The intricate details on a topographic map can be befuddling, even frustrating, if you are learning while out in the backcountry. But once you get familiar with the markings and symbols, reading maps will become a friendly aid, rather than a dreaded assignment.
Topographic Maps Grid System
Lines of latitude run parallel to the equator (east and west), and lines of longitude run perpendicular to the equator (north and south). These lines form a pattern of squares across the surface of the earth like a checker board.
One square, formed by lines of longitude and latitude, measures 90 degrees x 90 degrees. Degrees are further subdivided into minutes and seconds.
? 1 degree = 60 minutes
? 1 minute = 60 seconds
The important thing to understand, when we look for a topographic map for our hiking adventures, is that it will be located within this larger context of degrees, minutes, and seconds. Fortunately, it will also, usually, be identified with a place name.
An alternative method of notation within the Geographic Coordinate System is the decimal degree system. In the decimal degree system, minutes and seconds are replaced by a percentage of a degree, expressed as a decimal up to four places long. It is often used for Geographic Information Systems (GIS) applications,
Topographic Maps Scale Explained
A topographic map lists its scale in the margin or legend. The scale is the relationship between distances on a map and the corresponding distance on the ground. For example, a map with a scale of 1:50,000 means that 1 unit of measurement on the map equals 50,000 equivalent units on the ground.
Units can be in inches, feet, centimeters, or meters, depending on what scale map you are looking at and what measuring system the country uses. Most USGS maps are 1:24,000, also known as 7 ? minute maps. On this map, 1 inch = 24,000 inches on the ground. In Canada, most hiking maps are 1:50,000 scale, where 1 cm = 50,000 cm on the ground.
A small scale map (ex. 1:100,000) covers a large area; it shows less detail with fewer features. A large scale map (ex. 1:10,000) covers a small area; it shows great detail and small features. A 1:2,500, large scale map would show individual houses and street lights.
Topographic Maps Symbols and Colors
The symbols and colors used on Topographic maps are fairly straight forward:
? Black - man-made, "cultural," features such as roads, buildings, etc. It is also used to show geographical names (toponymy), certain symbols, geographic coordinates, precise elevations, border information and surround information.
? Blue ?water, lakes, rivers, streams, etc. 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.
? Brown - contour lines, contour elevations, spot elevations, sand.
? Green - areas with substantial vegetation like a forest, orchard, or vineyard
? Grey - used on the back of the map where the different symbols and a glossary of terms and abbreviations can be found.
? Orange - unpaved roads and unclassified roads and streets.
? Purple - features added to the map since the original survey. These features are based on aerial photographs but have not been checked on land.
? Red - major highways; boundaries of public land areas. A red tint is used to show an urban development.
? White - areas with little or no vegetation; also used to depict permanent snowfields and glaciers
Topographic Maps Glossary
? Bearing - Angular direction expressed in degrees.
? Contour Lines ? A line on a map joining points of equal elevation. These lines are used to illustrate relief on a map.
? Distortion - The difference in shape between the actual curved surface of the earth and the flat representation of a topographic map.
? Grid - A system of horizontal and vertical lines that provide coordinates for locating points on an image.
? Magnetic Declination - The angle between magnetic north and true north, expressed in degrees and minutes, east or west from true north.
? Magnetic North - The direction your compass needle points.
? Projection - A method by which the curved shape of the earth is represented on a flat surface, overcoming distortion.
? Relief ? The variations in elevation of the earth's surface.
? Scale ? The relationship between distance on a map and the corresponding distance on the ground. For example, a map with a scale of 1:50,000 means that 1 unit of measurement on the map equals 50,000 equivalent units on the ground.
? Topographic Map ? An illustration of the earth's different elevation levels by means of contour lines. They present both natural and manmade features.
? True North - Direction of the northern rotational axis of the earth ? the North Pole.
Outdoors Adventurer, Writer and Webmaster Will Robertson lives with his family in Little Rock, Arkansas.
Explore the best hiking vacations and gear on the planet at: http://www.hiking-vacations-and-gear.com
executive chauffeured services Bradford .. Madison to Airport carThe owner can attempt small inflatable boat repair if factory-gluing... Read More
Okay, it wasn't quite a sleeping bag. However, it was... Read More
A camping gear checklist is an important tool to help... Read More
Don't all of us love to have the money to... Read More
How to get the most out of your trekking poles... Read More
Contrary to what many think, ultralight backpacking is not just... Read More
Ask me which Pacific island has the most to offer... Read More
Having traveled from state to state and every city in... Read More
If you love the thrill and adventure of kayak travel,... Read More
Last week in Australia, one man's day at beach could... Read More
Ultralight backpackers want to give up weight, not comfort. Sleeping... Read More
There is something about a town tucked between the mountains... Read More
An African honeymoon safari is the perfect way to celebrate... Read More
River rafting is a major attraction in California. The most... Read More
We've all heard about whalewatching from boats or shore, and... Read More
Are you sick and tired of not knowing what to... Read More
When you think of "adventure travel," what crosses your mind?... Read More
Croatia has quickly become Europe's hottest destination, and for good... Read More
Going on a gorilla safari must rank as one of... Read More
Stay warm or die. That's what it comes down to... Read More
The beautiful Salmon River stretches through over 400 miles of... Read More
When you're on the Internet looking for discount camping gear,... Read More
We think that Cape Town has some of the best... Read More
A South Africa safari is the ideal wildlife trip to... Read More
Sun, Sand and Surf ? an apt description for Goa?... Read More
O'Hare Chicago prom limo ..Touted as one of the world's fifty destinations of a... Read More
Yuma, Arizona. In the winter, it's the best town in... Read More
A saddle is a static object, but your horse is... Read More
Hello Again,Today we will be talking about meal planning. Meals... Read More
A Hawaii volcano tour can be a most memorable experience,... Read More
The great state of Washington offers some of the best... Read More
Hawaii snorkeling is a fun activity available to almost any... Read More
Solo backpacking means peace and quiet. No one to talk... Read More
I stood at the observation point on the balcony at... Read More
Today Bookpleasures and Sketchandtravel are pleased to have as our... Read More
If you're looking to spot a whale, the first few... Read More
Do you like to take one day hiking trips? Do... Read More
If anyplace on earth is a natural paradise, Plitvice Lakes... Read More
It seems like the most adventurous thing in the world.... Read More
Have you taken up hiking as a new form of... Read More
If you're a birder, you want to keep a list... Read More
Every year around 40 million visitors come to Florida for... Read More
If you you find yourself saying "Hey, that's a good... Read More
Drive along one of South Africa's scenic strips and you... Read More
How many of you take the time to just relax... Read More
Everyone has a travel dream. For many it is hitting... Read More
Stay warm or die. That's what it comes down to... Read More
When you search online for a camping gear outlet you... Read More
A canoe trip is a great way to appreciate Nature!A... Read More
White Water on the Comal river in Central Texas is... Read More
Outdoors |