Question: What Are Contour Lines And What Do They Show?

How do you read contour lines on a site plan?

Closely spaced contour lines indicate steep slope.

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..

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 is the difference between two contour lines?

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 do contour lines mean?

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 is the elevation difference between contour lines?

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 contour lines on a site plan?

Contour lines are lines drawn to join points of equal elevation . On a plan or map, they represent the contours you found and marked in the field (see Section 8.3). Contour lines show the three-dimensional ground topography of a site on a two-dimensional map or plan.

How do you read a plan?

The Basics: How to Read Architectural PlansBe organized and diligent when reading plans. Start in upper left corner and work way across page so as not to miss any details.Read the plan cover sheet. … There are often reference points that are used between professionals and sets of drawings. … Review the plan index which provides a list of all plan sheets.

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.

What do contour lines on an OS map tell you?

Contours tell you whether the ground is flat, hilly, undulating, or steep. … Contours are shown on Ordnance Survey maps as thin orange or brown lines with numbers on them that show you the height above sea level of any point on the line. The contour lines join points of equal height together.

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…

How do we use contour lines?

Contour lines are lines drawn on a map connecting points of equal elevation, meaning if you physically followed a contour line, elevation would remain constant. Contour lines show elevation and the shape of the terrain. They’re useful because they illustrate the shape of the land surface — its topography — on the map.