Squares or grid method is suitable for contouring of plains or gently sloping grounds.
The steps adopted are as follows:
i) Mark square grids on the land to be surveyed. The grid size would depend on the extent of survey.
Generally a 1m x 1m grid is selected for small works and a larger grid size for large works
i) Mark square grids on the land to be surveyed. The grid size would depend on the extent of survey.
Generally a 1m x 1m grid is selected for small works and a larger grid size for large works
ii) Levels are taken at all the corners of the square and the intersection of the diagonal.
iii) Levels taken on the intersection of diagonals is used for verification of the interpolation.
vi) Contour map is plotted in the office by interpolating points of equal elevation based on the levels taken on the corners of the square.