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Methods of locating contours - Indirect method
Indirect method
In this method, some guide points are selected along a system of straight lines and their elevations are found. The points are then plotted and contours are then drawn by interpolation. There are three indirect methods in locating contours.
This method is used when the area to be surveyed is small and the ground is not very much undulating. The area to be surveyed is divided into number of squares. The size of the squares may vary from 5 to 20 m depending upon the nature of the contour and contour interval. The elevations of the corners of the square are then determined by means of a level and a staff. The contour lines may be drawn by interpolation.
In this method, some guide points are selected along a system of straight lines and their elevations are found. The points are then plotted and contours are then drawn by interpolation. There are three indirect methods in locating contours.
- By squares
- By cross-sections
- By Tachometric methods
This method is used when the area to be surveyed is small and the ground is not very much undulating. The area to be surveyed is divided into number of squares. The size of the squares may vary from 5 to 20 m depending upon the nature of the contour and contour interval. The elevations of the corners of the square are then determined by means of a level and a staff. The contour lines may be drawn by interpolation.
Last modified: Thursday, 12 May 2011, 9:15 AM