What is a map? Civil Drafting?

1. What is a map?Civil Drafting? • A map is any concrete or abstract image of the distributions and features that occur on or near the surface of the earth or other celestial bodies. • Civil drafting deals with the design and construction of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings.

2. Oldest known map discovered in the Nuzi Ruins in northern Mesopotamia 2500 B.C.

3. Why are drawings a better way to communicate Spatial Data than written descriptions? • They are dimensional representations of the whole picture. • They show patterns. • They record and communicate information (Spatial Data) about the environment. • They show the relationships between features and changes over time.

4. Types of Maps • Mental Map • Thematic Maps • Planimetric Maps/Planning Maps • Cadastral Maps • Engineering Maps • Topographic Maps • Geographical Maps • Digital Terrain Model Maps • Photogrammetric Maps • Bathymetric Maps/Nautical Charts

5. Mental Map • Images that we have in our minds • In The Image of the City, Kevin Lynch calls this “the environmental image, the generalized mental picture of the exterior physical world that is held by an individual.”

6. Thematic Maps • Used to show information about a special topic • Often use a variety of symbols and or hatch to show the arrangements of variables over areas

7. Planimetric Maps/Planning Maps • Planimetric maps do not show relief features in measurable form. • May show voting districts, school attendance, populations, taxing, land use, Geographic Information Systems.

8. Cadastral Maps • Large-scale maps that show features in a city or town • Includes the location of property-ownership lines, along with their bearings and lengths, the ownership and size of land parcels

9. Quadrangle maps are a type of cadastral map. • They are used in the rectangular survey system. • They show the division of land into grids known as sections.

10. Engineering Maps • Maps used for construction purposes • Provide information such as location and dimensions of all structures, roads, parking areas, drainage ways, utilities and topography

11. Plats are a type of engineering map • They are detailed maps of construction projects such as subdivisions showing building lots • They may also be a Plot or Site Plan which are for an individual project

12. Topographic Maps • Show the shape of the earth with contour lines • Contour lines represent all the points on the ground at an equal elevation above sea level • Spacing is determined by the grade • May be include with construction maps at times

13. Geographical Maps • Show large areas of the earth • Have a small scale • i.e. maps of continents or countries • Must account for the curvature of the earth

14. Bathymetric Maps/Nautical Charts • Used to aid in water navigation • Provide information such as water depths, clearances of bridges and cables, navigation lanes, lighthouses, beacons, and buoys

15. Photogrammetric Maps • Use aerial photographs • Most widely used • Information can be gathered from color differentiation • Accurate at the time photo was taken Aerial Photograph Map

16. Digital Terrain Model Maps (DTM) • 3-dimensional map of land features • Can be created using data from remote sensing equipment

17. Contour Map What are contour maps used for? Contour maps show elevation. Types of contour lines. Existing elevation. New elevation. Major contour. Minor contour.

18. Raster to Vector Conversion in AutoCAD (tracing) • What is a Raster Image (pixels) • What is a Vector (geometry)

19. Bringing an Image Into AutoCAD Attach Path Type Scale Insertion Point

20. Raster to Vector Conversion in AutoCAD (tracing) • Attach image • Scale image • Trace image using pline (lines & arcs) • Clean up the drawing