1. CONTOURS

2. What are contours? Imaginary lines Drawn on a map Connecting places
Which are at equal altitude (height above sea level)

5. S U R T Q E P G D F B M A C L I J H O K N

6. 238
240
252
276
263
297
279
280
300
317
320
285
325
314
289
309
298
280
254
281
264

7. 238
240
240
252
260
276
260
263
300
297
280
279
280
.300
317
320
285
325
314
320
289
309
300
298
280
280
280
254
281
260
264

8. INDEX CONTOURS

9. INDEX CONTOURS

10. Characteristics of Contours
All places on the contour line lie at the same altitude
Contours never intersect each other
Contour interval (difference between two successive contour values) is uniform throughout the map
All contour values are multiples of the contour interval
Height of any place on map can be determined

11. FORM LINES
Drawn where it is not possible to draw contours and there is a prominent relief feature which is lesser in height than the contour interval

12. Spacing between contours
Widely spaced contours
Gentle slope
Closely packed contours
Steep slope
Overlapping contours
Vertical slope

14. Uniform Gentle Slope

15. Uniform Gentle Slope
320
280
300
260
240
220

17. Uniform Steep Slope

18. Uniform Steep Slope
260
320
300
180
200
220
240
140
160
280

19. Concave Slope

20. Concave Slope
240
220
320
260
300
280

22. Convex Slope

23. Convex Slope

24. Features of Contour Diagrams
Spacing gives idea of slope
Shape of contours resembles shape of relief feature in ariel view
It is possible to visualise the shape of the relief feature

25. VISUALISATION

27. CONICAL HILL
320
300
280
260

30. ASYMMETRICAL HILL
320
300
280
260

32. CIRCULAR PLATEAU
320
300
280
260

34. RIDGE
320
300
280
260

37. SADDLE
320
300
280
260

39. V SHAPED VALLEY
320
340
300
280
260
240
220
200
180

40. WATERFALL
320
340
300
280
260
240
220
200

45. An Escarpment

46. CONTOURS:
PAGE: : Ridge : Ridge (uniform) : Ridge (steep)
PAGE: : Saddle/ col : Hill
PAGE: : Conical hill
PAGE: : Conical hill

47. PAGE:75. 9782: Escarpment. 9783: Col/ Saddle PAGE :83
PAGE: : Escarpment : Col/ Saddle PAGE : : Cliff( very steep) : River valley