 and south arms are separated by a railroad causeway, the straight line cutting across the images. Limited water circulates between the lake’s north and south arms through the Union Pacific Railroad Causeway breach, but because of the low water levels, the breach is now dry. The result is even saltier water in the north arm.
A USGS article published in late 2015 provides more information about Great Salt Lake.
Measuring Water Use with Landsat February 11, 2016
As drought conditions continue in the western United States, there is more demand for water for irrigation purposes. Increasing population also increases water demand.
Scientists at the USGS Earth Resources Observation and Science (EROS) Center developed a method to use remote sensing data to quantify water use in the Colorado River Basin. Using Landsat and other ancillary data, including Landsat’s thermal infrared data, scientists created the first ever evapotranspiration (ET) map for the entire basin. ET is water that transpires from plants and evaporates from the ground. It can be used as a measure of water usage. Landsat’s 30-meter resolution allows scientists to estimate ET at the field level.
The annual water use map on the left is based on Landsat data collected during 2010. The colors correspond to millimeters (mm) of water lost to the atmosphere through ET. Fields that are green and blue show the highest ET values. Relatively more water has been used on those irrigated fields. Orange hues are areas that have very little ET, such as sparsely vegetated desert. The Landsat 8 image on the right from September 28, 2015, shows many irrigated crop fields just south of Phoenix, Arizona. The image shows the same area as the water use map for comparison.
With the ET map, water managers get information not seen in just the natural color image. This method can be used to create annual water use maps of other regions or even nationwide. Accurate information on water availability and usage is necessary for planning sustainable use of water, particularly in an arid region like the southwestern United States.
On January 22–24, 2016, a major winter storm dropped 2 or more feet of snow on much of the U.S. East Coast. Landsat 8 images acquired before and after the storm offer a dramatic view of the Washington, DC, area. Before the storm, there was no snow on the ground; however, on January 24 the landscape had become blanketed in white.
In both of these natural color images, the Washington Monument casts a shadow, but the shadow shows up more clearly when the ground is white.
In the lower right part of the image, Andrews Field at Joint Base Andrews becomes a large swath of bright white in the January image. Ronald Reagan Washington National Airport, just south of DC, also exhibits this extra brightness. At Reagan, the main runway appears to have been cleared.
Warm temperatures in December meant the Potomac River was not frozen in the December image. By mid-January, parts of the Potomac froze, so some of the river is covered in white in the January image.
These Landsat images show the land use changes of the Liaodong Bay area in northeastern China. The Shuangtaizi River and the Daliao River carry large amounts of sediment from the loess plains and agricultural soil erosion upstream. The salt marshes on the river delta have been affected by an expanding aquaculture industry, visible as the dark geometrical shapes that have clearly expanded in the 2015 image. Also visible is the expanding city of Yingkou and ports extending into Liaodong Bay.
Salt marshes in this region decreased during the 1980s and early 2000s. Aquaculture ponds, and rice paddy and reed fields replaced the salt marsh; however, from 2004 to 2009, salt marshes showed a slow recovery. Researchers use Landsat imagery to monitor the recovery as well as human uses of this land to track salt marsh extent from year to year and how those changes affect habitats and wildlife.
Satellite images are necessary for this monitoring because large areas can be mapped relatively quickly where it is difficult to conduct field su