vegetation.
In the "pure" form considered areas (wooded, marshy, steppe and desert) are rare. In combination with the topography and objects they create other species, such as mountains and forests (mountain area is covered by forests), forest and moorland (forest Located in the swamp), etc.