Any card has its own special language - special symbols. Geography studies all these designations, classifies them, and also develops new symbols to designate certain objects, phenomena and processes. Having a general idea of ​​conventional cartographic signs is useful to absolutely everyone. Such knowledge is not only interesting in itself, but it will certainly be useful to you in real life.
This article is devoted to conventional signs in geography, which are used in compiling topographic, contour, thematic maps and large-scale plans for the area.
ABC cards
Just as our speech consists of letters, words and sentences, so any card includes a set of specific signs. With their help, topographers transfer this or that terrain to paper. Geographical symbols are a system of special graphic symbols used to designate specific objects, their properties and characteristics. This is a kind of "language" of the card, created artificially.
It is quite difficult to say exactly when the very first maps appeared. On all continents of the planet, archaeologists find ancient primitive drawings on stones, bones or wood, created by primitive people. So they depicted the area in which they had to live, hunt and defend themselves from enemies.
Modern conventional signs on maps by geography reflect all the most important elements of the area: landforms, rivers and lakes, fields and forests, settlements, communication lines, country borders, etc. The larger the image scale, the more objects you can map . For example, on a detailed terrain plan, as a rule, all wells and sources of drinking water are marked. At the same time, marking such objects on a map of an oblast or country would be foolish and inappropriate.
A bit of history or how the symbols of geographical maps changed
Geography is a science that is unusually closely connected with history. We will delve deeper into it to find out how the cartographic images looked many centuries ago.
So, for ancient medieval maps, the artistic transfer of the area with the wide use of drawings as conventional signs was characteristic. Geography at that time was just beginning to develop as a scientific discipline, therefore, when compiling cartographic images, the scale and outlines (boundaries) of areal objects were often distorted.
On the other hand, all the drawings in the old drawings and portulans were individual and completely understandable. But nowadays, you have to connect the memory in order to learn what certain symbols on maps mean by geography.
Around the second half of the 18th century, European cartography showed a tendency towards a gradual transition from individual perspective drawings to more specific planned symbols. In parallel with this, a need arose for more accurate display of distances and areas on geographical maps.
Geography: conventional signs of terrain plans and topographic maps
Topographic maps and plans of the area differ on a rather large scale (from 1: 100,000 or more). They are most often used in industry, agriculture, exploration, urban planning and tourism. Accordingly, the terrain on such maps should be displayed as detailed and detailed as possible.
For this, a special system of graphic symbols was developed. In geography, it is also often called the "map legend." For ease of reading and ease of memorization, many of these signs resemble the real appearance of the terrain objects depicted by them (from above or from the side). This cartographic notation system is standardized and mandatory for all enterprises that produce large-scale topographic maps.
The subject “Conventional signs” is studied in the school course of geography in the 6th grade. To check the level of mastering this topic, students are often invited to write a short topographical story. Each of you probably wrote a similar “essay” at school. Proposals with conventional signs in geography look something like the photo below:
All conventions in cartography are usually divided into four groups:
- large-scale (areal or contour);
- off-scale;
- linear
- explanatory.
Let us consider in more detail each of these groups of signs.
Large-scale signs and their examples
In cartography, large-scale signs are those signs that are used to fill any areal objects. It can be a field, a forest or an orchard. Using these symbols on the map, you can determine not only the type and location of a particular object, but also its actual size.
The boundaries of areal objects on topographic maps and plans of the area can be represented as solid lines (black, blue, brown or pink), dotted or simple dots. Examples of large-scale cartographic signs are presented below in the figure:
Scale Signs
If the terrain object cannot be depicted on a real scale plan or map, then in this case using off-scale conventional signs. We are talking about too small geographic features. This can be, for example, a windmill, a sculptural monument, an outlier, a spring or a well.
The exact location of such an object on the ground is determined by the main point of the symbol. For symmetrical signs, this point is located in the center of the figure, for signs with a wide base - in the middle of the base, and for signs based on a right angle - at the top of such an angle.
It is worth noting that the objects expressed on the maps as extra-scaled conventional signs serve as excellent landmarks on the ground. Examples of off-scale cartographic signs are presented in the figure below:
Linear signs
Sometimes the so-called linear cartographic signs are distinguished into a separate group. It is easy to guess that with their help, plans and maps designate linearly extended objects - highways, administrative unit boundaries, railways, fords, etc. An interesting feature of linear designations is that their length always corresponds to the scale of the map, but the width is significantly exaggerated.
Examples of linear cartographic signs are shown in the figure below.
Explanatory signs
Perhaps the most informative is the group of explanatory symbols. With their help indicate additional characteristics of the depicted terrain objects. For example, the blue arrow in the river bed indicates the direction of its flow, and the number of transverse strokes on the designation of the railway corresponds to the number of tracks.
On maps and plans, as a rule, the names of cities, towns, villages, peaks, rivers and other geographical objects are signed. Explanatory conventional signs can be numeric or alphabetic. Letter designations are most often given in abbreviated form (for example, the ferry service is indicated in the form of the abbreviation “par.”).
Conventional and thematic map symbols
An outline map is a special kind of geographic map designed for educational purposes. It contains only a coordinate grid and some elements of a geographical basis.
The set of symbols for contour maps in geography is not very wide. The name of these maps is quite eloquent: for their compilation, only the outline designations of the boundaries of certain objects — countries, regions and regions — are used. Sometimes rivers and large cities (in the form of points) are also applied to them. By and large, a contour map is a “dumb” map, which is just designed to fill its surface with certain conventional signs.
Thematic maps are most often found in geographic atlases. Symbols of such cards are extremely diverse. They can be represented as a color background, ranges or so-called isolines. Often used charts and cartograms. In general, for each type of thematic maps there is a set of specific conventions.