Hypsometric Method

a method of depicting the relief of the earth’s surface on geographic maps, based on the use of contour lines (isohypses) drawn at certain intervals of the chosen scale of cross section.

The possibility of using contour lines to depict relief was demonstrated by the Frenchman Ducarla in 1771. The first map of the territory of France with contour lines was made by Dupin-Triele in 1791. In the second half of the 19th century the hypsometric method became the principal method of depicting relief on general geographic, hypsometric, and many other topical maps of various scales.

The primary advantage of the hypsometric method in comparison with other methods is the possibility of achieving a geometrically precise, measurable representation of relief. The hypsometric method combined with elevation marks ensures precise transmission of the primary orographic lines and points (such as peaks, divides, thalwegs, and scarps), the directions and shapes of slopes, the angles of inclination, and absolute and relative elevations. Special designations are added to convey sharp disruptions of the relief (for example, cliffs, scarps, and precipices) that are not depicted by the contour lines.

The quality of depiction of relief depends to the greatest degree on the completeness and precision of initial data, the accuracy in selecting cross sections of the relief, and the quality of the generalization and drawing of the contour lines. An important stage in the development of the hypsometric method was the drawing of the Hypsometric Map of the European USSR (1930-40), which was published under the editorship of T. N. Gunbina in 1941. Major Soviet geographers, including A. A. Borzov, participated in the development of the methodology of graphic representation of the morphological characteristics of different types of relief on the basis of geomorphological study.

Further development of the hypsometric method is associated with the drawing of the State Map of the USSR during 1940-46 on a scale of 1:1,000,000 (hypsometric variant). Before the map was published, a manual had been published on how to draw it. This was the first theoretical summary of questions of generalizing the hypsometric representation of the relief of the entire country. Development of the Hypsometric Map of the USSR on a scale of 1:2,500,000 (published in 1949 under the editorship of I. P. Zarutskaia) first gave a unified, easily comparable representation of the relief of the land and the bottom of the surrounding seas. Many small-scale hypsometric maps (of the world, continents, and groups of countries) are included in Soviet world atlases (for example, the 1954 and 1967 world atlases).

The hypsometric method is also used in making maps of the relief of the ocean bottom.