What is a map? How to read it? What are the symbols of geographical maps? All this will be discussed in our article.
A geographic map is ...
The map is one of the oldest inventions of mankind. Initially, they were carved on stones, rocks and cave walls. These were primitive drawings of the area of primitive people. One of the oldest maps dates back to scientists in the seventeenth millennium BC. And this was not a map of the earth's surface, but of the starry sky. On it were marked Vega, Altair, Deneb and some other bright stars of the sky.
Similar maps of lands were created by ancient Greek researchers and travelers - Strabo, Anaximander, Hekatei, Ptolemy and others. Extraordinarily rapidly developing cartography in the XIV-XVI centuries, in the so-called era of great geographical discoveries. At this time, portulans were created - sea plans that describe in detail the waters of the Black and Mediterranean Seas, as well as the western shores and northern shores of Europe.
The geographical map at the present time absolutely does not lose its value and relevance. In the XXI century, it becomes not only the result, but also an important tool of many scientific research and research. Maps are widely used in geology, urban planning, meteorology, agriculture and other fields of human activity. School geography studies it (grade 6).
A geographic map is a model of the earth’s surface, reduced by hundreds or thousands of times, created using a system of special signs. Almost all students with great interest consider these colorful sheets of paper in the classroom. And many of them have legitimate questions: what is indicated on the map in brown? And what - in other colors and shades? Next, we will talk in detail about the symbols of modern maps. But first, you need to find out what kind of their exist at all?
Varieties of Geographical Maps
Geographic maps are classified by scale, territorial scope, purpose and content. According to their purpose, they can be:
- training;
- reference;
- scientific;
- tourist;
- sports;
- navigation, etc.
In scale, all maps are divided into small-, medium- and large-scale, and in content - into general geographical and thematic. Geographic maps display many natural and public objects: relief, vegetation, hydrography, cities and villages, roads, etc. Thematic ones display individual objects (phenomena) of nature, the economy, or the social sphere.
What is brown on the map?
The surface of our planet is heterogeneous. About 70% of its area is occupied by seas and oceans, and on land there are plains, elevated plateaus and mountains. How does this all appear on geographic maps?
All kinds of water bodies (rivers, lakes, seas, reservoirs, etc.) are marked in blue. And this is quite logical. But the surface of the land is decorated with a variety of shades: from dark green to brown. What is brown on the map?
The choice of color depends on the absolute height of a particular area in meters (above sea level). Green shades indicate lowlands and plains (up to 200 meters high), yellow - highs (200 to 500 meters), and brown - mountainous areas (over 500 meters).
Methods for marking terrain on maps
The designation of the relief on the map can be carried out in two main ways:
- using flowers;
- using contour lines.
The color method was described in detail in the previous section. It is used, as a rule, in compiling general geographic (physical) maps. In addition to colors, on such maps usually indicate individual points of the terrain and indicate their absolute height. It can be the highest mountain peaks or, conversely, the lowest troughs of a particular area.
By color, you can determine not only the height of the earth's surface, but also the depth of the seas and oceans. Shades of blue are used to indicate depths on maps. The more saturated the shade, the deeper the bottom is at a particular point.
Each physical map is necessarily accompanied by a scale of heights and depths. From it you can approximately determine the height of the terrain or the depth of the ocean.
The second way of depicting the relief involves the use of special lines - contour lines. It is used mainly in the preparation of topographic maps and plans of the area.
Topographic map and its features
Large-scale universal maps that depict the terrain in detail are called topographic maps. With their help, you can get a fairly detailed idea of a particular territory.
All topographic maps are divided into four categories, based on scale:
- large-scale (1: 500 000 and larger);
- medium-sized (1: 200,000, 1: 100,000);
- small-scale (1:50 000, 1:10 000);
- plans for the area.
The most detailed features of the terrain are displayed on topographic plans that have a scale of 1: 5000 (most often). They can show individual buildings, trees, stones, churches, etc. Another distinctive feature of the terrain plans is that when compiling them, the curvature of the Earth's surface is not taken into account.
Symbols of geographical maps and plans of the area
When compiling topographic maps and plans of the area, a set of certain conventional signs is used. With their help, a qualitative and quantitative characteristic of natural objects, social phenomena is supplied. What are the symbols of geographical maps? 4 of their types are distinguished by modern topographers. It:
- Large-scale.
- Linear
- Scale out.
- Explanatory signs.
With the help of large-scale signs, those objects and objects that can be expressed on a map scale are displayed. This can be a forest, a field, city blocks, etc. Extrabandal conventional signs look like small figures or graphic drawings. They allow you to display objects on the map that are too small (for example, wood, stone, coal mine or monastery). Using linear signs, extended objects are displayed - roads, borders, power lines (power lines). Explanatory graphic symbols are used for additional characteristics of certain objects of the area.
There are about two hundred conventional topographic signs. The figure below shows only some of them. Here, for example, you can see what the symbol for sand, forest, lake, ravine or bridge looks like.
Topographic map relief
As mentioned above, on topographic maps, the terrain is displayed using the so-called contour lines. These are conditional lines connecting the points of the earth's surface with the same height. Horizontal lines are held at intervals of 10, 20 or 50 meters. But it all depends on the scale of the map: the larger it is, the more detail you can show the local topography. What kind of horizontals do you can see in the picture below.
Horizontal lines are usually gray or pale brown. In places of breaks of these lines their absolute height is indicated. In addition, individual points are often noted on maps, signing their exact height above sea level. These can be individual mountain peaks or objects that serve as clear landmarks on the ground.
Learning to "read" the terrain on the map is easy. The density and amount of contour lines directly depends on the degree of dissection of the earth's surface. The closer these lines are to each other on the map, the steeper the slope on the ground. However, the best way to learn how to read a topographic map is to take it with you on a camping trip or trip.
The image of vegetation and landscapes on the maps
Landscapes, vegetation and soil cover are also displayed in rather detail on maps. At the same time, topographers use about 50 special characters.
Green spots and belts that can be seen on almost any topographic map are nothing more than forests. Forest boundaries are displayed as dotted dots. Additional characteristics of a particular forest are indicated using off-scale and explanatory signs.
Swamps on the maps are indicated by horizontal blue stripes. Moreover, if these strips are continuous - then the swamp is impassable, and if they are interrupted - then passable. Sands appear as randomly spaced brown dots.
There are special signs for vineyards, fruit and berry orchards, shrubs, light forests, rice fields, tea plantations and other forms of vegetation.
Conclusion
Now you know that the map means brown, what is green and what is blue. The choice of color depends on the height of the area. So, lowlands are green, highlands are yellow, and mountain systems are brown. On topographic maps, the relief of the earth's surface is displayed in a different way - using contour lines.