3. Isolines: contour lines on an elevation map
Isotherms: contour lines on a temperature map
Isobars: contour lines on an air pressure map

6. THE “V” BEND POINTS UPSTREAM.
RIVER AND STREAM FLOW
WHAT DIRECTION IS THE STREAM FLOWING?
North
West
East
South
THE “V” BEND POINTS UPSTREAM.
THE STREAM FLOWS OUT OF THE WIDE END OF THE “V” BEND.

7. Gradient= Change in field value Distance
GRADIENT: The rate of change in field values between two points in a field.
Quick (steep) change in elevation: closer lines
Slow (gradual) change in elevation: wider lines
ESRT formula
Gradient= Change in field value Distance

8. SAMPLE GRADIENT PROBLEM: -Calculate the average slope of a mountain trail from the 980-meter contour line to the 480-meter contour. The distance between these two elevation lines measures 4 Kilometers.
Gradient= change in field value distance
difference in elevation (m) distance between the points (km)
1) 980m – 480m =
4km
500m =
4km
125m/km

9. Wide lines
Close lines

10. Profile:
A cross-sectional view that shows the changes in elevation of the land from a side view.
What is the topography of this profile?
(the shape of this profile is a valley)

11. How do you create a topographic profile?:
Line the edge of a blank sheet of paper along the profile line A to A’. Where each contour line touches the paper , make a tick mark and label it with the appropriate elevation. Then transfer the tick marks onto the bottom of the grid paper as shown, then plot each elevation directly above on the grid as shown. Connect each dot to show the profile of line A – A’.

12. LATITUDE – measured NORTH or SOUTH of the Equator (horizontal imaginary lines)
LONGITUDE – measured EAST or WEST of the Prime Meridian (vertical imaginary lines)
Earth