Using National Geographic, January, 1992, pp. 54-85, answer and
discuss the following:
1. What is the age of
the Namib Desert?
2. Describe 3 sources of
water in the Namib Desert.
3. How often is there
water in the rivers? What is the annual average rainfall?
4. How do Namib
elephants differ from elephants that live in other places?
5. How often do Namib
elephants need to drink?
6. How does the fog form
and what part does it play in this ecosystem?
7. List land forms that
you see in the photographs in the article.
8. List some of the
animals and plants that live in the Namib Desert.
9. What are some of the
possible food sources in the desert?
10. Use the lists in #8
and 9 to draw a Namib Desert food web.
11. List water sources in the
desert.
12. Look at the map on page
67. What do the red arrows represent? Blue arrows?
In what direction is the wind
blowing? What direction does the ocean current flow?
13. How do these animals adapt
to surviving in the desert: giraffes, spiders, dune ants, lizards,
tenebrionid beetles, people, lions.
Vocabulary list
adapt
detritus
desert
ecotype
poacher
thermoregulating
Extension
Prepare a debate
about whether or not a desalinating plant should be built in this
desert.
What impact would
available fresh water have on the ecosystem of the Namib Desert?
Look at the issue
from the points of view of conservationists ground water and
developers.
Lesson
3
MEASURING
THE DEW POINT
PROBLEM:
How to determine dew point
?
MATERIALS:
thermometer
shiny can
stirring rod
room temperature
water
ice
PROCEDURE:
Note: You may want to draw a chart to record
your data.
1. Half fill a shiny can
with room temperature water. Be sure that the outside of the can is
dry when you begin.
2. Record the
temperature of the air and water.
3. Leave the thermometer
in the can. While carefully watching the outside of the can,
gradually add ice, stirring with the stirring rod
(DO NOT USE THE THERMOMETER TO STIR...IT MIGHT BREAK!). Beads of
moisture will appear on the outside of the can giving it a frosted
appearance. As soon as moisture appears on the outside of the can,
read the thermometer and record. This temperature is the dew point
for present conditions.
4. Repeat the experiment
two more times. Always start with room temperature water and a can
that is dry on the outside. Record your results.
5. Find the average of
your results.
QUESTIONS:
1. Define dew point.
2. Define
condensation.
3. What caused moisture
to form on the outside of the can?
4. Do you think the dew
point will vary under different conditions? Explain.
5. Did everyone in the
room get the same dew point? Did you get the same in each of your 3
trials? Why would all the answers be the same? Why would they be
different? Discuss.
EXTENSION: When would you expect dew to form in
the Namib Desert?
Lesson
4
Interpreting the Photo
PROBLEM: Animals and plants live in the Namib
Desert where it rains only about every decade. There is no surface
water in the desert. How do plants and animals survive without
rainfall?
Use the photo and maps to work through this sheet to help you
solve the problem.
1. Use a map to locate
the exact position of the photo. Identify the following:
continent
country
large body of
water
latitude and
longitude
2. Examine the photo and
identify the following by labeling photograph. (use washable marker
on laminated photo or clear plastic overlay)
surface
water
fog
change
in elevation
sand
dunes
beach
surf
rocky
formations
drainage
patterns
clouds
(over land)
evidence
of erosion
surf
3. Using the map, " Major
World Currents", identify the current along the Namib coast. Where
does this current come from? Is it a warm or cold current?
Identify the current to the
west of this current. Is it a warm or cold current?
4. Fog - What kinds of
conditions over the ocean are needed for evaporation?
Where does
evaporation occur?
What kinds of
conditions are needed for water vapor to condense?
Where does
condensation occur?
Summarize: what
causes fog in the photo to form over the ocean?
In this photo, winds blow from
west to east. What effects do the winds have on the fog? How does
this relate to our problem of survival without rainfall?
5. What may have caused the
drainage and erosion patterns in the photo?
6. Is there any evidence
of people living in this area? Why do people live or not live here?
What are some ways that plants and animals could adapt to this
environment?
7. In summary, describe
the effect the fog has on the ecosystem of the Namib Desert?