The Horn of Africa has been experiencing exceptional droughts over the last decade. Using data collected from the NOAA POES satellite, changes in the severity of the drought conditions in the Horn and around the world are shown.

This Climate Change Impacts Collection provides the teacher and their students the opportunity to explore some of the environmental changes already observed, from the Arctic to tropical regions. Data sources provide historic precipitation and temperature records, allowing students to compare changes in their own local area to others. Lessons included, provide opportunities for place-based instruction related to climate change, others provided a more global perspective. The background resources provided in this collection tend to be for the teacher and/or the advanced student.

Desertification, the degradation of formerly productive land into desert, is a complex process. It involves multiple causes, and it proceeds at varying rates in different climates. This web page, produced by the U.S. Geological Survey, features text and photographs that explain what desertification is, how human activities may contribute to it, how satellite imagery is used for monitoring vulnerable areas, and how its effects may be mitigated by improved agricultural and land management practices.

The product that generated these images is the Normalized Difference Vegetation Index (NDVI), which measures the health of plant life based on their levels of photosynthesis. The NDVI was developed by Compton Tucker, a senior scientist at NASA-Goddard.

In 1931, a severe drought hit the Southern and Midwestern plains. As crops died and winds picked up, dust storms began. As the "Dust Bowl" photograph shows, crops literally blew away in "black blizzards" as years of poor farming practices and over-cultivation combined with the lack of rain. By 1934, 75% of the United States was severely affected by this terrible drought.The one-two punch of economic depression and bad weather put many farmers out of business. In the early 1930s, thousands of Dust Bowl refugees ? mainly from Oklahoma, Texas, Colorado, Kansas, and New Mexico ? packed up their families and migrated west, hoping to find work. Entire families migrated together (such as the men shown in "Three generations of Texans now Drought Refugees") in search of a better life. Images such as "Midcontinent ? Family Standing on the Road with Car," "Drought Refugees," and "Untitled, ca. 1935 (Worn-Down Family in Front of Tent)" offer a glimpse into their experience on the road, and show that cars provided many families both transportation and shelter on the road. About 200,000 of the migrants headed for California. The state needed to figure out how to absorb the thousands of destitute people crossing its borders daily. One of their tactics was to document the plight of the refugees. In 1935, photographer Dorothea Lange joined the Rural Rehabilitation Division of the California State Emergency Relief Administration (SERA), a section of the Federal Emergency Relief Administration. She was assigned the job of using her camera to document the growing number of homeless Dust Bowl refugees migrating to California. She worked with Paul S. Taylor, a professor at the University of California, Berkeley, who was researching conditions of rural poverty in order to make recommendations on how to improve the workers' conditions. The work by Taylor and Lange played an important role in helping to raise public awareness of the crisis. The reports they made for the government included both data and striking images that revealed the desperate conditions in which the migrants lived and confirmed the need for government intervention. Stark images such as "Home of Oklahoma Drought Refugees" resonated with the public, and portraits of drought refugees like "Ruby from Arkansas" and others shown in this topic humanized the migrants for more fortunate citizens. In March 1936, Lange took what became one of her most famous images, "Migrant Mother." This image of a 32-year-old woman became an icon for the suffering of ordinary people during Great Depression.

This site provides a brief description of the Dustbowl in the American Great Plains during the 1930s and relates its effects to what is occurring presently in the Sahel of North Africa. In this dry savannah environment, human activity coupled with prolonged drought are causing desertification. The site features text, satellite imagery, and links to other related materials.

This video segment adapted from NASA's Goddard Space Flight Center discusses how a drought can have negative effects locally, for example by increasing the number of forest fires, and also globally, for example by impacting air quality thousands of miles away.

This activity helps students learn how to find, interpret, and describe weather data. Students learn also about drought, flooding, wind and dust storms, hurricanes, and lightning, as well as the Tropical Rainfall Measuring Mission (TRMM) satellite -- the information it provides and why that information is important.

Lake Mead reservoir is nestled between Arizona and Nevada and runs up to the Hoover Dam. The reservoir stores Colorado River water and supplies it to farms, homes and business in Southern Nevada, Arizona, southern California and northern Mexico. Scientists at NASA are releasing dramatic pictures of the dwindling water supplies in the drought-stricken western United States. According to the Bureau of Reclamation, the Colorado Basin is in its fourth year of drought and computer models project water levels will go down another 15 to 20 feet (4.6 to 6.1 m) by next year. Despite low water levels, The National Park Service says there is still plenty of water for recreation. The Landsat 7 satellite captured images of Lake Mead May 2000, and May 2003. The 2003 image clearly shows a shrinking lake.

Dissolve between Landsat imagery of Loch Raven, Maryland in May and August of 1999, showing the effects of the drought

Side-by-side comparison of Loch Raven, Maryland in May and August, 1999, from Landsat imagery

This is a side-by-side image of Marylands Liberty Reservoir. The image on the left is a Landsat image from July 1997. The image on the right is also a Landsat image, but it was taken in July of 1999 after two consecutive years of drought.

Zoom down to Liberty Reservoir comparing July, 1997 and July, 1999. This animation shows Landsats view of Marylands Liberty Reservoir from its normal levels in July of 1997 to its extreme low levels during the drought of 1999.

New satellite-derived images of vegetation confirm extremely dry conditions exist that are ripe for fires in the western United States, according to a data collaboration between NASA and the USDA Foreign Agricultural Service.

This National Oceanic and Atmospheric Administration website provides climate information and data. This site offers a variety of product links to climate monitoring, climate at a glance data, U.S. drought assessment, global climate change information, weather observation stations and more. Users can also link to organizations which participate in climate research such as the National Climate Data Center, Ocean Climate Laboratory and the National Weather service. This site is an excellent resource for climate data and information.

In the Rocky Mountain Edition of the Natural Inquirer you will learn about fungi, Lodgepole Pine adaptations, mountain streams, Quaking Aspen, the American Marten, skiing, snowboarding, and much more!

This site provides background information on the effects of the Dust Bowl in the 1930s, the 1950s drought, and the 1987-1989 drought in the Great Plains of the American Midwest. It features discussions of the extent of each drought and the economic damage incurred, using text, photographs and graphic illustrations. A link to a discussion of the Palmer Drought Severity Index is included.

Subject considers how the visual and material world of "nature" has been reshaped by industrial practices, beliefs, structures, and activities. Readings in historical geography, aesthetics, American history, environmental and ecological history, architecture, city planning, and landscape studies. Several field trips planned to visit local industrial landscapes. Assignments involve weekly short, written responses to the readings, and discussion-leading. Final project is a photo-essay on the student's choice of industrial site (photographic experience not necessary).

Satellite data can gauge the health of plants, which is a good indicator of drought. The Normalized Difference Vegetation Index (NDVI) measures how dense and green plant leaves are. NDVI images are useful as a measure of drought when compared to "normal" plant health. Scientists calculate average NDVI values for an area to find out what is normal at a particular time of year. This animation uses satellite imagery to show changes in vegetation between 1999 and 2003. In 2002, drought had settled across the Midwest. Large dark brown sections of eastern Colorado show where vegetation was less lush and healthy than normal. This version of the visualization is a wide view showing the western United States. The data were measured by the vegetation instrument on Europe's SPOT-4 satellite, and were provided by DigitalGlobe-SPOT under agreement with the U.S. Department of Agriculture Foreign Agricultural Service (USDA-FAS).