Question: What Are The Numbers On Contour 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.

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

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 2 types of lines show elevation differences?

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 does each contour line on a map show? Each contour line shows a different elevation.

What is 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.

What is meant by contour interval?

A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line. If the numbers associated with specific contour lines are increasing, the elevation of the terrain is also increasing.

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 do numbers on a topographic map mean?

Contour elevation numbers indicate the direction of elevation by always reading (pointing) uphill. What is scale? Maps are made to scale. In each case, the scale represents the ratio of a distance on the map to the actual distance on the ground.

How do you tell if contour lines are going up or down?

Remember contour numbering reads up hill – in other words the top of the number is uphill and the bottom is downhill. Also remember the closer contour lines are together, the steeper the slope.

How do you read contour lines?

Put simply, contour lines mark points of equal elevation on a map. If you trace the length of a line with your finger, each point you touch is the same height above sea level. If you were to walk the path of a contour line in real life, you would remain at the same elevation the whole hike, never traveling up or down.

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 does it mean when contour lines are far apart?

Contour lines that are relatively close together indicate a slope that is fairly steep. Contour lines that are further apart indicates a slope that is relatively flat.