Topographic maps are issued in separate sheets, limited by frames. The sides of the internal framework of topographic maps are the lines of parallels and meridians. They are divided into segments equal in degree one minute on maps of the scale 1:25 000 – 1: 200 000 and five minutes on maps of the scale 1: 500 000 and 1: 1 000 000. These divisions are filled with black paint or shaded through one.
Frames of sheets and border layout of topographic maps, completeness, detail and accuracy of maps, which objects are not shown on maps.
Each minute segment on maps with a scale of 1:25 000 – 1: 100 000 is divided by points into six parts of 10 seconds each, with the exception of sheets of a map with a scale of 1: 100 000 located within latitudes of 60–76 degrees, where minute segments are along the northern and the southern sides of the frame are divided into three parts for 20 seconds, and located to the north of the parallel 76 degrees – into two parts, for 30 seconds.
The topography of the topographic maps contains reference information about this map sheet, information supplementing the terrain characteristics, and data facilitating the work with the map.
The location of the out-of-frame design elements for maps on a scale of 1:25 000, 1:50 000, 1: 100 000, 1: 200 000 and 1: 500 000.
These elements mean:
1. The coordinate system.
2. Name of the republic and region whose territory is depicted on this sheet.
3. Name of the agency that prepared and issued the card.
4. The nomenclature of the sheet and the name of the most significant settlement. For maps of scale 1: 200,000 and 1: 500,000 – only the name of the settlement.
5. Number and year of publication. On cards with a scale of 1: 200 000 and 1: 500 000, the nomenclature, number and year of publication are indicated below the signature “Card signature”.
6. Vulture cards.
7. The method and year of shooting or the year of compilation and the source materials for which the map was compiled. Year of preparation for publication and printing of the map.
9. Scale of pledges, only on maps of scale 1:25 000, 1:50 000 and 1: 100 000.
10. Numerical scale.
11. The magnitude of the scale.
12. Linear scale.
13. Section height. On a map with a scale of 1: 500 000, a scale of steps of heights is also given here.
14. Elevation system, except for a map of scale 1: 500 000.
15. A diagram of the mutual arrangement of the vertical line of the coordinate grid, the true and magnetic meridians and the declination of the magnetic needle, the convergence of the meridians and directional corrections. Except for a map on a scale of 1: 500,000.
16. Data on the declination of the magnetic needle, the convergence of the meridians and the annual declination of the magnetic arrow (this information is not given on a map on a scale of 1: 500 000).
In addition to the location of elements on a map of a scale of 1: 200,000, to the right and left of the scale, conventional signs are given that characterize the terrain, and on the back or in the margins of the sheet a soil map and a reference about the terrain are printed. On a map with a scale of 1: 500,000, to the right of the scale, the layout of adjacent sheets and the administrative division are placed, and to the left of the scale are the basic symbols.
The completeness, detail and accuracy of topographic maps, which objects are not displayed on maps of different scales.
The completeness and detail of topographic maps depend mainly on their scale (the larger the scale, the more fully and in detail the terrain elements are depicted and characterized on the map) and the nature of the terrain. The smaller the number of different objects in the area, the more fully they are displayed on the map. The completeness and detail of the display of individual objects on topographic maps on a scale of 1:50 000 – 1: 500 000 on the average intersected habitat are indicated in the table below.
Basic standards for depicting terrain objects on topographic maps of different scales.
Hills, hollows, hollows and other landforms are shown on topographic maps at a height (depth) of more than 0.5 the height of the cross section of this map. On a map with a scale of 1: 1 000 000, terrain elements are depicted with a more significant selection. For example, on a map of a medium-cross-inhabited area, only the main highways, the most important settlements, but not more than one per 100 km2, rivers longer than 10 km, etc. are shown.
On all topographic maps, the terrain objects that substantially determine its tactical properties are shown as fully as possible. On the maps of desert – steppe regions up to a scale of 1: 200,000 inclusive, all hydrographic elements, roads, trails, and also local objects of indicative importance are given. Maps of hard-to-reach areas show the road network more fully, etc..
The accuracy of topographic maps is usually characterized by average position errors on the map of terrain features. Most accurately (with an average error of 0.1-0.2 mm on the map scale), geodetic points and some landmarks (individual towers, factory pipes, churches, etc.) are shown.
Elements of the terrain, clearly and clearly expressed on the terrain, are displayed on maps with an average error of 0.5 mm. On maps of hard-to-reach areas (mountainous, mountain-taiga, wooded-marshy, etc.), the same terrain elements are shown less accurately – with an average error of 0.75–1 mm.
The average errors of the horizontal position in height on the maps of flat and hilly terrain are half the height of the relief section of this map, and on the maps of mountainous regions – the height of the relief section.
When assessing the accuracy of the position on the topographic map of a given object, one should take into account not only its nature, but also its location. In settlements, only their external contour, as well as the main thoroughfares and buildings closest to the intersections, are shown with the necessary accuracy.
Based on the book Methods of Autonomous Human Survival in Nature.
Edited by L. A. Mikhailov.