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101 Contour

101 Contour (ISMTBOM 2022)

Geometry: line.


A line joining points of equal height. The standard vertical interval between contours is 5 m. A contour interval of 10 m may be used in steep terrain and 2.5 m may be used for sprint terrain.
Slope lines may be drawn on the lower side of a contour line to clarify the direction of slope. When used, they should be placed in re-entrants.
A closed contour represents a knoll or a depression. A depression has to have at least one slope line. Minimum height/depth should be 1 m.
Relationships between adjacent contour lines are important. Adjacent contour lines show form and structure. Small details on contours should be avoided because they tend to hide the main features of the terrain.
Absolute height accuracy is of little importance, but the relative height difference between neighbouring features should be represented on the map as accurately as possible. It is permissible to alter the height of a contour slightly if this improves the representation of a feature. This deviation should not exceed 25% of the contour interval, and attention must be paid to neighbouring features.
Smaller prominent knolls and depressions must be exaggerated on
the map to satisfy the minimum dimension.


Colour: brown.