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1 ((First Draft)) IOF International Specification for
OrienteeringMaps ISOM 201x
IntroductionIt is the aim of the International Specification for
Orienteering Maps (ISOM) to provide a map specification whichcan
accommodate the many different types of terrain around the world
that are suitable for orienteering. Thesespecifications should be
read in conjunction with the rules for International Orienteering
Federation (IOF)orienteering events. For IOF events, deviations
from the ISOM are permissible only with the sanction of the IOF.
Forother events such sanction must be given by the national
federation. The specifications for other orienteeringdisciplines
have much in common with the ISOM.The development of orienteering
maps reflects the needs of the sport and the technology available
to produce them.In the very early days, at the end of the 19th
Century, state topographical maps at very small scales (e.g.
1:100.000)were often used. These gradually came at larger scales
and additional detail was added. Aerial photographs andcolour
printing improved the accuracy and legibility of maps. This lead to
the production of special purposeorienteering maps in the 1950's.
In the early days of international orienteering, the contents and
symbols oforienteering maps varied from place to place. To ensure
fair international competitions, standardisation wasnecessary, and
this triggered the creation of the ISOM. The first official version
was published in 1969. InISOM1972, green was introduced to show
runability, and orienteering maps started to look very much like
they dotoday. Fortunately, the ISOM was very well received, and
most national federations have applied the ISOM also formaps at
local events. ISOM now specifies about one hundred different
symbols.Digital cartography entered the stage in the 1990's. Up to
that time, maps had been drawn with pen and ink or scribedonto
film. These were then copied to printing plates, one for each
colour, from which the maps were printed. Digitalcartography has
enabled greater precision in drawing and easier modification of
maps. Unfortunately, it has alsohelped mappers overload maps with
too much detail.Other technological developments have also
influencing orienteering mapping. Photogrammetry, and more
recentlyairborne laser scanning (or LiDAR - light detection and
ranging), has provided better base maps. Satellite
navigationsystems (GNSS) can be used to provide precise location
during fieldwork. Printing technology is evolving, anddigital
four-colour printing has provided challenges for orienteering map
printing. New types of paper (includingwaterproof paper) affect the
printing process.The previous ISOM version was published in 2000.
Since then there have been some technological developments,and
there have also been some development in the event programme. These
developments have been taken intoconsideration when revising the
ISOM. However, the basic requirements have not changed. Map
legibility is still themost important aspect of an orienteering
map. In the process of producing a readable map, generalisation is
akeyword. This means that the mapper always must deal with
selection, simplification, displacement andexaggeration.An
unfortunate effect of the technological developments is that the
art of generalisation has come out of focus. Thismust change. More
accurate and detailed basemaps must not lead to maps overloaded
with insignificant detail.Clever generalisation is necessary in
order to ensure that maps are readable and suitable for
orienteeringcompetitions. The orienteering map is read while
running fast through the terrain, and the perception capabilities
ofthe human eye and brain have their limits.
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ConventionsSeveral words are used to signify the requirements in
this specification. Must / Shall / Required mean that the
definition is an absolute requirement. Must not / Shall not mean
that the definition is an absolute prohibition. Should /
Recommended mean that there may exist valid reasons in particular
circumstances to ignore a particular
item, but the full implications must be understood and carefully
weighed before choosing a different course. Should not / Not
recommended mean that there may exist valid reasons in particular
circumstances when the
particular behavior is acceptable or even useful, but the full
implications should be understood and the casecarefully weighed
before implementing any behavior described with this label.
May / Optional mean that an item is truly optional.
2 General Requirements
2.1 Orienteering and the mapOrienteering is a sport in which the
competitor (orienteer) completes a course of legs between control
points in theshortest possible time, by navigating aided only by
map and compass. As in all forms of sport, it is necessary toensure
that the conditions of competition are the same for all
competitors.From the competitors' point of view, a legible and
accurate map is necessary for a qualfied choice of route, and
itenables them to navigate along the route chosen to suit their
navigational skills and physical abilities. However, skillin route
choice and map reading loses all meaning if the map is not a good
representation of the ground - if it is ofpoor legibility,
inaccurate, out-of-date. In the ideal case no competitor should
gain an advantage or suffer adisadvantage because of faults on the
map. For an international event, the map must be up-to-date in all
parts whichcould affect the end result of the competition. If it is
not up-to-date it must be improved.The steepness, elevation and
shape of the land forms is essential information, and is shown
using contours.Identifying anything which bars progress is crucial
to the orienteer: cliffs, water, dense thickets. The path and
tracknetwork shows where the going and navigation is easiest. A
detailed classification of the degrees of hindrance orgood going
helps the competitor to make the right decisions.The aim of the
course planner is a course where the deciding factor in the results
will be navigational skill. This canbe achieved only if the map is
clear and legible under competition conditions and sufficiently
accurate, complete andreliable. Controls are important building
blocks of a course. Choice of sites, placing of the markers,
checking theirpositions, and locating controls in competition, all
put definite demands on the map. The better the map the
courseplanner has, the greater the chance he has of setting good,
fair courses, whether for the elite or for the novice.For the
mapper, the task is knowing which features to map and how to
represent them. A continuing involvement inthe sport is important
for a basic understanding of the requirements for the orienteering
map: its content, the need foraccuracy, the level of detail and
above all the need for legibility.
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2.1 Orienteering and the map (ISOM2000 text)Orienteering is a
sport in which the orienteer completes a course of control points
in the shortest possible time,aided only by map and compass. As in
all forms of sport, it is necessary to ensure that the conditions
of competitionare the same for all competitors. The more accurate
the map, the better this can be done, and the greater
theopportunity for the course planner to set a good and fair
course.
From the competitors' point of view, an accurate and legible map
is a reliable guide for choice of route, and itenables them to
navigate along a route chosen to suit their navigational skill and
physical ability. However, skill inroute choice loses all meaning
if the map is not a true picture of the ground.if it is inaccurate,
out-of-date or of poorlegibility.
Anything which bars progress is essential information: cliffs,
water, dense thickets. The path and track networkshows where the
going and navigation is easiest. A detailed classification of the
degrees of hindrance or good goinghelps the competitor to make the
right decisions. Orienteering is first of all to navigate by map
reading. An accuratemap is therefore necessary for a good and
effective route choice. In the ideal case no competitor should gain
anadvantage or suffer a disadvantage because of faults on the
map.
The aim of the course planner is a course where the deciding
factor in the results will be navigational skill. This canbe
achieved only if the map is sufficiently accurate, complete and
reliable, and is also clear and legible undercompetition
conditions. The better the map the course planner has, the greater
the chance he has of setting good,fair courses, whether for the
elite or for the novice.
Controls are the most important building blocks of a course.
Choice of sites, placing of the markers, checking theirpositions,
and locating controls in competition, all put definite demands on
the map. The map must give a complete,accurate and detailed picture
of the terrain. For an international event, it must be up-to-date
in all parts which couldaffect the end result of the competition.
If it is not up-to-date it must be improved.
For the mapper, the task is knowing which features to map and
how to represent them. A continuing involvement inthe sport is
important for a basic understanding of the requirements for the
orienteering map: its content, the needfor accuracy, the level of
detail and above all the need for legibility.
2.2 ContentAn orienteering map is a topographic map with a
convenient size. It shall serve navigation through the terrain
byrepresenting a selection of prominent features, and it shall
serve route choice by showing variations in runability(impact on
speed) and visibility. The map shall contain sufficient information
for the competing orienteer while atthe same time being readable at
running speed and under varying weather and light conditions. This
is accomplishedby using a carefully designed set of symbols and
colours, and by emphasising generalisation.Consistent use of colour
is important to ease map reading: Blue is used for features that
have to do with water.Yellow is used for open areas. Green is used
for vegetation features. Brown is used for land forms. Purple is
used forcourses. Black and grey are used for everything else,
including rock and cliffs, paths and roads, and most man
madeobjects.The map shall only contain features which are obvious
on the ground to a competitor at speed. It should show thingswhich
could influence map reading or route choice: land forms, rock
features, ground surface, hindrance to progressthrough the
vegetation (runability), main land uses, hydrography, settlements
and individual buildings, the path andtrack network, other lines of
communication and features useful from the point of view of
navigation. However, themost important thing is to maintain the
clarity and legibility of the map through skillful
generalization.The shape of the ground is the most important
aspects of an orienteering map. The correct use of contours
(includingindex contours) to show a three dimensional picture of
the ground shape and height difference cannot beoveremphasized.
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An orienteer's speed and choice of route through the terrain is
affected by many factors. Information on all of thesefactors must
therefore be included on the map by classifying paths and tracks,
by indicating whether marshes, waterfeatures, rock faces and
vegetation are passable, and by showing the characteristics of the
ground surface and thepresence of dense vegetation and open
areas.Clear boundaries between different types of ground surface
and different types of vegetation provide valuablereference points
for the map reader. It is important that the map shows these.The
map must contain magnetic north lines that shall be parallel to the
sides of the map. It may additionally containsome place names and
peripheral text to help the competitor orientate the map to north.
Such text shall be oriented tonorth. Text within the map shall be
placed to avoid obscuring important features and the style of
lettering should besimple. Arrowheads may be used to show magnetic
north.
RunabilityThe runability depends on the nature of the forest
(density of trees/brushwood and undergrowth-bracken,
brambles,nettles, marshes, stony ground etc). Runability is divided
into 5 categories of speed.If speed through open runable forest is,
for example, 4 min/km, the following ratios apply:
No Percentage Description Examples Approx. speedmin/km
1 80-100% Normal running speed rough open land, forest faster
than 5:00min/km
2 60-80% Slow running stony ground, undergrowth, dense
vegetation 5:00-6:40 min/km
3 40-60% Difficult to run = fast walking very stony ground,
undergrowth, dense vegetation 6:40-10:00 min/km
4 1-40% Very difficult to run = walking /fight
extremely stony ground, very dense vegetation 10:00 -
400:00min/km
5 0% Impassable extremenly dense vegetation, extremely dense
hedges, water body,high cliff
not applicable
A combination of green and stony ground means that the
runability will be worse than for each one of them inisolation. The
steepness of the terrain also influences runability (the steeper
the terrain, the less runable).
2.2 Content (ISOM2000 text)An orienteering map is a detailed
topographic map. The map must contain the features which are
obvious on theground to a competitor at speed. It must show every
feature which could influence map reading or route choice:
landforms, rock features, ground surface, rate of progress through
the vegetation (known in foot- as runnability), mainland uses,
hydrography, settlements and individual buildings, the path and
track network, other lines ofcommunication and features useful from
the point of view of navigation.
The shape of the ground is one of the most important aspects of
an orienteering map. The correct use of contours toshow a three
dimensional picture of the ground shape and height difference
cannot be overemphasized.
The degree to which a feature is recognizable, the openness of
the forest and runnability of the terrain should betaken into
consideration at the survey stage.
Boundaries between different types of ground surface provide
valuable reference points for the map reader. It isimportant that
the map shows these.
An orienteer s speed and choice of route through the terrain is
affected by many factors. Information on all of thesefactors must
therefore be shown on the map by classifying paths and tracks, by
indicating whether marshes, waterfeatures, rock faces and
vegetation are passable, and by showing the characteristics of the
ground surface and the
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presence of open areas. Clearly visible vegetation boundaries
should also appear since they are useful for mapreading.
The map must show the features which are obvious on the ground
and which are of value from the point of view ofmap reading. An
attempt must be made when surveying to maintain the clarity and
legibility of the map, i.e. theminimum dimensions designed for
normal sight must not be forgotten when choosing the degree of
generalization.
The map must contain magnetic north lines and may additionally
contain some place names and peripheral text tohelp the competitor
to orientate the map to north. This text should be written from
west to east. Text within the mapshould be placed to avoid
obscuring important features and the style of lettering should be
simple.
The sides of the map should be parallel to the magnetic north
lines. Arrowheads may be used to show magneticnorth.
Map readingThe cartographer must always take into consideration
the special conditions for orienteering map reading.
Firstly,running makes reading a map more difficult. Secondary,
orienteering usually takes place in forests. The light inforests
with their dense canopy of leaves is dimmed even at noontime.
Therefore, it is obvious that legibility is ofutmost importantance
for orienteering maps. Minimum graphical dimensions need to be
respected and unnecessarydetail must be avoided.
GeneralisationGood orienteering terrain contains a large number
and a great variety of features. Those which are most essential
forthe runner in competition must be selected and presented on the
orienteering map. To achieve this, in such a way thatthe map is
legible and easy to interpret, generalization must be employed.
There are two phases ofgeneralization.selective generalization and
graphic generalization.Selective generalization is the decision as
to which details and features should be presented on the map.
Twoimportant considerations contribute to this decision.the
importance of the feature from the runners' point of view andits
influence on the legibility of the map. These two considerations
will sometimes be incompatible, but the demandfor legibility must
never be relaxed in order to present an excess of small details and
features on the map. Thereforeit will be necessary at the survey
stage to adopt minimum sizes for many types of detail. These
minimum sizes mayvary somewhat from one map to another according to
the amount of detail in question. However, consistency is oneof the
most important qualities of the orienteering map.Graphic
generalization can greatly affect the clarity of the map.
Simplification, displacement and exaggeration areused to this
end.Legibility requires that the size of symbols, line thicknesses
and spacing between lines be based on the perception ofnormal sight
in daylight. In devising symbols, all factors except the distance
between neighbouring symbols havebeen considered.The size of the
smallest feature which will appear on the map depends partly on the
graphic qualities of the symbol(shape, format and colour) and
partly on the position of neighbouring symbols. With immediately
neighbouringfeatures, which take up more space on the map than on
the ground, it is essential that the correct relationshipsbetween
these and other nearby features are also maintained.For
orienteering maps, the shape of the terrain is the most important
thing to communicate. Dangerous features, suchas high cliffs, must
be easy to see on the map. Anything that bars progress is essential
information: long cliffs, water,dense thickets. The road, path and
track network is important, since it shows where the going and
navigation iseasiest. Most point features are less importance than
line and area features. Generalisation guidelines for
orienteeringmaps are available in a separate document.
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2.4 Generalization and legibility (ISOM2000 text)Good
orienteering terrain contains a large number and a great variety of
features. Those which are most essentialfor the runner in
competition must be selected and presented on the orienteering map.
To achieve this, in such a waythat the map is legible and easy to
interpret, cartographic generalization must be employed. There are
two phases ofgeneralization.selective generalization and graphic
generalization.
Selective generalization is the decision as to which details and
features should be presented on the map. Twoimportant
considerations contribute to this decision.the importance of the
feature from the runners' point of view andits influence on the
legibility of the map. These two considerations will sometimes be
incompatible, but the demandfor legibility must never be relaxed in
order to present an excess of small details and features on the
map. Thereforeit will be necessary at the survey stage to adopt
minimum sizes for many types of detail. These minimum sizes mayvary
somewhat from one map to another according to the amount of detail
in question. However, consistency is oneof the most important
qualities of the orienteering map.
Graphic generalization can greatly affect the clarity of the
map. Simplification, displacement and exaggeration areused to this
end.
Legibility requires that the size of symbols, line thicknesses
and spacing between lines be based on the perception ofnormal sight
in daylight. In devising symbols, all factors except the distance
between neighbouring symbols areconsidered.
The size of the smallest feature which will appear on the map
depends partly on the graphic qualities of the symbol(shape, format
and colour) and partly on the position of neighbouring symbols.
With immediately neighbouringfeatures, which take up more space on
the map than on the ground, it is essential that the correct
relationshipsbetween these and other nearby features are also
maintained.
AccuracyThe general rule should be that competitors shall not
perceive any inaccuracy in the map. The accuracy of the map asa
whole depends upon the accuracy of measurement (position, height
and shape) and the accuracy of drawing.Accuracy of position on an
orienteering map must be consistent with that obtained by compass
and pacing. A featuremust be positioned with sufficient accuracy to
ensure that competitor using compass and pacing will perceive
nodiscrepancy between map and ground. In general if the distance
between neighbouring features deviates less than 5%this will
satisfy accuracy requirements.Absolute height accuracy is of little
significance on an orienteering map. On the other hand, it is
important that themap shows as correctly as possible the relative
height difference between neighbouring features.Accurate
representation of shape is of great importance for the orienteer,
because a correct, detailed and sometimesexaggerated picture of the
land form is an essential precondition for map reading. However,
the inclusion of a lot ofsmall detail must not disguise the overall
shapes. This means that form line usage must be limited to an
absoluteminimum (e.g. form lines with a shape that can be deduced
from the neighbouring contours shall not appear on themap), and
insignificant detail on contours must be removed. Drawing accuracy
is of primary importance to any mapuser because it is closely
connected with the reliability of the final map.Absolute accuracy
is important if an orienteering map is to be used with positioning
systems or together withgeographical data sets from other sources.
In such cases it must also be possible to transform the map to a
wellknown geographical reference system. Readability is much more
important than absolute accuracy. Relocation ofmap features is
encouraged if it makes the map better readable.
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GeoreferencingTo georeference a map means to locate it in terms
of map projections or/and coordinate systems. Georeferencing
isuseful when geographical data from different sources (e.g.
orienteering map, digital elevation model, aerial photos,GPS
positions) need to be combined. It is therefore strongly
recommended to produce georeferenced orienteeringmaps. However,
when printing the map, it shall first be rotated to make the
magnetic north lines parallel to the edgesof the map.
2.3 Accuracy (ISOM2000 text)The general rule should be that
competitors shall not perceive any inaccuracy in the map. The
accuracy of the mapas a whole depends upon the accuracy of
measurement (position, height and shape) and the accuracy of
drawing.Accuracy of position on an orienteering map must be
consistent with that obtained by compass and pacing. A featuremust
be positioned with sufficient accuracy to ensure that competitor
using compass and pacing will perceive nodiscrepancy between map
and ground. In general if the distance between neighbouring
features deviates less than5% this will satisfy accuracy
requirements.
Absolute height accuracy is of little significance on an
orienteering map. On the other hand, it is important that themap
shows as correctly as possible the relative height difference
between neighbouring features.
Accurate representation of shape is of great importance for the
orienteer, because a correct, detailed and sometimesexaggerated
picture of the land form is an essential precondition for map
reading. However, the inclusion of a lot ofsmall detail must not
disguise the overall shapes. Drawing accuracy is of primary
importance to any map userbecause it is closely connected with the
reliability of the final map.
Absolute accuracy is important if an orienteering map is to be
used with positioning system or together withgeographical data sets
from other sources. In such cases it must also be possible to
transform the map to a wellknown geographical reference system.
Colour vision deficiencyColour vision deficiency is the
decreased ability to perceive differences between some colours that
others candistinguish. That can effect orienteering map reading.
5-8% men and 0,5% women have some kind of colour relatedvisual
disorder. The most common disorder is deuteranomaly (green weak) -
5% M, 0,4% W. The other commondisorder is protanomaly (red weak) -
1% M, 0,02% W. The other disorders are deuteranopy (green blind) -
1,2% M,0,02% W and protanopy (red blind) - 1% M, 0,02% W, which are
deuteranomaly and protanomaly in its extremes.Tritanomaly,
tritanopy and monochromacy are very rare. Deuteranomaly and
protanomaly are very related in termsof colours. Both have troubles
in confusing red and green and vice versa. Orienteers have problems
to read maps ofthe following colours: purple and green (controls in
dark green area, very hard to see) yellow and green (hard to
distinguish between open and forested thick areas) brown and green
(problems with brown symbols in green areas)Greater clarity can be
brought to maps by: choosing unambiguous colour combinations using
alternative visual variables, and directly annotating features.An
obvious strategy is to avoid colours that lie along colour
confusion lines. As it would be difficult to avoidconflicting
colours for protans, deutans and tritans simultaneously, red-green
colour defective orienteers should betargeted. If the orienteer is
made aware that a map caters for red-green colour vision defects
through the use of
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2 General Requirements 8
unambiguous colours, then from a psychological point of view
greater trust might ensue and hence, greater fluencyin map reading.
The use of fewer and more saturated colours would also minimise
confusion by some colourdefective orienteers. Smith suggests that
only five to eight different colours can be reliably discerned
under goodconditions by normal observers. In addition, density
differences should be greater than 15 per cent (for example, 30per
cent grey and 45 per cent grey) to minimise map-reading errors due
to limitations in the discrimination of theeye. For red-green
colour defective orienteers, blue, yellow, white, grey and black
are readily discerned. (4) Yellowshould be limited to two or three
different tints, as differentiation between yellow tints is more
difficult than for othercolours and it is sometimes difficult to
print dark saturated yellows.When choosing colours for the ISOM,
the above has been considered. However, the chosen set of colours
is acompromise.Further information:
[4] Jenny Bernhard and Nathaniel Vaughn Kelso, 2007: Color
Design for the Color Vision Impaired,Cartographic Perspectives,
Number 2007, Issue 58, p. 61-67.
Media:2007_JennyKelso_ColorDesign_lores.pdfhttp:/ / colororacle.
cartography. ch/http:/ / www. vischeck. com/
Questions / Open issues Link to document Ales is working on (now
in wiki): http:/ / iomaps. org/ index. php/
Color_vision_deficiency.
Please add other CB orienteers. Ask federations for them. On
trapping colours, technique which might be helpful. Any opinions on
that? http:/ / iomaps. org/ index. php/
Trapping_colors
3 Map Specification
ScaleThe base scale for an orienteering map is 1:15'000. The
scale 1:15'000 shall be used for all long distancecompetitions. For
shorter competitions, enlarged maps with a scale of 1:10'000 may be
used. The scale 1:10'000 isrecommended for older age groups (age
classes 45 and above) where reading fine lines and small symbols
may causeproblems due to deteriorating vision. The scale 1:10'000
is also recommended for the youngest age groups (12 yearsand below)
where the capacity of reading complex maps is not fully
developed.Generalization shall follow the requirements for the
scale 1:15'000 in all cases. Terrain that cannot be
legiblypresented at a scale of 1:15'000 is not suitable for
international events.
Map enlargementWhen a map is enlarged, all lines, symbols and
screens shall be enlarged proportionally (for 1:10000 this means
by150%). Large maps are difficult to handle. Maps larger than A3
should be avoided. A map should not be larger than what
is necessary for the orienteering competition. Large maps should
be cut to fit the course (however, not smallerthan A5). Information
about scale, contour interval and north direction should be
available also on cut maps.
For the highest age classes in the WMOC, map scales larger than
1:15000 / 1:10000 may be used. Therecommended map scale for the
highest age classes is 1:5000. These maps shall also be strict
enlargements. Thecompetition rules regulates the use of map scales
for the WMOC.
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Contour intervalThe ability to easily assess the steepness of
the terrain is vital in orienteering. It is therefore very
important that thecontour interval for orienteering maps is
standardised.The contour interval for orienteering maps is 5
meters. In flat terrain, where the slope is less than 5% (or the
contourswould be more than 7 mm apart) all over the area, 2.5 meter
contours may be used. It is not permissible to usedifferent contour
intervals on the same map.The presence of a form line between
contours makes the terrain appear nearly twice as steep. It is
therefore veryimportant that form lines are used sparingly. Form
lines shall only be used to represent important land forms that
cannot be shown using contours. Instead of using form lines,
contours should be shifted slightly up or down to betterrepresent
the important land forms.
Dimensions of map symbolsNo deviations from the dimensions given
in this specification are permitted. It is, however, accepted that
due tolimitations in printing technology the final map symbol
dimensions may vary up to +/-5%. All line widths andsymbol
dimensions must be kept strictly to their specified values. Certain
minimum dimensions must also beobserved. These are based on both
printing technology and the need for legibility. Dimensions in this
specificationare given at the printed scale of 1:15'000.
On the ground (real world) minimum dimensionsFeatures that are
represented on an orienteering map shall be prominent and easily
identifiable by the orienteer whilerunning. Minimum on the ground
dimensions are provided for many of the symbols in this
specification, and thesemust be respected. Minimum dimensions do
not mean that all features bigger than that need to be represented
on themap. For complex terrain, it will often be necessary to
operate with larger minimum dimensions to get a legible
map.Prominent features with small terrain footprints must be
exaggerated to make them identifiable on the map. When afeature is
exaggerated on the map, neighbouring features may need to be
displaced to ensure that correct relativepositions are
maintained.
Graphical minimum dimensionThe dimensions are given for the map
scale 1:15'000. For larger map scales, the dimensions / numbers
will beproportionally larger (1.5 times larger for 1:10000). The
following are examples.
No Good Example Poor Example Description
1 The smallest gap between brown lines should be 0.15 mm
However, gaps betweencontours must vary with the slope of the
terrain. They may overlap in extremelysteep slopes (normally there
would be a cliff there).
2 The smallest gap between black lines shall be 0.15 mm
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3 The smallest gap between point features of the same colour
shall be 0.1 mm
4 The smallest gap between two blue lines shall be 0.25 mm
5 The shortest dashed line shall have at least 2 dashes
6 The shortest dotted line shall be at least 2 dots
7 The smallest area enclosed by a dotted line shall be 1.5 mm in
diameter and thedotted line shall contain at least 5 dots
((Contradiction, if diameter 1.5 mm = 9dots!))
8 An area of full colour Blue, Green, Grey or Yellow shall be at
least 0.7 mm by 0.7mm (0.5 mm)
9 An area of Black screen (regular or random) shall not be
smaller than 0.7 mm by0.7 mm (0.5 mm)
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10 An area of Blue, Green, or Yellow screen (regular or random)
shall not be smallerthan 1 mm by 1 mm (1.0 mm)
Fig. 2. Minimum graphical dimensions (examples)All features with
a map footprint smaller than the dimensions above must be either
exaggerated or omitted,depending on whether or not they are of
significance to the orienteer.
Combination of screen symbols (ISOM2000 version!)(A similar
illustration will be provided for the area symbols in the revised
ISOM)Vegetation, open areas, marshes, stony groun, etc. are shown
with different kinds of screens. The following tablelists the
permissible combinations of screens (currently the ISOM2000
version).
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4 Symbols 12
4 SymbolsDefinitions of features to be mapped and specifications
of map symbols are given in the following sections. Symbolsare
classified into 7 categories: Land forms (brown) Rock and boulders
(black) Water and marsh (blue) Vegetation (green or yellow)
Man-made features (mostly black) Technical symbols (black or blue)
Course symbols (purple)Dimensions are specified at the base scale
1:15000, with numbers for 1:10000 in parenthesis (always 150%!).
Alldrawings are at doulbe scale (1:7500) for clarity only.Notation
for the illustrations: gap or infill between two lines distance
from centre to centre or length of line diameter symbol is
orientated to northMost of the symbols in this specification shall
be orientated to north. That a symbol is to be orientated to north
isindicated with an arrow pointing upward beside the symbol. When a
symbol shall be orientated to north, it meansthat it shall be
orientated to magnetic north and hence relative to the edges of the
paper.Detailed graphical definitions for some of the symbols is
provided in the section Precise definitions of symbols.
Graphical minimum dimensionsThere has to be minimum dimensions
for line and area symbols on a map. These are termed graphical
minimumdimensions. The footprint of a symbol is the area the symbol
would cover if it was projected onto the terrain.For a line symbol,
the graphical minimum dimension concerns its length on the map. If
a line is too short on the map,it ceases to look like a line, and
can be mistaken for a point symbol. Also, styled line symbols must
not be made soshort that the symbol becomes unrecognisable. If
there is room on the map and the line feature is prominent
andsignificant, it could be mapped even if it is shorter than the
footprint of the minimum size line. However, it must beexaggerated
in size on the map to meet the graphical minimum length.For an area
symbol, the graphical minimum dimension concerns the area covered
by the symbol on the map. If thearea is too small, it will be
difficult to differentiate it from point symbols, it becomes noise
to the map user, or thestructure of the symbol will become
unrecognisable. If there is room on the map and the area feature is
prominentand significant, it can be mapped even if it is smaller
than the footprint of the minimum size area. However, it mustbe
exaggerated to meet the minimum graphical dimensions.
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Land forms (brown) 1
Land forms (brown)The shape of land is shown by means of very
detailed contours, aided by special symbols for small
knolls,depressions, etc. This is complemented in black by symbols
for rock and cliffs. Orienteering terrain is normally
bestrepresented with a 5 m contour interval.Excessive use of form
lines should be avoided as this will complicate the map and give a
wrong impression of heightdifferences. If the representation of an
area needs a large number of form lines, a 2.5 meter contour
interval providesa more legible alternative.The relative height
difference between neighbouring features must be represented on the
map as accurately aspossible. Absolute height accuracy is of less
importance. It is permissible to alter the height of a contour
slightly ifthis will improve the representation of land forms. This
deviation should not exceed 25% of the contour interval
andattention must be paid to neighbouring features.101 Contour102
Index contour103 Form line (((new / alternative graphical
implementations for consideration)))104 Slope line105 Contour value
((moved to 102 Index contour))106 Earth bank107 Earth wall (((new
graphical implementation for consideration)))108 Ruined earth wall
(((new graphical implementation for consideration)))109 Erosion
gully (((stricter bounds on graphical implementation
suggested)))110 Small erosion gully (((suggested to reduce the
distance between the dots)))111 Knoll ((eliminated))112 Small
knoll113 Small elongated knoll114 Depression ((eliminated))115
Small depression116 Pit117 Broken ground (((changed to fixed
density)))119 Very broken ground (((new)))118 Special prominent
land form feature (((new symbol suggested)))
CommentsSome symbols have been eliminated (application of other
symbols). It is suggested to reduce the size of some of thepoint
symbols slightly. It is suggested to introduce fixed densities for
broken ground, in order to stop the currentmisuse of the broken
ground symbol (mapping of very small point features).
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101 Contour 2
101 Contour
DefinitionA line joining points of equal height. The standard
vertical interval between contours is 5 metres.
Old ISOM2000 text
A line joining points of equal height. The standard vertical
interval between contours is 5 metres.
Graphic implementation
No Symbol Dimension mm Description Changes (from ISOM2000)
F101 0.14 contour line none
ApplicationContour lines are the most important elements for
representating the terrain and are used for all landforms.The
following must be considered: An individual contour line does not
state much. Several adjacent contour lines show form and structure.
Relationships between adjacent contour lines are important. Small
details on contours should be smoothed because they tend to hide
the main features of the terrain. Prominent features like
depressions, spurs, earth banks and terraces may have to be
exaggerated in order to
emphasize them.The relative height difference between
neighbouring features must be represented on the map as accurately
aspossible. However, absolute height accuracy is of less
importance. It is permissible to alter the height of a
contourslightly, if this will improve the representation of a
feature. This deviation should not exceed 25% of the
contourinterval and attention must be paid to neighbouring
features.To emphasize the three-dimensional effect of the contour
line image, contour lines shall be represented as continuouslines
through all symbols, also buildings (526.1) and open buildings
(526.2).However, contour lines shall be spaced out for better
legibility, if they touch the following symbols: earth wall(108.1),
small knoll (112), elongated knoll (113), small depression (115),
pit (116) and xxx (529.1).Form lines (103) can be used to
differentiate flat knolls from more distinct knolls.Contours lines
calculated out of airborne laser data or digital terrain models
(DEM) often contain too much detailand must be generalised
according to the principles described above.
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101 Contour 3
Minimum graphical dimensions The diameter of a contour knoll
must exceed 0.7 mm (footprint 10 m). Smaller, prominent knolls can
be
represented using small knoll (110) or elongated knoll (111), or
they can be exaggerated to satisfy the minimumdimension.
To accomodate a slope line, the diameter of a contour depression
must exceed 0.8 mm (footprint 12 m). Smalle,prominent depressions
can be represented using small depression (115) or pit (116), or
they can be exaggerated tosatisfy the minimum dimension.
The smallest bend in a contour line is 0.25 mm from centre to
centre of the line (footprint 4 m) ((example will beadded))
The mouth of a re-entrant, shoulder or a spur must exceed 0.5 mm
(footprint 8 m)
Minimum depth or hight A contour knoll should have a minimum
height of 1 meter compared to the surrounding terrain. A contour
depression should have a minimum depth of 1 meter compared to the
surrounding terrain.
102 Index contour
DefinitionEvery fifth contour shall be drawn with a thicker
line. This is an aid to the quick assessment of height difference
andthe overall shape of the terrain surface. It may have a hight
value assigned.
Old ISOM 2000 textEvery fifth contour shall be drawn with
thicker line. This is an aid to the quick assessment of height
difference andthe overall shape of the terrain surface. Where an
index contour coincides with an area of much detail, it may beshown
with normal contour line.
Graphic implementation
No Symbol Dimension Description Changes (from ISOM2000)
F102 0.25mm Index contour line none
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102 Index contour 4
Application For better legibility, an index contour can be
represented as an ordinary contour line (101) in an area with
much
detail. Small knolls and depressions are normally not
represented using index contours. The index value (label) shall be
represented in a sans-serif font, like Arial, and not smaller than
1.5 mm. A contour value (label) should only be inserted in an index
contour in places where other detail is not obscured.
The label shall be oriented to that the top of the label is on
the highest side of the contour.
Corresponding symbols for the control description
No. Picto Name Description
1.1 Terrace A level area on a slope.
1.2 Spur A contour projection or nose rising from the
surrounding ground..
1.3 Re-entrant A contour indentation; a valley; the opposite of
a spur.
1.9 Hill A high point. Shown on the map with.
1.11 Saddle The low point between two higher points.
1.12 Depression A depression or hollow from which the ground
rises on all sides. Shown on the map with contour lines..
Fig. 2: Control description for Index contour lines
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103 Form line 5
103 Form line
DefinitionForm lines are used where more information must be
given about the shape of the ground. They shall not be used
asintermediate contours. They are used only where representation
can not be made complete with symbols 101(contour) or 102 (index
contour). Only one form line may be used between neighbouring
contours. Colour: brown.
Old ISOM 2000 textAn intermediate contour line. Form lines are
used where more information can be given about the shape of
theground. They are used only where representation is not possible
with ordinary contours. Only one form line may beused between
neighbouring contours.
Graphic implementationThere are two issues with the ISOM2000
graphic implementation (dashed brown 0.14 mm line): Dashes are
problematic for curved lines, in particular for sharp bends /
corners. If a gap coincides with a sharp
bend, the perceived continuity of the line will suffer. If gaps
line up, for instance on winding lines or closed lines,it can cause
unwanted visual effects. Some possible solutions are presented
below: Full line, but thinner to distinguish it from ordinaray
contours Extremely short dashes or tightly spaced dots
Form lines give about the same visual impression as normal
contours, adding very much to the perceivedsteepness of the
terrain. Some possible solutions are presented below: Thinner line
Paler colour Simulated paler colour by using dots or very short
dashes
No Symbol Dimension[mm]
Description Changes from ISOM 2000
F103 0.14/1.25/0.25 Form line none
F103.1 0.14/0.25/0.15 Form line (very shortdashed line)
new. Goal: simulate pale brown and reduce dash problems
F103.2 0.14/0.15 Form line (dotted line) new. Toal: reduce the
visual impact and eliminate dash problems bysimulating pale brown
(centre to centre distance: 75%: 0.15mm; 50%:0.22mm)
F103.3 0.10 (or 0.07) Form line (thin line) new. Goal: reduce
the visual impact and eliminate dash problems
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103 Form line 6
F103.4 0.10/2.00/0.20 Form line (thin andlong dashed line)
new. Goal: reduce the visual impact and reduce dash problems
F103.5 0.14 Form line (lighterbrown 75% brown)
new. Goal: reduce the visual impact and eliminate dash
problems.Problem: not convenient with a new colour
Only one, or perhaps two of the suggested symbols will make it
into the ISOM.
Application Only one form line should be used between
neighbouring contours (101/102). Excessive use of form lines must
be avoided as this disturbs the pseudo three-dimensional effect of
the contour
line image and will complicate map reading. If the
representation of an area needs a large number of form lines, a2.5
meter contour interval provides a more legible alternative. It is
not allowed to use different contour intervalson the same map.
Graphical minimum dimensions The minimum length of a form line
is 4 mm (footprint 60 m in the terrain) The minimum diameter of a
knoll or a depression must exceed 0.7 mm (footprint 10 m)
Corresponding symbols for the control description
No. Picto Name Description
1.1 Terrace A level area on a slope.
1.2 Spur A contour projection or nose rising from the
surrounding ground..
1.3 Re-entrant A contour indentation; a valley; the oppo-site of
a spur.
1.9 Hill A high point. Shown on the map with.
1.11 Saddle The low point between two higher points.
1.12 Depression A depression or hollow from which the ground
rises on all sides. Shown on the map with contour lines..
Fig. 2: Control description for form lines
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103 Form line 7
CommentsDashed lines are problematic for complex shapes, because
the openings between the dashes can end up at importantplaces
(bends), resulting in a cluttered and chaotic map. Drawing with
dashed lines requires a lot of skill and time.
104 Slope line
DefinitionA slope line emphasizes / clarifies the direction of
slope.
Old ISOM 2000 textSlope lines may be drawn on the lower side of
contour line, e.g. along the line of re-entrant or in a depression.
Theyare used only where it is necessary to clarify the direction of
slope.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F104 0.14/0.4 Slope line 1/10 mm shorter
Application Slope lines may be drawn on the lower side of a
contour line, e.g. along the line of a re-entrant or in a
depression.
They are used only where it is necessary to clarify the
direction of slope. The slope line starts at the center of the
line. Should be placed in re-entrances and not on spurs.
CommentsThe tag has been slightly decreased in length to reduce
its visual impact and space occupied (for depressions).
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106 Earth bank 8
106 Earth bank
DefinitionAn earth bank is an abrupt change in ground level
which can be clearly distinguished from its surroundings,
e.g.gravel or sand pits, road and railway cuttings or
embankments.
Old ISOM 2000 textA steep earth bank is an abrupt change in
ground level which can be clearly distinguished from its
surroundings, e.g.gravel or sand pits, road and railway cuttings or
embankments.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F106 0.18/0.5/0.5 Earth bank (ISOM 2000) none
0.18 Upper edge none
0.25 Upper edge very high earth bank none
0.18/0.4 minimum tag shorter tag (0.5->0.4)
0.18/0.25/0.2 Graphical minimum size
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106 Earth bank 9
Application The tags represent the full extent of the earth
bank. However, if two earth banks are close together, tags may
be
omitted. Impassable earth banks should be represented with the
symbol impassable cliff (201). Large features should be
represented with contours only, as contours better depict the
real height or depth of features. A prominent dam or earth wall
which is so narrow that it can not be represented with two parallel
earth banks can
be represented as earth wall (107). A prominent dyke or steep
gully which is so narrow that it can not be represented with two
parallel earth banks
can be represented as erosion gully (109).
Graphical minimum dimensionsThe earth banks must exceed 0.6 mm
in length (footprint 9 m). Short prominent earth banks may be
exaggerated tothe minimum length.
Minimum dimensionsThe earth banks should exceed 1.0 m in
height.
Impact to runabilityCrossing an eart bank may disturb runability
by scrambling or climbing
Corresponding symbols for the control description
No. Picto Name Description
1.4 Earth bank An abrupt change in ground level which can
clearly be distinguished from its surroundings.
1.5 Quarry Gravel, sand or stone working in flat or in-clined
ground.
Fig. 2: Control description for earth bank
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107 Earth wall 10
107 Earth wall
DefinitionDistinct earth wall.
Old ISOM 2000 textDistinct earth wall. Minimum height is 1
m.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F107 0.14/2.5/0.4 Earth wall (ISOM 2000) none
F107.1 0.14/2.0/0.14/0.5 Earth wall dashes instead of dots
(locical? - two collapsed earth banks...)
2.0 (length) Earth wall (minimum length)
One of F107 and F107.1 will be chosen for the ISOM.
Graphical minimum dimensionsAn earth wall shall exceed 2.0 mm in
length (footprint 30.0 m). Shorter, prominent earth walls may be
exaggeratedto the minimum graphical dimension.
Minimum dimensionAn earth wall shall be at least 1.0 meter
high.
Corresponding symbols for the control description
No. Picto Name Description
1.6 Earthwall
A narrow wall of earth projecting above the surrounding terrain;
may be partially stone faced, usually man-made. Usedwith symbol
8.11 to indicate a ruined earth wall.
Fig. 1: Control description for earth wall
CommentsAn alternative graphical implementation is included for
consideration. The logic behind it is that it can be viewed astwo
earth banks (the sides of an earth wall) collapsed into one.
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108 Ruined earth wall 11
108 Ruined earth wall
DefinitionA small or partly ruined earth wall shall be shown
using a dashed line.
Old ISOM 2000 textA small or partly ruined earth wall shall be
shown with a dashed line. Minimum height is 0.5 m.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
.
F108 0.14/2.25/0.25/0.4
Ruined earth wall(ISOM2000)
none
F108.1 0.14/1.75/0.25/0.5 Ruined earth wall dashes instead of
dots (logical? - collapsed earthbanks...)
One of F108 and F108.1 will be chosen for the ISOM.
Graphical minimum dimensionsAn small or partially ruined earth
wall must exceed 3.5 mm in length (footprint 50 m). Shorter,
prominent ruinedearth walls must be exaggerated or represented as
earth walls.
Minimum dimensionsAn small or partially ruined earth wall must
be higher than 0.5 meters.
Corresponding symbol for the control description
No. Picto Name Description
1.6 Earthwall
A narrow wall of earth projecting above the surrounding terrain;
may be partially stone faced, usually man-made. Usedwith symbol
8.11 to indicate a ruined earth wall.
Fig. 2: Control description for earth wall
CommentsAn alternative graphical implementation is included for
consideration. The logic behind it is that it can be viewed astwo
earth banks (the sides of an earth wall) collapsed into one.
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109 Erosion gully 12
109 Erosion gully
DefinitionAn erosion gully or trench which is too small to be
shown using earth banks (symbol 106) is shown by a single line.
Old ISOM 2000 textAn erosion gully or trench which is too small
to be shown by symbol 106 is shown by a single line.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F109 0.25 line width, 0.75 ends length, ends pointed Erosion
gully (ISOM2000) none
1.6 (minimum dimension) Erosion gully (ISOM2000)
Graphical minimum dimensionsAn erosion gully must exceed 1.6 mm
in length (footprint 24 m). Shorter, prominent erosion gullies may
beexaggerated to the minimum graphical dimension.
Minimum dimensionsAn erosion gully must be deeper than 1.0
meter.
Corresponding symbols for the control description
No. Picto Name Description
1.7 Erosion gully An erosion gully or trench, normally dry.
Fig. 2: Control description for earth wall
CommentsIt is suggested to add a fixed length for the ends of
the symbol and a minimum length to make it easier to
distinguishshort erosion gullies and elongated knolls.
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110 Small erosion gully 13
110 Small erosion gully
DefinitionA small erosion gully, dry ditch or trench.
Old ISOM 2000 textA small erosion gully or trench.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F110 0.35/ 0.25 Small erosion gully (ISOM2000) dots closer
(0.5->0.35)
Graphical minimum dimensionsA small erosion gully must consist
of at least two dots (exceed 0.75 mm in length - footprint 12
m).
Minimum dimensionsA small erosion gully must be deeper than 0.5
meter.
Corresponding symbols for the control description
No. Picto Name Description
1.8 Small erosion gully A small erosion gully or trench,
normally dry.
Fig. 2: Control description for earth wall
CommentsIt is suggested to place the dots closer together to
empasize that it is a linear feature that is represented.
Thesuggested reduction in spacing may be a bit too large?
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112 Small knoll 14
112 Small knoll
DefinitionA small obvious mound or rocky knoll which cannot be
drawn to scale with a contour (diameter less than ca. 5meters).
Old ISOM 2000 textA small obvious mound or rocky knoll which
cannot be drawn to scale with a contour (diameter of mound less
thanca. 5 m).
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F112 0.5 Small knoll (ISOM2000) none
ApplicationThe symbol shall not touch or overlap other brown
symbols.
Minimum ground dimensionsA knoll should be at least 1.0 m heigh
(approximately waist height for an adult).
Corresponding symbols for the control description
No. Picto Name Description
1.10 Knoll A small obvious mound. Used with symbol 8.6 to
indicate a rocky knoll.
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113 Small elongated knoll 15
113 Small elongated knoll
DefinitionA small obvious elongated knoll which cannot be drawn
to scale with a contour.
Old ISOM 2000 textA small obvious elongated knoll which cannot
be drawn to scale with a contour (length less than 12 m and width
lessthan 4 m).
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F113 0.8/0.4 Enlongated knoll (ISOM2000) none
ApplicationKnolls larger than this must be shown by contours The
symbol shall not be drawn in free form or such that twoelongated
knoll symbols overlap. The symbol shall not touch other brown
symbols.
Minimum dimensions on groundAn elongated knoll should be at
least 1.0 m heigh. The knoll must be clearly elongated. Knolls that
are longer than12 m shall be represented using contour lines.
Corresponding symbols for the control description
No. Picto Name Description
1.10 Knoll A small obvious mound. Used with symbol 8.6 to
indicate a rocky knoll.
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115 Small depression 16
115 Small depression
DefinitionA small shallow depression or hollow without steep
sides, that are too small to be shown by contours.
Old ISOM 2000 textSmall shallow natural depressions and hollows
(minimum diameter 2 m) which cannot be shown to scale by
contoursare represented by semicircle. Minimum depth from the
surrounding ground should be 1 m.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F115 0.7/0.18 Small depression (ISOM2000) slightly smaller
(0.8-0.7)
Application Location is the centre of gravity of the symbol,
which is orientated to north. Symbol Pit (116) is used for
depressions / pits with steep sides.
Minimum dimensions on ground A small depression should be at
least 1.0 m deep. The minimun diameter is 2.0 m
Corresponding symbols for the control description
No. Picto Name Description
1.13 Small depression A small, shallow, natural depression or
hollow from which the ground rises on all sides.
Fig. 2: Control description for small depression
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116 Pit 17
116 Pit
DefinitionPits and holes with distinct steep sides which cannot
be shown to scale by symbol 106.
Old ISOM 2000 textPits and holes with distinct steep sides which
cannot be shown to scale by symbol 106 (minimum diameter 2 m)
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F116 0.8/0.18 Pit ((current implementation)) none
Application A pit larger than 5x5 meters should normally be
drawn using the earth bank symbol. The symbol may not touch other
brown symbols. Location is the centre of gravity of the symbol
which is orientated to north. Symbol Small depression (115) is used
for depressions without steep sides.
Minimum dimensionsA pit should be at least 1.0 meter deep and
have a diameter of more than 2.0 meters.
Corresponding symbols for the control description
No. Picto Name Description
1.13 Pit A pit or hole with distinct steep-sides. Usually man
made. Used with symbol 8.6 to indicate a rocky pit.
Fig. 2: Control description for pit
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117 Broken ground 18
117 Broken ground
DefinitionAn area of pits and/or knolls which is too intricate
to be shown in detail, or other types of rough and uneven
groundthat is clearly distinguishable, but does not affect
runability.
Old ISOM 2000 textAn area of pits or knolls which is too
intricate to be shown in detail. The density of randomly placed
dots may varyaccording to the detail on the ground. Colour:
brown.
Graphic implementation
No Symbol Dimension [mm] Description Changes fromISOM 2000
F117 Screen of semi-randomised dots, 0.2, 4 dots / mm2 -
maximum(centre-to-centre) neighbour distance 0.6, minimum neighbour
distance 0.4
Brokenground
fixed density ofdots
Application This is an area symbol. The minimum number of dots
is three. The maximum center to center distance between
neighbouring dots is 0.55 mm. The minimum center to center distance
between neighbouring dots is 0.5 mm. Contours shall not be cut in
broken ground areas.
Graphical minimum dimensionThe minimum area covered by the
symbol must exceed 0.7 mm by 0.7 mm (footprint 12 m by 12 m).
Impact to runabilityNone
Corresponding symbols for the control description
No. Picto Name Description
1.15 Brokenground
Clearly disturbed ground with features too small or too numerous
to be mapped individually; including animalearths.
Fig. 2: Control description for broken ground
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117 Broken ground 19
CommentsA fixed density of dots has been introduced to emphasize
that this is an area symbol. There has been some misuse ofthis
symbol for representing point features (e.g. very small mounds).
Only one size of dots are suggested in order notto encourage
representing very subtle differences in appearance.
119 Very broken ground
DefinitionAn area of pits and/or knolls which is too intricate
to be shown in detail, or other types of rough and uneven
groundthat is clearly distinguishable and affects runability.
Old ISOM 2000 textAn area of pits or knolls which is too
intricate to be shown in detail. The density of randomly placed
dots may varyaccording to the detail on the ground. Colour:
brown.
Graphic implementation
No Symbol Dimension [mm] Description Changes fromISOM 2000
F119 Screen of semi-randomised dots, 0.2, 10 dots / mm2 -
maximum(centre-to-centre) neighbour distance 0.4, minimum neighbour
distance0.25
Broken ground,slow running
fixed density ofdots
Application This is an area symbol. The minimum number of dots
is three. The maximum center to center distance between
neighbouring dots is 0.45 mm. The minimum center to center distance
between neighbouring dots is 0.4 mm. Contours shall not be cut in
broken ground areas.
Graphical minimum dimensionThe minimum area covered by the
symbol must exceed 0.6 mm by 0.6 mm (footprint 9.0 m by 9.0 m).
Impact to runabilitySignificant
Corresponding symbols for the control description
No. Picto Name Description
1.15 Brokenground
Clearly disturbed ground with features too small or too numerous
to be mapped individually; including animalearths.
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119 Very broken ground 20
Fig. 2: Control description for broken ground
CommentsA fixed density of dots has been introduced to emphasize
that this is an area symbol. There has been some misuse ofthis
symbol for representing point features (e.g. very small mounds).
Only one size of dots are suggested in order notto encourage
representing very subtle differences in appearance.
118 Special prominent land form feature
DefinitionThis symbol can be used for special small, prominent
land form features. The definition of the symbol must be givenon
the map.
Old ISOM 2000 textThis symbol can be used for special small land
form feature. The definition of the symbol must be given in the
maplegend.
Graphic implementationSymbol(s) to be decided.
No Symbol Dimension [mm] Description Changes from ISOM 2000
F118 0.18/0.7/0.7 Prominent land form feature (ISOM2000)
slightly smaller (0.8->0.7)
F118.1 0.18/0.8 Prominent land form feature (open triangle) new
shape
Application Location is the centre of gravity of the symbol,
which is orientated to north. The symbol may not touch other brown
symbols.
Minimum Dimensions in the terrainA special prominent land form
feature must be very clearly distinguishable from its
surroundings.
Corresponding symbols for the control description
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118 Special prominent land form feature 21
No. Picto Name Description
1.16 Ant hill (termitemound)
The mound made by ants or termites.
6.1 Special item If used, an explanation of its meaning must be
supplied to competitors in the pre-race information.
5.19 Platform A clearly distinguishable small level (man made)
area, normally on a slope. For instance the remains of acharcoal
burning place.
CommentsSlight decrease in size for the brown cross to decrease
the visual impact of the symbol. It represents a prominentfeature,
but so do all the other ISOM symbols.
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Rock (black) 1
Rock (black)
RockRock is a special category of land form. The inclusion of
rock gives useful information about danger and runnability,as well
as providing features for map reading and control points. Rock is
shown in black to distinguish it from otherland form features. Care
must be taken to make sure that rock features such as cliffs fit
with the shape of the terrain.201 Impassable cliff202 Rock
pillars/cliffs ((eliminated --> see 201))203 Passable cliff204
Rocky pit or cave (note: changed from "rocky pit")205 Cave
(removed, see 204)206 Boulder207 Large boulder209 Boulder
cluster208 Boulder field217 Dense boulder field211 Open sandy
ground212 Bare Rock216 Trench (artificial) ((new))210 Stony ground
((redefined --> see 213-215))213 Stony ground: slow running214
Stony ground: difficult to run215 Stony ground: very difficult to
run
CommentsSome symbols have been eliminated (application of other
symbols). It is suggested to reduce the size of some of thepoint
symbols slightly. A new symbol is suggested for trench (could also
end up among the man made features).To emphasize that stony ground
is an area symbol, it has been turned into three symbols to show
the runnability inrocky areas (is there a need for three densities,
or can we do with two?). For the same reasons, the boulder
fieldsymbol has been turned into two symbols to show density (and
runnability). The stony ground symbols could becombined with the
boulder field symbols.
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201 Impassable cliff 2
201 Impassable cliff
DefinitionA cliff, rock pillar, quarry or earthbank that is so
high and steep that it impossible to pass / climb or is
dangerous.
Old ISOM 2000 textAn impassable cliff, quarry or earth bank (see
106) is shown with 0.35 mm line and downward tags showing its
fullextent from the top line to the foot. For vertical rock faces
the tags may be omitted if space is short, e.g. narrowpassages
between cliffs (the passage should be drawn with width of at least
0.3 mm) The tags may extend over anarea symbol representing detail
immediately below the rock face. When a rock face drops straight
into water makingit impossible to pass under the cliff along the
water's edge, the bank line is omitted or the tags should clearly
extendover the bank line. Colour: black.
Graphic implementation
No Symbol Dimension mm Description Changes from ISOM 2000
F201 0.35 / 0.5 / rounded line caps top line of impassable cliff
rounded line caps
0.12/0.4 tag of impassable cliff (minimumlength)
shorter tags (0.5 in ISOM 2000)
F202 plane shape (minimum width0.35)
rock pillar or massive impassablecliff
ISOM 202
0.8 Impassable cliff (min. length) minimum length increased due
to roundedends
Application If the direction of fall is not evident, tags should
be added. For cliffs that are not vertical, tags shall be used to
show the full horizontal extent. For rock pillars, the minimum
width is 0.35 mm. The gap between two impassable cliffs must exceed
0.4 mm, When an impassable cliff drops straight into water making
it impossible to pass under the cliff along the waters
edge, the bank line is omitted or the tags should clearly extend
over the bank line. A rock pillar must exceed 0.6 mm in diameter on
the map, otherwise it shall be represented as large boulder.
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201 Impassable cliff 3
Graphical minimum dimensionsAn impassable cliff shall exceed 0.8
mm in length (footprint 12 m).
Minimum dimensionsA high cliff should be more than 2.5 m
heigh.
Impact to runabilityCrossing a high cliff is forbidden.
Corresponding symbols for the control description
No. Picto Name Description
2.1 Cliff, Rock face A cliff or rock face. May be passable or
impassable.
2.9 Narrow passage A gap between two cliffs or rock faces that
face each other
Fig. 2: Control description for high cliff
Comments201 and 202 show the same kind of features and have been
combined. Minimum dimensions have been added toavoid misuse of the
plane shape version. Rounded end caps are suggested, as cliffs very
seldom have a distinct end.The minimum tag length has been slightly
decreased to reduce the visual impact.
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203 Passable cliff 4
203 Passable cliff
DefinitionA low cliff.
Old ISOM 2000 textA small vertical rock face (minimum height 1
m) may be shown without tags. If the direction of fall of the rock
faceis not apparent from the contours or to improve legibility,
short tags should be drawn in the direction of the fall.
Forpassable rock faces shown without tags the ends of the line may
be rounded to improve legibility. Colour: black.
Graphic implementation
No Symbol Dimension mm Description Changes from ISOM 2000
F203 0.25 / rounded linecaps
Passable cliff Rounded line cap
0.7 Minimum length Increased from 0.6 due to roundedends
0.12/0.4 Tag width and minimum length (from centre of
baseline)
Shorter tag (ISOM2000 0.5)
0.5 Spacing between the tags (centre to centre) none
Application If the direction of fall of the cliff is not
apparent from the contours or to improve legibility, short tags may
be
drawn in the direction of the slope. For non-vertical cliffs,
the tags should be drawn to show the full horizontal extent of the
cliff. A narrow passage between two cliffs must be at least 0.25
mm. A low cliff shall interplay with the contour lines.
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203 Passable cliff 5
Graphical minimum dimensionsA low cliff should be at least 0.7
mm long (footprint 10.5 m).
Minimum dimensionsA low cliff should be at least 1 m high.
Impact to runabilityCrossing a low cliff is possible, but it
will normally slow progress.
Corresponding symbols for the control description
No. Picto Name Description
2.1 Cliff, Rock face A cliff or rock face. May be passable or
impassable.
2.9 Narrow passage A gap between two cliffs or rock faces that
face each other
Fig. 2: Control description for low cliff
CommentsThe version with 0.18 mm line width has been removed. It
did not have any justification in ISOM2000.
204 Rocky pit or cave
DefinitionRocky pits, holes, caves or mineshafts which may
constitute a danger to the runner. Location is the centre of
gravityof the symbol. The symbol shall be orientated to north,
except for caves with a distinct vertical entrance, where thesymbol
should point up the slope.
Graphic implementation
No Symbol Dimension mm Description Changes from ISOM 2000
F204 0.16/0.7/0.8 Rocky pit
F204 0.16/0.7/0.8 Cave
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204 Rocky pit or cave 6
ApplicationPits larger than 10 m in diameter should be shown
represented using the cliff symbols (201, 203)
Minimum dimensions on groundA rocky pit should exceed a minimum
of 1.0 m depth from the surrounding ground.
Impact to runabilityCrossing a rocky pit may not be possible,
and it may constitute a danger to competitors.
Corresponding symbols for the control description
No. Picto Name Description
1.14 Pit A pit or hole with distinct steep-sides. Usually man
made. Used with symbol 8.6 to indicate a rocky pit.
2.3 Cave
Fig. 1: Control description for rocky pit
CommentsRocky pit and cave are so similiart that we suggest to
combine them.
206 Boulder
DefinitionA distinct boulder (minimum heigtt 1 m), which should
be immediately identifiable on the ground.
Old ISOM 2000 textA small distinct boulder (minimum height 1 m).
Every boulder marked on the map should be immediatelyidentifiable
on the ground. To be able to show the distinction between boulders
with significant difference in size itis permitted to enlarge this
symbol by 20 % (diameter 0.5 mm). Colour: black.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F206 0.4/( 0.5) Single boulder none
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206 Boulder 7
Application A boulder shall be immediately identifiable on the
ground, otherwise it must be omitted or represented as a part
of
a boulder field. To be able to show the distinction between
neighouring (closer than 30 meters apart) boulders with
significant
difference in size, it is permitted to enlarge this symbol by
20% (diameter 0.5 mm).
Minimum dimensions on groundA boulder should have a height that
exceeds 1 m above the surrounding ground.
Corresponding symbols for the control description
No. Picto Name Description
2.4 Boulder A prominent free-standing block of rock or
stone.
207 Large boulder
DefinitionA particularly large and distinct boulder..
Old ISOM 2000 textA particularly large and distinct boulder. For
gigantic boulders symbol 202 should be used. Colour: black.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F207 0.6 Large single boulder none
ApplicationFor gigantic boulders symbol 201 should be used.
Minimum dimensions on groundA large boulder should be higher
than 2 m above the surrounding ground.
Corresponding symbols for the control description
No. Picto Name Description
2.4 Boulder A prominent free-standing block of rock or
stone.
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209 Boulder cluster 8
209 Boulder cluster
DefinitionA distinct group of boulders so closely clustered
together that they cannot be marked individually.
Old ISOM 2000 textA small distinct group of boulders so closely
clustered together that they cannot be marked individually. The
symbolis an equilateral triangle orientated to the north. To be
able to show the distinction between boulder clusters
withsignificant difference in size it is permitted to enlarge this
symbol by 25% (1.0 mm). Colour: black.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F209 0.8/0.8/0.8 boulder cluster none
Application A boulder cluster shall be easily identifiable as a
group of boulders on ground. The symbol is orientated to north. To
be able to show the distinction between neighouring (maximum 40
meters apart) boulder clusters with
significant difference in size it is permitted to enlarge this
symbol by 20% (0.96 mm).
Minimum dimensions on groundEach boulder should be higher than 1
meter.
Corresponding symbols for the control description
No. Picto Name Description
2.6 Boulder cluster A small distinct group of boulders so
closely clustered together that they cannot be individually
mapped.
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208 Boulder field 9
208 Boulder field
DefinitionAn area which is covered with so many scattered blocks
of stone that they cannot be marked individually is shownwith
randomly orientated solid triangles with sides of ratio 8:6:5. A
minimum of two triangles should be used. Onetriangle may be used
when it is placed directly below a cliff symbol. Colour: black.
Graphic implementation
No Symbol Dimension [mm] Density (1:15000) Description Changes
from ISOM 2000
F208 0.8/0.6/0.5 1 triangle / mm2 Boulder field Introduced fixed
density
Minimum dimensions on groundThe area must exceed 1.4 mm by 1.4
mm (footprint 20 m by 20 m).
Impact to runabilityNone
Corresponding symbols for the control description
No. Picto Name Description
2.5 Boulder field
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217 Dense boulder field 10
217 Dense boulder field
DefinitionAn area which is covered with so many blocks of stone
that they cannot be marked individually, and that the going
isaffected is shown with randomly orientated solid triangles with
sides of ratio 8:6:5. A minimum of two trianglesshall be used.
Colour: black.
Graphic implementation
No Symbol Dimension [mm] Density (1:15000) Description Changes
from ISOM 2000
F208 0.8/0.6/0.5 3 triangles / mm2 Dense boulder field
Introduced fixed density
Minimum graphical dimensionsThe minimum area must exceed 1 mm by
1 mm (footprint 15 m by 15 m).
Impact to runabilitySignificant to considerable.
Corresponding symbols for the control description
No. Picto Name Description
2.5 Boulder field
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211 Sandy ground 11
211 Sandy ground
DefinitionAn area of soft sandy ground or gravel with no
vegetation and where running is slow.
Old ISOM 2000 textAn area of soft sandy ground or gravel with no
vegetation and where running is slow.(401/402). Colour: black 12.5%
(22 lines/cm) and yellow 50% (see 403).
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F211 0.16/0.45, black Open sandy ground dots slightly smaller
(0.18->0.16)
Application Used for areas with a sandy surface that reduces
runability.
Graphical minimum dimensionsThe minimum area is 1 mm by 1 mm
(footprint 15 m by 15 m.
Corresponding symbols for the control descriptionNo
corresponding control description symbols, but the following are
related / relevant.
No. Picto Name Description
4.1 Open land An area with no trees. Grassland, a mead-ow or a
field. Also heath or moorland.
8.8 Sandy Where the feature is in an area of sandy ground not
indicated on the map; e.g. Spur, sandy.
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212 Bare Rock 12
212 Bare Rock
DefinitionA runnable area of rock without earth or vegetation
should be shown as bare rock. An area of rock covered withgrass,
moss or other low vegetation should be shown as open land
(401/402).
Old ISOM 2000 textA runnable area of rock without earth or
vegetation is shown as bare rock. An area of rock covered with
grass, mossor other low vegetation is shown as open land (401/402).
Colour: black 30 % (60 lines/cm) or grey.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F212 Bare rock none
ApplicationAn area of rock covered with grass, moss or other low
vegetation should be shown as open land (401/402).
Minimum graphical dimensionsThe minimum area must exceed 2mm by
2mm (footprint 15 m by 15 m).
Impact to runabilityWill normally provides good to very good
runnability.
Corresponding symbols for the control description
No. Picto Name Description
2.8 Bare rock A runnable area of rock with no earth or
vegetation cover.
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216 Trench (artificial) 13
216 Trench (artificial)
DefinitionA trench is a landform of excavation or depression in
the ground. Trenches are generally defined by being deeperthan they
are wide (as opposed to a wider gully), and by being narrow
compared to their length (as opposed to asimple hole).
Old ISOM 2000 textNone. A new symbol.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F216 0.10/0.10/0.10 Trench new
Minimum graphical dimensionsA trench must be longer than 2 mm
(footprint 15 m).
Minimum dimensions on the groundA trench must be deeper than 1
m.
Impact to runabilityCrossing a trench may disturb runability by
scrambling, climbing or jumping over.
Corresponding symbols for the control descriptionNone for this
new symbol.
CommentsDeep and narrow trenches are not uncommon in places
where there has been military activity (many places inEurope). They
are virtually impossible to represent with the ISOM2000 symbol
set.
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213 Stony ground: slow running 14
213 Stony ground: slow running
DefinitionStony or rocky ground which affects going should be
shown on the map. The dots should be randomly distributed. Aminimum
of three dots should be used. Colour: black.
Graphic implementation
No Symbol Dimension [mm] Density Description Changes from
ISOM2000
F213 0.2 stochastic raster 4 / mm2
(12%)
Stony ground: slow running ISOM 2000 / 0.16-0.2
F213.1 0.2 regular raster 45 deg,0.5
4 / mm2
(12%)
Stony ground: slow running ISOM 2000 / 0.16-0.2
0.2 4 / mm2
(12%)
Stony ground: slow running (minimumdimension)
ISOM 2000 / 0.16-0.2
Note: Only one of F213 and F213.1 will be in the ISOM.
ApplicationThe dots shall not be arranged to form a single
line.
Minimum graphical dimensions2 mm2, corresponding to an area of
about 20 m by 20 m.
Impact to runabilitySlow running.
Corresponding symbols for the control description
No. Picto Name Description
2.7 Stony ground An area covered with many small stones or
rocks.
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214 Stony ground: difficult to run 15
214 Stony ground: difficult to run
DefinitionStony or rocky ground which affects going should be
shown on the map. The dots should be randomly distributed. Aminimum
of three dots should be used. Colour: black.
Graphic implementation
No Symbol Dimension [mm] Density Description Changes from ISOM
2000
F214 .2 stochastic pattern 11 / mm2 (35%) ISOM 0.16-0.20
F214.1 .2 regular pattern 45 degrees, 0.3 11 / mm2 (35%) ISOM
0.16-0.20
.2 (minimum dimension) 11 / mm2 (35%) ISOM 0.16-0.20
Note: Only one of F214 and F214.1 will make it into the
ISOM.
ApplicationThe dots shall not be arranged to form a single
line.
Graphical minimum dimensions1mm x 1mm, corresponding to 15 m by
15 m on the ground.
Impact to runabilityDifficult to run.
Corresponding symbols for the control description
No. Picto Name Description
2.7 Stony ground An area covered with many small stones or
rocks.
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215 Stony ground: very difficult to run 16
215 Stony ground: very difficult to run
DefinitionStony or rocky ground which affects going should be
shown on the map. The dots should be randomly distributed. Aminimum
of three dots should be used. Colour: black.
Graphic implementation
No Symbol Dimension [mm] Density Description Changes from ISOM
2000
F214 .2 stochastic pattern 20 / mm2 (55%) ISOM 0.16-0.20
F214.1 .2 regular pattern 45 degrees, 0.24 20 / mm2 (55%) ISOM
0.16-0.20
.2 (minimum dimension) 20 / mm2 (55%) ISOM 0.16-0.20
Note: Only one of 214.1 and 214.3 will make it into the
ISOM.
ApplicationThe dots shall not be arranged to form a single
line.
Graphical minimum dimensions0.7mm x 0.7mm, corresponding to 10 m
by 10 m on the ground.
Impact to runabilityVery difficult to run.
Corresponding symbols for the control description
No. Picto Name Description
2.7 Stony ground An area covered with many small stones or
rocks.
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Water and marsh (blue) 1
Water and marsh (blue)This group includes both open water and
special types of vegetation caused by the presence of water
(marsh). Theclassification is important because it indicates the
degree of hindrance to the runner and provides features for
mapreading and control points. A black line around a water feature
indicates that it shall not be crossed. In dry areas thefeatures
listed in this section may only contain water in some
seasons.Waterbodies and marshes may affect runnability. Some
waterbodies and marshes are not crossable withoutswimming, and
since swimming abilities are not to be tested in an orienteering
competition, crossing of such areasmust be forbidden (for safety
and fairness reasons). Some waterbodies are crossable without
swimming, and may bemapped as such. This is most relevant for
rivers and streams. Passing crossable waterbodies will generally
slowdown the competitor.Marshes may offer varying runnability. In
some regions, marshes are very runnable, but most often they
implyreduced runnability. Marsh symbols may be combined with
symbols for openness (yellow) and runnability (greenand yellow).301
Uncrossable water body302 Pond ((eliminated see 301))303 Waterhole
((eliminated see 301))304 Uncrossable river ((eliminated see
301)305 Shallow water body306 Crossable small water course
((eliminated see 305))307 Minor water channel Drainage ((moved see
315))309 Uncrossable marsh310 Marsh308 Narrow marsh311 Indistinct
marsh312 Well / Fountain313 Spring314 Prominent water feature
(((new symbol suggested)))
CommentsSome symbols have been eliminated (application of other
symbols). It is suggested to reduce the size of some of thepoint
symbols slightly. Shallow water body is introduced, as in the
ISSOM. The line symbols for passable waterfeatures are found as
applications of shallow water body.
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301 Uncrossable water body 2
301 Uncrossable water body
DefinitionA body of water thay shall not be crossed.
Old ISOM 2000 text301 Lake. Large area of water are shown with
dot screen Small of water should be shown with full colour. A
blackbank line indicates that the feature can not be crossed.304
Uncrossable river. An uncrossable river or canal is drawn with
black bank lines. The bank lines are broken at aford. Colour: blue
50% (60 lines/cm), black.
Graphic implementation
No Symbol Dimension [mm] Description Changes from ISOM 2000
F301 plane shape with border line Uncrossable water body
(uncrossable) none
plane shape with border line Uncrossabel water course
(uncrossable) none
0.18 Border line of uncrossable water body none
min 0.7 Uncrossable water body (minimum area) none
min 0.35 Uncrossable water course (minimum width) none
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301 Uncrossable water body 3
Application The black bank line emphasizes that the feature
shall not be crossed. Large areas of water may be shown with 70%
colour. Small areas of water and water bodies with narrow places
shall be shown with full colour.
Impact to runabilityCrossing an uncrossable water body is
forbidden.
Corresponding symbols for the control description
No. Picto Name Description
3.1 Lake A large area of water, normally uncrossable
3.2 Pond A large area of water, normally uncrossable
3.4 Watercourse A natural or artificial watercourse with either
moving or standing water
CommentsThe ISOM symbols 301 Lake and 304 Uncrossable river (and
partly 302 pond) have been combined to uncrossablewaterbody. For
fairness reasons, uncrossable waterbodies are forbidden to
cross.
305 Shallow water body
DefinitionA shallow water body that can be crossed.
Old ISOM 2000 text301 Lake. Large areas of water are shown with
dot screen. Small areas of water should be shown with full
colour.black bank line indicates that the feature cannot be
crossed. Colour: blue 50% (60 lines/cm) black.305 Crossable
watercourse. A crossable watercourse, minimum wide. The width of
watercourses over wide shouldbe shown to scale. Colour: blue.
Graphic implementation
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305 Shallow water body 4
No Symbol Dimension [mm] Description Changes from ISOM2000
F305 plane shape with border line Shallow water body (crossable)
new
plane shape with border line Shallow water course (crossable)
new with border line
0.10 Border line of shallow water body new
F315 0.10/1.25/0.25 Border line of seasonal or periodic
waterbody
new
0.7 (area minimum dimension) Shallow water body new
0.35 (minimum total width with borderline)
Shallow water course new with border line
F305.1 0.25 Crossable watercourse none
F305.2 0.14 Small crossable watercourse none
F315.2 0.14/1.25/0.25 Minor / seasona