Canada Topographic Maps

Read Topographical Maps - Help

How to Understand Topographic Maps

Reading Topographical Maps

Read Topographical Maps - Help

Do you want to learn how to better understand topographic maps? It is easier than you might think. You do not need to be a cartographer in order to have a basic understanding of how to read and interpret a topo map.

What are Contours?

Contour lines connect a series of points of equal elevation and are used to illustrate topography, or relief, on a map. They show the height of ground above Mean Sea Level (M.S.L.) in either feet (imperial) or metres (metric) and can be drawn at any desired interval. For example, numerous contour lines that are close together indicate steep, hilly or mountainous terrain; when far apart, they represent a gentler slope.

Use contour lines to determine elevations of mountains and flat areas. The closer together the lines are, the steeper the slope. Note that contour numbers are often positioned differently, since they indicate the direction of elevation by always reading (pointing) uphill.

Remember: Rivers form V-shaped contour lines. The closed V end of a contour line points upstream, while the open V always indicates the downstream direction.

What's my Scale?

Know what map scale you're using in order to measure distance. Refer to the scale bar that is usually at the bottom of the map.
1/50 000 scale: 1 cm = km
1/250 000 scale: 1 cm = 2 km

What do the map symbols mean?

A legend explaining the symbols used on a National Topographic System (NTS) map can be found here: Topo Map Symbols.

Some water feature symbols also reveal water flow direction (e.g. direction of flow arrow in rivers, falls symbols pointing downstream).

Do I need a compass?

Using a compass along with a topographic map ensures an exact direction for locating features. An approximate but quick way to orient your map is to align the compass needle (when it is pointing north) with the top of the map. Remember that north is always at the top of an NTS map. Learn more about compass orientation here.

A map is oriented when it is made to correspond to the ground features it represents. If you know your location and can also identify the position of a distant object, you can orient your map by turning it so it corresponds to the ground features.

When allowing for magnetic declination, remember: declination west, magnetic best (add); declination east, magnetic least (subtract).

How do I interpret colors?

At a glance, you can easily identify wooded areas (green) and clearings (white).

Seven colours can be found on a map, each relating to different types of features. Northern areas of Canada are mapped in black and white (monochrome).

  • BLACK shows cultural features such as buildings, railways and power transmission lines. It is also used to show geographical names (toponymy), certain symbols, geographic coordinates, precise elevations, border information and surround information.
  • RED is used for paved roads, highway numbers, interchange exit numbers, certain symbols as well as for names of major transportation routes. A red tint is used to show urban development.
  • ORANGE indicates unpaved roads and unclassified roads and streets.
  • BROWN shows contour lines, contour elevations, spot elevations, sand and eskers.
  • BLUE represents water features, such as lakes, streams, falls, rapids, swamps and marshes. The names of bodies of water and water courses are also shown in blue, as are magnetic declination and UTM (Universal Transverse Mercator) grid information.
  • GREEN indicates wooded areas, orchards and vineyards.
  • GREY is used on the back of the map where the different symbols and a glossary of terms and abbreviations can be found.

Note: PURPLE can be used to show information added over the original map detail (updates).

Do I need Air Photos?

Aerial photographs can enhance the use of your topographic map by providing an aerial view of the ground features shown on the map sheet. They are available for all NTS map sheets and may be obtained from the National Air Photo Library.

Can a GPS be used with Topographic Maps?

Answer: Yes. Location can be obtained very quickly with a Global Positioning System (GPS) receiver. This satellite receiving system displays a position in terms of latitude, longitude, and height, providing you with exact coordinates for map reference. (Some receivers also provide a direct conversion of position to a selected map grid such as UTM.)

How can I determine where I am on a map?

Answer: Identify as many features around you as you can, whether cultural or natural, and locate those same features on your map. Then orient the map so that it corresponds to the ground features that you have identified. If you have a GPS position, you can use the geographic or UTM grid reference system on the map to determine where you are.

 
This page contains data © Department of Natural Resources Canada. All rights reserved.
 
Bookmark and Share