Florida’s Everglades is a region of broad, slow-moving sheets of water flowing
southward over low-lying areas from Lake Okeechobee to the Gulf of Mexico. In
places this remarkable ‘river of grass’ is 80 kilometers wide. These images from
the Multi-angle Imaging SpectroRadiometer show the Everglades region on January
16, 2002. Each image covers an area measuring 191 kilometers x 205 kilometers.
On the left is a natural color view acquired by MISR’s nadir camera. A portion
of Lake Okeechobee is visible at the top, to the right of image center. South of
the lake, whose name derives from the Seminole word for ‘big water,’ an
extensive region of farmland known as the Everglades Agricultural Area is
recognizable by its many clustered squares. Over half of the sugar produced in
United States is grown here. Urban areas along the east coast and in the
northern part of the image extend to the boundaries of Big Cypress Swamp,
situated north of Everglades National Park.
The image on the right combines red-band data from the 46-degree backward, nadir
and 46-degree forward-viewing camera angles to create a red, green, blue
false-color composite. One of the interesting uses of the composite image is for
detecting surface water. Wet surfaces appear blue in this rendition because sun
glitter produces a greater signal at the forward camera’s view angle. Wetlands
visible in these images include a series of shallow impoundments called Water
Conservation Areas which were built to speed water flow through the Everglades
in times of drought. In parts of the Everglades, these levees and extensive
systems such as the Miami and Tamiami Canals have altered the natural cycles of
water flow. For example, the water volume of the Shark River Slough, a natural
wetland which feeds Everglades National Park, is influenced by the Tamiami
Canal. The unique and intrinsic value of the Everglades is now widely
recognized, and efforts to restore the natural water cycles are underway.
For more than 100 years, groups in the western United States have fought over water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late 1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement. Today, farmers are fighting fishermen, environmentalists, and Native American tribes over the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and operated by the U.S. Geological Survey, documented an extreme drought in the area along the California/Oregon border in the spring of 2001.
Acquired on April 10, 2010, and and March 7, 2009, these natural-color images show changes in a central Australian saltpan, Lake Frome. In 2010, water has seeped into the salt lake, leaving standing water in some areas and muddying much of the ground surface.