Part 3—Explore Sabino Canyon's Features

Step 1 –
Explore the Sabino Canyon Watershed in Google Earth

Tucson
Tucson is located in southern Arizona. Click the image for a larger view.
Over one-third of the world's surface is considered arid or semi-arid, including one-quarter of the U.S. mainland. In this chapter, you will examine a semi-arid watershed in southern Arizona, near Tucson. You will discover the relationship between seasonal precipitation and streamflow in the watershed. The Sabino Canyon watershed is nestled in the front range of the Santa Catalina Mountains near Tucson, Arizona, a densely populated metropolis of nearly one million people. Sabino Creek and its recreation area are a main attraction to visitors of this desert city.

ge_win_icon

  1. Launch Google Earth by clicking on its icon on your dock (Mac) or on the Start menu (PC).
  2. Choose File > Open..., then navigate to where you saved the Sabino_Creek.kmz file in the Monsoon Data folder. Select the file and click Open. Your map will open showing Sabino Creek from an aerial view. The creek is shown as a blue line on your Google Earth map. Examine the location of the creek, and the shape of the mountains and landscape (topography) around the creek.
    1


  3. Next, navigate to where you saved the Sabino_Canyon_Watershed.kmz file in the Monsoon Data folder. Choose File > Open... to open the file. You should see the entire area that includes the Sabino Canyon watershed (shaded pink) on your map, in addition to Sabino Creek. Any precipitation that falls inside the boundary of the Sabino Canyon watershed will exit the watershed by way of a common outlet—the Sabino Creek drainage.
    sabino canyon watershed


  4. Turn on the Photos database, located in the Layers panel in the lower left-hand corner of the Google Earth window. You should see several Photo markers (they will appear as blue dots or camera icons) on your map. These Photo markers represent locations where visitors to the area took photographs.
  5. Click on any of the Photo markers in and around Sabino Creek and its watershed to view photographs of the landscape in the canyon. These photographs will allow you to visually explore the watershed in more detail.
  6. After you have explored some of the photographs taken in the canyon, activate Show terrain from the Google Earth Preferences Window.
  7. Use the Tilt and Rotate tools located in the upper-right corner of the Google Earth map to explore the topography around Sabino Creek.
  • Which direction does stream water flow in Sabino Creek?
  • Finally, open the Rillito_Subbasin.kmz file located in the Monsoon Data folder. Note how much larger this watershed is than the Sabino Canyon watershed.
    The Sabino Canyon watershed is a small watershed situated within the larger Rillito watershed, or subbasin. There are many small watersheds within the Rillito subbasin. In fact, there are many watersheds that are situated within the Santa Catalina Mountains alone, all of which have their own separate drainages or creeks that drain water out of each watershed. Next, you will examine how the Sabino Canyon watershed compares to some of the other watersheds in the Santa Catalinas.
  • Quit Google Earth and do not save changes.

    • Step 2 –
    Launch My World and Compare the Area of Sabino Canyon to Similar, Nearby Watersheds

    My World Icon

    1. Launch My World by double-clicking its icon on your desktop or by clicking its icon in the dock (Mac) or Start menu (PC).
    2. Choose File > Open Project..., then navigate to the sabino_watershed.m3vz project file. It should be located in the My World GIS data folder.
      When the map launches, the view shows the major streets in the city of Tucson and the Santa Catalina Mountains to the northeast of the city.
      sabino canyon layer is on


    3. Turn on (show) the Catalina Watersheds layer.
    4. Activate the Catalina Watersheds layer.
    5. Click the Show Table button at the top of the Layer List. This opens the Table of the Active layer.
    6. When the table is open, click the Area (computed) m2 field name (in the top row of the table) to sort the rows in ascending and descending order (greatest to least). List the names and areas of the three largest watersheds in the Santa Catalina mountains in the table below. Round the area to the nearest million m2 (1,000,000).
      7. Watershed name Area (m2) Highest annual precipitation received (cm)
      your answers here
      your answers here
      your answers here

    7. Once you have sorted the table, select the three largest watersheds.
    • Click anywhere in the first row of the layer table and then drag the pointer down to select the first three rows. These rows will be highlighted blue when selected properly.
    • Choose Make Selection From Rows at the top of the table.
    • Accept the default name for the selection and click OK. The table will automatically close.
    • Choose Hide Unselected in the Highlight Mode drop-down list under the Catalina Watersheds layer name. Now only the three largest watersheds in the Santa Catalina Mountains should be highlighted on your map.
  • Learn more about your selection.
    • Click the Get Information Tool to activate it.
      get info tool

    • Then click each of the three watersheds to identify and familiarize yourself with their names.
    • When you are done exploring, close the Get Information window.

    Step 3 –
    Discover the Amount of Precipitation in the Canyon

    1. Discover the amount of precipitation in the canyon.
      • Hide (turn off) the Shaded Relief Map layer. Note: you may need to scroll down to view all the available layers.
      • Show (turn on) the Precipitation (cm/yr) layer. This layer shows the annual precipitation, in centimeters, received in Tucson and surrounding areas.
        precip is on

      • Activate the Precipitation (cm/yr) layer.
      • Use the the Get Information Tool and click on the zone of highest precipitation within each of the three watersheds to determine the maximum precipitation received in that watershed each year.
    2. Enter the highest precipitation amount (in centimeters) received in each watershed in Table 1. above.
    3. When you are done, close the Get Information window.