1. Seventh Edition By David A. Madsen, Terence M. Shumaker, and David P. Madsen Civil Drafting Technology Chapter 9 Contour Lines

2. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 2 Figure 9 – 1: Contour lines formed by lapping water at different levels in a reservoir. (Reproduced by permission of City of Portland Oregon)

3. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 3 Figure 9 – 2: Uniform gentle slope.

4. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 4 Figure 9 – 3: Uniform steep slope.

5. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 5 Figure 9 – 4: Concave slope.

6. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 6 Figure 9 – 5: Convex slope.

7. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 7 Figure 9 – 6: Contours merge to form a cliff.

8. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 8 Figure 9 – 7: (a) Contours form a “ V ” pointing upstream. (b) Contours form an “ M ” above stream junctions. The tops of the M point upstream. (c) Contours form a “ U ” around ridges. The bottom of the U points downhill.

9. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 9 Figure 9 – 8: (a) Dome-shaped hill. (b) Saddle. (c) Depression. (d) Overhang.

10. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 10 Figure 9 – 9: Types of contour lines.

11. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 11 Figure 9 – 10: Every fifth line is an index contour, and the contour interval determines the value of the index.

12. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 12 Figure 9 – 11: Contour map plotted using control point survey.

13. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 13 Figure 9 – 12: Interpolating contour lines.

14. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 14 Figure 9 – 13: When interpolating contour lines using the uniform slope theory, always space contours evenly as in part c of the figure.

15. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 15 Figure 9 – 14: Mathematical interpolation of contour lines allows you to calculate the distance between two points.

16. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 16 Figure 9 – 15: The map distance between two points can be used to determine the percent of slope. The slope is converted to a distance between a given elevation and a contour line.

17. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 17 Figure 9 – 16: (a) For a grid survey, land is divided into a checkerboard and labeled. (b) All grid intersections are labeled. (c) Connect the elevations with courved lines or splines. (d) Completed contour map of grid survey.

18. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 18 Table 9 – 1: Grid survey field notes for the map in Figure 9 – 16

19. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 19 Figure 9 – 17a: The theory of uniform slopes is used to calculate contours in a grid survey.

20. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 20 Figure 9 – 17b: After elevation values are located on the grid, points of the same value are connected to form contour lines.

21. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 21 Figure 9 – 18: Field notes of a radial survey contain azimuths and distances, property corners, and additional control points.

22. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 22 Figure 9 – 19: A property plat can be constructed from the radial survey field notes.

23. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 23 Figure 9 – 20: Contour line labeling should be on index contours, placed at regular intervals, and should not appear upside down.

24. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 24 Figure 9 – 21: The Carlson SurvCom program transfers data from a survey instrument to an office computer. (Courtesy Carlson Software)

25. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 25 Figure 9 – 22: Options in the Triangulate tab control how the triangulated mesh is represented in the drawing as well as the naming and placement of the external TIN file. (Courtesy Carlson Software)

26. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 26 Figure 9 – 23: The Contour tab is where all aspects of the generated contours are controlled, including the interval and smoothing. (Courtesy Carlson Software)

27. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 27 Figure 9 – 24: In the Labels tab, the user specifies the details of the creation of contour labels. (Courtesy Carlson Software)

28. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 28 Figure 9 – 25: The Selection tab is where the user specifies what type(s) of data is to be used to generate the surface. (Courtesy Carlson Software)

29. Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 07458. All Rights Reserved. 29 Figure 9 – 26: An example of a contour map generated from a raw data file and displayed in the Carlson Survey program. (Courtesy Carlson Software)