Goodwell’s NSF-funded research studies the critical interfaces for material transport in the environment

A multi-institutional research team, including civil engineering assistant professor Allison Goodwell, has received a grant of more than $6 million from the National Science Foundation (NSF) to study “critical interfaces” in the environment that affect the transport and transformation of materials such as water, sediment, carbon and nutrients.

The project, entitled “Network Cluster CINet: Critical Interface Network in Intensively Managed Landscapes,” is an outgrowth of work by a team of researchers designed to increase our understanding of the critical zone – the region of the landscape from the top of the plant canopy to the bedrock beneath. This is a highly complex system with a lot of moving parts and processes that act on different timescales from minutes to millennia, and it necessitates a convergent approach to research, where collaborators with different expertise converge to address a broad set of interrelated issues. In this project, researchers have expertise in civil engineering, geography, geology, hydrology, chemistry, education, and microbial ecology, and are collaborating from several institutions.

Goodwell said, “Convergence research enables us to address societally relevant problems that are outside of any individual research expertise, and to develop new perspectives on how complex systems, such as the intensively managed critical zone, function.”

The ecosystems involved are intensively managed agricultural areas in the midwestern United States; interfaces such as the land-atmosphere, floodplain-river, and soil-surface transitions are changing faster and in different ways compared to the natural prairie ecosystems that were there before. Glacial history sets the topography, stream network, and soil characteristics inherent to an area, but human activities like drainage, planting and harvesting, tillage, and fertilizer application make a large impact and potentially change the entire trajectory of a landscape. These changes can have a long-lasting influence.

The NSF grant will allow the team to build on the existing network of observational sites by augmenting them with novel observational systems. The team will use innovative data analytic and machine learning techniques along with integrated modeling approaches to look at the structure, evolution, and functioning of three critical interfaces that are particularly affected by human action and weather: the near-land surface, the active root zone and the river corridor.

Goodwell’s work involves ecohydrologic modeling at the near-surface interface, which is concerned with fluxes of water, energy, and carbon between the land surface and the atmosphere.

“My research focuses on causal dependencies between different variables in this system – for example how do wind speed or air temperature combine to influence carbon fluxes measured at a flux tower,” she explained. To address these questions, the team has a 25m tall flux tower in Illinois that measures dozens of weather-related variables every 15 minutes. This large dataset, along with other high-resolution observational data, can greatly improve the understanding of these processes, but requires advanced computational methods to help researchers move from data, to information, to problem solutions.

Goodwell, whose research is on the computational side, will use information theory-based methods to characterize joint types of dependencies in space and time. These methods involve computing probability distributions in high dimensions, and dealing with challenges involved in estimating and interpreting this data.

Another aspect the CU Denver team will be involved in is ecohydrologic modeling and model analysis. “This modeling uses the observational data from different sources as inputs and for validation,” explained Goodwell. “This data are what enables the team to make predictions about the system and test different hypotheses.”

Goodwell is excited to be a part of this research and hopes it will lead to advances in the understanding of causality in complex intensively managed systems. This understanding can enable more sustainable agricultural practices in different types of landscapes. CU Denver is one of ten participating institutions, and in addition to Goodwell, two CU Denver graduate students are working on CINet related topics and are starting to collaborate with students at the other institutions as part of a Junior Scientist Council. She’ll also be advising an undergraduate researcher this summer as part of the National Great Rivers Research and Education Center internship.

“This type of project is geared to train the next generation of interdisciplinary engineers and scientists, who will work in diverse teams and be exposed to a range of field and computational opportunities,” said Goodwell.

In addition to Goodwell, the research team is led by Praveen Kumar, professor, Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign; Ashlee L. Dere, associate professor of Geology at the University of Nebraska Omaha; and Timothy Filley, professor, Department of Earth, Atmospheric and Planetary Sciences at Purdue University. The multi-institution team also includes Bruce Rhoads (University of Illinois, Geography and Geographic Information Science), Alison Anders (University of Illinois, Geology), Jennifer Druhan (University of Illinois, Geology), Laura Keefer (Illinois State Water Survey), Erin Bauer (Illinois State Water Survey), Andrew Stumpf (Illinois State Geological Survey), Luigi Marini (National Center for Supercomputing Applications), Ximing Cai (University of Illinois, Civil and Environmental Engineering), Neal Blair (Northwestern University), Sean Schaeffer (University of Tennessee at Knoxville), Marian Muste (University of Iowa), Lisa Welp (Purdue University), Ted Kratschmer (National Great Rivers Research and Education Center (NGRREC), and Sarah Fisher, NGRREC.

By: Laura Quantz, student writer & communications major