1. Maps Base maps Coordinate Systems, Datums, Projections
Lat-long, Township-Range, UTM
NAD27, WGS84
Topographic Maps
Contours
Distance
Scale
Declination
Location and Navigation

2. Referring to Differences in Topography
Examine this figure and the different ways you could convey differences in topography from one place to another
Relief: elevation difference
Steepness of slope
Elevation: height above sea level
INSTRUCTIONS TO STUDENTS
Examine this figure and the different ways you could convey differences in topography from one place to another
02.08.b1

3. Topographic Maps
Depicts the shape of the earth by showing lines of constant elevation (contours).
Contours are shown at regular intervals of elevation (on USGS maps typically 20 ft).
Understanding shape and density of contours is critical skill for effective use of topographic maps.

6. Topographic Maps Rule of Vs… Spacing of contours…. Hatched contours….
Contours can’t cross….
Saddles, peaks, valleys…

9. Topgraphic Maps Closely-spaced contours = steep topography.
Hatched contour lines are closed contours (depressions).
Contour lines can never cross!
Peaks, valleys, and saddles are useful for locating yourself…

10. Topographic Map Rules Contours “never” cross.
Contours “never” branch/merge.
Contours don’t disappear (except at edge of the map).
Also…

15. Maps Ground distance vs. Map distance…
Ground distance is the total distance you would have to walk from point A to point B. Takes into account that terrain isn’t flat.
Map distance is the straight line distance you could take if you could fly from point A to point B. Assumes flat surface (no relief).
In general Map distance < Ground distance.

16. Maps
Map scale: the relationship between the size of a feature on the map and the actual size on the ground.
Indicated on maps by a scale bar, a verbal scale, or a fraction….

19. Maps Large scale vs. small scale… not intuitive!!!
Large-scale maps show details of small areas. Large scale-fractions e.g. 1:1000.
Small-scale maps show large areas. Small scale-fractions e.g. 1:

21. Topographic Map Symbology

22. Topographic Map Symbology

23. Topographic Map Symbology

24. Topographic Map Symbology

25. Topographic Map Symbology

26. Topographic Map Symbology

27. Topographic Map Symbology