A series of wildfires, started by lightning strikes the weekend of August 21–22, 2010, has burned over 300,000 acres of sage and grasses in the south-central region of Idaho. On August 23, the fire burned over 200,000 acres in a single day. Smoke from the fires has had a dramatic negative effect on air quality in a number of regional communities.
Image of the Week
Images found during the week that show change from our past that correlate to current events.
Major flooding in the Indus River Valley in Pakistan has been described by the United Nations relief teams as "...one of the worst humanitarian disasters in history..." Over 21 million people have been directly affected, 10 million left without shelter, and more than 1,800 killed by flooding caused by historic monsoon rains. The flooding inundated over a million acres.
Landsat satellite imagery, acquired and processed by the U.S. Geological Survey, illustrates a major change in agricultural practices in the northeastern portion of the Mexican state of Chihuahua. Increased diversion of water from the Luis L. Leon Reservoir for center pivot irrigation has affected the vegetation patterns in the region and significantly diminished the amount of water reaching the Rio Grande River. The center pivot irrigation systems (marked in the 2010 image by intense red circles) are being used for growing alfalfa and sorghum to supply dairy farms and cattle feedlots.
Landsat satellite data, acquired and processed by the U.S. Geological Survey, illustrate the effects of water demands and upstream drought on Lake Mead in Nevada. Lake Mead is the largest water reservoir in the United States and provides water and, through dam turbines, power for Nevada, southern California, and northern Mexico.
Landsat satellite data, collected and processed by the U.S. Geological Survey, illustrate the retreat of the terminus of Bear Glacier in southern Alaska.
Bear Glacier is one of the larger outlet glaciers flowing from the northeastern part of Harding Icefield toward Resurrection Bay in the Kenai Fjords National Park in the Kenai Mountains. The park is a popular area for camping, hiking, exploring, and photography.
Landsat satellite data, acquired and processed by the U.S. Geological Survey, illustrate extreme changes in the Devils Lake, North Dakota, area over the past 20 years. Devils Lake and smaller regional lakes have inundated farm land, roads, and buildings. Devils Lake, alone, has flooded over 150,000 acres.
Devils Lake is a closed basin and has no natural river or stream to carry away excess rain and snow melt. Landsat imagery, acquired in 1991, shows the area before a record period of precipitation. 2010 imagery shows the same area with expanded lake surfaces and wetland units.
Seasonal changes in the Senegal River Delta are illustrated by Landsat images acquired and processed by the U.S. Geological Survey. The region has been suffering from an extended drought. The July 2010 image shows the region during a dry period. The September image shows major inundation of the delta after significant late summer rains upstream.
Regional governments have taken broad measures to regulate the river flow. Upstream dams have lessened the impact of the rainy season on delta flooding. The dams have also provided hydroelectric power to the area.
Landsat satellite data, acquired and processed by the U.S. Geological Survey and drawn from the 38+ year archive, are being used to monitor changes to a major Caspian Sea bay. The Kara-Bogaz-Gol basin on the eastern edge of the sea undergoes periodic, dramatic change in the water level. Because the basin is significantly more shallow than other near shoreline areas, the changes are more visible and affecting.
Landsat satellite data, acquired and processed by the U.S. Geological Survey, illustrate the rapid growth in the San Antonio, Texas region. San Antonio has grown to be the 7th largest city in the nation, with a current population of approximately 1.4 million. In 1991 when the June 16 image was acquired, the population was approximately 790,000. In the past 20 years it has been the 4th fastest growing city in the United States.
Owens Lake is a significant inland water body approximately 130 miles north of Los Angeles, California. Situated in the Owens Valley between the Sierra Nevada and Inyo Mountains, the lake has, historically, been fed by the Owens River. The lake was one of the most important stopover sites for migrating waterfowl and shore birds in the western United States for thousands of years. However, in the early 20th century the lower Owens River was largely diverted to the Los Angeles aqueduct.