A team led by University of Illinois Civil and Environmental Engineering professor Praveen Kumar has received a grant of more than $6 million from the National Science Foundation (NSF) for a five-year project to study “critical interfaces” in the environment that affect the transport and transformation of materials such as water, sediment, carbon, and nutrients.
Scientists from the Illinois State Water Survey (ISWS) and Illinois State Geological Survey (ISGS) are part of this collaboration, which is an outgrowth of prior work to increase understanding of the critical zone—the region of the landscape from the top of the plant canopy to the bedrock beneath. The surveys will contribute expertise in long-term monitoring, mapping, and water quality to “Network Cluster CINet: Critical Interface Network in Intensively Managed Landscapes.”
“Both operationally and scientifically, PRI brings a lot of value,” Kumar said.
Several CINet collaborators recently discussed the project’s goals and how the surveys will contribute.
Q. How does CINet differ from and build on the Intensively Management Landscapes Critical Zone Observatory (IML-CZO) project, on which ISWS and ISGS also were collaborators?
Laura Keefer, Illinois State Hydrologist and leader of the ISWS watershed science team: The IML-CZO was a place-based observatory, examining the issues in three watersheds (in Illinois, Iowa, and Minnesota). The commonality was that we were primarily studying former prairie landscapes that have become intensively managed landscapes, very human-impacted landscapes.
Now the focus is shifting from monitoring separate observatory watersheds to better coordination of sampling between different observatory locations as a network. The focus is, how can we relate what we’ve already learned, collaborate with other researchers, and understand this interface between the water infiltration to the lower water table, in all of these different places. CINet is creating a network hub with more collaboration around how data are collected, shared, and leveraged to develop insights.
ISWS research project coordinator Erin Bauer: The CINet builds on the IML-CZO project in several ways. From the beginning, there will be a baseline or standardized level of data and sample collecting across all the CINet watersheds so these data will be scientifically comparable when analyzed between the different observatory regions. I'll be the dedicated ISWS field coordinator, monitoring and managing the research data collection of stream, climate, and soil moisture data for the duration of the project.
CINet will incorporate a high-resolution, real-time, stream sampling and measurement field-laboratory, RiverLab, in addition to the original network of stream and field monitoring sites. I’ll be assisting with the installation and operation of that field lab.
Q. What expertise does the Water Survey contribute to these projects?
LK: The Water Survey has expertise in surface water data monitoring—long-term and intense scales of monitoring across Illinois watersheds. When we do monitoring work, we’re around for the long haul!
Data collection is a profession as well as a partnership with researchers. There’s science and experience behind monitoring. Knowing the many approaches to sampling and when, how, where, and which instrumentation is needed is critical. Many of us at the Water Survey have made monitoring and data collection a central part of our professional careers. Erin, for example, is bringing more than 20 years of experience in watershed monitoring design, instrument programming, and field sampling to this study.
In addition, one of the original watersheds in the IML-CZO, Illinois’ Upper Sangamon River, is also in the CINet project. The Water Survey had done extensive prior work there and intimately understands the water, sediment, and nitrate movement in the watershed.
The Water Survey had been working with the city of Decatur regarding sedimentation issues in Lake Decatur since the 1950s, helping the city to understand their reservoir capacity. So we have decades of lake sedimentation surveys under our belt.
The Water Survey’s Benchmark Sediment Monitoring Network has had a monitoring station on the Upper Sangamon River that has been sampled weekly since 1980. (see ISWS Report of Investigation 124, “Benchmark Sediment Monitoring Program for Illinois Streams: Analysis of 36 Years of Sediment Data.”)
In 1993, the city of Decatur contracted with the Water Survey to monitor nitrates in the Upper Sangamon River watershed, and we monitored the watershed through 2008. That data, along with ISWS hydrologic modeling efforts, allowed the city to develop mitigation and watershed projects to treat and reduce the nitrates.
And when Illinois experienced a severe drought in 2012, the Water Survey worked with Decatur again, performing a massive low-flow study of the watershed. (see ISWS Report of Investigation 123, “The 2012 Drought in Illinois”)
ISWS brings this long history of engaging with water quality sampling and hydrologic data collection across Illinois to this project.
Q. How is the Illinois State Geological Survey contributing to CINet?
Andrew Stumpf, ISGS geologist: ISGS will be contributing to several CINet research areas. The first is understanding the history of the Sangamon River valley, from the pre-historic era when the land was covered by glacial ice to the present, both as a natural and managed system. Studying the geologic history as recorded in the near-surface deposits provides a context for the modern processes of erosion and deposition and a baseline for modeling the landscape into the future.
This involves looking at surface features, like gullies and ridges. ISGS has used lidar to collect high-resolution digital elevation data across Illinois; that lidar data can help us identify features that have been obscured by modern use of the land. There are depressions in the basin that are too subtle to see when you’re on the ground, but the lidar maps show those features clearly. Before intensive farming, water would have ponded in these depressions, and cascaded from depression to depression during the largest storms. Post-settlement ditching and installation of tile drains has hydrologically connected these landscape features. We will also collect core samples by drilling down about 20 feet into the floodplain. Other CINet partners will perform Carbon-14 dating and analyses of radiometric isotopes on these cores, which will help identify periods of erosion and aggregation that are captured in the floodplain deposits.
Another theme is studying the processes at the land’s near surface, looking at how farming affects erosion across the landscape. ISGS will assist with installation of monitoring systems to measure water and gases in the near surface soil and sediments (roughly the upper two meters).
The third thematic area that ISGS is involved in is studying landscape connectivity. In other words, how do water, sediment, etc. move from agriculture fields into ditches and then into the Sangamon River? This will include using tracers, such as Beryllium-7, to map that sediment journey.
Steve Sargent’s expertise as a research technician is critical to the three themes and the associated data collection and modeling activities. He will continue to support the design, operation, and maintenance of field sensors and monitoring systems, which are contributions he made to the IML-CZO project as well.
One of my primary responsibilities will be to coordinate the collection of soil and sediment cores for the three themes. This will involve interfacing with other CINet researchers and land owners, and ensuring that the cores collected from the Sangamon River floodplain are fully described before further characterization is done and core subsamples are sent to participating labs.
Q. What expertise does ISGS bring to this project, and how does CINet connect to other ISGS activities?
AS: This project is complementary to ISGS geologic mapping efforts in central Illinois, which have included detailed surficial geologic mapping, near-surface hydrogeological and geophysical modeling, and geologic material characterization. This information has been critical for determining soil health, guiding land use decisions, and protecting groundwater and aggregate resources. CINet can draw on this wealth of data.
ISGS also brings knowledge from numerous studies characterizing glacial and post-glacial deposits in the Upper Sangamon River Basin and other river basins throughout Illinois.
To assist the study of glacial and post-glacial deposits, the ISGS Optically Stimulated Luminescence Dating Labwill help build a chronology of coarse-grained sediments in the valley fill and near-surface fluvial landforms. Fly-ash and radiocarbon dating will be used to refine the post-settlement alluvial history. ISGS geologist David Grimley will continue the research he undertook as part of the IML-CZO project into using magnetic fly ash to identify post-settlement alluvium and its record of atmospheric pollution.
