11 10 map reading
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TRANSCRIPT
Map ReadingTerm: Topographic Map
Website:•http://www.uwsp.edu/geo/faculty/lemke/topographic_maps/
•Or google topographic map symbols•Draw the symbols for:
–Bench Mark – checked spot elevation–Unimproved (gravel) road–Depression–Quarry
Topographic Map
• A topographic map is a detailed and accurate graphic representation of cultural and natural features on the ground.
Small-scale map (1:100,000,000)VERY LITTLE DETAIL
Medium-scale map (1:250,000) MORE DETAIL
Large-scale map (1:24,000)LOTS OF DETAIL
Map Scale
PART 1 Basic Land NavigationBasic Land Navigation
What a Topo map,Aerophoto map,
And actual Land features show
TOPO MAPTOPO MAPAERIAL PHOTOAERIAL PHOTO
LANDLAND
Map Information – Identification
PART 1 Basic Land NavigationBasic Land Navigation
What a Topo mapand actual Land features show
Map Information – Identification
PART 1 Basic Land NavigationBasic Land Navigation
CONTOUR LINESCONTOUR LINESContour Interval ~ The contour interval is the distance between each contour line. The contour interval is found along the bottom edge, center of the map.
Intermediate Contour ~ a brown line on a topographic map and represents a line of equal elevation.
Index Contour ~ a bolder/wider brown line that has the elevation value marked at various intervals as a part of the line. Example: contour is 20 feet intervalExample: contour is 20 feet interval
A=700 ftB=740 ftC=770 ftD=820 ft
PART 1 Basic Land NavigationBasic Land Navigation
CONTOUR LINESCONTOUR LINES• There is a dimension to establishing position which does depend on map reading skills.
• This is the vertical dimension. On a map it is referred to as “relief”.– Knowledge of the relief of an area is extremely important to a wilderness navigator.
• The most graphic technique ever devised to show relief information is the contour line.– If you were to walk a contour line you would never go down hill and never up hill, and eventually
you would arrive back where you started.
PART 1 Basic Land NavigationBasic Land Navigation
Contour
• Topographic Maps use contour lines to show changes in terrain.
• All points on a contour line are the same ______________
• All contour lines connect to _________• Two Contour lines never ________• Contour lines never split or branch
RIDGE
PART 1 Basic Land NavigationBasic Land Navigation
HILL
PART 1 Basic Land NavigationBasic Land Navigation
SADDLE
PART 1 Basic Land NavigationBasic Land Navigation
VALLEY
PART 1 Basic Land NavigationBasic Land Navigation
DEPRESSION
PART 1 Basic Land NavigationBasic Land Navigation
SPURS
PART 1 Basic Land NavigationBasic Land Navigation
DRAWS
PART 1 Basic Land NavigationBasic Land Navigation
CLIFF
PART 1 Basic Land NavigationBasic Land Navigation
What a Topo mapand actual Land features show
Map Information – Identification
PART 1 Basic Land NavigationBasic Land Navigation
PART 1 Basic Land NavigationBasic Land Navigation
What a Topo mapand actual Land features show
Map Information – Identification
Compare the next five slideswith this map, to get view point perspective of what you see on this map and what you see on the landscape in front of you.
View 1
View 2
PART 1 Basic Land Navigation
GRAND CO.
BOULDER CO.
PART 1 Basic Land Navigation
GRAND CO.
BOULDER CO.
View 1
PART 1 Basic Land NavigationBasic Land Navigation
What a Topo mapand actual Land features show
Note: here the map is turned upside down so you can get a better perspective
Map Information – Identification
View 1
GRAND CO.
BOULDER CO.
View 2
PART 1 Basic Land NavigationBasic Land Navigation
What a Topo mapand actual Land features show
Map Information – Identification
View 2
GRAND CO.
BOULDER CO.
View 1
View 2
PART 1 Basic Land NavigationBasic Land Navigation
GRAND CO.
BOULDER CO.
GRAND CO.
BOULDER CO.
Map Sheets
• USGS topo maps• Datum• Declination Diagram• Scale• Adjoining quadrangles• Few symbols
– Other symbols with attachment or online• 7.5 minutes top to bottom & left to right
Terrain Features• Hill• Saddle• Ridge• Valley• Depression – how big would it have to be to
show up on the map?• Draw• Spur• Cliff -
Grid Coordinates
• Start at the lower left• Read to the right• Read up
VGT 23
VGT 24