Land and Water Study Guide
1.
Water Cycle: the continuous process by which water is used and re-used
on earth
a. Evaporation: when a liquid (water) is changed to a gas (water vapor)
because it has been heated by the sun
b. Condensation: when a gas (water vapor) changes to a liquid (water
droplets) because it has been cooled
c. Precipitation: rain, sleet, snow, or ice that falls from the sky to
earth
d. Runoff: water that flows over the surface of earth and re-enters
oceans, lakes, rivers, and streams
e. Groundwater: water that soaks into the ground and flows beneath
the earth’s surface
2.
Weathering: the breaking down and wearing away of rock
a. Caused by 4 main forces: water, wind, ice, and gravity
3.
Erosion: when sediment materials (soil, rock, etc.) are picked up and moved
to another location
a. Also caused by 4 main forces: water, wind, ice, and gravity
b. More erosion happens at the beginning of a stream or river (head)
because the water is moving faster
4.
Deposition: when sediment that has been eroded is deposited (dropped off)
in a new location
a. More deposition occurs at the end of a stream or river (mouth)
because the water is moving slower
5.
Sediment: rock, soil, and other earth materials that have been eroded or
deposited by moving water
6. Landforms: physical features of earth’s surface
a. Examples include mountains, valleys, canyons, plains, plateaus, etc.
7. Aerial view: a view from above; also called a “birds-eye view”
8.
Model: a smaller version of something that is too large or too complicated
for scientists to study in real life
a. Example: stream tables; globe; model car; dollhouse
9. Tributary: a small stream that feeds into a larger river or stream
10. Flood: a large amount of water in a given place at one time
a. Flood increases the amount of erosion in an area because there is a
larger volume of water flowing through the area
11. Floodplain: the flat land surrounding the banks of a river that is likely to
flood; formed by deposition of sediment
a. Increased deposition occurs in floodplains, which means that lots of
nutrients are deposited in the area; as a result, floodplains are very
fertile.
12. Meander: a curvy river or stream that changes directions many times
a. Meanders occur in slow-moving streams; fast-moving streams are
very straight instead of curvy.
13. Channel: the path or course a river or stream follows
14. Head: beginning of stream or river
15. Mouth: end of a stream or river
16. Slope: a change in height
a. A greater slope will cause an increase in erosion, because the force of
gravity pulling downward is increased.
17. Delta: a triangle-shaped area of sediment that is formed by increased
deposition at the mouth of a stream or river
a. Also called an alluvial fan
18. Valley: a U-shaped cut in the Earth’s surface bounded by areas of higher
land on both sides
a. Usually contains a river or stream.
b. Not as deep or steep as a canyon.
19. Canyon: a deep, V-shaped cut in the Earth’s surface with steep sides
a. Usually does not contain a river or stream
b. Deeper and steeper than a valley
c. Typically formed by the constant wearing away of rock and soil by
moving water over hundreds or thousands of years
20. Glacier: a slow-moving river of ice
a. Glaciers are typically found on steep mountains
b. Glaciers are always moving, but at an extremely slow rate—only an
inch or so over a long period of time.
21. Dam: a barrier to the flow of water in a river
a. Dams may be natural or man-made
b. Dams cause increased erosion upstream and decreased erosion
downstream
22. Clear-cutting: clearing an area of all its trees and plants
a. Clear-cutting causes erosion to increase because there are no plants
to hold down the soil with their roots
Additional information:
 About 70-75% of earth’s surface is covered by water.
 Moving water creates many landforms because this constant movement of
water wears away rock and soil.
 Erosion is increased by flood (increased volume of water), fast-moving
water, and the downward pull of gravity.
 Humans also increase erosion by clear-cutting. Humans slow down erosion by
planting vegetation, because the roots of plants act like arms to hold down
soil and other earth materials.