This chapter is most appropriate for students in grades 9-12. The Case Study and the variations suggested in the Going Further section can also be introduced in grades 5-8.
Learning GoalsAfter completing this chapter, students will be able to:
- examine an environmental issue with Synthetic Aperture Radar (SAR) images;
- process SAR images by scaling, filtering, measuring, stacking, and creating color composites; and
- interpret processed SAR images of a region in the Amazon rainforest of Brazil to determine how deforestation has changed over time.
The techniques introduced in this chapter can be used with SAR data from all over the world to measure land cover changes such as deforestation, urban expansion, and coastal erosion.
Synthetic Aperture Radar (SAR), is a source of satellite data that is used to generate maps of the Earth's surface; the images you will be working with were taken by the first Japanese Earth Resources Satellite (JERS-1). Other, optical methods are also used to take pictures of the Earth, but those methods cannot "see" through clouds. The Amazon rainforest is a very cloudy place, and those clouds are invisible to SAR, so SAR images are especially useful for studying land cover changes in any Earth location that tends to be cloudy.
A tutorial on the basics of remote sensing is hosted at Canada Centre of Natural Resources.
To introduce SAR to a younger audience in a story format, visit Treasure Hunt in Alaska.
Brazil is the largest country in South America and the fifth largest country in the world; only Russia, Canada, China, and the US (with Alaska and Hawaii included) are bigger. It is more than 8,500,000 square kilometers or 3,200,000 square miles in size, and more than half of Brazil is covered in Amazonian rainforest. This rainforest is the largest and most species-rich tropical forest in the world, and has been called the "Lungs of the Planet" because it produces about 20% of the Earth's oxygen! It is estimated that this rainforest may contain half of all the species of plants and animals in the world, including 30 million insect species. Many useful drugs have been developed from rainforest plants including quinine (malaria), neostigmine (glaucoma), novacaine (local anesthesia), and cortisone (anti-inflammatory). However, only a few percent of the rainforest plant species have been tested for medicinal applications. Of course people also live in and around the rainforest, and they need to make a living. Valuable hardwood trees are harvested for export, and forests are cleared for cattle ranches, mining, and subsistence farming.
To read more about the rainforest, including plants, animals, and climate, you can visit NASA's Earth Observatory and type "Amazon Rainforest" in the search window for many articles, including articles about deforestation in Brazil. To learn about medicines from rainforest plants and much, much more visit the environmental science and conservation news site "Mongabay".
The following National Science Education Standards are supported by this chapter:
- 8ASI1.2 Design and conduct a scientific investigation.
- 8ASI1.3 Use appropriate tools and techniques to gather, analyze, and interpret data.
- 8ASI2.4 Technology used to gather data enhances accuracy and allows scientists to analyze and quantify results of investigations.
- 8FSPSP2.1 When an area becomes overpopulated, the environment will become degraded due to the increased use of resources.
- 8FSPSP2.2 Causes of environmental degradation and resource depletion vary from region to region and from country to country.
- 12ASI1.2 Design and conduct scientific investigations.
- 12ASI1.3 Use technology and mathematics to improve investigations and communications.
- 12ASI2.2 Scientists conduct investigations for a wide variety of reasons. For example, they may wish to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories.
- 12ASI2.3 Scientists rely on technology to enhance the gathering and manipulation of data. 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.
Geography StandardsThe following National Geography Standards are supported by this chapter:
- How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information from a spatial perspective.
- The processes, patterns, and functions of human settlement.
- How the forces of cooperation and conflict among people influence the division and control of Earth's surface.
- How human actions modify the physical environment.
- The changes that occur in the meaning, use, distribution, and importance of resources.
- Case Study: 5 to 10 minutes
- Part 1: 20 minutes
- Part 2: 30 minutes
- Part 3: 20 minutes