What Are The Factors On Which Contour Lines Are Based?

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 3 types of contour lines?

There are 3 kinds of contour lines you’ll see on a map: intermediate, index, and supplementary.Index lines are the thickest contour lines and are usually labeled with a number at one point along the line. … Intermediate lines are the thinner, more common, lines between the index lines.More items…

What are the importance of contour lines?

The purpose of contour lines is to represent the tridimensional shape of the terrestrial surface on a bidimensional map. Contour lines are the intersection of an horizontal plane parallel to the reference level and the topographical surface to describe. Consequently: Contour lines are always closed curves.

Why are contour lines useful?

These contour lines are an important way of showing the rise and fall of the land on a map. Contour lines show all the places that are the same height above sea level. They also tell us about the slope of the land. On a steep slope, the lines are close together.

What is a contour line used for?

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.

What does contour line indicate?

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. map: contour lines. The diagram illustrates how contour lines show relief by joining points of equal elevation.

What are the basic features of contour lines?

Other characteristics of contour lines are: – Uniform slopes have uniformly spaced lines. – Along plane surfaces, contour lines are straight and parallel. – Contour lines are perpendicular to lines of steepest slopes. – For summits or depressions, contour lines most close upon themselves.

Why can’t contour lines cross?

Contour lines can never cross one another. Each line represents a separate elevation, and you can’t have two different elevations at the same point. … Moving from one contour line to another always indicates a change in elevation.

What is the space between contour lines called?

The space between the contour lines is called the contour interval and represents a specific (set) distance. If the contour interval is 50 feet, the vertical space between the two contour lines is 50 feet.

What is the shape of contour lines?

Contour lines never split. Instead, contours form closed loops. These loops follow the shape of the land, and may extend past the edge of the map. Closely spaced contours indicate a steep slope, whereas contours that are spaced far apart indicate a gentle slope or almost flat surface.