Conventional signs of topographic maps give full information about the area. They are generally accepted and are used for topographic maps and plans. Topographic maps are important material not only for tourists, but also for geodetic organizations, for authorities that are engaged in planning the area and transferring site boundaries.

Knowledge of conventional signs helps not only to read the map correctly, but also to draw up detailed plans terrain, taking into account the new objects that have appeared.

Topographic maps are a kind of geographical maps. They carry detailed information about the terrain plan, indicating the location of various technical and natural objects relative to each other.

Topographic maps vary in scale. All of them carry less or more detailed information about the area.

The map scale is indicated on the side or bottom of the map. It shows the ratio of sizes: indicated on the map to natural. Thus, the larger the denominator, the less detailed the material. Let's say a 1:10,000 map will have 100 meters in 1 centimeter. To find out the distance in meters between objects, the distance between two points is measured using a ruler and multiplied by the second indicator.

1. The most detailed is the topographic plan of the area, its scale is 1:5,000 inclusive. It does not count as a map and is not as accurate as it does not take into account that the earth is round. This somewhat distorts its informativeness, nevertheless, the plan is indispensable when depicting cultural, domestic and economic objects. In addition, the plan can also show micro-objects that are difficult to find on the map (for example, vegetation and soil, the contours of which are too small to be depicted in other materials).
2. Topographic maps at a scale of 1:10,000 and 1:25,000 are considered to be the most detailed among maps. They are used for household purposes. They depict settlements, industrial and agricultural facilities, roads, hydrographic network, swamps, fences, borders, etc. Such maps are most often used to obtain information about objects in areas that do not have significant forest cover. The objects of management are depicted most reliably in them.
3. Maps with a scale of 1:50,000 and 1:100,000 are less detailed. They schematically depict the contours of forests and other large objects, the image of which does not require much detail. It is convenient to use such maps for air navigation, compiling road routes and so on.
4. Less detailed maps are used for military purposes to carry out assigned planning tasks for various operations.
5. Maps with a scale of up to 1:1,000,000 allow you to correctly assess the overall picture of the area.

Having decided on the task at hand, the choice of material seems to be absolutely challenging task. Depending on how detailed information about the area is needed, the desired map scale is also selected.

Working with a topographic map requires a clear knowledge of the schematic designation of the depicted objects.

• areal (scale) - for large objects (forest, meadow, lake), their dimensions are easy to measure on the map, correlate with the scale and obtain the necessary information about the depth, length, area;
• linear - for extended geographic objects, the width of which cannot be indicated, they are applied as a line corresponding to the scale in order to correctly display the length of the object (road, power strip);
• off-scale - they are used to designate strategically important objects, without which the map would be incomplete, but in a rather arbitrary size (bridge, well, individual tree);
• explanatory - characterizing an object, for example, the depth of a river, the height of a slope, a tree that indicates the type of forest;
• depicting landscape components: relief, rocks and stones, hydrographic objects, vegetation, artificial structures;
• special - are applied to maps for individual sectors of the economy (meteorological, military signs).

• the main information that the image of the settlement carries is the building density and the location of the boundaries of the object, for this it is not necessary to mark each building, you can limit yourself to the main streets, intersections and important buildings;
• conventions groups of homogeneous objects allow the image of only the extreme ones;
• when drawing a line of roads, it is necessary to indicate their middle, which should correspond to the situation on the ground, and the width of the message object itself should not be displayed;
• strategically important facilities such as factories and factories are marked on the spot where the main building or factory chimney is located.

Due to correct application signs on the map, you can get a detailed idea of ​​the relative position of objects on the ground, the distance between them, their heights, depths, and other important information.

The map must be objective and this requirement includes the following provisions:

• well-chosen standard conventional signs, if it is a special map, then the designations must also be well known in a certain area;
• the correct image of line elements;
• one map must be drawn in one image style;
• micro-objects must also be marked exactly, if there is a certain number of such objects of the same size on the ground, they must all be marked on the map with the same sign;
• the color indicators of the elements of the landforms must be maintained correctly - heights and lowlands are often depicted in colors, next to the map there should be a scale that shows what height on the ground this or that color corresponds to.

Conventional signs of topographic maps and plans are applied in accordance with uniform rules.

1. Object sizes are displayed in millimeters. These signatures are usually placed to the left of the conventional signs. In relation to one object, two numerical indicators are given, indicating the height and width. If these parameters match, one signature is allowed. For round objects, their diameter is indicated, for signs in the form of a star, the diameter of the circumscribed circle. For an equilateral triangle, the parameter of its height is given.
2. The thickness of the lines should correspond to the scale of the map. The main objects of plans and detailed maps (factories, mills, bridges, locks) are plotted with lines of 0.2–0.25 mm, the same designations on small-scale maps from 1:50,000 - with lines of 0.2 mm. The lines denoting minor signs are 0.08–0.1 mm thick. On plans and large-scale maps, signs may be increased by one third.
3. The symbols of topographic maps should be clear and legible, the gaps between the inscriptions should be at least 0.2–0.3 mm. Strategically important objects can be slightly increased in size.

Separate requirements are put forward for color scheme.

• green - designations of glaciers, eternal snows, swamps, solonchaks, intersections of coordinate lines and hydrography;
• brown - landforms;
• blue - water bodies;
• pink - line gaps of the highway;
• red or brown - some signs of vegetation;
• black - shading and all signs.

1. Objects marked with off-scale symbols on topographic maps and plans must correspond to the position on the ground. To do this, they need to be placed according to certain rules.

• the center of the sign of objects of the correct form (round, square, triangular) on the plan;
• the middle of the base of the symbol - for perspective displays of objects (lighthouses, rocks);
• designation corner vertices - for icons with an element of right angles (tree, pole);
• the middle of the bottom line of the sign - for designations in the form of a combination of figures (towers, chapels, towers).

Knowledge of the correct placement and application of signs will help to correctly draw up a topographic map or terrain plan, making it understandable to other users.

The designation of groups of objects by conventional signs should occur in accordance with the rules below.

1. Geodetic points. These objects should be marked as detailed as possible. The mark of the centers of the points is applied exactly to the centimeter. If the point is located on an elevated area, it is necessary to note the height of the mound or mound. When drawing the boundaries of land surveys, which are marked with pillars and numbered on the ground, the numbering should also be displayed on the map.
2. Buildings and their parts. Building outlines should be plotted on the map according to building layout and dimensions. High-rise and historically important buildings are depicted in the most detail. The number of floors is indicated starting from two floors. If the building has an orientation tower, it must also be displayed on the map.

Small buildings, such as pavilions, cellars, building elements, are displayed at the request of the customer and only on detailed maps. The numbering of buildings is reproduced only on large maps. Additionally, letters can indicate the materials from which the building is built, its purpose, fire resistance.

Conventional signs are used to highlight buildings under construction or dilapidated buildings, cultural and religious buildings. Objects on the map should be placed exactly as in reality.

In general, the detail and detail of the description of the characteristics depends on the purpose of compiling the map and is negotiated by the customer and the contractor.

1. Industrial objects. The number of storeys in buildings does not play a role. More important objects are administrative buildings and pipes. For pipes over 50 meters, it is necessary to sign their actual height.

At enterprises with mines and mining, it is customary to designate objects located on the surface. The display of underground routes is carried out in agreement with the customer, indicating the working and non-working branches. For quarries, a numerical designation of their depth is required.

1. Railways shown with the designation of their track gauge. Inactive roads must also be marked on the maps. For electrified roads and tram tracks, a power line should be displayed nearby.

The designation of road slopes, embankments and their height, slopes, tunnels and their characteristics are applied on the map. Dead ends, turntables and road endings must be applied.

Highways are marked with a certain sign, which depends on the coverage. The roadway must be marked with a line.

1. Hydrographic objects are usually divided into three groups:

• permanent;
• indefinite - existing all the time, but whose outlines often change;
• intermittent - changing depending on the season, but with a pronounced source and direction of the channel.

Permanent reservoirs are depicted with solid lines, the rest - with a dash-dotted line.

1. Relief. When depicting the terrain, horizontal lines or contour lines are used indicating the heights of individual ledges. Moreover, lowlands and elevations are depicted similarly, using strokes: if they go outward, then an elevation is depicted, if inward it is a depression, beam or lowland. In addition, if the contour lines are close to each other, the slope is considered steep, if they are far away - gentle.

A good topographic map should be extremely accurate, objective, complete, reliable and clearly define the contours of objects. When drawing up a map, it is necessary to take into account the requirements of the customer.

Depending on the purpose for which the topographic map is intended, some simplifications or minor distortions of secondary objects are allowed, but the general requirements must be met.

To depict various objects and processes, their qualitative and quantitative characteristics on maps, a special language is used - conventional signs (symbols).

Conventional signs on geographical maps perform two functions at once - they determine the spatial position of objects and indicate their appearance and some characteristics. There are areal (or scale), linear, off-scale and explanatory symbols. The list of all symbols used on the map and their explanations contains map legend. From reading the legend, you can get an idea of ​​the map without looking at it.

The objects depicted on the maps can be any objects, phenomena or processes. For their image, the most various ways. Let's look at the cards we already know.

The relief of the earth is depicted layered coloring. Thus, lowlands with heights from 0 to 200 m are painted over in green, and hills with heights from 200 to 500 m are light brown. What height each color corresponds to can be seen from the table placed at the bottom of the map. It's called the elevation scale. Using it, you can quickly determine the approximate height of any part of the territory. The same is true for the depth scale. The heights of some mountain peaks or lowlands, as well as the depths of oceanic depressions, are shown on the map and globe in meters.

Mineral resources of the Earth (coal, oil, gas, gold, diamonds, etc.) are shown on the map special icons. These are international badges, they are clear to everyone.

Contours(from the Greek isos - equal) - lines on geographical maps passing through points with the same values any geographical phenomenon, for example, atmospheric pressure - isobars, air temperature - isotherms, height earth's surface — isohypses (horizontal).

Habitat method used on maps of vegetation, wildlife, forest maps. With its help, the areas of distribution (ranges) of certain species of plants, animals or forests of different composition are shown: coniferous, mixed, etc.

Traffic signs depict movement of various objects and phenomena on the map: sea currents, winds, air masses, as well as transportation cargo and passengers.

Quality background used, for example, to depict religious or national composition population.

Cartogram depicts geographical objects or phenomena on a map with diagrammatic figures, for example, the industry of large cities on an industry map.

map- a schematic map that does not have a degree grid, depicts geographical objects and phenomena simply and clearly. For example, a weather chart, a chart trade relations countries, route and travel schemes, etc.

Selected symbols for topographic plans on a scale of 1:500 and 1:1000:

№	Name with characteristics of a topographic object	Conditional topographical signs on the ground plan
1	Points of the state geodetic network
2
3
4
5
6
7
8
9
10	Buildings: Residential fire-resistant: (stone, brick, concrete) 1) one-story; 2) more than one floor	1) 2)
11	Fire-resistant non-residential buildings: (stone, brick, concrete) 1) one-story; 2) more than one floor	1) 2)
12	Non-fire-resistant residential buildings: (wooden, adobe, etc.) 1) one-story; 2) more than one floor	1) 2)
13	Non-residential non-fire-resistant buildings (wooden, adobe, etc.) 1) one-story; 2) more than one floor	1) 2)
14	Buildings under construction
15	Dilapidated and destroyed buildings
16	Marking the height of the floor of the first floor (inside the contour); Ground mark on the corner of the house
17	Church buildings: 1) stone with domes of different heights; 2) wooden with one dome	1) 2)
18	Mosques: 1) stone; 2) wooden	1) 2)
19	Small buildings: 1) individual garages; 2) toilets	1) 2)
20	Slopes: Unreinforced (figure 2, 5 - slope height in meters)
21	Unreinforced slopes (figure 102, 5 - slope height in meters)
22	Reinforced slopes (number 102, 5 - slope height in meters; inscription - a way to strengthen)
23	Open pit mining of solid minerals (quarries, etc.) (figure - depth in meters)
24	gas stations
25	Electrical substations, transformer boxes with their numbers
26	Wells and wells combined with water towers
27	Electric lamps on poles
28	Inspection wells (hatches) of underground utilities: 1) without appointment; 2) on water supply networks; 3) on sewer networks; 4) on heating systems; 5) on gas pipelines	1) 2) 3) 4)
29	Power transmission lines (Power lines) in an undeveloped area (figures - truss heights in meters, voltage in kV, number of wires or cables): 1) power lines high voltage on reinforced concrete farms; 2) high voltage power lines on metal trusses; 3) cable overhead power line high voltage on reinforced concrete and wooden poles; 4) Low voltage power lines on metal and wooden poles	1) 2) 3) 4)
30	Power transmission lines (Power lines) in the built-up area: 1) high voltage power lines on wooden farms; 2) high voltage power lines on poles; 3) high voltage cable overhead power lines on poles; 4) Low voltage power lines on wooden poles	1) 2) 3) 4)
31	Pipelines: Ground ( G- gas pipeline, AT- water pipes, To- sewerage, H- oil pipelines; pipe material - bet., st. and etc.; numbers - pipe diameter in millimeters): 1) ground on the ground; 2) on supports (numbers are the height of the supports in meters)	1) 2)
32	Underground pipelines: 1) pipelines with inspection wells (numbers - numbers and elevations of wells; ch. 12— pipe laying depth); 2) pipelines laid side by side in one trench (numbers - the number of gaskets); 3) the direction of fluid flow in gravity gaskets	1) 2) 3)
33	Waste gratings
34	Surface pipelines on supports (green wash)
35	Pipelines on the bottom surface (green hillshade)
36	Communication lines and technical means air wired controls (telephone, radio, television, etc.)
37	Masts, towers, radio and television repeaters (numbers are their heights in meters)	1:1000 1:500
38	Landfill (dashed lines brown)
40	Wasteland, Construction sites
42	Roads: 1) highways (covering material - concrete); cuvettes in green. 2) car roads with improved surface (asphalt); cuvettes in green.	1) 2)
43	Roadways and sidewalks: Washing in pink 1) carriageways of streets in the presence of side stone; 2) carriageways of streets without side stone; 3) sidewalks with a hard surface; 4) unpaved sidewalks
44	Unpaved roads: 1) improved dirt roads; cuvettes in green. 2) dirt roads (field, forest, country roads);	1) 2) 3)
45	Roads in recesses (numbers are the depths of recesses in meters); cuvettes in green.
46	Railways
47	Narrow gauge railways (appointment and gauge in millimeters)
48	Railways on embankments (figures - height of embankments in meters)
49	Station tracks	1:1000 1:500
50	Pedestrian bridges over railways (letters - bridge material)
52	Horizontals (in brown): 1) thickened (through a given interval of section height); 2) basic; 3) semi-horizontal (half the height of the section); 4) quarter-horizontal (in 1/4 section height)	1) 2) 3) 4)
53	Slope direction indicators (bergstrokes)
54	Height marks
55	Ground cliffs (in brown): (numbers - depth in meters)
56	Pits (numbers - depth in meters)
57	Mounds (numbers - height in meters)
59	watercourses, coastlines and marks of water edges (height and date of measurement), Land and water boundary in green, hillshade in blue.
60	Streams (width not expressed in plan scale) in blue.
61	Characteristics of watercourses: 1) direction and speed of the current in m/s; 2) width in meters (numerator), depth in meters and bottom soil (denominator)
62	Bridges: 1) in general superstructure(metal - metal, stone - stone, reinforced concrete, figures - load capacity in tons); 2) small wooden; 3) on foot	1) 2) 3)
63	Vegetation: Contours of vegetation, agricultural land, soil, etc.
64	Characteristics of forest stands in terms of composition: 1) deciduous; 2) coniferous; 3) mixed; according to qualitative data: 4) average height of trees in meters (numerator), average thickness of trunks in meters (denominator), average distance between trees in meters (number on the right), tree species	1) 2) 3) 4)
65	Natural tall forests
66	Young forest plantations (figure - average height in meters)
67	Forest areas cut down
68	Shrubs separate groups
69	Thickets (with indication of species and average height)
70	Vegetation herbaceous, meadow
71	Fruit orchards (figure - average height in meters)
72	Lawns, flower beds
73	arable land
74	Hayfields with groups of shrubs
75	Pasture with light forest
76	Soils: 1) sands are even (brown);

Symbols on a map or plan are a kind of their alphabet, by which they can be read, find out the nature of the area, the presence of certain objects, and evaluate the landscape. As a rule, the symbols on the map convey common features with existing in reality geographic features. The ability to decipher cartographic symbols is indispensable when making hiking trips, especially to distant and unfamiliar areas.

All objects marked on the plan can be measured on the scale of the map to represent their actual size. Thus, the conventional signs on a topographic map are its "legend", their decoding for the purpose of further orientation in the area. Homogeneous objects are indicated by the same color or stroke.

All outlines of objects located on the map, according to the method graphic image are divided into several types:

• Areal
• Linear
• Point

The first type consists of objects that occupy large area on a topographic map, which are expressed by areas enclosed in boundaries in accordance with the scale of the map. These are objects such as lakes, forests, swamps, fields.

Linear designations are outlines in the form of lines, they can be seen on the scale of the map along the length of the object. These are rivers, railways or roads, power lines, clearings, streams, etc.

Dot outlines (off-scale) denote objects of small size that cannot be expressed on the scale of the map. It can be both individual cities and trees, wells, pipes and other small single objects.

Symbols are applied in order to have the most complete picture of the indicated area, but this does not mean that absolutely all the smallest details real individual area or city. The plan indicates only those objects that have great importance for National economy, services of the Ministry of Emergency Situations, as well as military personnel.

Types of symbols on maps

To recognize the signs of the map, you need to be able to decipher them. Conditional symbols are divided into scale, off-scale and explanatory.

• Scale symbols indicate local objects that can be expressed in terms of their size on the scale of a topographic map. Them graphic designation appears as a small dotted line or thin line. The area inside the border is filled with conditional icons that correspond to the presence of real objects in this area. Scale signs on a map or plan can be used to measure the area and dimensions of a real topographic object, as well as its outlines.
• Out-of-scale symbols indicate objects that cannot be displayed on the scale of the plan, the size of which cannot be judged. These are some separate buildings, wells, towers, pipes, kilometer posts and so on. Out-of-scale symbols do not indicate the dimensions of the object located on the plan, so it is difficult to determine the actual width, length of the pipe, elevator or separately standing tree. The purpose of off-scale markings is to accurately indicate a particular object, which is always important when navigating when traveling in unfamiliar terrain. The exact indication of the location of the indicated objects is carried out by the main point of the symbol: it can be the center or the lower middle point of the figure, the top of the right angle, the lower center of the figure, the axis of the symbol.
• Explanatory signs serve to disclose information about scale and off-scale designations. They give additional characteristics to objects located on a plan or map, for example, arrows indicate the direction of the river flow, designate forest species with special signs, the carrying capacity of the bridge, the nature of the road surface, the thickness and height of trees in the forest.

In addition, topographic plans place other designations on themselves that serve as an additional characteristic for some of the indicated objects:

• Signatures

Some signatures are used in full, others are abbreviated. Names are fully deciphered settlements, names of rivers, lakes. Abbreviated signatures are used to indicate more detailed characteristics some objects.

• Numerical symbols

They are used to indicate the width and length of rivers, roads and railways, transmission lines, the height of points above sea level, the depth of fords, etc. The standard designation of the map scale is always the same and depends only on the size of this scale (for example, 1:1000, 1:100, 1:25000, etc.).

In order to navigate as easily as possible on a map or plan, conventional signs are indicated different colors. To distinguish even the smallest objects, more than twenty various shades, from intensely colored areas to less bright ones. To make the map easy to read, at the bottom of it is a table with a decoding of color designations. So, usually water bodies are indicated in blue, light blue, turquoise color; forest objects in green; terrain - brown; city ​​blocks and small settlements - gray-olive; highways and highways in orange; state borders– purple, neutral area – black. Moreover, blocks with fire-resistant buildings and structures are marked in orange, and blocks with non-fire-resistant structures and improved dirt roads - yellow.

one system symbols of maps and plans of the area is based on the following provisions:

• Each graphic sign always corresponds to a certain type or phenomenon.
• Each sign has its own clear pattern.
• If the map and plan differ in scale, the objects will not differ in their designation. The difference will only be in their size.
• Drawings of real terrain objects usually indicate an associative connection with it, therefore, they reproduce a profile or appearance these objects.

To establish an associative connection between a sign and an object, there are 10 types of formation of compositions:

Topographic maps and plans depict various objects of the area: the contours of settlements, orchards, orchards, lakes, rivers, road lines, power lines. The collection of these objects is called situation. The situation is portrayed conventional signs.

Standard symbols, mandatory for all institutions and organizations compiling topographic maps and plans, are established Federal Service geodesy and cartography of the Russian Federation and are published either separately for each scale, or for a group of scales.

Symbols are divided into five groups:

1. Areal symbols(Fig. 22) are used to fill the areas of objects (for example, arable land, forests, lakes, meadows); they consist of a sign of the object boundary (a dotted line or a thin solid line) and images that fill it or conditional coloring; for example, symbol 1 shows a birch forest; the numbers (20/0.18) *4 characterize the stand, (m): the numerator is the height, the denominator is the thickness of the trunk, 4 is the distance between the trees.

Rice. 22. Areal symbols:

1 - forest; 2 - felling; 3 - meadow; 4 - garden; 5 - arable land; 6 - orchard.

2. Linear symbols(Fig. 23) show objects of a linear nature (roads, rivers, communication lines, power transmission lines), the length of which is expressed in a given scale. Conditional images show various characteristics objects; for example, highway 7 (m) shows: the width of the carriageway - 8 and the entire road - 12; on single-track railway 8: +1.800 - embankment height, -2.900 - excavation depth.

Rice. 23. Linear symbols

7 - highway; 8 - railway; 9 - communication line; 10 - power line; eleven - main pipeline(gas).

3. Off-scale symbols(Fig. 24) are used to depict objects whose dimensions are not expressed on a given scale of a map or plan (bridges, kilometer posts, wells, geodetic points). As a rule, off-scale signs determine the location of objects, but they cannot be used to judge their size. Various characteristics are given on the signs, for example, the length of 17 m and the width of 3 m of the wooden bridge 12, the mark of 393.500 points of the geodetic network 16.

Rice. 24. Off-scale symbols

12 - wooden bridge; thirteen - windmill; 14 - plant, factory;

15 - kilometer post, 16 - geodetic network point

4. Explanatory symbols are digital and alphabetic inscriptions characterizing objects, for example, the depth and speed of the flow of rivers, the carrying capacity and width of bridges, the type of forest, the average height and thickness of trees, the width of highways. These signs are put down on the main areal, linear, off-scale.

5. Special symbols(Fig. 25) establish the relevant departments of the branches of the national economy; they are used to compile specialized maps and plans for this industry, for example, signs for mine surveying plans for oil and gas fields - oilfield facilities and installations, wells, field pipelines.

Rice. 25. Special symbols

17 - track; 18 - plumbing; 19 - sewerage; 20 - water intake column; 21 - fountain

To make the map or plan more visual, colors are used to depict various elements: for rivers, lakes, canals, wetlands - blue; forests and gardens - green; highways - red; improved dirt roads are orange. The rest of the situation is given in black. On the survey plans they make color underground utilities(pipelines, cables).

Terrain relief and its representation on topographic maps and plans

terrain called the set of irregularities of the physical surface of the Earth.

Depending on the nature of the relief, the area is divided into mountainous, hilly, flat. The whole variety of landforms is usually reduced to the following main forms (Fig. 26):

Rice. 26. Basic landforms

1. Mountain - dome-shaped or conical elevation of the earth's surface. The main elements of the mountain:

a) peak - the highest part, ending either in an almost horizontal platform, called a plateau, or a sharp peak;

b) slopes or slopes, diverging from the top in all directions;

c) sole - the base of the hill, where the slopes pass into the surrounding plain.

The small mountain is called hill or hill; an artificial hill is called mound.

2. Basin- a bowl-shaped, concave part of the earth's surface, or unevenness, opposite the mountain.

In the basin there are:

a) bottom - the lowest part (usually a horizontal platform);

b) cheeks - lateral slopes, diverging from the bottom in all directions;

c) the outskirts - the border of the cheeks, where the basin passes into the surrounding plain. The small basin is called depression or pit.

3. Ridge- a hill, elongated in one direction and formed by two opposite slopes. The meeting line of the slopes is called ridge axis or watershed line. The descending parts of the spinal line are called passes.

4. Hollow- recess, elongated in one direction; the shape is opposite to the ridge. In the hollow, they distinguish: two slopes and a thalweg, or water-connecting line, which often serves as the bed of a stream or river.

A large wide hollow, with a slightly inclined thalweg, is called valley; a narrow hollow with steep slopes, rapidly descending, and a thalweg cutting through the ridge, is called gorge or gorge. If it is located in a plain, then it is called ravine. A small hollow with almost sheer slopes is called girder, rut or ravine.

5. Saddle- the meeting place of two or more opposite hills, or opposite hollows.

6. Ledge or terrace- an almost horizontal platform on the slope of a ridge or mountain.

The top of the mountain, the bottom of the basin, the lowest point of the saddle are characteristic points of the relief.

The watershed and thalweg are characteristic lines of relief.

Currently, for large-scale plans, only two methods of depicting the relief are accepted: signing marks and drawing contour lines.

horizontal called a closed curved line of terrain, all points of which have the same height above sea level or above a conditional level surface.

The contours are formed like this (Fig. 27). Let the hill be washed by the surface of the sea with a mark equal to zero. The curve formed by the intersection of the water surface with a hill will be a horizontal line with a mark equal to zero. If we mentally cut a mountain, for example, by two level surfaces with a distance between them h = 10 m, then the traces of the section of the hill by these surfaces will give horizontals with marks of 10 and 20 m. If we design the traces of the section of these surfaces on horizontal plane in a reduced form, we get a plan of elevation in horizontal lines.

Rice. 27. Image of relief by contour lines

On the plan, in horizontal lines, elevations and depressions have the same look. To distinguish a hill from a depression, short strokes are placed perpendicular to the horizontals in the direction of lowering the slope - indicators of the slopes. These strokes are called berghashes. The lowering and raising of the terrain can be set and the signatures of the contour lines on the plan. The image of the main landforms is presented in Figure 28.

In cases where the elements of the slope are not reflected by the section of the main contour lines, half-horizontals and quarter-horizontal lines are drawn on the plan at the height of half and a quarter of the main section.

For example, the ledge and the bottom of the slope of a hill are not reflected by the main contours. The drawn semi-horizontal reflects the ledge, and the quarter-horizontal reflects the sole of the ramp.

Rice. 28. Image of the main landforms by contour lines

The main horizontals are drawn in brown ink with thin solid lines, semi-horizontals - broken lines, quarter horizontal - short dash-dotted line (Fig. 27). For greater clarity and ease of counting, some horizontal lines are thickened. With a section height of 0.5 and 1 m, each horizontal line is thickened, a multiple of 5 m (5, 10, 115, 120 m, etc.), when the relief is cut through 2.5 m - horizontal lines that are multiples of 10 m (10, 20 , 100 m, etc.), with a section of 5 m thicken the horizontals, multiples of 25 m.

To determine the height of the relief in the gaps of the thickened and some other contour lines, their marks are signed. At the same time, the bases of the digits of the horizontal marks are placed in the direction of lowering the slope.

At first glance, printed maps of the area have lost their relevance and have been replaced by applications for smartphones and GPS-navigators. Electronic options are convenient, they help to quickly determine your own location on the ground, but they have a number of significant drawbacks, one of them is unreliability. The ability to recognize symbols on a topographic map is necessary for orientation in an unfamiliar area without electronic devices. Whatever modern model navigator you did not possess, it will need regular connection to the mains or portable chargers to maintain stable performance. Also, navigation programs do not always correctly determine the location, which contributes to the lengthening of the route and complicates the process of reaching the destination. Paper schemes do not need such careful care and will always come to the rescue in survival conditions. In the life of every person, situations arise when knowledge is needed about how conventional signs on a topographic map are deciphered. Thanks to the ability to determine them, you can easily go through any route, having only a printed circuit with you. In conditions of survival or getting lost, the presence of a terrain map in a backpack contributes to quick orientation and significant time savings. In the article we will consider what topographic maps are, their classification, symbols and correct interpretation.

Symbols on the topographic map

To begin with, let's consider what a large-scale topographical plan of the area is (Figure 1).

Figure 1. Example of a topographic plan

By default, this is a generic scheme that provides the maximum possible number information about a particular area and introduces the user to all important details landscape: from the classification of plants and soil types to gas stations and railway crossings. The versatility lies in the fact that travelers, motorists, surveyors, military, engineers, agents can use such a plan for completely different purposes. construction companies, foresters, hunters, fishermen and many others without restrictions.

Certain prohibitions are imposed exclusively on objects of military importance.

Diagrams are created in the same way as online applications: by using pictures taken with aircraft (in recent times photographs taken by space orbiting satellites are popular), after which they are transferred to a plane and simplified. This allows you to create the most accurate scaled-down landscape plan, on which the designations of the most important objects are subsequently applied. There are two main criteria by which the topography of the map, conventional signs, should be created.

Criteria for creating a map:

1. visibility. Since the topographic plan conveys all the details of the area visually, it must be as clear as possible for perception. The features of the relief, the presence of flora (rarely fauna), railway and transport interchanges, reservoirs, large structures, settlements are clearly displayed;
2. Measurability. Since any terrain scheme has a scale, all designations can be measured with a ruler and a simple mathematical calculation can be made, according to which the length of, for example, a building or a forest belt is calculated.

How are symbols of topographic maps selected? This process called generalization, it involves the selective placement of icons that are of maximum importance to the reader (Figure 2). Unimportant buildings are not displayed in any way to save free space.

Symbol meanings

Area maps reached the peak of popularity in the USSR, almost every inhabitant of the country had maps of a particular area. But even today, the book of conventional signs of topographic maps is in great demand. This is due to the fact that there are more than seven main groups of symbols, each of which includes dozens and even hundreds of different icons. All of them are considered the so-called legend (Figure 3) of any map (from the scheme in the subway car to highly specialized military or engineering copies). A detailed explanation of each character is placed in separate fields, which greatly simplifies the reading process. There are no standards in cartography regarding the drawing of icons, so their design may differ in each instance while maintaining the general similarity and the mandatory explanation in the margins.

Common signs on a topographic map and their meanings

Conventional symbols are designed to display on the landscape plan all phenomena and objects, their main characteristics.

They are divided into three groups according to the scale criterion:

Strongholds and settlements

Conventional signs of the military topographic map "strongholds and residential areas (Figure 5)" - help to initially orient:

Industrial and agricultural facilities

Conventional signs of topographic maps indicating industrial (Figure 6) and household buildings can also serve as a guide.

Landmark for industrial and agricultural facilities:

• The pipe dot symbol is used to display businesses with pipes that stand out from the surrounding landscape. Next to it, the main direction of the plant, factory or workshop is indicated. However, it is worth remembering that information about the activities of the enterprise may become outdated. For this reason, it is recommended to use modern maps, where the exact activity of production is indicated;
• Farm buildings are also indicated with off-scale symbols if they are medium in size. At small sizes, they are indicated by an abbreviated inscription (for example, a poultry farm is indicated by "bird."), and at large sizes it has clear scaled contours.

A distinctive feature of drawing all industrial and rural buildings on the plan is the accuracy of the location of the midpoint.

Socio-cultural objects

Cultural monuments and social facilities are applied to the landscape plan, which are located on the outskirts, placed outside the city and serve as a guide. However, in tourist copies, monuments and the most important buildings of social purpose are given Special attention. These may include cathedrals, fortresses, ruins, estates, museums, exhibition centers, as well as sanatoriums, hospitals, tourist bases, resorts, selected according to their importance. Next to the off-scale icon, the main definition is indicated in small italic type: monasteries "monast.", Monument "memorial", sanatorium "sanat.", mineral spa"min.kurt" (Figure 7).

Railroads, highways and dirt roads

Such conventional signs of topographic maps as road and rail (Figure 8) junction are present on any diagrams. The road junction plays the most important role for the reader and helps to get out both on foot and on vehicle. It is indicated by linear symbols, the scale of which is accurately measured only in length.

All diagrams show:

Rivers, lakes, canals, etc.

Water symbols on the topographic map are divided into linear and scale.

Linear are rivers, springs, springs and water channels, which have a clear length.

Large-scale indicates lakes, seas, reservoirs, which can be measured both in length and in width. Clarification for water bodies is written in small italics (for a river "river" or a lake "lake"). All reservoirs are executed in blue or blue color(Figure 9), on some maps depth is indicated by darker shades of blue.
Figure 9. An example of the designation of rivers and lakes

terrain

Since all terrain plans are presented in a two-dimensional plane, contrary to the original shape of the ellipsoid of the planet Earth, volume and relief are depicted using isogypsum. Isogypses are lines that allow you to display the volume of the relief in two-dimensional space. The relief is represented not only by land and hills, but also by reservoirs and depressions. Depending on the convexity or concavity, the landscape is indicated different colors. Consists of elements: base, slope, top or bottom, height or depth of the object (Figure 10).