UW Students Research Value of Satellite Images for Monitoring Wyoming Resources
May 18, 2012 — Students at the University of Wyoming found that aspen had budded earlier in a drought year, and that surface area estimates from satellite images matched well with corresponding water levels in Woodruff Narrows Reservoir near Evanston.
Other students used information derived from remotely sensed images to monitor crop growth on a southeast Wyoming wheat farm and the effects of the 2004 Basin Draw fire in northeast Wyoming. The research taught students how to use satellite images and its effectiveness.
Every spring semester, three to five students -- in the Department of Ecosystem Science and Management in the UW College of Agriculture and Natural Resources -- conduct research using remotely sensed data on a topic of their interest, says Ramesh Sivanpillai, research scientist in the Wyoming Geographic Information Science Center. He teaches the college's digital image processing for natural resources management course.
"Most of these students select the farms or ranches owned by family members or forests and public land they have worked on during summer months," he says. "Familiarity about their study areas provides them a unique advantage when analyzing and interpreting satellite images, and for conveying the findings of their study to the landowners or agencies."
Matthew Thoman of Riverton worked on a dryland winter wheat farm east of Cheyenne and was familiar with the fields. By processing Landsat images from the growing seasons of 2007 and 2009, he found growth variations within fields -- despite higher soil moisture levels in 2009 than 2007.
He will share the information with the producer, who could devise plans to correct the deficiencies, Sivanpillai says.
Brandt Schiche of Buffalo used Landsat images to glean information about surface area changes on Woodruff Narrows Reservoir. Water from the reservoir is used for irrigation, recreation and industry, and is shared between Utah and Wyoming.
"He found a significant relationship between the surface area estimates derived from Landsat images and the corresponding water levels in the reservoir," Sivanpillai says.
Jason Pindell of Wheatland used MODIS (Moderate Resolution Imaging Spectroradiometer) data to assess differences in the growing pattern of aspen stands in the Medicine Bow National Forest. His research showed aspen put out leaves relatively earlier (bud-burst) in a drought year (2002) in comparison to the bud-burst in a normal year (2009).
Orin Hutchinson of Newcastle had worked with the U.S. Forest Service managing wildfires. He evaluated indices derived from Landsat images that highlighted burned (immediately) and revegetated (few years later) areas after the 2004 Basin Draw fire northwest of Aladdin in Crook County. The fire burned more than 4,500 acres in three days, but its impact and severity varied throughout the landscape.
"His results pointed out that burn severity index values were in good agreement with the data collected in the field," Sivanpillai says. "However, extraneous factors, such as precipitation and management practices, influenced the vegetation regrowth, limiting the effectiveness of satellite data for monitoring regrowth after several years."
Students presented their findings during UW's recent Undergraduate Research Day.
Orin Hutchinson analyzes Landsat images acquired after a wildfire on the Wyoming side of the Black Hills National Forest. (UW Photo)