Topographic maps, also called contour maps, topo maps or topo quads (for quadrangles), are maps that show topography, or land contours, by means of contour lines. Contour lines are curves that connect contiguous points of the same altitude (isohypse). In other words, every point on the marked line of 100 m elevation is 100 m above mean sea level.
Early topographic maps illustrated topography, in the original sense of the word, with the depiction of the natural, man-made and historical aspects of the landscape.[1] In the eighteenth and nineteenth centuries, military authorities introduced topographic surveys to record features that are important to an army, such as the physical relief, water sources and tree cover, which were not usually shown on the cadastral maps maintained for public administration.[2] In Europe and Canada, the term "topographic map" still retains the meaning of being a detailed general-purpose map.[3] [4] [5]
There are several rules to note when viewing topographic maps:
* The rule of Vs: sharp-pointed vees usually are in stream valleys, with the drainage channel passing through the point of the vee, with the vee pointing upstream. This is a consequence of erosion.
* The rule of Os: closed loops are normally uphill on the inside and downhill on the outside, and the innermost loop is the highest area. If a loop instead represents a depression, some maps note this by short lines radiating from the inside of the loop, called "hachures".
* Spacing of contours: close contours indicate a steep slope; distant contours a shallow slope. Two or more contour lines merging indicates a cliff.
Of course, to determine differences in elevation between two points, the contour interval, or distance in altitude between two adjacent contour lines, must be known, and this is given at the bottom of the map. In most cases, contour intervals are consistent throughout a map. Sometimes dashed contour lines are present; these represent half the noted contour interval.
These maps usually show not only the contours, but also any significant streams or other bodies of water, forest cover, built-up areas or individual buildings (depending on scale), and other features and points of interest.
Today, topographic maps are prepared using photogrammetry to interpret aerial photography. Older topographic maps were prepared using traditional surveying instruments.
2006-11-30 13:16:30
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answer #1
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answered by Anonymous
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Generally, it's a map that appears three-dimensional. Like if you have to build one, you should show elevations.
Build mountains, carve out rivers, etc.
2006-11-30 21:17:17
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answer #2
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answered by Anonymous
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yes please!.....lol think of the first part of the word "top" it's a map displaying the physical features of an area...such as mountain ranges, rivers lakes, etc (that's the simplest way I can put it)
check out this site:
2006-11-30 21:16:09
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answer #3
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answered by curious cat 3
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Here is a web site to try them out.. they are cool... you can type in your address and it shows you just where you are..
2006-11-30 21:24:57
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answer #5
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answered by sno_ball_2002 2
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