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Tags: topographic mapping
Slide 1 - Models of the Earth
Slide 2 - Technological Advances in Map Making
- Air photos and satellite images relate to actual 3-D landforms
- Satellite technology gives an even broader view of Earth by gathering data from broad areas of Earth’s surface.
Slide 11 - Difference between geomagnetic and geographic poles
- The angle between the geomagnetic and the geographic
- poles is called magnetic declination.
Slide 13 - Scales
- Map scales show the relationship between the distance on the map and the actual distance on the Earth.
- Fractional scales indicate how much
- the map has been reduced from actual
- size, this is a 1:24,000 scale
- Graphic or bar scale is divided into segments that show the relationship between actual distance on the map and distance on Earth
Slide 14 - Topographical Maps
- Show the surface features or topography of the land
- Contours lines are used to show elevation
- Contour interval is the distance between each line
- Index contour are bolded lines that give the elevation
Slide 18 - Lines close together indicates steep terrain
- Lines far apart indicates gradual change
- V shape indicates valleys with a river flowing toward the open end of the V
- Depressions are indicated by hachured lines
Slide 22 - Drawing Topographical Maps
Slide 23 - Gradient
- = Drop in elevation between 2 points
- Distance between two points
- 20 = 4 m/km
Slide 24 - 1. What is the contour interval for this map?
- 2. What is the distance between points E and F?
- 3. What direction does Cedar River flow?
- 4. What is the gradient between points D and E?
- 5. Which side of hill C has the steepest slope?
- 6. What is the elevation of the last depression line
- on hill B?
Slide 26 - Now the Fun begins…read this map and tell me