Contour Survey:

Contour may be defined as an imaginary line passing through points of equal elevation.

A contour line may also be defined as the intersection of a level surface with surface of the earth With the help of contour map proper , precise location and economy of Engineering works such as Roads , Canals, Transmission Lines , Design of Dams Aqueducts etc., can be decided.

Total Stations, Leveling Instruments are used in Preparation of contour maps. Contour maps are also used for earth work calculations.