Draft Basic Lesson 2
Studying Topography, Orographic Rainfall, and Ecosystems (STORE)
Basic Lesson 2: Using Google Earth to Analyze
the Connection between Topography and Rainfall
Introduction
Read the Introduction section on the full lesson packet and answer
the following below:
 1. What is the purpose of this activity?
 2. What will you, the student be doing and why is this
important?
 3. Where does all the data come from?
Image 1. California Study Area.
Objective
To introduce and teach the basics of GIS to the students. To challenge students to see rainfall
patterns over mountains and valleys.
Requirements

Google Earth software

Download “STORE CA Data.kmz” .
Part 1 – Set up
1. Open Mozilla/Firefox and go to http://store.sri.com/data_software_light.html.
2. Click on “- Click here to get the master STORE data for California that ALSO includes…..two
storms…” . When this is done downloading go to Step 3.
3. Open Google Earth from your computer. Once Google Earth (GE) is open, click “File” at the
top right corner of the Google Earth window, and click on “Open” from the drop down menu.
In this window, navigate to the “STORE CA Data.kmz file downloaded on your computer.
Once you have selected the kmz file, click “Open”.
4. Save “STORE Data” file in GE to “My Places” by dragging and dropping the folder into
“My Places” under the “Places” Panel on the right of the screen.
5. Remember: It can get confusing when you have multiple layers selected at once and multiple
folders and subfolders open. To avoid confusion, close layers, folders and subfolders you are
finished with before opening new ones.
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Part 2 – The Weather Stations
6. Five weather stations (e.g., Twin Lakes, Sonora RS, etc.) within the California Study Area
may already be displayed on the map. If they are not, click the box next to the subfolder
called “CA Weather Stations” within the Places Panel on the left side of your Google Earth
window. By clicking that box, a check mark appears and the five layers in the subfolder
become visible on the map – one layer for each weather station.
7. Click on each of the weather stations to view a table of information about that station.
Remember, you must click on the red dot and not on the name of the weather station. The
table appears in a “pop up window” on the map next to the weather station. To close the
popup window, clicking on the “x” in its upper right corner.
 Complete the following table with information for each station:
Name
Elevation (ft.)
Ann. Ave. Temp.
Ann. Ave. Precip.
 Looking at each station’s elevation and precipitation, what correlation(s) can you
make? Is there a relationship between elevation and precipitation?
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Part 2 - Visualize variations in precipitation corresponding to changes in elevation
(Orographic Rainfall)
1. Keep the weather station layers on the map. In
the Places panel, click the box next to the layer
name “Terrain Path through the Weather Stations.
2. You will now call up an “elevation profile” of
the terrain path to examine the topography along the
path. First, make sure that you’ve select the layer
“Terrain Path through the Weather Stations by
clicking its name. You will know if is selected when
a blue frame appears around the name. Then, as
shown below, click “Edit”. A menu of editing choices
should appear on top.
3. In the list of choices, click “Show Elevation Profile”.
4. As shown below, an elevation profile of the terrain path will appear. It is
a cross-sectional view showing the changing elevation and topography.
In other words, it is a two-dimensional view that mimics what you would see from the
ground if you were looking at a vertical slice (i.e., cross-section) of land with all of its
changes in elevation.
Move your cursor along the elevation profile to study the changing elevation by clicking
anywhere on the profile’s moveable dark vertical line. To move the line, hold the mouse
down, move it, then release the mouse.
Image 9:
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Name
 Trace the elevation terrain profile path and find the elevation, slope gradient and
distance along the path for each weather station and record below.

Elevation (ft.)
% Gradient
Distance along path
 Do these elevation values match what your recorded from the tables ?
 What do the slope gradients tell you about the terrain for each station (flat, gentle
slope, steep….) See page 10 in the reference packet for more info.
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The terrain path through the weather stations has been pre-developed for you as a layer.
However, you can also create your own terrain paths and make your elevation profiles for
them. To create your own path, click on the path-creation icon:
It is the fourth icon from the left on the horizontal bar at the top of the Google Earth
window. In Image 11, it is circled in green.
Image 11:
As shown in Image 12, a dialog box will then appear on top of the map with a default name:
“Untitled Path.”
Image 12:
In the dialog box, first replace “Untitled Path” with a meaningful name (such as “My path
through mid-California”). Then, keep the dialog box on the screen and draw your path. If the
dialog box is in the way, you can resize it by clicking lower right corner, then holding your
mouse down and making it smaller. You can also move it around by holding the mouse
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Draft Basic Lesson 2
anywhere on it and dragging it to a better spot out of the way). (NOTE: do not close the
dialog box until you have completed drawing the path. Otherwise you cannot draw it.)
To draw your path, click once with your mouse at the place where you want the path to
begin, then drag the mouse to the place where you want it to end, then click again. This will
create a path with a single line segment. If however you want to create a path with more than
one line segment, continue drawing new segments with your mouse and clicking where you
want each segment to end. If you want to change the shape of one of the segments, simply
click the segment, hold the mouse down and move it. When you are done moving it, let up on
the mouse. In Image 13, the new path appears on the map as a thin white line.
Image 13:
When you are done drawing your path, click the OK button on the path dialog box. Notice
how the dialog box then disappears but the name of the path appears on the Places panel. If
you don't like where it appears on the panel, hold your mouse down on the path name and
move it somewhere else.
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For example, in Image 14, the new path appears as a layer in the “2099 Precipitation
Projections” subfolder, which is not the best place for it. So, it is being moved to appear
instead below the “Terrain Path through the Weather Stations” layer (shown on the image by
a horizontal black line line)
Image 14:
Once you’ve created your path, you can bring up an elevation profile for it just like you did
for the path through the weather stations.
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3. Keeping the weather station and terrain profile layers open, you will now study layers
showing 30-year averages of annual amounts of rainfall. Each layer consists of a single
polygon representing an area on the map that has a certain range of values for average annual
precipitation totals, such as from 5.01 to 12 inches, 12.01 to 20 inches, etc. To make these
layers visible on the map all at once, click the box in the Places panel next to the subfolder
called “Recent Average Annual Precipitation Totals” (circled in red on Image 15). When you
click the box, a check will appear in it and your map will look like it does in Image 15.
Image 15:
TIP: You can zoom in and out of the map area, depending on how much detail you want to
see. To zoom, scroll your mouse over the top right corner of the map area. A toolbar for
zooming in and out should appear below a compass rose (In Image 14, it is circled in green).
Question 2: As you move your eye along the terrain path, what pattern do you see in precipitation in
relation to elevation? Based on your understanding of orographic rainfall (first introduced in Basic
Lesson 1), provide a simple explanation as to why this pattern occurs. For another view of the
terrain, examine Figure 2.
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Image 16. Average annual precipitation overlain on a topographic relief map for the California
Study Area. The darker blue areas over the land represent greater average annual precipitation.
Additional Information
The Hydrologic Cycle at http://snow.cals.uidaho.edu/clim_map/koppen_usa_map.htm. This link
shows how climate zones in the US are very closely related with elevation. Mountainous areas have
colder/wetter climates than adjacent lower areas.
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