Earth Science Chapter 3 Study Guide
1. Know the definitions of the vocabulary words listed on page 90 in textbook.
a. barrier island-an island near the shore, formed by currents that deposit sediments
b. beach nourishment-the practice of dumping sand onto an eroded beach
c. contour plowing-the practice of plowing soil in curved rows that follow the shape of
the land
d. dam-a wall across the river or other waterway, designed to hold back the water
e. dredging-deepening or widening, typically to a river or harbor
f. flood-an event in which water flows over land that is usually dry
g. floodway-a path for flood waters to flow over
h. jetty-a thin, narrow wall built from the shoreline into the ocean
i. levee-a wall along the banks of a river or lake, designed to prevent flooding
j. reservoir-an artificial lake, used to hold water for future use and to control floods
k. sea wall-a tall wall built along the rear edge of a beach, designed to prevent erosion
l. soil-a natural resource that is made up of minerals, small rocks, water, gases, and
organic matter
m. storm drain-a system of pipes or channels that carry away water from storms
n. subsoil-the soil layer just below the topsoil; less rich than topsoil
o. terrace farming-the practice of planting crops in leveled sections along a hillside
p. topsoil-the surface layer of soil that is rich in humus and nutrients
2. What are three ways that floods can form?
Floods can form from heavy rainfall from hurricanes or other storms, repeated rainfall
over several days, and the overflowing of rivers and lakes.
3. How can heavy rains in one place lead to flooding far away?
Rainwater can flow as runoff into streams and rivers, which may carry the water a great
distance, and then cause flooding.
4. How do swamps, estuaries, and other wetlands help to control floods?
They soak up excess water that otherwise would flow as runoff.
5. Name four structures that help control floods.
Storm drains, levees, dams and reservoirs, floodways
6. What happens when a dam or levee fails?
Huge amounts of water can rush through the broken dam or levee, causing terrible
flooding and great damage.
7. How do beaches form? Rivers carry sediments to the ocean, which deposits them on
land.
8. What events can change a beach from day to day? Wind blows beach sand, while ocean
waves and tides may both deposit new sand and erode sand away.
9. Name three events that may cause beach erosion?
Building a dam, dredging a harbor, building a jetty
10. How might a dam on a river change ocean beaches near the mouth of a river? The dam
may block the flow of sediments into the ocean. Beaches near the river’s mouth may
erode.
11. What are three ways to slow or stop beach erosion? Beach nourishment, building a sea
wall, or leaving a beach free from development
12. What is global warming? Global warming is the gradual increase of Earth’s average
temperature.
13. How could global warming affect ocean shorelines? Melting of ice and snow in polar
regions could cause ocean levels to rise, which could lead to beach erosion.
14. Why is it in everyone’s interest to protect topsoil? Healthy topsoil yields healthy crops
that support the economy and provide food.
15. Name three ways farmers can protect topsoil. Contour plowing, planting cover crops
and wind breaks, and terrace farming