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Maps
1. What is a Topographic Map?
Do You Have a Road Map? Do you have map data in digital form? How was the Map produced? Who uses the Map and why? Why do you need to update the map? How accurate is the data? 2. What information can I find on a topographic map? 3. What do the different colours represent? 4. Is a topo map similar to a road map? 5. What is "scale"? 6. What scale do I need? 7. What is a "grid"? 8. Can a GPS be used with Topographic Maps? 9. What are "Contour Lines"? 10. How can I determine where I am on a map? 11. How can I navigate with a compass and a map? 12. How are map sheet areas defined? 13. How do I know which map sheet I need? 1. What is a Topographic Map? Answer: A topographic map is a detailed and accurate graphic representation of cultural and natural features on the ground. 2. What information can I find on a topographic map? Answer: A topographic map identifies numerous cultural and natural ground features which can be grouped 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 an NTS 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, here you will find the map scale and scale conversion, the legend, and the year the information on the map was last updated. 3. What do the different colours represent? Answer: 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). 4. Is a topo map similar to a road map? Answer: 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 more features. Topographic maps show both a geographic grid (latitude/longitude) and a UTM grid (kilometres), allowing the user to determine precise positions. 5. What is "scale"? Answer: 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. 6. What scale do I need? Answer: 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 8 000 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 unfamiliar areas. 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 scale maps. 7. What is a "grid"? Answer: A grid is a pattern of parallel lines intersecting at right angles and forming squares or rectangles; it is used to identify precise positions. To help you locate your position accurately on the surface of the earth (or map sheet), topographic maps have two kinds of referencing systems: Geographic: degrees, minutes and seconds (latitude/longitude) Universal Transverse Mercator (UTM) 8. 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.) 9. What are "Contour Lines"? Answer: 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. 10. 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. 11. How can I navigate with a compass and a map? Answer: A compass provides direction through bearings (degrees). However, you must take into account the magnetic declination (found in the right margin of a topographic map) to obtain accurate bearings. The magnetic declination is calculated for the centre of the map and fluctuates annually; the annual change (increasing or decreasing) is shown on the map. For example: 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°. 12. How are map sheet areas defined? Answer: Topographic maps produced by Natural Resources Canada conform to the National Topographic System (NTS) of Canada. 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. The 1/250 000 scale maps are identified by a combination of numbers and letters, from "A" through "P" (e.g. 12A). The 1/250 000 blocks are divided intosixteen segments (1 to 16), forming blocks used for 1/50 000 scale mapping. 13. How do I know which map sheet I need? Answer: 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 from the Centre for Topographic Information, from local map dealers, and at Map Libraries. |