Cooperative Institute for Research in Environmental Sciences

From Peaks to Prairie: Two Natural Experiments in Decadal Landscape Evolution

From Peaks to Prairie: Two Natural Experiments in Decadal Landscape Evolution

Numerical models of landscape evolution play a vital role in geomorphology, but there remains a pressing need to test these models against field data. We are developing two case studies for model-data comparison testing. The two case studies are sites of rapid, decadal landscape change.

The decadal scale is particularly important because:

it is a critical time scale for societal adaptation to rapid environmental change,
it is short enough to take advantage of historical records, and
models of longer-term landscape dynamics should be consistent with shorter-term behavior.

The study pairs two very different environments: a low-relief, semi-arid, soft-rock setting dominated by rapid gully erosion and scarp retreat, and a steep, montane, forested, crystalline-rock setting responding to a 1996 wildfire. The first site, located on the high plains of eastern Colorado, provides a unique opportunity to reconstruct erosion rates and channel growth patterns over a 70-year period. The second site, in the Colorado Front Range, contains an extraordinarily rich 14-year database of post-fire geomorphic response, thanks to intensive monitoring efforts by the U.S. Geological Survey.

The project relies on a variety of methods, including aerial photo analysis, reservoir sediment volumes, 137Cs measurements, LiDAR DEM analysis, and oral history interviews. Modern hydrology and geomorphology are documented with a network of rain gauges and flow sensors, combined with biennial tripod-laser scans to measure rates of channel-head retreat (estimated at ~0.5m/yr). The two data sets are used to test a physically based numerical model of landscape evolution using a Monte Carlo calibration method.

 

 

Related Links:

Plains Conservation Center 
Hydrologic and Erosion Responses of Burned Watershed (USGS) 

 

Research Group

Participants

Greg Tucker, University of Colorado at Boulder
Francis Rengers, Ph.D. candidate in Geological Sciences, CU Boulder
John Moody, U.S. Geological Survey
David Phillips, UNAVCO

Funding Information

Supported by National Science Foundation grant EAR-0952247, 2010-2013