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Depression 114

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This page contains content from ISOM2000   This page contains content from Ashby Mapping  Ski-O symbol  Mountain Bike-O symbol  revision 05/00


114 Depression

Depressions are shown with contours or form lines and slope lines. Prominent depressions falling between contour lines may be represented by a contour line if the deviation from the actual contour level is less than 25%. Smaller or shallower depressions should be shown by form lines.

Colour: brown.

Line width 0.14mm

ISOM 1990 Definition

As ISOM 2000 but line width was 0.125mm and the ISOM number has changed (was 113)

OCAD Methods

No symbol is provided in the default.ocd symbol set. The feature may be drawn by using symbol 101, contour or 103, form line for normal or shallower depressions as appropriate.

See the topic on slope lines for the tags in the depression.

Drawing Considerations

Check the general comments on land forms note especially the following:-

It is permissible to alter the height of a contour slightly if this will improve the representation of a feature. This deviation should not normally exceed 25% of the contour interval and attention must be paid to neighbouring features.

With careful editing some form lines and knoll/depression groups can be generalised with contours to improve legibility.

Pictorial Descriptions

- BOF Rules, Appendix One

A hollow from which the ground rises on all sides, shown on the map by contours.

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International Specification for Orienteering Maps produced by the International Orienteering Federation
OCAD produced by Hans Steinegger Software. 1988-1999 Hans Steinegger. OCAD is a registered trademark of Hans Steinegger
This document has been written and coded by Peter Hornsby of Ashby Mapping
Apologies for any mistakes and errors; please inform details of any problems, thanks.
Produced for the Ashby Mapping internet site on 20 November 1997 and 1 December 1999  1997-2000 Ashby Mapping
Revised 28 December 1999, 23 March 2000