Published: Nov. 27, 2007

A team of researchers led by the University of Colorado at Boulder has received a $4.25 million grant from the National Science Foundation to study the Boulder Creek watershed's "critical zone," which is made up of layers of soil and weathered rock.

Awarded to CU-Boulder's Institute of Arctic and Alpine Research, the grant will allow the researchers to gain a better understanding of the critical zone, which is significant because it supports terrestrial life, according to Assistant Professor Suzanne Anderson of INSTAAR, the principal investigator on the NSF grant.

Understanding more about the critical zone, such as what controls the depth of soil and how it affects the flow of water, can be extremely valuable on several fronts, according to Anderson.

"One issue we have along the Front Range is convective storms that dump water on the landscape and can produce catastrophic flash floods," she said. "One thing we'll be looking at is how different watersheds within Boulder Creek respond to rainstorms, and ultimately which ones are more likely to produce flash floods."

CU-Boulder will coordinate with the U.S. Geological Survey, Stanford University, Technical University of Munich and Williams College in Williamstown, Mass., on the five-year project.

The CU-Boulder researchers will focus on different areas within Boulder Creek's 400-square-mile watershed beginning at its headwaters near the Continental Divide down to the Front Range plains. Much of the project is designed to understand how weathering and erosion processes control the structure of the critical zone. They also will test how the critical zone's structure impacts the hydrological, geochemical and biological functions of the landscape.

The large drop in elevation within the Boulder Creek watershed -- about 8,500 feet -- provides an important contrast in climate and ecological regimes, presenting an ideal contrast in erosion processes, according to Anderson. Glaciers carved the headwaters of Boulder Creek, while the river carved Boulder Canyon and shaped the lower reaches.

"We're focused on understanding how the critical zone develops and evolves, and this area will be an ideal spot to do this," she said.

CU-Boulder received one of only three grants given by NSF to establish critical zone observatories. Pennsylvania State University and the University of California, Merced also will build critical zone observatories in their regions.

While soil and the processes of soil creation have been studied extensively, the critical zone needs to be studied more, according to Anderson, because it is the region that supports life on the Earth's surface.

"When you think about it, this is where soils form, and soils are the basis of the terrestrial ecosystem, so it's important to understand how the critical zone functions," she said.

"It's also the region where water is cycled through. This is the region that both purifies and filters our water, if we're extracting water from groundwater or a stream," she said. "It may also be the source of contaminants, so we want to understand how contaminants are moving through the system."

The grant includes support for education and outreach projects, including developing a graduate-level critical zone course and research opportunities for undergraduate students. The researchers will partner with the Science Discovery program at CU-Boulder to offer classroom and field programs for fifth graders and summer field courses for middle school students.

"When you ask the question of how we go from hard rock up to soil that can support life, that's a system we really need to understand," Anderson said.