i Som Revision First Draft 201305

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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.

05/2013 ISOM revision, first draft 1/133

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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.


2 General Requirements 3

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.



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



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.



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.



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



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.


3 Map Specification 9

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



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)



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).


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.


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).


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.


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.


No Symbol Dimension Description Changes (from ISOM2000)

F102 0.25mm Index contour line none


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


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


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)



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


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.


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).


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.



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


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



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


107 Earth wall 10

107 Earth wall

DefinitionDistinct earth wall.

Old ISOM 2000 textDistinct earth wall. Minimum height is 1 m.



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.



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.


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.


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


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.


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.


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.



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.



1.7 Erosion gully An erosion gully or trench, normally dry.


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.


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.



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.



1.8 Small erosion gully A small erosion gully or trench, normally dry.


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?


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).



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).



1.10 Knoll A small obvious mound. Used with symbol 8.6 to indicate a rocky knoll.


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).



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.



1.10 Knoll A small obvious mound. Used with symbol 8.6 to indicate a rocky knoll.


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.



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



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


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)



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.



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


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.


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



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


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.


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



1.15 Brokenground

Clearly disturbed ground with features too small or too numerous to be mapped individually; including animalearths.


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.


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.



118 Special prominent land form feature 21


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.


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.


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.


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.


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.



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.


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.



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.


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.



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.



F204 0.16/0.7/0.8 Rocky pit

F204 0.16/0.7/0.8 Cave


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.



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.



F206 0.4/( 0.5) Single boulder none


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.



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.



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.



2.4 Boulder A prominent free-standing block of rock or stone.


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.



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.



2.6 Boulder cluster A small distinct group of boulders so closely clustered together that they cannot be individually mapped.


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.


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



2.5 Boulder field


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.


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.



2.5 Boulder field


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).



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.


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.


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.



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.



2.8 Bare rock A runnable area of rock with no earth or vegetation cover.


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.



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.


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.


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.



2.7 Stony ground An area covered with many small stones or rocks.


214 Stony ground: difficult to run 15

214 Stony ground: difficult to run



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.


Graphical minimum dimensions1mm x 1mm, corresponding to 15 m by 15 m on the ground.

Impact to runabilityDifficult to run.





215 Stony ground: very difficult to run 16

215 Stony ground: very difficult to run



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.


Graphical minimum dimensions0.7mm x 0.7mm, corresponding to 10 m by 10 m on the ground.

Impact to runabilityVery difficult to run.





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.


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.



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


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.



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.



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

i Som Revision First Draft 201305

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