How do you read contour lines on a map?

1. Index lines are the thickest contour lines and are usually labeled with a number at one point along the line.
2. Intermediate lines are the thinner, more common, lines between the index lines.
3. Supplementary lines appear as dotted lines, indicating flatter terrain.

What are the 3 contour lines on a map?

There are 3 kinds of contour lines you’ll see on a map: intermediate, index, and supplementary.

How do you read a contour survey?

Widely spaced contour lines indicate gentle slope. Equally spaced contour lines indicate uniform slope. Closed contour lines with higher elevation towards the centre indicate hills. Closed contour lines with reducing levels towards the centre indicate pond or other depression.

What is the shape of contour lines?

At a stream junction, contour lines form a “M” or “W” shape. This can be interpreted as two “V-shaped contours intersecting.

How do you read contour elevations?

You can figure out the elevation of any point by finding the nearest labeled line, counting the number of lines above or below it, multiplying by the contour interval, and adding or subtracting the result from the nearest marked contour line. The more closely spaced the contour lines, the steeper the slope.

What do contour lines represent on a topographic map?

A topographic map illustrates the topography, or the shape of the land, at the surface of the Earth. The topography is represented by contour lines, which are imaginary lines. Every point on a particular contour line is at the same elevation. These lines are generally relative to mean sea level.

What is the zero contour line?

contour interval. The zero contour line is. sea level. the line that is shaded darker than the rest is the. index contour.

What is an example of a contour line?

In cartography, a contour line (often just called a “contour”) joins points of equal elevation (height) above a given level, such as mean sea level. A contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.