Topographic

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Topographic Maps
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TOPOGRAPHIC MAP
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
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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
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STEEPNESS OF SLOPES
CLOSER CONTOUR LINES STEEP SLOPES
WELL-SPACED CONTOUR LINES FLATTER, GENTLE
SLOPES
THE SHAPE OF THE LAND AT VARIOUS HEIGHTS
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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
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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 )
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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
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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)
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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)