By
Judy Boyce
Figure 1-1. This image was obtained from: http://www.topo.com/trails/index.html
Introduction
Contouring Rules
Images
ReferencesBy
Judy Boyce
Figure 1-1. This image was obtained from: http://www.topo.com/trails/index.html
Introduction
Contouring Rules
Images
References
Topography is the configuration of the land surface and is illustrated on topographic maps by contour lines. These maps show the elevation of the land and localities through three basic elements: contour, township, and ranges lines. Contours are brown lines on the map representative of elevations and the lines connect points of equal elevation. Locations of specific places are found with township and range lines. The range lines run north-south and show the east and west boundaries of a township. Township lines run east-west and show the north and south boundaries of a township.
Contouring Rules 2. Closed contours, as seen on a map sheet as an ellipse or circle, will represent hills.
3. Closed contours shown with hachures, short lines pointing downslope, represent a closed drepression or in other words a basin with no outlet.
4. Steep slopes on the surface are shown by closely spaced contours, whereas gentle slopes are noted if the contour lines are widely spaced.
References
This site was created by Judy Boyce, and please send me some mail!
There are important rules regarding contour lines given below that will help you to read or interpret a map.
1. When contour lines cross streams, the lines bend upstream. The contour line will resemble a "U" or "V" which points upstream, and indicates the stream is flowing in the opposite way in which the letter points. This is illustrated on Figure 1-1 in the lower left portion of the image (brown contour line "V" across the blue line representing a stream), where the stream is flowing off to the left of the page.
Topographic maps have changed format capabilities over the years. They are no longer only in static, two-dimensional images. This orthographic projection or digital elevation map, shown below in Figure 1-2, displays a digital representation of a topographic map. 
Figure 1-2. This image of Yosemite Valley was taken from the examples for sale at: www.3DMaps.com
Figure 1-3. This image of Mt. Whitney, in California, was taken from the examples for sale at: www.3DMaps.com
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