EXPERIMENT NO: 04 NAME : AKASH K
DATE : 25-06-2021 REG NO. : 20BCL0081
CLE1003 – SURVEYING LAB
Contouring
Problem Statement
Write the contouring procedure for an area of 6 m x 6 m by taking 1.5 m x 1.5 m grid size. Take suitable
values of R.L. for each point on the grid and draw at least two contours of any R.L.
Aim
To Prepare a Contour map for a given area taking suitable values of RL.
Apparatus Required
1. Dumpy level
2. levelling staff
3. Wooden peg
4. Tape
5. Ranging rod
Procedure
1. Mark square grids on the land to be surveyed. The grid size would depends on the extent of survey.
Generally a 1m x 1m grid is selected for small works and a larger grid size for large works.
2. Levels are taken at all the corners of the square and the intersection of the diagonal.
3. Levels taken on the intersection of diagonals is used for verification of the interpolation.
4. Contour map is plotted in the office by interpolating points of equal elevation based on the levels
taken on the corners of the square.
Observations
S. No Point Reduced Level
1. A 100m
2. B 108m
3. C 106m
4. D 107m
5. E 110m
6. F 108m
7. G 112m
8. H 106m
9. I 102m
10. J 112m
11. K 112m
12. L 103m
13. M 103m
14. N 113m
15. O 109m
16. P 107m
17. Q 100m
18. R 105m
19. S 107m
20. T 100m
21. U 102m
22. V 106m
23. W 112m
24. X 114m
25. Y 102m
Contour Map plotted using graph paper
Result
The Contour map with 2 contour lines of RL 100 m & 106 m were drawn.
