QUESTION 1 (basic measurement for sinkholes) - 4 points A sinkhole is a natural depression in a land surface communicating with a subterranean passage, often occurring in limestone regions and formed by solution or by collapse of a cavern roof. A. For the Malaspina Glacier, the yellow pushpin is immediately over a sinkhole. Using the measure tool, measure the width of this sinkhole and at least four more. List all 5 measurements and determine the average width. B. Do the same for the Florida site. C. Do the same for the Mexico site (the yellow pushpin icon is not visible here; you'll need to identify the sinkholes on your own here.) Timeline Tool Measure Tool Double Click Drag slider to desired date D. Are there any similarities in sinkhole size from site to site? If so, describe them.
QUESTION 2 (Elements of recognition) - 6 points For each site location (A = Alaska, B = Florida, C = Mexico), identify three items you see on the satellite imagery and explain how you identified each feature using any of the 8 elements of recognition. Example: if you were to identify a treeline, you may indicate that the darker green tone or color relative to surrounding grassy or dirt fields helped you identify this feature, or that the texture (rounded, coarse features next to surrounding features with smoother textures) helped you with the identification. A. ALASKA: B. FLORIDA: C. MEXICO: QUESTION 3 (Spectral properties of satellite imagery) - 5 points Navigate to the Mexico imagery. This area is about 30m above sea level and about 20- 24m above the local water table. There are three image overlays: A 2009 near-infrared image (where healthy vegetation looks bright red); A 2009 true-color image (same date as near-infrared image); and a 2006 near-infrared image (where healthy vegetation looks bright red). Note: The two Rejolladas IR files should display red images for this exercise. If this is not the case, navigate on Blackboard Learn to Module 12 > Lab 8
Question 3. Use this file to complete the following questions. A. Describe the differences in vegetation health between 2006 and 2009. B. One of the images (2006 or 2009) occurs during the dry season. Which image is it and why? (Note: this site is firmly in the Aw climate zone). C. Where does the healthiest vegetation occur on the images? What factors contribute to this?