Name_______________________
Watersheds Study Guide Answer Key2015
1. Be prepared to define the term watershed. It is an area of land where water
drains into a common body of water such as a pond, stream, river or lake.
2. What is turbidity, and why is it important? Turbidity is the amount of sediment,
or dirt, in the water. High turbidity blocks sunlight, so it makes it tough on
plants, and it’s hard for many fish to live there.
3. Given a map of the Chesapeake Bay Watershed, be prepared to identify
Maryland, Virginia, the Delmarva Peninsula, West Virginia, Harpers Ferry, the
Shenandoah, Washington, D.C. SRMS, and Norfolk, VA, plus the Susquehanna,
the Potomac, the Rappahannock, the York, and the James Rivers, plus the
Chesapeake Bay from end to end, plus the Atlantic Ocean.. See your map
4. Given a map of the major watersheds of Virginia, be prepared explain where the
Eastern Continental Divide is, and what that term means. Find the New
Watershed, and its eastern boundary is also a portion of the Eastern
Continental Divide.
5. Given a piece of aluminum foil, be prepared to shape it in the form of the United
States (Florida will be important to show) with the appropriate continental divides
in place to actually function as they do in real life. Be sure to show the Rocky
Mountains in the West. In the East, the divide never reaches Florida, but
flattens out before reaching Florida.
6. Be prepared to explain the meaning of the term estuary, including a description of
flows of water and examples of the two major estuaries in the U. S. An estuary is
a body of water where fresh water from rivers and streams mixes with salty
water from the ocean. The two major estuaries in the U.S. are the Chesapeake
Bay, and Puget Sound in Washington State.
7. Be prepared to explain the meaning of the term dead zone or eutrophication as
applied to bodies of water, and how too much fertilizer runoff water can result in
dead zones. A dead zone is where the body of water will not support life. The
water has eutrophied, or is a dead zone. It can happen from pollution, such as
an oil spill, or from too much fertilizer. Fertilizer runoff leads to runaway
algae growth, called an algae bloom. Then the algae die off at the same time,
and the decaying stuff sucks up the dissolved oxygen, so nothing can live there.
Bad stuff.
8. Be prepared to (a) define the following terms: biotic and abiotic. Biotic = living
factors, such as plants and fish. Abiotic are the nonliving factors, such as salinity (salt
content), pH, other chemicals in the water, and the temperature of the water.
(c) Explain what dissolved oxygen in water is, to include a drawing
below of dissolved oxygen, water, and a fish. Dissolved oxygen is
where Oxygen molecules in gas form dissolve in water, or fit between
H2O molecules.
H2O H2O
O2
H2O H2O H2O H2O H2O H2O O2
H2O
(d) Explain the relationship between water temperature and dissolved
oxygen. The hotter the water is, the less dissolved oxygen that the
water can hold.
9. Beginning 35 million years ago describe the many events resulting in the modernday Chesapeake Bay. It all began 35 million years ago, when an asteroid came
hurtling towards Earth. It exploded in the air, making it a bolide, directly over
an area where we now have the end of the Bay near the tip of the Delmarva
Peninsula. Water levels were higher then, so the whole place was covered by
water, but even so a deep crater was created. Fast forward to about 12000 years
ago, and some major ice ages. So much H2O was locked up as ice on the
continents, especially Europe, that the ocean levels were way lower. Meaning
that there was a land bridge from Asia to North America, AND that the entire
area where the Chesapeake Bay now is found was dry, dry, dry. And the
continental shelf was dry too. What this meant was that when the glaciers
started to melt, they caused major erosion, like a long, long canyon from where
the Bay now starts to the crater at the end. Later, as ocean levels rose, they
filled in that canyon. Voila, that is the story of how the Bay was formed.
10.