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U.S. Department of Energy
Office of Scientific and Technical Information

A geomorphic threshold for valley-floor erosion in reclaimed surface-mined drainage basins, northwestern Colorado

Conference ·
OSTI ID:56917
 [1]
  1. Geological Survey, Denver, CO (United States)
Surface-coal mining and reclamation in northwestern Colorado has caused substantial changes in geology, pedology, vegetation, hydrology, and geomorphology of many drainage basins. These changes have increased the potential for gully erosion on reclaimed valley floors. Gullies on some reclaimed valley floors may be affected by geomorphic variables that can be manipulated during reclamation. Valley-floor erosion in several reclaimed drainage basins is related to three geomorphic variables: drainage area, valley gradient, and valley-floor width. The product of drainage area and valley gradient defines the area-gradient index. Unstable valley floors were associated with larger area-gradient indicies than were stable valley floors. Clustering of data from stable and unstable valley-floor reaches and the relation between valley-floor width and the area-gradient index defined the valley-erosion threshold. Reclaimed valley floors that had valley-floor width less than the threshold were more likely to be gullied than valley floors that had widths greater than the threshold. Geomorphic thresholds may be useful as planning tools in future reclamation projects.
OSTI ID:
56917
Report Number(s):
CONF-9003298--
Country of Publication:
United States
Language:
English