Seventh Edition By David A. Madsen, Terence M. Shumaker, and David P. Madsen Civil Drafting Technology Chapter 9 Contour Lines With some additions by adjunct instructor SPayne from: “Architecture Exam Review, Vol. II” by D. Ballast – Professional Publications Inc.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ 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)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 3 Contour lines are the greatest distinguishing feature of a topographic map. Contour lines are lines drawn on a map connecting points of equal elevation, meaning if you physically followed a contour line, elevation would remain constant. Contour lines show elevation and the shape of the terrain

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 4 Why Contours are important to building and site design A Site Section is not usually drawn by the civil engineer but it’s important in building design. Using contours, the architect can generate a section cut through the site and adapt the footings and retaining walls to the slope.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 5 Site Section through a new development - shows Levels (Elevations above sea level)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 6 Many cities have regulations about new building height in relation to a slope, for example to preserve Views to the ocean. Section below is cut through lots shown at left.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 7 How to create a Section Cut Through Contour Lines -use Projection Lines - similar to drawing architectural sections & elevations by projecting from plan view right where the section is ‘CUT”

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 8 Design tasks- Determine how contour lines must be revised for new buildings or roads For drainage and stability Calculate cut and fill Note 2 linetypes/ layers for new vs. existing contours How to design is not in scope of this class, just describing how contours information is used

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 9 Identify common Contour conditions/ Site Profiles such as: Convex, Valley, Uniform Slope, Concave, Ridge

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 10 Figure 9 – 2: Uniform gentle slope.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 11 Figure 9 – 3: Uniform steep slope.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 12 Figure 9 – 4: Concave slope. -Flattens more towards the bottom

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 13 Figure 9 – 5: Convex slope -- steeper towards the bottom.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 14 Figure 9 – 6: Contours merge to form a cliff.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 15 (a) Contours form a “ V ” pointing upstream. (b) Contours form an “ M ” above stream junctions. Top of the M points upstream.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 16 A valley is a stretched-out groove in the land, usually formed by streams or rivers. A valley begins with high ground on three sides, and lower ground on the 4 th side. It usually has a course of running water through it, which flows toward the lower elevation Depending on its size and where a person is standing, it may not be obvious that there is high ground in the third direction, but water flows from higher to lower ground. Contour lines forming a valley are either U-shaped or V-shaped. To determine the direction the water flows, look at the contour lines. The closed end of the contour line (U or V) always points upstream or toward high ground.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 17 (c) Contours form a “ U ” around the end of a Ridge. A Ridge is essentially the high point of an elongated hill. Diagram above shows a Ridge but it could be much longer and narrower in many cases. Diagram below shows one end of a ridge. The bottom of the U points downhill.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved This web site has more great diagrams and information on Contours. Notice at left the dashed line indicating a Ridgeline i.e. connecting a row of high points along a mountaintop.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 19 Figure 9 – 8: (a) Dome-shaped hill. (b) Saddle.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 20 Figure 9 – 8: (c) Depression. (d) Overhang. A depression is a low point in the ground or a a sinkhole. It could be described as an area of low ground surrounded by higher ground in all directions, or simply a hole in the ground. Usually only depression that are equal to or greater than the contour interval will be shown. On maps, depressions are represented by closed contour lines that have tick marks pointing toward low ground

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 21 Figure 9 – 9: Types of contour lines. Index line is every 5 th line – labeled and heavier weight intervals depending on scale/area

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 22 Figure 9 – 10: Every fifth line is an index contour, and the contour interval determines the value of the index.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 23 Figure 9 – 11: Contour map plotted using control point survey.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 24 Field Surveying Control Points - Stations

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 25 Figure 9 – 12: Interpolating contour lines. USEFUL AUTOCAD TOOL: ‘DIVIDE’

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 26 Figure 9 – 13: When interpolating contour lines using the uniform slope theory, always space contours evenly as in part c of the figure.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 27 Figure 9 – 14: Mathematical interpolation of contour lines allows you to calculate the distance between two points on a map. IF know 2 spot elevations + a ruler distance, can calculate intervals between them

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 28 Figure 9 – 15: ALTERNATE METHOD 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 elev. Diff. map dist. Of 260’ =.098 percent slope

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 29 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 curved lines or splines. (d) Completed contour map of grid survey.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 30 Table 9 – 1: Grid survey field notes for the map in Figure 9 – 16

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 31 Figure 9 – 17a: The theory of uniform slopes is used to calculate contours in a grid survey. Amount abv whole foot contour, hi pt. = Difference in elevation to next lower distance betw. Grid intersections Only 2 calc’s needed per side-the 2 nd formula calc’s distance for 1 ft. of elevation After locating contour line elevations on edges of grid:: connect points of same value = contour lines

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 32 Figure 9 – 17b: After elevation values are located on the grid, points of the same value are connected to form contour lines. INTERPOLATED FROM CALCULATIONS P / summary previous slide

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 33 Figure 9 – 18: Field notes of a radial survey contain azimuths and distances, property corners, and additional control points. In a Radial survey, a series of angular and distance measurements are taken from a central point ‘TRANSIT STATION’ to specific CONTROL POINTS

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 34 Figure 9 – 19: A property plat can be constructed from the radial survey field notes.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 35 Figure 9 – 20: GRAPHICS Contour line labeling should be on index contours, with the labels placed at regular intervals, and the text should not be upside down.

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 36 Figure 9 – 21: The Carlson SurvCom program transfers data from a field survey instrument to an office computer. (Courtesy Carlson Software) -Some other programs include AutoDesk Civil 3D,Land Desktop, Eagle Point, TerraModel, and others

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 37 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)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 38 Figure 9 – 23: The Contour tab is where all aspects of the generated contours are controlled, including the interval and smoothing. (Courtesy Carlson Software)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 39 Figure 9 – 24: In the Labels tab, the user specifies the details of the creation of contour labels. (Courtesy Carlson Software)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 40 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)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 41 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)

Civil Drafting Technology, Seventh Edition David A. Madsen, Terence M. Shumaker, David P. Madsen © 2010 Pearson Higher Education, Upper Saddle River, NJ All Rights Reserved. 42 Point Cloud Data in AutoCAD Map 3d