Erosion and Channel Development in the Arctic

The Science

Thawing permafrost, melting ground ice, and changing hydrological regimes are all predicted to cause expansion of channel networks and increase hydrological connectivity across Arctic watersheds. However, observed erosion of new channels has been isolated in both space and time and has yet to lead to widespread expansion of new channelization or evolution of Arctic watersheds. The presence of permafrost, ice in the ground, and thermal sensitivity of land-surface processes in the Arctic has inhibited predicting and quantifying how a thawing Arctic landscape will alter fluxes of sediments, carbon, and nutrients into streams and rivers.

The Impact

More detailed, mechanistic studies of how rapid erosion in permafrost landscapes is triggered are needed to understand how these disturbances may either propagate or be damped out. If newly formed channels begin to consolidate and grow, new networks of drainage channels may form.

Such networks will dramatically alter hillslope integration with river channels and affect how carbon and water are routed through Arctic watersheds. The pathways and rates that water, carbon, and nutrients move across watersheds strongly influence biogeochemical cycles and control carbon’s release from permafrost to the atmosphere, hydrosphere, and ocean.

Summary

Despite increasing observations of erosion and channel formation in permafrost watersheds, researchers lack predictive tools to identify when, where, and how rapidly permafrost landscapes will erode. Detailed studies of new channel formations’ location and timing are needed to link these disturbances to specific drivers. These data will allow researchers to test existing models and develop new models capable of capturing permafrost landscapes’ unique characteristics. Developing an understanding of surface processes and accompanying models will allow incorporation of disturbance processes into regional and pan-Arctic models to quantify coupled system responses to permafrost thaw and shifts in Arctic hydrology driven by climatic change.

Principal Investigator

Joel Rowland
Los Alamos National Laboratory
[email protected]

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
[email protected]

Funding

This research was supported by the Biological and Environmental Research program in the U.S. Department of Energy’s Office of Science, as a contribution to the Next-Generation Ecosystem Experiments Arctic project.

References