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. Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables. They should also develop the ability to clarify their ideas that are influencing and guiding the inquiry, and to understand how those ideas compare with current scientific knowledge. Students can learn to formulate questions, design investigations, execute investigations, interpret data, use evidence to generate explanations, propose alternative explanations, and critique explanations and procedures.
- 8ASI1.3 Use appropriate tools and techniques to gather, analyze, and interpret data. 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.
- 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. Designing and conducting a scientific investigation requires introduction to the major concepts in the area being investigated, proper equipment, safety precautions, assistance with methodological problems, recommendations for use of technologies, clarification of ideas that guide the inquiry, and scientific knowledge obtained from sources other than the actual investigation. The investigation may also require student clarification of the question, method, controls, and variables; student organization and display of data; student revision of methods and explanations; and a public presentation of the results with a critical response from peers. Regardless of the scientific investigation performed, students must use evidence, apply logic, and construct an argument for their proposed explanations.
- 12ASI1.3 Use technology and mathematics to improve investigations and communications. 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.
- 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