Topography Lab
Purpose: To understand topographic maps and how land forms influence water movement.
Background
Topography represents the contour or the arrangement of the land surface. Topography determines
the general direction of water flow, and it influences groundwater recharge. A recharge area is where
water moves downward from a topographical high area into the zone of saturation. In other words,
recharge areas replenish groundwater.
Drawing Topographic maps:
- Contour lines indicate land that is at a specific elevation.
- When drawing a depression in the land, use hachure marks (short tick
marks perpendicular to the contour pointing downhill into the depression)
Materials:
Plastic box with lid
Ruler
Marking pencil
Procedure:
1. Make marks one centimeter apart up the side of the box beginning at the bottom.
2. Label the elevations: 0 cm, 1 cm, 2 cm, etc.
3. Fill the container up to the 1 cm mark.
4. Use the marking pencil to trace the water line on the clear lid.
5. Raise the water level to the 2 cm mark and mark the water line.
6. Continue this process until all parts of the mountain are submerged.
Data/Observations:
Trace the contour lines into your lab notebook.
Analysis:
Assume the following:
The base of the mountain begins at 6250 ft above sea level
1 cm = 250 ft
What is the maximum elevation of this mountain?
Discussion:
 How do you distinguish between a mountain and a basin on a topographic map?
 Describe the relationship between the closeness of the contour lines and the slope of the land.
 How would the slope of the land affect water flow?
 In what areas would you expect to find the greatest erosion rates? Why?