Teaching Notes

Example Output
Distances across the widest portion of the Aral Sea in September of 2001 and 2003. Click on image for a larger view.

In this chapter, students will select from a series of images and will measure changes in the area of the lake and distance across the lake using ImageJ. The images, right, show one example of the types of images and output from this chapter.

• download, install, and use ImageJ image analysis software to quantify change over time in satellite images;
• access and download satellite images for specific locations and times;
• set a scale (spatial calibration) for an image in ImageJ; and
• select and measure distances and areas on images in ImageJ.

Satellite images are composed of a rectangular array of pixels, or picture elements. Each pixel represents a single measurement made by a satellite instrument, and each measurement corresponds to a specific amount of area on Earth's surface or in the atmosphere. Though we are limited to measuring across pixels on a satellite image, knowing exactly how much area is represented by each pixel allows the image analysis program to convert from pixels to real-world units. To set the spatial calibration or scale of an image, students enter the desired units of measure and a conversion factor that indicates the distance on the ground represented by each pixel in the image.

The following links may be of interest to teachers and students:

• Aral Sea Crisis—an in-depth article from Columbia University.
• Aral Sea Basin (The World Bank Group)
• The Shrinking Aral Sea
• Dust Storm, Aral Sea
• Windswept Shores of the Aral Sea
• Aral Sea
• Image of the Day: Aral Sea
• Aral Sea, 2000-2008
• Aral Sea Continues to Shrink, August 2009

Grades 5-8

• Use appropriate tools and techniques to gather, analyze, and interpret data.
  Show remainder of standard 8ASI1.3
  Hide
  The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.
• Communicate scientific procedures and explanations.
  Show remainder of standard 8ASI1.7
  Hide
  With practice, students should become competent at communicating experimental methods, following instructions, describing observations, summarizing the results of other groups, and telling other students about investigations and explanations.

Grades 9-12

• Use technology and mathematics to improve investigations and communications.
  Show remainder of standard 12ASI1.3
  Hide
  A variety of technologies, such as hand tools, measuring instruments, and calculators, should be an integral component of scientific investigations. The use of computers for the collection, analysis, and display of data is also a part of this standard. Mathematics plays an essential role in all aspects of an inquiry. For example, measurement is used for posing questions, formulas are used for developing explanations, and charts and graphs are used for communicating results.
• Scientists rely on technology to enhance the gathering and manipulation of data.
  Show remainder of standard 12ASI2.3
  Hide
  New techniques and tools provide new evidence to guide inquiry and new methods to gather data, thereby contributing to the advance of science. The accuracy and precision of the data, and therefore the quality of the exploration, depends on the technology used.
• Interactions among the solid earth, the oceans, the atmosphere, and organisms have resulted in the ongoing evolution of the earth system.
  Show remainder of standard 12DESS3.3
  Hide
  We can observe some changes such as earthquakes and volcanic eruptions on a human time scale, but many processes such as mountain building and plate movements take place over hundreds of millions of years.

• How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information from a spatial perspective
• How to analyze the spatial organization of people, places, and environments on earth's surface
• The physical processes that shape the patterns of earth's surface
• How human actions modify the physical environment

• Case Study: 5 minutes
• Part 1: 20 minutes.
• Part 2: 10 minutes
• Part 3: 10 minutes
• Part 4: 20 minutes

• Zipped folder of Aral Sea images 2000-2010 (Zip Archive 2.1MB Aug10 11)—Save this zipped folder of jpeg images to your downloads folder or desktop. Unzip the file and open the images in ImageJ.
• File of stacked images (TIFF 16.3MB Aug10 11)—Save this stack to your downloads folder of desktop and open with imageJ.

• Completed measurements 2000-2010 (Excel 2007 (.xlsx) 348kB Aug10 11)—Save this file to your downloads or desktop. Open with Microsoft Excel.