2. Mapping the SF Bay Overview

3. SF Bay: Know the waterways and bridges

4. Topographic Maps A. Definition:  A map showing changes in elevation

5. Contour Line A. Definition:  A line that connects points of equal elevation. Contour Interval A. Definition:  The difference in elevation between two side by side contour lines.  Lines close together represent steep terrain.

6. Using Contour Lines What is the contour interval on this map? Contour interval = Change in elevation ÷ # lines Go from bank of spillway (blue arrow: 800 ft) to next dark line (green arrow: 1000ft). There are 5 contour lines. Contour interval = 200 ft ÷ 5 lines = 40 ft What is the change in elevation from the spillway bank (blue arrow) to the end of the West Fork of Lauguanitas Creek (red arrow)? Change in elevation = # lines x contour interval Change in elevation = 24 lines x 40ft Change in elevation = 960 ft

7. Map Legend/Key A. Definition:  Explains what symbols on maps represent Map Scale A. Definition:  The ratio between the distances on a map and the actual distances on the surface of the earth In this example, 50 km = 1.8 cm

8. Using Map Scale 50 km = 1.8 cm So… area of entire shown map area is… Length: 10.6 cm x = = Width: 3.2 cm x = = 0 1112 294.4km 88.9km Area = Length x Width Area = 294.4km x 88.9km Area = 26,172.16 km 2

9. Nautical Charts A. Definition:  A map produced for marine navigation.  Water depths are recorded as soundings in feet, meters or fathoms.

10. Latitude A. Definition:  The distance in degrees North or South of the equator  The lines run parallel to the equator

11. Longitude A. Definition:  The distance in degrees East or West of the Prime Meridian  The lines run perpendicular to the equator

12. Using Lat. And Long.: What is the latitude and longitude of New Orleans? Answer: 29 degrees 57’ N, 90 degrees 04’ W.

13. Further consideration: Time Zones