Map Symbols
Map Symbols
standard line and background designations of terrain objects used on topographic maps. Map symbols are intended to provide designations of common outline and color for similar groups of objects; there are no major differences among the basic symbols used on topographic maps in various countries. Map symbols generally convey the appearance (shape and dimensions), location, and certain qualitative and quantitative characteristics of the objects, contours, and relief elements shown on maps. They are conventionally divided into area, non-scale, line, and explanatory symbols.
Scale map symbols are used to reproduce topographic features whose shape and dimensions in plan can be expressed within the scale of a particular map. The area occupied by the scale symbol may be delimited and colored, as in the case of forests, bodies of water, or blocks in population centers; it may be hachured, for the depiction of swamps, solonchaks, and floodwaters; or it may be filled in with graphic signs, usually in checkerboard fashion, as in the case of grass and semishrub vegetation or clayey and hum-mocky surfaces. Sandbars in rivers, as well as orchards and vineyards, may be emphasized by a combination of these methods, Nonscale symbols are used to show objects that are not expressed in the scale of the map (primarily local objects); such objects are shown in a top or side view.
The point on a map symbol that indicates the actual position of the real object depends on the type of object. In the case of a figure of regular shape, such as a triangle designating a point on the geodetic grid or a circle for a tank or well, the position should be shown by the center of the figure; for a symbol in the form of a perspective drawing, such as a factory smokestack or monument, the middle of the base of the figure; for a symbol with a right angle in the base, such as a windmill or gasoline pump, the apex of the angle; and for a symbol that combines several figures, such as a radio or petroleum tower, the center of the lowest figure.
Line map symbols are used to depict—with as much graphic precision as possible—such objects as shorelines, streams and ditches, roads, forest clearings, fences, transmission lines, boundaries of agricultural lands, and political and administrative borders. If some such object can only be reproduced on the map with an exaggerated width, its position in plan is fixed by the axis of the symbol. Contour lines are also depicted by line symbols.
Explanatory map symbols are used for additional description of the objects shown on the map. For example, a point is used to fix the place where absolute relief measurements or relative differences, such as the height of a kurgan or cliff, have been determined. Various types of arrows are used to show the direction of flow of a river or the point of measurement of the depth of a swamp, and symbols for tree species are used to indicate the composition of forests.
As the scale of topographic maps becomes smaller, similar symbols are combined into groups, the groups are joined under a single generalized symbol, and so on. The entire system of designations may be represented in the form of a truncated pyramid whose base is composed of symbols for topographic plans on a scale of 1:500, whereas the apex is for survey topographic maps with scales of 1:1,000,000.
The colors of map symbols are uniform for maps of all scales. Line symbols for agricultural lands and their contours and for buildings, structures, terrain features, reference points, and boundaries are printed in black; elements of relief in brown; bodies of water, streams, swamps, and glaciers in blue (water surfaces in light blue); areas of tree and shrub vegetation in green (light green for dwarf and stunted forests, brush, and vineyards); highways and blocks with fireproof structures in orange; and improved dirt roads and blocks with nonfireproof structures in yellow.
In addition to map symbols, topographic maps use standard abbreviations of proper names for political and administrative units and explanatory terms. For example, Moscow Oblast is shown as Mosk., an electric power plant is designated by el. st. (from the Russian elektrostantsiia), southwest is IuZ (from iugo-zapadnyi), and a workers’ settlement is r. p. (from rabochii poselok).
Standardized typefaces for captions on topographic maps make it possible to give important information in addition to that provided by symbols. For example, the typefaces for the names of population centers show their classification, political and administrative significance, and population. The typefaces for rivers indicate size and navigability. The typefaces for elevation markers and the characteristics of passes and wells make it possible to identify the most important of these objects.
Map symbols, standard abbreviations for captions, and typefaces for topographic maps are collected according to scale groups in a series of tables that is updated about once every ten years.
L. M. GOL’DMAN