1. Topographic
Maps

2. TOPOGRAPHIC MAP CONTOUR LINES
A MAP WHICH SHOWS ELEVATION OF THE LAND WITH THE USE OF CONTOUR LINES, SHAPES , AND SYMBOLS
CONTOUR LINES
LINES DRAWN TO CONNECT POINTS OF THE SAME ELEVATION

3. THREE THINGS CONTOUR LINES SHOW US
ELEVATION
CONTOUR INTERVAL- THE DIFFERENCE IN ELEVATION BETWEEN TWO CONSECUTIVE CONTOUR LINES
INDEX CONTOUR- EVERY FOURTH OR FIFTH LINE WHICH IS DARKENED FOR EASY READING

4. THE SHAPE OF THE LAND AT VARIOUS HEIGHTS
STEEPNESS OF SLOPES
CLOSER CONTOUR LINES = STEEP SLOPES
WELL-SPACED CONTOUR LINES = FLATTER, GENTLE SLOPES
THE SHAPE OF THE LAND AT VARIOUS HEIGHTS

5. ELEVATIONS OF LAND BELOW SEA LEVEL
( SINKHOLE, QUARRY, MINE)
MEASURED USING A HACHURE LINE
THE “WHISKERS” POINT TO THE LOWER ELEVATION
**FIRST DEPRESSION LINE TAKES THE VALUE OF THE CONTOUR LINE SURROUNDING IT

6. INFORMATION LEARNED FROM A
TOPOGRAPHIC MAP
A BENCHMARK POINT IS A LOCATION WHOSE EXACT ELEVATION IS KNOWN AND IS NOTED ON A BRASS ALLUMINUM PLATE ( BM )

7. A MAXIMUM ELEVATION- HIGHEST POSSIBLE ELEVATION
FIGURE OUT WHAT THE NEXT POSSIBLE CONTOUR LINE WOULD BE THEN SUBTRACT 1 UNIT
MINIMUM ELEVATION- LOWEST POSSIBLE ELEVATION
THE NEXT POSSIBLE DEPRESSION LINE, THEN PLUS 1 UNIT

8. RIVERS CUT A VALLEY AND CAUSE CONTOUR LINES TO FORM A V-SHAPE POINTING TO THE SOURCE OF THE STREAM (UPSTREAM).
GRADIENT = CHANGE IN ELEVATION (ft)
DISTANCE (mi)

9. PROFILE- SIDE VIEW OF THE SHAPE OF THE LAND ON A TOPOGRAPHIC MAP
RELIEF- DIFFERENCE IN ELEVATION
RELIEF MAP – RAISED MAP WHICH SHOWS DIFFERENCE IN ELEVATION(3-D)