Landsat’s Role in Managing Water Resources
Water is essential for life. A third of Earth’s populace has unreliable access to clean water. With current population growth and environmental trends, the U.N. Environmental Program estimates that 1.8 billion people will face water scarcity by 2025. Water means survival for people and other species we rely upon to thrive, making proper stewardship of our water resources vital. Good decisions require good data. Since 1972 the Landsat series of satellites has been providing such data. Landsat-based decisions on how to manage limited water resources have impacted millions of people worldwide. From finding water for refugees in arid nations to reducing pollution in our national waterways, Landsat enables decisions that directly help people.
How Landsat Helps: New Agricultural Case Studies from USGS
The Social and Economic Analysis team at the Fort Collins Science Center recently added five new agriculture focused case studies to their “Landsat Imagery: A Unique Resource” website.
Avoiding Rock Bottom: How Landsat Aids Nautical Charting
On the most recent nautical chart of the Beaufort Sea where the long narrow Tapkaluk Islands of Alaska’s North Slope separate the sea from the shallow Elson Lagoon (Nautical Chart 16081) a massive shoal is immediately noticeable just west of the entrance to the lagoon. On the chart it looks like a massive blue thumb jutting out into the sea. The National Oceanographic and Atmospheric Administration (NOAA) identified this prodigious, 6-nautical mile-long, 2-nm-wide shoal using Landsat satellite data.
A Satellite View of River Width
Hydrologists from the University of North Carolina have come up with an innovative way to estimate the size of rivers via satellite images. Combing through data acquired by Landsat satellites, George Allen and Tamlin Pavelsky have compiled a new database of river widths for North America.
![The sensors aboard Landsat 8 were designed to have higher sensitivity to brightness and color; they use 4,096 values to digitize their signals (12-bit data) whereas the last-generation sensor on Landsat 7 was slightly less sensitive and used only 256 data values (8-bits) to describe the range of brightness it recorded. Visually, this translates into a smoother, less noisy looking images as can been seen here when comparing these natural color Landsat 7 [left] and Landsat 8 [right] images of the extensive coral reefs on the northern shore of Vanua Levu, Fiji’s second largest island, acquired on September 19, 2002 and May 10, 2015, respectively.](https://landsat.gsfc.nasa.gov/wp-content/uploads/2015/06/Levu_Fiji_L8_sm-1.jpg)
Satellites Enable Coral Reef Science Leap from Darwin to Online
With Earth-observing satellite data, scientists can now monitor the health of coral reefs, even in the most remote regions scattered around the globe where it is otherwise difficult to see changes.
Historical Satellite Images Reveal Snow is Melting Earlier in Wyoming
A NASA study of a basin in northwestern Wyoming revealed that the snowmelt season in the area is now ending on average about sixteen days earlier than it did from the 1970s through the 1990s.
Water Mapping Technology Rebuilds Lives in Arid Regions
Turkana County in northwest Kenya has been reeling from several years of crippling drought. As a consequence, the nomadic peoples in the region have suffered. Livestock such as goats and cattle, the sole source of income for these pastoralists, have perished by the droves from starvation, and the resulting economic hardship has left many children malnourished. Many have also died from violent clashes over increasingly scarce resources.
