Biomes: Detecting Vegetation Through Remote Sensing By Barclay Anderson and Rebecca McDonnell ABSTRACT This activity introduces the use of satellite imagery to obtain ecological information. To begin the activity, an untitled satellite image showing vegetation across the U.S. is displayed on the monitor. Groups of students are asked to hypothesize about what the satellite image is showing. They are then sent to various stations containing data that will provide them with information which they will use to confirm or reject their original hypothesis. During this activity, they will use actual scientific data found on the CD-ROM disc, debate hypotheses formulated by other groups, and exchange information and ideas. During the summary and conclusion session students support their original hypothesis or reject it in favor of a newer one. The teacher concludes the session by showing the visible and reflected infrared images and explaining how the image shown at the beginning of the period was obtained. Title: Biomes: Detecting Vegetation Through Remote Sensing 2061 Theme: Change, Patterns of Change, Interrelationships, Scale Major Concepts: Change, Patterns of Change, Global change, Mapping, Computations Process: Mapping models, Computations, Cooperative learning, Data analysis Attitudes: Global awareness, Demand for verification, Respect for data Disciplines:Biology, Botany, Geography, Mathematics, Science, Climates Grade Level:High school Key Word Search: vegetation, biomes, climate, remote sensing BACKGROUND The image used with this activity was made using data from a National Aeronautics and Space Administration's Advanced Visible High Resolution Radiometer (AVHRR) satellite. The AVHRR instrument sends data back to earth from three different bands of the electromagnetic spectrum: visible light, reflected infrared, and thermal infrared energy received from the earth. Each packet of data contains the intensity of these spectral bands for an area of about one square kilometer, actually 1100 square meters. Images can be made using data from any of the five sensors on the satellite. However, images made from any one sensor alone will give little information about the vegetation on earth. On the other hand if we produce an image by transforming values from both visible sensors and reflected infrared sensors we get an image based on the amount of light which is being reflected by the plants on earth at each 1 square kilometer. This transformation of data from two sensors allows us to produce images which show the difference between light absorbing activities on the earth. In summary, the image was made by using a vegetation index which is calculated by using the following equation. Reflected Infrared - Visible Light Vegetative Index = -------------------------------------- Reflected Infrared + Visible Light These vegetation index values provide us with images which indicate the photosynthetic activity on the earth and are easy to view and understand. OBJECTIVES Content 1. Students will be able to identify various biomes and the vegetation found in each. 2. Students will be familiar with the effects of different climates on the formation of biomes. 3. Students will understand the use of remote sensing in determining the areas occupied by different biomes. Process 1. Using deductive reasoning and group discussion, students will predict hypotheses about what this remote sensing image displays. 2. Utilizing data found on the CD-ROM disc, students will investigate evidence to support or reject their hypothesis about the remote sensing image. 3. Students will become familiar with the use of remote sensing and its applications to biology. MATERIALS: JEdI B CD-ROM disc, source of climate data (see Appendix A [F9]), colored pencils, photocopies of blank U.S. maps for students (Figure l [F9]) and Climate Data Table (Figure 2 [F9]), shaded relief U.S. map/elevation contour sketch, U.S. map/population, slides, magazine pictures, or laser disk images of various fauna and flora. These should include the following: a. Deciduous forest plants and animals b. Coniferous forest plants and animals c. Desert plants and animals d. Grassland plants and animals PROCEDURE Note: Press [Enter] after each command. Tutorial 1. Insert the JEdI B disc into the CD-ROM drive. With the C:\> prompt, type L: and strike [Enter]. 2. Type CD GNA and then GNA. 3. Press any [key]. 4. Main menu. 5. Select "Tutorial." Complete tutorial. This is a "slide show" which will not allow any command of the functions other than advancing one frame ahead with a key stroke. 6. At the end of the tutorial ":\GNA>" will appear on the screen. Selecting an Image 1. Type in GNA and a title screen will appear. 2. Press any [key]. 3. Main menu screen will appear. 4. Select "VIEW DATA (IN EGA GRAPHIC MODE)." 5. A menu bar will appear. 6. Select "Image." 7. Image Selection will appear. 8. Select "Satellite Imagery Summer - Vegetation." 9. Palette will appear. 10. Select "System Default." 11. Menu bar will appear. Selecting an Area: Image #1 1. Select "Area." 2. Select "New." 3. Select "Enter Limits." 4. Select Upper latitude - 53.000 N Lower latitude - 24.000 N Left longitude - 125.333 W Right longitude - 69.333 W 5. After you have entered the coordinates of the image, strike [Enter] and then strike [Go]. 6. A small image will appear at the bottom left hand corner of your screen; to enlarge it to full screen, strike Page Up [PgUp], once. Processing Image #1 1. Strike [Enter]. This returns you to the menu bar. 2. Select "Image;" strike [Enter] at the Vegetation highlight; select "New" under system palette and a color palette selection screen will appear. 3. On the left hand side of the screen there will be a vertical color bar with values from 0 to 255. On the right side will be a histogram divided into a range of colors. The next step will allow you to change the colors for these data intervals. 4. The image presented here has the background (data intervals 0-10) the same color as the water (data intervals 10 - 40). 5. To change these to blue (water color): a. Strike [Enter], and then 2, and then [Enter]. These keystrokes have selected the data value of zero to be shown as color #2. b. Now move the up arrow until the arrow to the left of the histogram is at the data value of 40. The data value will also be shown numerically between the vertical columns of EGA colors and the text column saying "DATA INTERVALS." c. When the cursor is at the data value of 40, strike [Enter], then 2, and then [Enter] again. The color for values 0-40 should change to the color blue. d. Strike the [F10] function key to tell the computer that you are finished changing the color palette. Strike [Go] and the image will reappear with the background colors showing the same as the ocean. (You may have to [PgUp] one time to get the full size image.) Saving Image #1 1. This step allows you to save the image to the hard disk and cut down on the image access time. 2. From the image, strike [Enter] to return to the menu bar; select "Screen" and then select "Save." 3. A file save line will appear. After the "File:" prompt, enter the drive letter followed by a file name. These images are rather large and they may have to be saved to a large hard disk. Your file entry may look like this: File: C:IMAGEONE 4. After the image has been saved you can return to the image by selecting "View menu" and then selecting [Go]. Image #2 1. Image #2 is the Satellite Imagery Summer - Visible image which uses the same area as Image #1. 2. At the menu bar for Image #1, select "Image" and then select "Satellite Imagery Summer - Visible." 3. Accept the system palette default and then select [Go]. (Be sure that the area is still 53.000 N to 24.000 N latitude and 125.333 W to 69.333 W longitude.) 4. Strike [PgUp] to get the full screen size. 5. Now save the image as "Imagetwo" using the directions found in "Saving Image #1." Image #3 1. Image #3 is the Satellite Imagery Summer - Reflected Infrared image which uses the same area as Image #1 and Image #2. 2. At the menu bar for Image #1 or #2, select "Image" and then select "Satellite Imagery Summer - Reflected Infrared." 3. Accept the system palette default and then select [Go]. (Be sure that the area is still 53.000 N to 24.000 N latitude and 125.333 W to 69.333 W longitude.) 4. Strike [PgUp] to get the full screen size. 5. Now save the image as "Imagethr" using the directions found in "Saving Image #1." Using Image #1 1. At this time students should use Image #1 to color their original map, (Fig. 1 [F9]). 2. Assign each of the class members to one of four groups. Have the group members pick a leader. 3. Have each team brainstorm for about 10 minutes to try to interpret what the colors on their map represent. You may want to suggest they consider: temperature population precipitation elevation cloud cover vegetation 4. The students should discuss as a team, the possible explanations for the colors shown on the satellite image. Each group should formulate one or two hypotheses about the reasons for the different colors. They will then gather additional data from four data stations. Setting up Stations Prior to setting up the computer, the following stations need to be established: 1. Station 1, Elevation - At this station, students will sketch 1000 meter topographic contours. Use the contour routine on the GNA program to sketch the contours on the original map. 2. Station 2, Pictures - At this station, students will view pictures of different fauna and flora characteristic of different biomes. Each picture should have a number and the city and state written on it. (The teacher should have a large map of the United States displayed so students can locate the particular location given on each picture.) Then the corresponding number is placed on the student's original map (Fig. 1 [F9]). Note: The Teacher should label the pictures according to the following key: 1. plants and animals found in deciduous forests 2. plants and animals found in coniferous forests 3. plants and animals found in grasslands 4. plants and animals found in the desert 3. Station 3, Population - At this station, students will use a population map and will add pencil dots to their map corresponding to those shown. Instruct students to indicate only high population areas. 4. Station 4, Climate - At this station, students will utilize raw data on climate. This includes maximum high and low mean annual temperatures and precipitation for specific cities. We have chosen areas that show vegetation characteristic of specific biomes. Have the students select the appropriate state and city as indicated in the procedure. Students should enter this information on the Climate Data Table (Fig. 2 [F9]). Using the Information at the Stations 1. Each group will spend time at each one of the four stations. They are responsible to gather as much information as possible from each station. After gathering and analyzing the data, the group will then evaluate their hypotheses. 2. Rotate the groups through the four stations. 3. Have each group record their data on a group record. Station #1 - Elevation (Figure 1 [F9]) 1. Draw contour lines which represent the mountains and valleys depicted. 2. Discuss with your team if there is any correlation between elevation and the drawing you sketched of the satellite image. Station #2 - Pictures At Station 2, transfer the number shown on each picture to the correct location on your map (Fig. 1 [F9]). Again discuss with your team the relevancy of this new information. Station #3 - Population 1. Discuss and design a system that your group can use for showing population on Figure 1 [F9]. 2. Use this system so that the areas of highest population are represented. 3. Discuss with your team any correlation between population and the satellite image. Station #4 - Climate 1. Use a source climate information (see References) to complete the Climate Data Table (Fig. 2 [F9]). 2. Locate and label on Figure 1 [F9] the cities for which you have researched the climate. CONCLUSION 1. Discuss with your group conclusions as to what the satellite image is showing. You will have to be able to justify your conclusions to the class at the end of this activity. 2. Discuss as a class your findings and decide what the satellite image is showing (see Appendix B [F9]). EXTENSIONS 1. At this time, the teacher can display other satellite images of the same area. 2. To see the difference between the vegetation, visible light and reflected infrared light, images you will retrieve the three saved images: Imageone, Imagetwo and Imagethr. (See Saving Image #1.) 3. At the menu bar select Screen, and then Restore. 4. Select the image (Imageone, Imagetwo or Imagethr), and then strike [Enter], twice. 5. After viewing the image repeat steps 3 and 4 for each image you have saved and want to see. REFERENCES Cayan, Daniel R., Ropelewski, Chester F., Karl, Thomas R., An Atlas of United States Monthly and Seasonal Temperature Anomalies, December 1930 - November 1984, La Jolla, California: Scripps Institution of Oceanography, Climate Research Group, 1986, 344 p. Hattemer-Frey, Holly A., An Annotated Inventory of Climatic Indicies and Data Sets, Washington, D.C.: U.S. Department of Energy, Office of Energy Research, 1986. 195 p. Ruffner, James A., Climates of the States: national Oceanic and Atmospheric Administration Narrative Summaries, Tables, and Maps for Each State, with Overview of State Climatologist Programs, Detroit, Michigan: Gale Research Co., 1985, Ruffner, James A.,Bair, Frank E., The Weather Almanac: A Reference Guide to Weather, Climate and Air Quality in the United States and Its Key Cities, Detroit, Michigan: Gale Research Co., 1987, 811p. Southeastern climate Review, Columbia, S.C.: Southeastern Regional Climate Center, Quarterly, vol. 1, no. 11.