See Also...401 404 ISOM Index Vegetation index previous next
revision 05/00
403 Rough open land
Heath, moorland, felled areas, newly planted areas (trees lower than ca. 1m) or other generally open land with rough ground vegetation, heather or tall grass. Symbol 403 may be combined with symbols 407 and 409 to show reduced runnability.
Colour: yellow 50% (60 lines/cm).
As ISOM 2000 but line frequency was 40 lines/cm.
Defined as area symbol 403.0, and can be drawn with any drawing tool.
Care is needed at joins, overlap only where it is safe (usually if it is the same colour and always if it is the same symbol). If you need to share a common boundary with another symbol, draw along the edge with the control key to follow it exactly.
See minimum dimensions but specifically -
- Smallest area enclosed by a dotted line: 1.5mm (diameter) with 5 dots.
- Smallest area of colour yellow dot screen: 1.0mm˛.
This symbol is used where the visibility is good. If there are trees or bushes that reduce the visibility then the rough open land with scattered trees or the Forest symbols should be used. There is a runnability topic.
The ISOM lays down the permissible combination of screens.
Rough open land is allowed with broken ground, stony ground, marsh, indistinct marsh, undergrowth: slow running, undergrowth: difficult to run, and now uncrossable marsh,
but not with open land, open land with scattered trees, rough open land with scattered trees, forest: slow running, forest: difficult to run, or vegetation: very difficult to run.
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