CAD students investigate creating a contour map.
by Dan Harms
October 23, 2006
CAD/GIS Class Create Contour Maps – The hard way
Contour maps show the relative elevation of the land with lines connecting points of equal elevation. Contour maps are important tools for engineers, designers, farmers and foresters, they are also used by hikers and others enjoying the outdoors.
Source: Terra-ServerUSA.com
The image above is a USGS topographic map. The lines are contour lines connecting points of equal elevation.
Students used the level and Philadelphia rod to find the relative elevations of points in the lawn at the AVC.
The points were recorded using azmith and the statia lines in the level. This allowed the location of the points to be plotted and the ground elevation.
After the points were taken, they were plotted on paper.
Lines connecting the points were drawn, creating a TIN (Triangulated Irregular Network).
Source: http://hds.essex.ac.uk/g2gp/gis/sect25.asp
The 1 foot elevations between the points, on the line, were calculated to create to create points to connect with contour lines…
After creating a contour map by hand, the points and their elevations were entered into AutoCad Land Desktop.
The AutoCad software was used to create a TIN.
The software then created the contour lines, applying the same mathematical concepts done by hand.
The contour maps created were very similar!
