We all know how well google maps works when we are close to civilization and have good cell reception. In fact, for many of us, this has become a critical tool that affects our everyday lives.
Now imagine you are out enjoying what nature has to offer on a wild canoe adventure. Unfortunately (Or fortunately), things are a bit different once you leave the comfort of civilization behind. No or minimal cell service means that Google maps with no longer be any help. In this situation, you must be prepared to go back to a simpler time. Knowing how to use a physical topographical map can be an essential skill that will be helpful to know when travelling in the backwoods.
What is a topographical map?
A topographical map is a map that represents a detailed and accurate picture of the features of the Earth as well as any human-made structures that might be present. One of its distinguishing features is contour lines signify elevation. This is an essential feature that allows a two-dimensional map to represent the three-dimensional world. Topographical maps are designed to be detailed enough to be used for navigation and understanding terrain features. Topographical maps are often referred to as topo maps for short.
Understanding contour lines
The area between contour lines on the map represents an area with a specific elevation. Contour lines on the map never intersect. The closer the lines are together, the steeper the elevation. Contour lines are accurate to the lay of the land and all of the topographical features that are present.
This graphic represents what two hills located beside each other would look like on a topo map.
Putting this information together, we can tell that the hill on the right starts at 800 meters and has a summit at 1500 meters, while the slope on the left begins at 750 meters and continues until 1450 meters.
Index lines
You will also notice that every 5th line, there is a slightly thicker/darker line with numbers. These are called index lines, and the numbers represent the exact elevation at that line.
Contour interval
The distance between contour lines is known as the contour interval. The contour interval is always the same throughout the map. Typical topographical maps have a contour interval of between 40 or 80 feet between lines.
Depressions
Topo maps can also represent negative altitude or depressions. This feature describes physical features like valleys and holes in the terrain. Depressions use small lines pointing inward to show this negative altitude.
Map scales
Topographical maps always include a scale to help to reader get a realistic sense of how far the distances portrayed in the map are in the real world.
For example, a typical scale is 1:50000. For a map with this scale, 2cm on the map represents 1km in the physical world.
Maps are placed in one of two different classifications, either “Large scale” or “Small scale.” These terms are slightly counter-intuitive and can be easily misused.
A Large-scale map is actually a map with a smaller scale, meaning that the detail of the map is better than that of a small-scale map. A 1:50000 is a reasonably large-scale map.
A Small-scale map is a map with a larger scale, meaning that the map covers less real-world detail. In contrast to a 1:50000 size map, a typical small-scale map might be more like 1:250000.
Map legends
Maps will also always include a legend. Legends exist to show the reader what different types of symbols and features on the map represent. Legends are typically located at the bottom of the map. Legends typically include information like a compass to show which orientation is facing as well as the magnetic declination, used to set a compass. Unless otherwise stated, the top of a topographical map is almost certainly facing the North. The map scale will also be located on the legend.
Colour coordination
Colours are widely used on topographical maps to express different types of terrain. When you see green on a map, it usually represents an area with trees or forest, whereas an area without colour might represent a flat plain. These details will also be noted in the map’s legend for reference.
Advanced section
With the above information, you will know most of what you need to recognize a topographical map and get an idea of the lay of the land. However, in the following section, we will discuss some more advanced topics to help you gain a masters understanding of how to navigate in the backwoods using a topo map.
Topographical maps are divided into sections using standard units of measuring coordinates on Earth.
Coordinates are expressed using the following terms:
Latitude
Lines of latitude are imaginary lines that circle the globe parallel to Earth’s Equator and are measured in degrees. In total, there are 180 degrees of latitude. The Equator is 0, the north pole is 90 North, and the south pole is 90 south.
Longitude
longitude is an imaginary line that circles the globe passing from north to south of the globe.
Longitude starts at a line prime meridian 0 degrees and stretches 180 around the globe.
Together latitude and longitude form a grid that allows us to pinpoint our position on a map accurately.
Minutes
Minutes are a larger unit of degrees. Just like time, there are 60 degrees in one minute.
Topographical maps come in various minute scales showing how many latitudes and longitudes are visible on that map. This number determines what area of the Earth that, that map represents. For example, a 1:25000 scale map is referred to as a 7.5-minute map because it covers 7.5 minutes of latitude and longitude.
We really wished they hadn’t decided to use words that already have another meaning when they started a system for understanding maps, but hey, we don’t make the rules.
UTM
UTM stands for Universal Transverse Mercator and was first created by the US army during the 1940s. This is an exact coordinate system that can be used to calculate your exact position on the Earth. In UTM, the Earth is divided into 60 unique zones, each stretching from pole to pole and starting at the international dateline. One UTM zones covers 6 degrees of latitude.
UTM Then divides the Earth into a 1-meter by 1-meter grid.
A topographical map has grid lines that are spaced 1km (1000m) apart. The vertical grid lines determine the East-West position, and the horizontal grid lines define the North-South position. The vertical position is referred to as an “Easting,” and the horizontal position is the “Northing” position. The further east you go, the higher the easting value, and the further north you go from, the higher the northing value is.
Using the zone position, Northing position and the Easting position, you can accurately determine your position on Earth down to the square meter.
Together a UTM coordinate can be expressed with the acronym Z-E-N. This stands for Zone, Easting, Northing and is the correct way to write or say a UTM coordinate. A typical UTM Coordinate would look like 8 4587346 N 487349 E.
In this example, the position referred to is in zone 8 with a Northing position of 4587346 N and an Easting position of 487349 E.
Quadrangles
The Earth on a topographical map is separated into different sections called quadrangles. One topographical map typically covers one quadrangle.
It is crucial to get the proper topographical maps that cover the area you will be In. Sometimes you might have to get multiple different maps because the boundary of one map prevents you from viewing the area that you are travelling to. If the area that you are planning to travel through is within multiple quadrangles, you will need a different map for each one to navigate properly.
Be Prepared
It’s always a good idea to study a map of an area you are planning on canoeing before heading out on your adventure, and make sure to bring it with you on your trip. You don’t always have to look at the map if you know the area, but it will be necessary if you lose your way in the backcountry.
Where to get maps?
Below are a few good places we recommend checking out when looking for topographical maps for your trip.
Canada wide
Canada map sales is probably the most well-known place to get topographical maps in Canada.
You can either order online or browse in person at their location at 1007 Century St, in Winnipeg, MB.
Backroad map books (BRMB) has a lot of tools on their website for adventurers like yourself. This includes a marketplace for Topographical maps. Here you can find both standard topo maps in a variety of scales as well as digital maps for pre-loading into GPS devices.
Although not a place to buy physical topo maps, this is an official resource from the government of Canada that includes lots of details and information about the land. We recommend this as a planning tool before you begin on your journey.
Manitoba
This website has all kinds of map products, including topographical maps
Conclusion
The use of a topographic map is a skill that everyone can benefit from. If you are heading out into the wilderness, a topographic map can help you to find the best routes and avoid any treacherous terrain. When you are planning a trip, the map can give you a good sense of what you might expect. By knowing what terrain you may run into, you can prepare for your trip. If you lose your way, a topographic map can help you to figure out where you are and how to get back on track. This is especially useful if you are in an area where you have never been before. Hopefully, this article has given you a good understanding of topographic maps and why you should be using them.