WETMAAP Technique 2
La Parguera, Puerto Rico - Element 1
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Technique 2: Manual GIS
Element 1: Making Feature Overlays

Materials:

1:20,000 Scale 1966, Parguera, Puerto Rico, USGS Topographic Quadrangle

(3) 11"x 17" clear film overlays

drafting tape

Colored marker pens: Blue, Red, Green

Exercise:

1. Use 1:20,000 scale 1966 Parguera, Puerto Rico, USGS Topographic Quadrangle

2. Use clear film 11"x 17"overlay.

3. Tape clear film overlay on top of 1:20,000 scale map. 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 shoreline of the mainland and all islands in Blue on the overlay.

7. At the bottom of the overlay (in blue) draw a short horizontal line and label beside it "1966 Shoreline."

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

8. Remove the "1966 Shoreline" overlay.

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

10. Tape clear film overlay on top of 1:20,000 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 18 foot bathymetric with aRed line on the overlay.

14. At the bottom (in Red) draw a short horizontal line the same length as the Blue line and label it "18 foot Bathymetric Line."

15. Remove the "18 foot Bathymetric Line." overlay.

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

17. Tape clear film overlay on top of the 1:20,000 scale map. Tape the top edge.

18. Use the Green pen.

19. Use the Green pen to make four "corner marks" (tick mark _) on the overlay, one at each corner of the study site.

20. Outline all mangrove areas with Green on the overlay.

21. At the bottom (in Green) make a small polygon and label it "1966 Mangroves." Remove this overlay.

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

22. on the 2004 aerial photo, tape the "1966 Shoreline," "18 foot Bathymetric Line," and the "1966 Mangroves" overlays one on top of each other. 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 alignment. You have created a manual GIS.