Topographic Maps
There are Planimetric (street) maps,…
Physiographic (bumpy) maps…
TOPOGRAPHIC Maps combine information from these two into one map!
Topographic Map of the same land form. . . . TOPOGRAPHY: Three-dimensional characteristics of land. Topographic maps show elevation as well as distance on a map 3 – D land form 2 – D surface Topographic Map of the same land form. . . .
Can you see the relationship? Point out some common key locations, if you can. . .
There are MANY Topographic Map Symbols, but you will only be held responsible for a few. .
Copy/draw the following common patterns/symbols with your teacher: Depression contour: Hilltop/mountain top feature: Stream or canyon: Cliff or steep slope:
Map Scale (FRACTIONAL) Found in bottom margin of topographic map. Scale will look something like this 1:24,000 This means one unit of measurement is equal to 24,000 units of measurement.
Example: One cm on the map is equal to 24,000 cm on the ground. Same as saying the map is 1/24,000 the size of the area it represents.
Map Scale (GRAPHIC) The kind you can use 1.0 ½ 0 1.0 The kind you can use As a bar of measure that you hold up to a map to find distance Map Scales here
Some map Scale advice. . . . The larger the second number is in the ratio, the less detail seen on the map (zoom out). 1:24,000 scale 1:75,000 scale
CONTOUR LINES A line connecting points of the same elevation. INDEX CONTOUR – has an elevation number on it INTERMEDIATE CONTOUR – has no number
Basic Contour Line Rules (1) Where a contour line crosses a stream or valley, the contour line bends to form a “V” that always points upstream. Valley “V” points upstream
(2) Contour lines are widely spaced on gentle slopes or flatter land. (3) They are closely spaced on steep slopes. (4) Evenly spaced contour lines indicate a uniform slope.
(5) Contour lines do not cross or intersect each other (6) All contour lines eventually close on the map or beyond its margins. (7) Contours that form closed loops indicate a hill or mountainous structure.
INTERVAL – How many feet in elevation you go up with each line. . . High Index Line Number – Low Index number Number of Spaces in Between Contour Interval = 200 – 100 5 spaces Contour Interval = 20 feet
What’s the contour interval of this map?
About what elevation would the “Corral” be?
Let’s say point D is at 500 feet, and the Contour Interval = 20 ft Let’s say point D is at 500 feet, and the Contour Interval = 20 ft. Name the elevations of all the letters. . .
Bench Mark (X) – elevation 4392 What is a Benchmark? A benchmark is a known elevation at a certain point Usually seen at high elevations Bench Mark (X) – elevation 4392
** END OF PART I ****
A person’s PROFILE is a side view of the contours of their face A person’s PROFILE is a side view of the contours of their face. A land profile is the same thing.
PART II: How to Make a PROFILE of a Topographic Map PART II: How to Make a PROFILE of a Topographic Map. (This is making a “side view” of a land form from a “flat” map.) Area of Profile
Area of Profile with contour lines added:
Map Profile (side view of 3-D)
Map Profile with elevation:
Drawing a Profile
Drawing a Profile
Connect the elevation points: