Which Instrument Is Used For Establishing Grade Contour?

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 are the 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.

Which method is suitable for contouring of hilly areas?

Tacheometric methodSolution: Tacheometric method: This is practically suitable for hilly areas and at places where plane tabling is impractical. This discussion on Which of the following methods of contouring is most suitable for a hilly terrain?

How do you contour a survey?

In this method, the contours to be located are directly traced out in the ground by locating and making a number of points on each contour. These points are then surveyed and plotted on plan and the contours drawn through them.

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.

How many methods of contouring are present?

two methodsThere are two methods of contour surveying: Direct method. Indirect method.

What is the term used for an imaginary line on the ground joining points of equal elevation?

Explanation: A Contour is an imaginary line on the ground joining the points of equal elevation. It is a line in which the surface of the ground is interested in a level surface. … A Contour line is a line on the map representing a contour.

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 are the different methods of contouring?

Methods of Contouring Direct Method • In the direct method of contouring, the reduced level of various selected points on a contour line are obtained and their positions are located. The contours are then drawn by joining these points. It is a very accurate method but it is slow and tedious.

What is contour line method?

Contour lines are curved, straight or a mixture of both lines on a map describing the intersection of a real or hypothetical surface with one or more horizontal planes. The configuration of these contours allows map readers to infer the relative gradient of a parameter and estimate that parameter at specific places.

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 uses of contours?

Uses of contours mapsUses of contours maps. Contours provide valuable information about the nature of terrain. … Nature of Ground. To visualize the nature of ground along a cross section of interest,To Locate Route. … Intervisibility between Stations. … To Determine Catchment Area or Drainage Area. … Storage capacity of a Reservoir.

What is the shape of contour lines in case of a valley?

What is the shape of contour lines in case of a valley? Explanation: Contour lines cross a valley line at right angles. They form sharp curves of V shape across it with the convex side of the curve towards the higher ground.

Why do we need contours?

Teaching points: Maps are flat unlike some of the ground which they represent so we use contour lines on a map to show how high the ground is. … 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.