|(L-R) Biology majors Brianna Loeks and Bayli Holstad measure the depth, width, and area of Tischer Creek, a designated trout stream which cascades down the Duluth hillside to Lake Superior.
|Karen Gran brings eight of the first nine labs in her geomorphology class outdoors to Tischer Creek, the Bagley Nature Area, Jay Cooke State Park and other places.
Geomorphologist Karen Gran and
Lessons from the Landscape
Karen Gran sees what most of us never recognize – how the land changes shape when touched by volcanoes, waves, wind, and rain. She is a geomorphologist, a scientist who seeks to understand landform dynamics through field observations and physical experiments.
Gran, an associate professor of geological sciences in UMD’s Swenson College of Science and Engineering, often shares her enthusiasm for research with her students, and that process offers UMD students remarkable opportunities.
SUSTAINING THE MINNESOTA RIVER BASIN
In 2012, Gran and a group of researchers from the University of Minnesota and five other institutions were awarded a $4.3 million five-year Water Sustainability and Climate grant from the National Science Foundation to examine the climate and human impact of land and water management in the Minnesota River Basin.
The key to understanding the project is the history of the river’s formation. Some 13,000 years ago Lake Agassiz, which covered much of the Midwest and into Canada, drained and carved out the very deep Minnesota River valley. After many decades, the torrents of water left behind a deeply incised valley that now has high bluffs and steep ravines.
“Minnesota’s land use began another change in the mid-1800s with European settlements,” said Gran. Wetlands were drained and the hardwood forest and long-grass prairie were converted to row crop agriculture. The existing cliffs and ravines continued to cause natural erosion but they also amplified the man-made agricultural and urban erosion.
The problem is devastating. Millions of tons of mud stop the sunlight from reaching down through the water, suppressing the growth of plants and the aquatic life that depends on them. “Silt and clay can be damaging to the aquatic biota food chain, all the way through the water column,” Gran said. To bring the river back, the amount of sediment in the Minnesota River will need to be drastically reduced.
Gran is helping lead the research which will create action steps to repair the damage. “We use geochemical methods to fingerprint sediment and positively determine where the sediment came from,” she said. From the high tech methods such as LIDAR images collected from the air, to low tech methods she teaches in her UMD classes, Gran is gathering the facts to inform policy makers.
“Our first step is to set a ‘sediment budget’ for Minnesota’s rivers,” she said. “We are presenting a vision of a way to reverse the trend.”
State agencies and other organizations have begun to gather the stakeholders. Gran’s students, including Nate Mitchell, a geological sciences graduate student, sat in on the project meetings. “We tried to get everyone at the table,” Gran said. “Corn growers, soybean growers, and the Minnesota Agricultural Water Resource Center were there.” Dozens of farmers, citizen groups, federal agencies, and pollution control officials also attended.
"I see farmers as an important part of the solution, not the problem," Gran said. "They are just as concerned as the rest of us." Simple steps can make a big difference. "We can help figure out where wetlands are most effectively placed to hold back water and reduce flows that are eroding streambanks and bluffs downstream. But installing wetlands means farmers have less land to farm. Minnesota can help with incentives so it isn't as big of a financial burden for them."
Students in Gran’s geomorphology classes get real life, real time experience collecting data. “Eight of the first nine lab classes are conducted outdoors,” said Gran. Students examine landforms, lakes, rivers, and creeks in the Duluth area. They travel to Park Point beach, Tischer Creek, Jay Cooke State Park, the North Shore of Lake Superior, and UMD’s Bagley Nature area.
CASE STUDY: A 500-YEAR FLOOD
Gran’s class was provided a rare opportunity. They were assigned the documentation of the June 2012 massive flash flood, which caused extensive damage at Jay Cooke State Park, about 20 miles from the UMD campus.
Within a 24-hour period, 8-10 inches of rain fell. A levee was breached on Forbay Lake, causing a flood wave to carve a deep valley. The water destroyed much of the park and part of Highway 210.
The students in the geomorphology class set out to reconstruct the magnitude and effects of the flood wave. They recreated major events and mapped the site. They determined the volume of water needed to break the levee, how much sediment was moved, how much was deposited, and how much was washed downstream. Graduate students developed independent research projects on more complex issues.
Collectively, Gran’s students were able to extensively document what happened during the flood event at this site. The students put all of their research together in a scientific paper format and prepared a presentation for geology students and faculty of the University of Wisconsin-Superior, and naturalists at Jay Cooke State Park.
Gran gives her students relevant experiences. She invites them to join her on the Minnesota River Basin research and she designs her classes around spectacular and everyday natural events. Most importantly she gives them a deep understanding of the natural world.
Story by Cheryl Reitan. September, 2013.
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