Section 2 EO M390.02 – IDENTIFY MARGINAL INFORMATION AND CONVENTIONAL SIGNS

The margins provide information important to the understanding and use of the map. Before using an unfamiliar map, it is important to have a good look at the information contained in its margins. The layout and contents of the marginal information is normally in the same place for all topographical maps, but will always be found within the margins. This information includes:

Have cadets point out each piece of marginal information on a topographical map as it is being described.

Name of Map Sheet. For ease of reference the name of the map is usually a major community or district located on the map (found at the bottom centre of the margin, as well as in the top or bottom right corner).

Number of the Map and Index of Adjoining Maps. A diagram showing the position of the map sheet in relation to adjoining sheets is shown near the lower right-hand margin. The diagram shows the sheet numbers of the adjoining sheets and accentuates the sheet in hand.

Date of Map Data. Helps to indicate the amount of change that may have occurred since the map was printed (found in the bottom left corner).

Map Scale. Indicates the scale of the map, most commonly 1 : 25 000 or 1 : 50 000. Scale is used to represent distances on the map in direct relation to the ground. On a 1 : 50 000 scale map 1 cm on the map represents 50 000 cm (500 m) on the ground.

Scale Bars. Used as a measuring aid for determining distance on the map (found bottom centre below the map name). The left end of the scale bars is divided into tenths for measuring distances more accurately.

Contour Interval. Indicates the vertical (height) interval between contour lines and is given in metres or feet. The contour interval is found in the bottom margin.

Legend of Conventional Signs. A table showing the conventional signs used on the sheet in their correct colours with their descriptions is shown in the bottom or side margin, plus in a more complete list on the back of the map.

Military Index Number. The index is found in the top right corner of the map sheet and used for ordering additional maps.

Declination Diagram. Contains the information for the map on how true, grid, and magnetic north relate to each other. This information is given in the form of a diagram with explanatory notes. The diagram is in the right side margin.

Universal Transverse Mercator Grid System (UTM). The UTM grid system divides the earth’s surface into zones, each covering six degrees of longitude and eight degrees of latitude. The 60 longitude bands are numbered and the 20 latitude bands are lettered. Each grid zone is one rectangle of the grid pattern, established by the bands and designated by the figures of the longitude band followed by the letter of latitude band.

Canadian Forces, Maps, Field Sketching, Compasses and the Global Positioning System, Department of National Defence (p. 11)

Figure 1  Marginal Information

A number of symbols are used to indicate an object or item of detail that cannot be shown either by outline or by a line symbol. Most have been established through long usage and standardization agreements. The meaning of most symbols is obvious. However, if there is doubt consult the table of conventional symbols located on every map. Located on the back of most maps you will find many additional conventional signs.

Map-reading not only involves the ability to interpret the symbols shown on the map and to understand the information given in pictorial or written form, but it also involves a true understanding of the ground portrayed and an appreciation of the reliability and value of the particular map being used.

Where the symbol may have more than one meaning, the sign or symbol will be accompanied by a descriptive word (eg, tank or tower).

The use of colour aids in distinguishing details.

Red. Used to identify paved roads and highway numbers. Red is also used to shade in areas of urban development.

Director Cadets 3, 2008, Ottawa, ON: Department of National Defence

Figure 3  Red Conventional Signs

Orange. Used to represent unpaved roads.

Director Cadets 3, 2008, Ottawa, ON: Department of National Defence

Figure 4  Orange Conventional Signs

Black. Used for cultural features, toponyms (place names), some symbols and precise elevations.

Director Cadets 3, 2008, Ottawa, ON: Department of National Defence

Figure 5  Black Conventional Signs

Brown. Used for contour lines, contour elevations, spot elevations, sand, cliffs, and other geographical features.

Director Cadets 3, 2008, Ottawa, ON: Department of National Defence

Figure 6  Brown Conventional Signs

Blue. Used for water or permanent ice features (eg, rivers, lakes, swamps and ice fields), names of water features and the grid lines.

Director Cadets 3, 2008, Ottawa, ON: Department of National Defence

Figure 7  Blue Conventional Signs

Green. Used for vegetation features such as woods, orchards and vineyards.

Director Cadets 3, 2008, Ottawa, ON: Department of National Defence

Figure 8  Green Conventional Signs

White. Used to represent open fields.

Grey. Used for the legend of conventional signs on the back of the map.

Purple. Used for updates that are made over top of the original map information.

The objective of this activity is to have the cadet identify conventional signs through the creation of a topographical map of Mapville.

The cadets should be seated in front of a flip chart/whiteboard with topographical maps available.

1.Draw a large outline of a topographical map on the flip chart/whiteboard at the front of the room.

2.Have the cadets approach the front, one at a time, and draw a conventional sign on the developing map of Mapville.

3.Have the cadets explain what the sign is for and why they chose to put it where they did. No sign may be used more than once.

4.Have cadets continue to add conventional signs until the time is used up.

Based upon the number of cadets in the class, each cadet may have to add several different conventional signs to the map.

N/A.

The cadets’ participation in the in-class activity will serve as confirmation of this TP.

The cadets’ participation in the creation of the topographical map of Mapville will serve as confirmation of this lesson.