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Staff Accomplishments

High-flying satellites give land managers the low-down on cheatgrass

March 2006
Fast-growing, fire-fueling cheatgrass has met its match thanks to new software that takes advantage of satellite data and complex computer algorithms. Developed by the Pacific Northwest Regional Collaboratory, the software uses imagery from NASA satellites and complex algorithms to show the location and growth of this invasive weed. Scientists at Idaho State University, Idaho National Laboratory, and Pacific Northwest National Laboratory are providing their expertise in analyzing satellite data to understand vegetation growth and the spread of weeds in the arid west. "We're using all the technological weapons we can muster to attack cheatgrass because it's an expensive major problem facing land managers in the west," said PNNL ecologist Janelle Downs. "The Collaboratory brings together experts in plant growth, image analysis, and computer analysis to work with local and regional resource specialists on the ground." The other members of the Collaboratory are Oregon State University, University of Idaho, and University of Washington. "Remote sensing data can provide accurate and timely information; however, the data are not really accessible to many resource managers because of the cost, time, and training required," said Collaboratory Program Manager and PNNL researcher Roger Anderson. "The Collaboratory is striving to make that data available in tools that can support critical Northwest resource decisions." Picking on cheatgrass Cheatgrass now dominates vast sagebrush grasslands in the Northwest, increasing the frequency of wildfires and destroying wildlife habitat. In addition, cheatgrass spreads so quickly and vigorously that it elbows out native species and promotes soil erosion reducing the value of grazing land for livestock. This weed and other invasive plants cost billions each year and have encroached upon more than 100 million acres in the United States according to the National Invasive Species Council. Moving from the pickup truck to the desktop "This new software is a significant improvement over the previous method," said Jeff Pettingill, Superintendent of the Bonneville County weed board. The previous method? "Get in the pickup truck, get up to about 60 miles per hour and look out the window," said Pettingill with a smile. How does the software work? First, the NASA Earth Observing System satellites measure the energy bounced back by the earth's surface. Terabytes of spectral signature data are transmitted every day to NASA stations on earth. NASA provides series of images from the Landsat satellite and from MODIS (Moderate Resolution Imaging Spectroradiometer) to the Collaboratory. Because land managers need to see broad sweeping areas, not individual plants, the Collaboratory uses images where each pixel is between 30 and 250 meters square. The 30-meter pixels in Landsat images are about 32 yards on a side or about the length of the average municipal swimming pool. Then, the Collaboratory's software analyzes the spectral signature data using computer algorithms and sophisticated data processing. The Collaboratory developed these algorithms, complex calculations and associations, specifically to look at cheatgrass spread. Cheatgrass has a different lifecycle than native grasses, so the Collaboratory methods focus on these "temporal differences" to detect areas of cheatgrass spread over time. Once analyzed, the information is displayed as maps that show the density levels of cheatgrass infestation as different colors. The software allows land managers to make decisions about fire prevention and target areas for treatment. "The best way to get a handle on the extent of cheatgrass and target land areas for treatment is to look at the big picture. NASA satellite imagery provides that big landscape picture and lets land managers be smarter in using their treatment dollars," said Downs. Managers can also gain a better understanding of an ecosystem's health. "Land managers and agencies like the Bureau of Land Management are concerned with the accelerating downward spiral of public rangelands dominated by cheatgrass," said Mike Pellant, Director Great Basin Restoration Initiative, Bureau of Land Management. Satellite data helps solve complex water issues in the Northwest The Collaboratory is also using remote sensing data to help land managers make complex water management decisions. For example, the Collaboratory is developing improved techniques to estimate snow-cover and incorporate this data into advanced scientific or hydrologic models, improving streamflow forecasting and, ultimately, water use in the Pacific Northwest. While recent regulations in Washington and Oregon limit activities near stream banks and shores, forest owners and regulators lack the detailed information to pinpoint the streams. On another effort, the Collaboratory is in the early stages of developing a technique to more accurately identify streams and riparian habitat. Buildings, parking lots, and other impervious surfaces affect the nearshore habitat in the Puget Sound. The Collaboratory is using remote sensing data to study how impervious surfaces alter surface and groundwater dynamics and change the habitat on the shores of Bainbridge Island. In addition, the Collaboratory is developing a Northwest Sustainability Web Portal to help inform government agencies, policymakers, interest groups, and commercial entities on regional sustainability issues. The decision support system will allow users to see map-based and other geospatial data representations and visualize the impacts and tradeoffs of different resource policy options all the way from local to regional scales. Gulf of Mexico in the Collaboratory's future A new collaborative project, modeled on the Pacific Northwest Regional Collaboratory, is being developed to focus on the Gulf of Mexico. Partnered with the University of Alabama in Huntsville, PNNL will develop a prototype Integrated Earth Observation System to address needs such as the restoration of coastal wetlands. Contacts: Ed Baker, Environmental Sustainability Lead or Charlie Brandt, Resource and Ecosystem Product Line Manager.

Page 804 of 1035

Energy and Environment

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