WETMAAP Technique 2
Weedon Island - Element 1

Technique 2: Manual GIS
Element 1: Making Feature Overlays

Materials:

1:24,000 scale 1998 Safety Harbor/Gandy Bridge/ Saint Petersburg, FL; 1956/81 Port Tampa, FL,USGS Topographic Quadrangle

(3) 11"x 17" clear film overlay

drafting tape

Colored marker pens: Blue, Red, Black

Exercise:

1. Use 1:24,000 scale 1998 Safety Harbor/Gandy Bridge/ Saint Petersburg, FL; 1956/81 Port Tampa, FL,USGS Topographic Quadrangle

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

3. Tape clear film overlay on top of 1:24,000 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 edges of mangroves in Blue on the overlay.

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

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

8. Remove the "Mangroves" overlay.

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

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

11. Use the Black pen.

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

13. Trace the primary, secondary, and light duty roads in Black on the overlay.

14. At the bottom (in Black) 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 clear film overlay on top of the 1:24,000 scale map. Tape the top edge.

18. Use the Red pen.

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

20. Outline all purple areas in Red on the overlay.

21. Outline the power plant site in Red on the overlay.

22. At the bottom (in Red) make a dashed line and label it "New Areas" Do not remove this overlay.

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

23. Tape the "Mangroves" and "Roads" overlays one on top of each other, over the "New Areas" 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 alignment. You have created a manual GIS.