Technique 2: Manual GIS
Element 1: Making Feature Overlays

 Materials:
            1963/80 Delcambre Topographic Quadrangle
            (3) 11"x 17" clear film overlay
            drafting tape
            Colored marker pens: Blue, Red, Black

Exercises:

            1. Use the 1:24,000 scale Delcambre Topographic Quadrangle

2.      Use a clear film 11”x 17”overlay.

3.      Tape the clear film overlay on top of the 1:24,000 scale map.  Use (2) pieces of  tape at the top edge.

4.      Use the Blue pen.

5.      Use the Blue pen to make four “corner marks” (tick mark) on the overlay, one at each corner of the study site.

6.      Trace the shorelines of Bayou Petite and ponds in Blue on the overlay.

7.      At the bottom of the overlay (in blue) draw a short horizontal line and label beside it “Bayou Petite and ponds.”

                        Hint:            Use of a symbol with a short description beside it is a “key,” or means of identifying selected features.

            8.      Remove the "Bayou Petite and ponds" overlay.

9.      Use a second 11"x 17”clear film overlay.

10.  Tape the clear film overlay on top of 1:24,000 scale map. Tape at top edge.

11.  Use the Red pen.

12.  Use the Red pen to make four  “corner marks” (tick mark) on the overlay, one at each corner of the study site.

13.  Trace the primary and secondary roads in Red on the overlay.

14.  At the bottom (in red) draw a short horizontal line the same length as the Blue line and label it  “Roads.”  

15.  Remove the “Roads” overlay.

16.  Use the third 11" x 17” clear film overlay.

17.  Tape the clear film overlay on top of the 1:24,000 scale map. Tape the top edge.

18.  Use the Black pen.          

19.  Use the Black pen to make four  “corner marks” (tick mark) on the overlay, one at each corner of the study site.     

20.  Using the Black pen, make a dot on the overlay for each oil and gas well.

21.  At the bottom (in Black) make a dot and label it “oil and gas wells.”  Do not remove this overlay.

Hint:              Combining several single “key” items creates a “legend.” Every map should have a legend

  22. Tape the “Bayou Petite and ponds” and “Roads” overlays one on top of each other, over the “oil and gas wells” overlay. Use the four corner
        marks to line-up (“register”) the overlays on top of each other.

Hint:              Tape one overlay at the bottom edge and the other overlay at the left or right edge. By attaching the overlays at opposite edges, you can flip the overlays up and down in various alignments.You have created a manual GIS.