Methods of Locating Contours

Methods of locating contours might be classified as (a) direct, and (b) indirect.

Direct Method

In this method, the contour to be plotted is actually located on the ground with the help of a level or hand level through marking various points on the contour. These points are surveyed and plotted to draw the contours by them on the plan. Though the method is slow and tedious other than it is most accurate and is used for contouring small areas along with great accuracy.

In contouring, field work consists of horizontal and vertical control. For a small area, horizontal control could be performed through a chain or tape, although for a large area compass, theodolite or a plane table could be employed. For vertical contour, a level and staff or a hand level may be used.