11 10 map reading

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

http://www.uwsp.edu/geo/faculty/lemke/topographic_maps/

http://www.uwsp.edu/geo/faculty/lemke/topographic_maps/

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


What a Topo mapand actual Land features show



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


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.


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


HILL


SADDLE


VALLEY


DEPRESSION


SPURS


DRAWS


CLIFF





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.

View 1



Note: here the map is turned upside down so you can get a better perspective


View 1

GRAND CO.

BOULDER CO.

View 2




View 2

GRAND CO.

BOULDER CO.

View 1

View 2


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