Contour symbols of topographic maps. Conventional signs, crosses, scale of topographic survey. Conventional explanatory signs of age and forest species

Topographic maps and plans depict various terrain objects: the outlines of settlements, gardens, vegetable gardens, lakes, rivers, road lines, power transmission lines. The collection of these objects is called situation. The situation is depicted conventional signs.

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

Conventional signs are divided into five groups:

1. Area 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 boundary of an object (a dotted line or a thin solid line) and images or conventional coloring that fill it; for example, symbol 1 shows a birch forest; numbers (20/0.18) *4 characterize the tree stand, (m): numerator - height, denominator - trunk thickness, 4 - distance between trees.

Rice. 22. Area symbols:

1 - forest; 2 - cutting; 3 - meadow; 4 - vegetable 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 on a given scale. The conventional images show various characteristics of objects; for example, on highway 7 (m) the following are shown: the width of the carriageway is 8 and the width of the entire road is 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; 11 - main pipeline (gas).

3. Off-scale symbols(Fig. 24) are used to depict objects whose dimensions are not expressed at 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 their size cannot be judged from them. The signs give various characteristics, for example, the length of 17 m and the width of 3 m of wooden bridge 12, elevation 393,500 points of the geodetic network 16.

Rice. 24. Off-scale symbols

12 - wooden bridge; 13 - windmill; 14 - plant, factory;

15 - kilometer pole, 16 - geodetic network point

4. Explanatory symbols are digital and alphabetic inscriptions that characterize objects, for example, the depth and speed of river flows, load capacity and width of bridges, forest species, average height and thickness of trees, width of highways. These signs are placed on the main areal, linear, and non-scale ones.

5. Special symbols(Fig. 25) are established by the relevant departments of the national economy; they are used to draw up specialized maps and plans of this industry, for example, signs for survey plans of oil and gas fields - oil field structures and installations, wells, field pipelines.

Rice. 25. Special symbols

17 - route; 18 - water supply; 19 - sewerage; 20 - water intake column; 21 - fountain

To give a map or plan greater clarity, colors are used to depict various elements: for rivers, lakes, canals, wetlands - blue; forests and gardens - green; highways - red; improved dirt roads - orange. The rest of the situation is shown in black. On survey plans, underground communications (pipelines, cables) are colored.

Terrain and its depiction on topographic maps and plans

Terrain is a set of irregularities on the physical surface of the Earth.

Depending on the nature of the relief, the terrain is divided into mountainous, hilly, and flat. All the variety of landforms is usually reduced to the following basic forms (Fig. 26):

Rice. 26. Basic landforms

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

a) apex - the highest part, ending either with an almost horizontal platform called a plateau, or with 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 fell; artificial hill called mound.

2. Basin- a cup-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) margin - 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 line where the stingrays meet is called ridge axis or watershed line. The descending parts of the spine line are called passes.

4. Hollow- a recess extended in one direction; shape opposite to the ridge. In the hollow there are 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 ravine with steep slopes that quickly descend and a thalweg cutting through the ridge is called gorge or gorge. If it is located in a plain, it is called ravine. A small hollow with almost vertical slopes is called beam, pothole or gulley.

5. Saddle- a meeting place of two or more opposite hills, or opposite valleys.

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 relief points.

The watershed and thalweg represent characteristic relief lines.

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

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

Horizontal lines are formed like this (Fig. 27). Let the hill be washed by the surface of the sea with an elevation equal to zero. The curve formed by the intersection of the water surface with a hill will be a horizontal line with an elevation equal to zero. If we mentally dissect 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 with these surfaces will give horizontal lines with marks of 10 and 20 m. If we project the traces of the section of these surfaces onto a horizontal plane in a reduced form, we will obtain a plan of the hill in horizontals.

Rice. 27. Image of the relief with horizontal lines

On the horizontal plan, the elevations and depressions have the same appearance. To distinguish a hill from a depression, short strokes are placed in the downward direction of the slope perpendicular to the horizontal lines - slope indicators. These strokes are called berg strokes. Lowering and raising the terrain can be established and the signatures of contour lines on the plan. An image of the main relief forms is presented in Figure 28.

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

For example, the protrusion and the bottom of the slope of a hill are not reflected by the main horizontal lines. The drawn semi-horizontal reflects the protrusion, and the quarter-horizontal reflects the bottom of the slope.

Rice. 28. Representation of the main forms of relief with horizontal lines

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

To determine the height of the relief in the gaps of thickened and some other contours, their marks are signed. In this case, the bases of the numbers of the horizontal marks are placed in the direction of lowering the slope.

To use a topographic map correctly, you need to become familiar with generally accepted symbols and designations. When preparing topographic maps and plans, various objects located on the displayed area are indicated by special symbols.

The main objects on the map include the following points:

Cities.
Villages.
Rivers, ponds and other bodies of water.
Mountains.
Industrial enterprises.

The presented list does not include all objects located on the maps.

Types of symbols

Symbols of topographic maps can be scale (contour), non-scale, linear, explanatory.

Scale symbols of topographic maps are used to depict terrain features that are expressed at the appropriate scale. The area of such objects can be measured directly on the map using a graduated ruler.

For example, in order to approximately find out the size of a lake, forest, or settlement, you need to calculate the area of the object on the map (draw it into 1 cm2 cells, count the number of full and incomplete cells), and then, using a scale, convert the result to kilometers.

Using off-scale symbols, specific objects located on the ground that are not shown to the scale of the map are shown. For example, if it is necessary to put on a map a separate pillar, tree, building, geodetic point, etc. They are deliberately depicted in an enlarged form.

To indicate the exact position of a given object on the map, the main point is placed in the center of the symbol - square, circle, asterisk, etc.

Linear symbols depict horizontal lines and extended objects on the ground. These include the following designations:

railways;
highways;
electrical lines;
clearings;
rivers, streams;
boundary designations.

The extent of such objects is expressed in accordance with the map scale. The width of these symbols is shown regardless of scale. It usually exceeds the actual dimensions. The longitudinal axis of the symbol is applied to the area plan in accordance with the location of the object (parallel).

To give additional characterization to one or more objects on the ground, explanatory conventional topographical signs, symbols and captions are used.

Eg:

the outlines of a deciduous or coniferous tree in a forest area indicate the predominant species of plantings, the average height and thickness of their trunks;
using transverse strokes on the conventional railway track icon, the number of tracks is indicated;
letters and numbers on the highway - road surface material, route width;
designation of bridge dimensions, as well as their load capacity.

Explanatory symbols on topographic maps and plans provide more complete information about the nature of a given area.

Proper names, explanatory inscriptions, etc. are written on the topographic map in a special font; the letters have a certain size.

Acceptable conventions on the map

Sometimes a topographic map contains a symbolic image of individual objects. For example, the external boundaries of a particular settlement are drawn. At the same time, main highways and intersections are indicated. If some buildings are depicted, they characterize the density of buildings, but not their exact number.

To show the dense arrangement of homogeneous objects (houses, mounds, wells, etc.), only objects located on the boundaries of a given area are depicted, in accordance with their exact location.

Conventional symbols of industrial enterprises (factories, factories) are placed in places where the main building or the highest factory chimney is located.

Symbol sizes

To the left of the symbol there are numbers displaying its dimensions in millimeters on the map. The two signatures indicate the height and width of the rectangular sign. If there is one inscription, this indicates that both quantities are equal to each other.

The conventional symbol is familiar to everyone - a circle has a digital signature indicating its diameter. A star is the diameter of the circumscribed circle, an equilateral triangle is its height.

Symbol colors

Regardless of the scale of the map, various topographical symbols are painted in certain colors and shades:

Border contours, line marks of land plots are black.
Relief elements - brown background color.
Rivers, glaciers, swamps - blue lines, shading.
Water mirror - blue background.
Areas with trees and shrubs - green.
Vineyards - light green.
Fire-resistant buildings, asphalt roads - orange.
Non-fireproof buildings, dirt roads - yellow.

In addition to conventional symbols, topographic maps contain their own names in abbreviated form for various regions, districts, and other significant objects (Moscow, El.-St., South-West, Bol. - swamp). Additional information is provided on topographic maps using standard fonts.

For example, the depth, flow of the river, as well as the possibility of navigation along it. Special fonts indicate the heights of the hills, the depths of the wells, and the number of people in towns and cities.

When depicting various objects on terrain plans, a universal system of cartographic symbols is used. Often such designations are called “map legend”. Their designs resemble the objects they depict. For example, trees, bridges, oil rigs. In general, there are quite a lot of such signs, so special reference books are published containing a list of accepted abbreviations and designations.

Initial information

Cartographic symbols are used to symbolically designate objects and phenomena on maps, indicating qualitative and quantitative parameters. Each graphic symbol has its own type of object or phenomenon associated with it. Depending on the scale of the image, the sizes of the characters may vary, but their design remains unchanged.

The drawing of the icon is made with clear lines. Explanatory captions are used to indicate additional characteristics. For example, they are used to indicate the predominant type of trees in the forest and the covering material of a transport road. Proper reading of topography allows you to obtain detailed information about any part of the area.

The notation uses the concept of isoline. This is a line connecting points on the map with the same values of phenomena. Thus, a line with equal atmospheric pressure along it is called an isobar, and with equal air temperature - an isotherm. In cases of coinciding heights of the earth, such a line is called isohypsum (horizontal). The plans also show lines, isotachs, connecting points with the same wind speed.

There are several notation methods:

iconic - can be of any geometric shape, in the form of letters or pictures;
linear signs - used to depict extended objects, for example, rivers, borders, communication routes;
quality fund - used to identify areas with the same socio-economic, administrative characteristics, location of titanic slabs, type of soil or vegetation;
diagrams - indicate quantitative characteristics, for example, wind rose, precipitation;
map diagrams - widely used to indicate static and economic indicators, indicators of production volume, structure of the land fund, reserves of substances;
movement - using this method, sea currents, travel routes, and bird migration routes are marked on maps;
area - used to design map boundaries.

Most symbols can be combined with each other, but not all. For example, the point method cannot be combined with symbolic and cartogram images. The application of symbols also depends on the scale of the map or plan.

Classification of designations

It is impossible to remember all the symbols on the map, so there are topographic reference books with a detailed description of the accepted symbols. Basic information can be obtained in a geography textbook for the sixth grade. But schoolchildren are given only general, meager information, which, however, should be enough for tourism. More detailed information is contained in the reference books. For example, “Handbook of Military Topography” by A. M. Govorukhin or “Fundamentals of Topography” by A. L. Vostroknutov.

There are three types of symbols:

areal (contour);
off-scale;
explanatory.

Using contour symbols, you can determine not only geographic coordinates, but also the sizes of objects and their outlines. The perimeter of objects is depicted by solid lines, and their color matters. Black marks the boundaries of structures, fences, roads, blue marks water resources, brown marks the relief, light pink marks the routes of movement in populated areas.

The dotted line is used to mark the boundaries of agricultural land, embankments, tunnels, and clearings. Linear signs are a type of scale signs. They are used to depict power lines and roads.

If a map or plan is depicted at such a scale that, due to its smallness, the outline designation becomes cumbersome, use an out-of-scale type. In this case, a point is placed that is located at the location of the object. For signs of a symmetrical shape, it is drawn in the center, having a base in the form of an angle - at the top, consisting of a combination of various figures - in the center of the bottom.

Explanatory signs serve as a complement to scale and non-scale symbols. With their help, the characteristics of objects and their features are indicated. For example, when depicting a forest consisting of coniferous trees, along with the sign there may be a description of the height and additional species present.

Using explanations, indicate the names of settlements, rivers, lakes and the like. Within the city limits, the names of avenues, districts, schools, kindergartens, and streets are indicated. To enhance the visual representation, a group of symbols related to the same type of signs is made in the same color.

Image Features

Images and designations of symbols for various topographic scales were developed on the basis of the Central Research Institute of Geodesy, Aerial Photography and Cartography of the GUGK USSR. The complete reference book was published in 1977 by the Main Directorate of Geodesy and Cartography under the Council of Ministers of the USSR by the Nedra publishing house. It replaced the 1968 edition. The last edition was released in 1989. In addition, the symbols of geographical maps are specified in GOST 21 .204−93, as well as SNiP 11−02−96.

When placing signs on the map, the following requirements are taken into account:

off-scale signs for depicting objects are placed at a distance from each other of at least 0.3 mm perpendicular to the southern frame;
if the center of the sign falls on the frame, then it is applied on the original sheet and on the one adjacent to it;
the dotted line is not used if it coincides with the boundaries of linear objects, as well as when the contour passes at a distance of less than one millimeter;
the outlines of buildings must coincide with the true form;
the presence of towers on buildings is indicated by special signs or highlighted outlines with explanations;
light portable buildings are not indicated on the plans;
images of residential objects are signed with the letter “Zh”, non-residential ones - “N”, and the number of storeys is indicated by a number;
metro entrances are marked with a capital letter “M”;
cellars are indicated with an explanatory inscription and signed with the word “Cellars”;
Cemeteries during topological surveys are depicted with the transfer of buildings;
when indicating quarries nearby, their depth is shown;
symbols of oil and gas rigs are depicted only when they are located near wells;
signs of supports with consoles more than two meters long are accompanied by strokes;
the name of a separate tree or forest is placed before the sign of vegetation cover;
when indicating the sign “forest”, write down the height of the trees in the numerator, and the thickness in the denominator; the number after the fraction indicates the distance between the trees;
ice cliffs and aufeis are painted in blue, and inscriptions are also made with it;
meadow vegetation is depicted in white;
clayey areas in the desert, expressed on a map scale, are outlined, but if not to scale, then the boundaries of the area are not marked;
on a map of scale 1:25,000, all sands are designated by a single sign - “flat sands”.

Common signs

Knowing the correct interpretation of topographic signs allows you to confidently navigate the area using a map, understanding where and what is located. Of the large number of different symbols, the most common symbols are symbols of strongholds and settlements, railways and roads, signs of relief and land cover, and indications of water areas.

The main geodetic signs include:

Residential and non-residential buildings are depicted with a picture and numbers indicating the size of the building.
Destroyed and dilapidated objects - unlike whole ones, their outline is depicted with dots.
Churches are marked on the map with a cross indicating the height.
Chapels and mosques - respectively, a circle with a cross and a circle with a crescent.
The blocks are a solid line outline with internal shading; the color of the stroke indicates the material from which the buildings are made.
Tunnels and overpasses - the first are two parallel lines with a dotted line in the middle, and the second with a solid line.
Plants, factories - a black rectangle is drawn with the image of a pipe on top; if it is not in the factory, the pipe is not shown, and the rectangle changes to the form of a channel.
Mines - their sign represents two crossed pickaxes; if the mines are not working, the sign is turned over.
Oil and gas rigs are indicated by a picture of a pipe, on the right side of which the type of resource is indicated, and on the left the height of the rig is indicated.
Parks are identified if their area on the map scale is at least 1.5x2.0 mm.
Gullies and gullies - to designate them, indicate the mouth, alluvial cone, bottom and slopes. Their relief is drawn in brown. Narrow objects are depicted with one thick line or two with a width of more than one and a half meters.
Cemeteries - outline a contour in the middle of which crosses are placed.
Swamps - clean spaces are depicted with a solid outline, shaded in green and periodically marked with marks; if there are hummocks or bushes, then their images are evenly distributed throughout the space.

It is worth noting that depending on the congestion of the areas, fonts may be changed. Numerical characteristics are drawn in italics, except for signing contour lines and number of storeys of buildings.

Water bodies

The watermark table occupies a separate place in cartography. The image of the coastal parts of the seas, lakes, rivers, canals, wells and various reservoirs is called hydrography. The larger the scale of the plan, the more detailed the water marks are depicted.

Small bodies of water are indicated only for arid areas or deserts, and also if it is impossible to use other landmarks. Rivers, main ditches and streams must be marked on the maps. On large-scale maps, rivers up to five meters wide are drawn with one line, and wider ones with two. The arrow indicates the direction of the flow. The names of navigable rivers and canals are written in capital letters, while non-navigable ones are written in lowercase letters.

For dams and artificial embankments indicate heights in meters. Near the fords they place a shot. In the numerator, the numbers indicate the depth and length in meters, and in the denominator - the type of soil and flow speed. When designating bridges, indicate the material from which they are made. You need to read “K” - like stone, “ZhB” - reinforced concrete, “M” - metal, “D” - wooden. Then they write down the physical length of the bridge, the width of the roadway and the height above the water. All dimensions are indicated in meters.

Marinas and anchorages are not drawn to scale. The first ones sign the abbreviation “adj.” in lowercase letters with italics, and the latter are indicated by a pictogram with an image of an anchor. Recently, it has become fashionable among tourists to swim along rivers and, using GPS, try to independently sign the location of the rapids. But you shouldn’t really trust such designations. They are indicated by a line across the river with the caption “por”.

If it is necessary to designate a water tower, then do this using a drawing with the image of a drop and the inscription “water.” next to it. The lighthouse is represented by an asterisk, and the well is represented by a circle indicating the depth. Lakes are indicated by a completed outline shaded blue. A number is placed above it indicating the height in meters, and next to it in parentheses the abbreviated type of water is written. It can be fresh (pr.), salty (sol.), bitter-salty (g-salt.).

Thus, local objects on geographical or geodetic plans and maps are depicted with conventional topographic signs. Their designations are defined in GOST and GUGK and are of the same type. At the same time, even without knowing which sign means what, you can intuitively guess its purpose by its appearance.

Scale, or contour, conventional topographic signs are used to depict local objects whose size can be expressed on a map scale, that is, their dimensions (length, width, area) can be measured on the map. For example: lake, meadow, large gardens, residential areas. The contours (external boundaries) of such local objects are depicted on the map with solid lines or dotted lines, forming figures similar to these local objects, but only in a reduced form, that is, on the scale of the map. Solid lines show the contours of neighborhoods, lakes, and wide rivers, and the contours of forests, meadows, and swamps are dotted lines.

Figure 31.

Structures and buildings, expressed on the scale of the map, are depicted with figures similar to their actual outlines on the ground and are painted over in black. Figure 31 shows several on-scale (a) and out-of-scale (b) symbols.

Off-scale symbols

Explanatory topographic signs serve for additional characterization of local objects and are used in combination with large-scale and non-scale signs. For example, a figurine of a coniferous or deciduous tree inside the outline of a forest shows the dominant tree species in it, an arrow on a river indicates the direction of its flow, etc.

In addition to signs, maps use full and abbreviated signatures, as well as digital characteristics of some objects. For example, the signature “mash.” with a plant sign means that this plant is a machine-building plant. The names of settlements, rivers, mountains, etc. are fully signed.

Digital symbols are used to indicate the number of houses in rural settlements, the height of the terrain above sea level, the width of the road, the characteristics of the load capacity and the size of the bridge, as well as the size of trees in the forest, etc. Digital symbols related to conventional relief signs are printed in brown. , the width and depth of rivers are in blue, everything else is in black.

Let us briefly consider the main types of topographic symbols for depicting the area on the map.

Let's start with the relief. Due to the fact that observation conditions largely depend on its nature, the terrain's passability and its protective properties, the terrain and its elements are depicted on all topographic maps in great detail. Otherwise, we could not use the map to study and evaluate the area.

In order to clearly and completely imagine the area on the map, you must first of all be able to quickly and correctly determine on the map:

Types of unevenness of the earth's surface and their relative location;

Mutual elevation and absolute heights of any terrain points;

The shape, steepness and length of the slopes.

On modern topographic maps, the relief is depicted by horizontal lines, that is, curved closed lines, the points of which are located on the ground at the same height above sea level. To better understand the essence of depicting relief with horizontal lines, let’s imagine an island in the form of a mountain, gradually flooded with water. Let us assume that the water level sequentially stops at equal intervals, equal in height to h meters (Fig. 32).

Then each water level will have its own coastline in the form of a closed curved line, all points of which have the same height. These lines can also be considered as traces of the cross-section of uneven terrain by planes parallel to the level surface of the sea, from which heights are calculated. Based on this, the height distance h between the secant surfaces is called the section height.

Figure 32.

So, if all lines of equal heights are projected onto the level surface of the sea and depicted to scale, then we will receive an image of the mountain on the map in the form of a system of curved closed lines. These will be the horizontal lines.

In order to find out whether it is a mountain or a basin, there are slope indicators - small lines that are drawn perpendicular to the horizontal lines in the direction of the descent of the slope.

Figure 33.

The main (typical) landforms are presented in Figure 32.

The height of the section depends on the scale of the map and the nature of the relief. The normal height of the section is considered to be a height equal to 0.02 of the map scale, that is, 5 m for a map of scale 1:25,000 and, accordingly, 10, 20 m for maps of scales 1: 50,000, 1: 100,000. Contour lines on the map corresponding to those established for below the height of the section, are drawn in solid lines and are called main or solid horizontal lines. But it happens that at a given section height, important details of the relief are not expressed on the map, since they are located between the cutting planes.

Then half semi-horizontals are used, which are drawn through half the main height of the section and are plotted on the map with broken lines. To determine the count of contours when determining the height of points on the map, all solid contours corresponding to five times the height of the section are drawn thickly (thickened contours). So, for a map of scale 1: 25,000, each horizontal line corresponding to the section height of 25, 50, 75, 100 m, etc. will be drawn as a thick line on the map. The main section height is always indicated below the south side of the map frame.

The altitudes of the terrain depicted on our maps are calculated from the level of the Baltic Sea. The heights of points on the earth's surface above sea level are called absolute, and the elevation of one point over another is called relative elevation. Contour marks - digital inscriptions on them - indicate the height of these terrain points above sea level. The top of these numbers always faces the upward slope.

Figure 34.

Marks of command heights, from which the terrain from the most important objects on the map (large settlements, road junctions, passes, mountain passes, etc.) is better visible than from others, are marked in large numbers.

Using contour lines you can determine the steepness of slopes. If you look closely at Figure 33, you can see from it that the distance between two adjacent contour lines on the map, called the lay (at a constant section height), changes depending on the steepness of the slope. The steeper the slope, the smaller the overlay and, conversely, the lower the slope, the greater the overlay. The conclusion follows from this: steep slopes on the map will differ in the density (frequency) of contours, and in flat places the contours will be less frequent.

Usually, to determine the steepness of the slopes, a drawing is placed in the margins of the map - depth scale(Fig. 35). Along the lower base of this scale are numbers that indicate the steepness of the slopes in degrees. The corresponding values of the deposits on the map scale are plotted on perpendiculars to the base. On the left side, the depth scale is built for the main section height, on the right - at five times the section height. To determine the steepness of the slope, for example, between points a-b (Fig. 35), you need to take this distance with a compass and put it on the scale and read the steepness of the slope - 3.5°. If it is necessary to determine the steepness of the slope between the thickened horizontal lines, then this distance must be set aside on the right scale and the steepness of the slope in this case will be equal to 10°.

Figure 35.

Knowing the properties of contours, you can determine from the map the shape of various types of slopes (Fig. 34). For a flat slope, the depths will be approximately the same throughout its entire length; for a concave slope, they increase from the top to the bottom; and for a convex slope, on the contrary, the formations decrease towards the bottom. In wavy slopes, the positions change according to the alternation of the first three forms.

When depicting relief on maps, not all of its elements can be expressed as contours. So, for example, slopes with a steepness of more than 40° cannot be expressed as horizontals, since the distance between them will be so small that they will all merge. Therefore, slopes that have a steepness of more than 40° and are steep are indicated by horizontal lines with dashes (Fig. 36). Moreover, natural cliffs, ravines, gullies are indicated in brown, and artificial embankments, recesses, mounds and pits are indicated in black.

Figure 36.

Let's consider the basic conventional topographical signs for local objects. Settlements are depicted on the map while maintaining external boundaries and layout (Fig. 37). All streets, squares, gardens, rivers and canals, industrial enterprises, outstanding buildings and structures of landmark significance are shown. For better visibility, fire-resistant buildings (stone, concrete, brick) are painted orange, and blocks with non-fire-resistant buildings are painted yellow. The names of settlements on maps are written strictly from west to east. The type of administrative significance of a settlement is determined by the type and size of the font (Fig. 37). Under the signature of the name of the village you can find a number indicating the number of houses in it, and if there is a district or village council in the settlement, the letters “RS” and “SS” are additionally placed.

Figure 37 - 1.

Figure 37 - 2.

No matter how poor the area is in local objects or, on the contrary, saturated, there are always individual objects on it that, by their size, stand out from the rest and are easily identified on the ground. Many of them can be used as guides. This should include: factory chimneys and prominent buildings, tower-type buildings, wind turbines, monuments, gas pumps, signs, kilometer posts, free-standing trees, etc. (Fig. 37). Most of them, due to their size, cannot be shown on the scale of the map, so they are depicted on it as out-of-scale signs.

The road network and crossings (Fig. 38, 1) are also depicted with out-of-scale symbols. Data on the width of the roadway, road surface, indicated on the conventional signs, make it possible to evaluate their throughput, load capacity, etc. Depending on the number of tracks, railways are indicated by dashes across the conventional road sign: three dashes - three-track, two dashes - double-track railway . Stations, embankments, excavations, bridges and other structures are shown on railways. For bridges longer than 10 m, its characteristics are signed.

Figure 38 - 1.

Figure 38 - 2.

Figure 39.

For example, the signature on the bridge ~ means that the length of the bridge is 25 m, the width is 6 m, and the load capacity is 5 tons.

Hydrography and structures associated with it (Fig. 38, 2), depending on the scale, are shown in greater or less detail. The width and depth of the river is written as a fraction 120/4.8, which means:

The river is 120 m wide and 4.8 m deep. The speed of the river flow is shown in the middle of the symbol with an arrow and a number (the number indicates the speed of 0.1 meters per second, and the arrow indicates the direction of the flow). On rivers and lakes, the height of the water level during low water (water line mark) in relation to sea level is also indicated. For fords it is signed: in the numerator - the depth of the ford in meters, and in the denominator - the quality of the soil (T - hard, P - sandy, V - viscous, K - rocky). For example, br. 1.2/k means that the ford is 1.2 m deep and the bottom is rocky.

Soil and vegetation cover (Fig. 39) is usually depicted on maps with large-scale symbols. These include forests, shrubs, gardens, parks, meadows, swamps, salt marshes, as well as sand, rocky surfaces, and pebbles. Its characteristics are indicated in the forests. For example, for a mixed forest (spruce with birch) the numbers are 20/\0.25 - this means that the average height of the trees in the forest is 20 m, their average thickness is 0.25 m, and the average distance between tree trunks is 5 meters.

Figure 40.

Swamps are depicted depending on their passability on the map: passable, difficult to pass, impassable (Fig. 40). Passable swamps have a depth (to solid ground) of no more than 0.3-0.4 m, which is not shown on maps. The depth of impassable and impassable swamps is written next to the vertical arrow indicating the location of the measurement. On the maps, the corresponding symbols show the cover of the swamps (grass, moss, reed), as well as the presence of forests and shrubs on them.

Lumpy sands differ from smooth sands and are indicated on the map with a special symbol. In the southern steppe and semi-steppe regions there are areas with soil abundantly saturated with salt, which are called salt marshes. They are wet and dry, some are impassable and others are passable. On the maps they are indicated by conventional symbols - blue “shading”. An image of salt marshes, sands, swamps, soil and vegetation cover is shown in Figure 40.

Off-scale symbols of local objects

Answer: Off-scale symbols are used to depict small local objects that cannot be expressed on a map scale - free-standing trees, houses, wells, monuments, etc. When depicting them on a map scale, they would appear in the form of a point. Examples of depicting local objects with out-of-scale symbols are shown in Figure 31. The exact location of these objects, depicted with out-of-scale symbols (b), is determined by the center of the symmetrical figure (7, 8, 9, 14, 15), in the middle of the base of the figure (10, 11) , at the top of the corner of the figure (12, 13). Such a point on the figure of an off-scale symbol is called the main point. In this figure, the arrow shows the main points of symbols on the map.

It is useful to remember this information in order to correctly measure the distance between local objects on the map.

(This question is discussed in detail in question No. 23)

Explanatory and conventional signs of local objects

Answer: Types of topographical symbols

The terrain on maps and plans is depicted by topographical symbols. All conventional signs of local objects, according to their properties and purpose, can be divided into the following three groups: contour, scale, explanatory.

Symbols of topographic maps

Tikhonova L.Ya. Geography teacher MBOU "Lyceum No. 3" Prokhladny, KBR

Do you know the symbols?

Read the letter

Hello mother!

We went camping. We left early in the morning

from, let's go to,

turned west along and approached

.To our right was

. Then, past along

but we returned to.

There lived in Rus' the glorious hero Alyosha Popovich,

and he only knew how to lie on the stove, and with Tugarin

Let's fight snakes. He once set off for gold

To free the folk from the clutches of the Tugarin people.

His path lay through birch forest , past the rotten

swamps , through which path was. Came in

Alyosha goes into the thicket of the forest and sees a picturesque lake ,

and next to him forester's house . He asks the forester,

how to get to him river , where is the Tugarin army

settled down. And the old man answers him, it’s a long way

you have to. First you will go along dirt road ,

turn into Pine forest . There you will see well done ,

boldly go from him to spring , by the spring

there is deep ravine , cross it and you will see meadow ,

stands in that meadow lonely tree .

If you approach him, Tugarin himself will appear.

Write the story in symbols

http://aida.ucoz.ru

Determine the direction

Measure the distance using the scale shown in Fig. 39

in 1 cm 100 m

Determine the scale of the plan.
Measure the distance from the birch tree to the barn with a ruler.
Calculate the distance using a scale.
Determine the distance from the birch tree to the point 162.3 m; to the lake; to the wooden bridge.

0.9 cm

0.9 cm x 100 m = 90 m