Surface Modelling

In this exercise, a representation of the surface of the Earth is generated using TINs (Triangulated Irregular Network) to generate a 3D surface model. A 3D model provides a very convenient representation for visualizing the surface of the Earth as well as any phenomenon that can be represented in three dimensions (such as temperature and precipitation over a certain location).

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A: Surface Modelling: Generating A TIN

      1. Open a New Blank Map in ArcMap
      2. Add the waypoints shapefile provided (Points_ge.shp)
      3. Click on the search Tab and look for the “Create Tin” tool
      4. Run the Create Tin (3D Analyst) tool that comes out in the Search Window)
      5. Name the Output TIN “surf-TIN”; Select “Points_ge.shp” as the input feature
      6. Click on OK
      7. The modelled TIN surface is displayed

B: Generating the Contours and converting to Raster
      1. Look for the tool “Surface Contour in the Search Window
      2. When the tool comes up, set the Input surface to be the “surfTIN” file
      3. Provide the name for the Output Feature Class as “surfContour”
      4. Set the contour intervals to 0.2
      5. Leave the rest of the fields as is
      6. Click on OK and the contours should be generated showing the contours at the specified intervals
      7. Using the Search, create a TIN to Raster (3D Analyst), convert the surfTIN into a raster format and name it “surfRaster”
      8. Click on OK

C. Generate Aspect and Hillshade from Raster

    1. Search for the Tool “Aspect” in the Search Window
    2. Use the “surfRaster” as input
    3. Name the output “aspectsurf ”
    4. Click on OK
    5. Search for the Tool “Hillshade” in the Search Window
    6. Use the “surfRaster” as input
    7. Name the output “hillshadsurf ”
    8. Click on OK

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