1. Topographic Maps

2. Contour lines A line which connects points of equal elevation.
Index Contours: Thick contour lines which have the elevation written on them.

4. Contour line properties:
Contour lines never cross.
The closer the lines the steeper the hill.
At valleys, contour lines form “V”s which always point up hill.

6. Contour Interval The vertical distance between adjacent contour lines.
Ratio Scale
Graphic Scale

7. Benchmarks – Spot Elevations
A benchmark: a mark on a topographic map and the earth which shows elevation to the nearest foot. (BM 377)
Spot Elevations: elevations measured at road crossings or tops of hills. ( or X1127)

8. Latitude and Longitude
Latitude and Longitude are measured in degrees. °
1 degree = 60 minutes. 60’
1 minute = 60 seconds. 60”
Example 44° 30’ 15” N , 92° 15’ 54” W
Found in the corners of topo. maps and along the edges.

9. Latitude
Parallel lines which indicate angles North and South of the equator.
Equator 0° Latitude
North pole 90 ° N Latitude
South pole 90 ° S Latitude

10. Longitude
Meridians measuring angles East or West of the Prime meridian.
Prime meridian 0 ° long.
International Dateline 180 ° long.