Topographic Map Basics
Topographic maps are used for a wide variety of applications, from
camping, canoeing, hunting and fishing, to urban planning, resource
development and surveying.
Why? Because they accurately represent, to scale, the earth's features
on a two dimensional surface; that is to say, every feature shown on a
map is where it actually is on the earth's surface.
Topographic maps offer detailed information on any particular area. They
are an excellent planning tool and guide and at the same time, help to
make your outdoor adventures enjoyable and safe.
To help you understand what topographic maps are and how to use them, we
have answered some of the most commonly asked questions. You will also
find tips on how to get the most out of a topographic map, an
explanation of topographic terms and the symbols used to depict popular
WHAT IS A TOPOGRAPHIC MAP?
A topographic map is a detailed and accurate graphic representation of
cultural and natural features on the ground.
WHAT TYPE OF INFORMATION CAN I EXPECT TO FIND
ON A TOPOGRAPHIC MAP?
A topographic map identifies numerous cultural and natural ground
features, which can be divided into the following categories: culture:
roads, buildings, urban development, boundaries, railways, power
transmission lines; water:lakes, rivers, streams, swamps, rapids;
relief:mountains, valleys, slopes, depressions; vegetation:wooded and
cleared areas, vineyards and orchards; toponymy:place names, water
feature names, highway names. Refer to the legend on the back of a
national topographic map for a complete listing of all features and
their corresponding symbols. Information along the map borders and on
the back of the map provides valuable details to help you understand and
use a topographic map; for example, the map scale and scale conversion,
the legend and the currency of the map information.
WHAT DO THE DIFFERENT COLOURS REPRESENT?
Seven colours can be found on a map, each relating to different types of
- 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 water bodies and water
courses are also shown in blue, as are magnetic declination and UTM
(Universal Transverse Mercator) grid information.
- Green is used for wooded areas, orchards and vineyards.
- Grey is used on the back of the map to indicate the different
symbols and a glossary of terms and abbreviations.
- Note: Purple can be used to show added information (update) over
the original map detail
COLOUR BLIND FRIENDLY COLOURS
Map colours need to change to make it easier for those with partial
red-green colour blindness to access maps more easily. A good source of
modern map colour-blind friendly colours can be found at :
WHAT IS THE DIFFERENCE BETWEEN A TOPOGRAPHIC MAP AND A
They both show roads, water features, cities and provincial parks, but
that" s where the similarity ends.
Topographic maps also show relief, forest cover, marsh, pipelines,
transmission lines, buildings, various types of boundary lines, and many
Topographic maps also show both a geographic grid (latitude/longitude)
and a UTM grid (kilometres), allowing the user to determine precise
WHAT IS SCALE?
Scale refers to the relationship between distance on a map and the
corresponding distance on the ground. At a scale of 1:50 000 for
example, one unit of measure on the map represents 50 000 equivalent
units of measure on the ground. Medium-scale maps (e.g. 1:50 000) cover
smaller areas in greater detail, whereas smaller-scale maps (e.g. 1:250
000) cover large areas in less detail.
WHAT SCALE DO I NEED?
A 1:250 000 scale map gives a general overview of a large area and is a
perfect guide for pre-trip planning. It covers an area of approximately
18,000 square kilometres or 160 km x 110 km, and depicts numerous
aspects of the terrain.
Refer to the map detail and natural landmarks to guide yourself through
A 1:50 000 scale map is highly detailed and covers an area of
approximately 1 100 square kilometres or 40 km x 28 km. It shows
vegetation, cultural information, approved names (toponymy), land
elevation and water bodies, in great detail.
Note: A 1:250 000 scale map covers the same area as sixteen 1:50 000
WHAT IS A GRID?
A grid is a pattern of parallel lines intersecting at right angles and
forming squares or rectangles, and is used to identify precise
positions. For locating your position accurately on the surface of the
earth (or map sheet), topographic maps have two kinds of referencing
(1 ) geographic: degrees, minutes and seconds [latitude/longitude);
(2) Universal Transverse Mercator (UTM).
CAN GPS BE USED WITH TOPOGRAPHIC MAPS?
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.)
WHAT ARE CONTOUR LINES?
Contour lines connect a series of points of equal elevation and are used
to illustrate relief on a map. For example, numerous contour lines that
are close to one another show hilly or mountainous terrain; when far
apart, they indicate a gentler slope.
Profile and Plan View of Contour Lines (will mount cleaner image)
HOW CAN I DETERMINE WHERE I AM ON A MAP?
Identify as many features around you as you can, cultural or natural,
and locate those same features on your map. Then position the map so
that it corresponds with 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.
HOW CAN I NAVIGATE WITH A COMPASS?
A compass provides direction through bearings (degrees); however, you
must consider the magnetic declination (found in the right margin of a
topographic map) to obtain accurate bearings. The magnetic declination
is calculated for the center of the map and fluctuates annually; the
annual change (increasing or decreasing) is shown on the map.
If the declination in an area is 10° west, add 10° to the setting. If
the dial setting was 30°, it should now read 40°.If the declination is
10° east, subtract 10°. so that the 30 setting will be changed to 20°.
Be sure to check the annual rate of declination change before you set
your final compass bearing.
HOW ARE MAP SHEETS DEFINED?
Topographic maps, conform to the National Topographic System (NTS) .
They are available in two standard scales, 1:50 000 and 1:250 000. The
area covered by a given map sheet is determined by its latitude and
longitude. Because of the standard NTS numbering system, knowing the map
number allows you to quickly identify adjacent maps.
The 1:250 000 scale maps are identified by a combination of numbers and
letters, A through P (e.g. 12A). The 1:250 000 blocks are divided into
sixteen segments (1 to 16), forming blocks used for 1:50 000 scale
HOW DO I KNOW WHICH MAP SHEET COVERS MY AREA OF
To order a topographic map, you must know either the location
(latitude/longitude)or the name of your area of interest (e.g. major
cities, large bodies of water).
You may also order by map sheet number. Index maps are available.
TOPOGRAPHIC TERMS OFTEN USED
bearing: the horizontal angle at a given point, measured
clockwise from magnetic north or true north to a second point.
classified roads:roads for which surface type, width and
use are identified.
contour lines:lines on the map connecting points of equal
elevation above mean sea level; using contour lines, relief features can
be profiled into a three-dimensional perspective.
elevation:vertical distance from a datum (usually mean sea level)
to a point or object on the earth's surface.
horizontal datum:the positional reference or basis for the
geographic location of features on a map.
magnetic declination:the angles between the magnetic north and
true north expressed in degrees and minutes, east or west from true
magnetic north: direction to which a compass needle points.
mean sea level: the average height of the surface of the sea for
all stages of tide, used as a reference surface from which elevations
projection:geometric representation of the curved surface of the
earth on a flat sheet of paper.
relief:the physical configuration of the earth's surface,
depicted on a topographic map by contour lines and spot heights.
spot elevation:a point on a map where height above mean sea level
is noted, usually by a dot and elevation value; it is shown wherever
practical (road intersections, summits, lakes, large flat areas and
surveying:the operation of taking observations or measurements to
determine geographic location.
topography:surface features both natural and cultural,
collectively depicted on topographic maps.
true north: direction of the northern rotational axis of the
earth the North Pole.
unclassified roads:roads for which the surface is unidentified.
UTM (Universal Transverse Mercator) grid: a square grid system
based on the transverse Mercator projection, depicted on maps. It can be
used to locate the position of features on the map accurately by
distance or direction.
vertical datum:the reference or basis for elevations (usually
mean sea level).
Know what map scale you're using in order to measure distance. Refer to
the scale bar (at the bottom of the map).
1:50 000 scale:
1 cm = .5 km
1:250 000 scale:
1 cm = 2.5 km
A legend explaining the symbols used can be found on the back of the map
for easy reference.
Remember that north is always at the top of the map.
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.
A map is oriented when it is made to correspond with 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 with the ground features.
When allowing for magnetic declination, remember: declination in the
west, magnetic best (add); declination east, magnetic least (subtract).
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.
Some water feature symbols also reveal water flow direction (e.g.
direction of flow arrow in rivers, falls symbols pointing downstream).
At a glance, you can easily identify wooded areas (green) and clearings
(white). Aerial photographs can be used to enhance the use of your
topographic map, by providing an aerial view of the ground features
shown on your map sheet.