The elevation difference between two adjacent contour lines is called the contour interval (CI) . Usually the contour interval is noted on the map legend. In most topographic maps every 5th contour line is drawn in bold print or wider than other contours. Such lines are called index contour lines.
What is the difference in elevation between contour lines called?
Two contour lines next to one another are separated by a constant difference in elevation (such as 20 ft or 100 ft). This difference between contour lines is called the contour interval .
What is the difference between each contour line called?
The contour interval of a contour map is the difference in elevation between successive contour lines. The gradient of the function is always perpendicular to the contour lines. When the lines are close together the magnitude of the gradient is large: the variation is steep.
What is the area between two contour lines on topographic maps called?
The elevation difference between adjacent contour lines, called the contour interval , is selected to best show the general shape of the terrain. A map of a relatively flat area may have a contour interval of 10 feet or less. Maps in mountainous areas may have contour intervals of 100 feet or more.
What is the distance between two contour lines called?
Untitled Document. The difference in elevation between successive contour lines on a given map is fixed. This vertical distance between any two contour lines in a map is called the contour interval (C.I.) of the map.
What are the 5 Rules of contour lines?
Rule 1 – every point of a contour line has the same elevation. Rule 2 – contour lines separate uphill from downhill. Rule 3 – contour lines do not touch or cross each other except at a cliff. Rule 4 – every 5th contour line is darker in color .
What are the 3 types of contour lines?
Contour lines are of three different kinds. They are the Index lines, Intermediate lines and the Supplementary lines .
What exactly does a contour line show?
Contour line, a line on a map representing an imaginary line on the land surface, all points of which are at the same elevation above a datum plane, usually mean sea level . ... Numbers on the lines give the height in feet. (Sea level is zero.) Lines drawn closely together indicate that a slope is steep.
What is the other name of contour lines?
| contours hachures | isoheights isohypses | isolines |
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What 2 types of lines show elevation differences?
How can a flat map show elevations? Contour lines are used to show elevation on a topographic map. Lines or isolines on a map that connect points with the same elevation.
What are the 5 colors on a map?
- RED -Overprinted on primary and secondary roads to highlight them. ...
- BLACK -Manmade or cultural features.
- BLUE -Water-related features.
- BROWN -Contour lines and elevation numbers.
- GREEN -Vegetation features.
- WHITE -Sparse or no vegetation. ...
- PURPLE -Denotes revisions that have been made to a map using aerial photos.
How do you calculate contour lines?
What Is the Contour Interval Equal To? Divide the difference in elevation between the index lines by the number of contour lines from one index line to the next . In the example above, the distance 200 is divided by the number of lines, 5. The contour interval is equal to 200 / 5 = 40, or 40-unit contour intervals.
What is major and minor contour lines?
The major contour lines at the decades are logarithmic values that are equally spaced , and the minor contour lines are linear values that are logarithmically spaced.
What are the methods of contouring?
- Direct Method of Contouring : High degree of precision is required for large-scale maps with small contour interval. ...
- Indirect Method of Contouring : It is suitable for undulated ground and hilly areas.
