Research

► Overview

The National Center of Earth-surface Dynamics (NCED) was developed to build our predictive ability, and therefore our scientific understanding, of the near-surface Earth environment. Through the development of this knowledge, we aim to transform management and restoration of the Earth-surface environment.

NCED research concentrates on the most widespread self-organized processes and spatial structures that recur across the Earth-surface system – channels networks and their surroundings. We approach these networks from a source-to-sink perspective, using our three Integrated Programs (IPs) to look at watersheds (Watersheds), individual stream reaches (Streams), and depositional systems (Deltas).

► Landscape-Ecosystem Co-evolution

Landscapes and their associated ecosystems co-evolve – rivers grind their way into bedrock, meander into alluvial plains, and deliver water, sediment, and nutrients into deltas. The processes of incision and sediment transport form a network of channels, which forms the physical template for ecosystem structure and dynamics. The physical template also depends on biotic processes – rock weathering, soil formation, and erosion are influenced by biotic processes that mediate chemical reactions, dilate soil, disrupt the ground surface, and add strength with a weave of roots. Biota also affect climate, and climatic conditions dictate the mechanisms and rates of erosion that control topographic evolution. Landscapes and ecosystems therefore co-evolve.

Humans affect the operation of the coupled ecosystem-landscape system through land-use change, anthropogenic climate change, and landscape management. Understanding how human-induced landscape alterations will influence future Earth-surface and ecosystem function requires a mechanistic understanding of Earth-surface dynamics. NCED was created to provide that understanding.

► Integrative, Predictive Science

Historically, progress in developing a mechanistic understanding of, and therefore predicting the behavior of the near-surface environment has been impeded by a combination of disciplinary fragmentation (e.g., geomorphology, ecology, hydrology, geochemistry, social sciences) and a tradition of descriptive science in some of the key disciplines. NCED was founded to address this situation, developing multi-disciplinary, predictive science for understanding the coupled evolution of landscapes and their associated ecosystems. We aim to use that understanding to inform management and restoration of the Earth-surface environment in the face of human-induced change, by transferring our understanding to decision makers, students, and the public.

 

► Innovative Approaches to Research and Communication

 
NCED has developed a predictive science for understanding coupled landscape-ecosystem dynamics by creating an innovative approach that combines experimental, field, and modeling techniques to build mechanistic understanding. We have also developed unique, bi-directional strategies for communicating with decision makers, students, and the public, facilitating the transformation of Earth-surface management and restoration. Such strategies include the development of tools and methods for making management and restoration decisions and integrating those decisions into society; the foundation of research-industry meeting forums and partnerships to ensure that NCED research is informed by the most pressing societal concerns and that the tools and insights gleaned through the work of NCED are disseminated throughout the broader community; and the creation of a unique academia-museum partnership that enables us to communicate our work to the broader public. For more information, see our Knowledge Transfer, Education, and Diversity pages.

 

Featured Stories:


Collaborative Work on Granular Flows in the Big Wheel

Scientists visiting from Austria and Switzerland are working with NCED researchers to study the dynamics of granular flows, acquiring data that can be used to parameterize numerical models for flow behavior and hazard mapping. This work, conducted in the 4-meter vertically rotating flume (drum)—Big Wheel—at the University of California, Berkeley, Richmond Field Station (RFS), is a continuation of an initial set of debris flow erosion experiments and will involve debris flows and rock-ice avalanches. Research by Roland Kaitna, University of Natural Resources and Applied Life Sciences (also known as BOKU University), Vienna, focuses on the pore pressure fluctuations at the base of muddy debris flows.
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GeoNet Tool Now Available

Today’s high resolution topography data presents new opportunities for geomorphologic research in the area of environmental prediction and hazard assessment. To use this data for such research, NCED scientists created a new computational tool: GeoNet. GeoNet extracts channels and channel networks from high resolution digital elevation data. During the extraction process, GeoNet incorporates nonlinear filtering, for the initial preprocessing of data, and energy minimization principles, for feature extraction. The use of nonlinear filtering, with a variable diffusion coefficient, achieves noise removal (in low gradient areas) and edge enhancement (in high gradient areas, ie, feature boundaries).
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News from the Le Sueur River

A group of researchers, including NCED PIs, postdocs, and graduate students, have been tasked with creating an integrated sediment budget for the Le Sueur River basin—the goal of the Minnesota Le Sueur River project. To do so, researchers will develop a model that shows sediment fluxes contributed by various sources along the Le Sueur River watershed. Work on this sediment routing model, through the use of parameterization, is currently in process. By partitioning the Le Sueur River watershed into four source types (bluffs, ravines, streambanks, and flat uplands), researchers are able to independently quantify the sediment contribution from each type.
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iSURF: A Mixed-Size Sediment Transport Tool

Sediment transport formulas can be used for much more than predicting transport. Usually, we specify flow and channel properties and use a formula to predict transport rate. But we can turn the problem around and specify the flow and transport rates to calculate channel properties. In this inverse application, originally developed by NCED PI Gary Parker, we think of the transport as the supply of sediment to the stream and calculate the conditions needed to produce that transport. This allows us to ask how a river bed will change in response to changes in sediment supply, such as from a forest fire or a change in land use.
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Tradeoffs When Improving Water Quality

Water quality impairments remain a pressing concern in the Minnesota River Basin. Selecting appropriate management actions to improve water quality involves tradeoffs between cost and effectiveness. In addition, significant uncertainties exist in the scientific understanding of this natural system.
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