November 6
4:00 p.m.
Wagar 231
Abstract
Watershed response to mountaintop removal mining
Erosion following human disturbance threatens ecosystem health and inhibits effective land use. We assess how changes to topography and vegetation driven by mountaintop removal mining influence erosion and deposition patterns in mined watersheds. We use landscape evolution models starting from pre- and post-mining topography to isolate the influence of mining-induced topographic change. We constrain ranges of erodibility from incision depths of gully features on mine margins and use those estimates to model the influence of vegetation recovery on erosion. Topographic alterations alone reduce sediment export from mined catchments. Model runs that incorporate the disturbance and recovery of vegetation show that complete vegetation recovery keeps millennial, but not decadal to centennial, sediment export from mined catchments within the range of unmined catchments. If vegetation recovery is anything less than complete, vegetation disturbance drives greater total sediment export from mined catchments than unmined catchments. Full vegetation recovery causes sediment fluxes to decline over millennia beyond the recovery period, while watersheds without full recovery experience fluxes that increase over the same period. Erosion patterns depend on 1) the extent of vegetation recovery and 2) the extent to which mining creates slope–area disequilibrium. Rapid erosion of valley fills drives deposition in colluvial hollows, headwater stream valleys, and below scarps. Results suggest that reclamation focused on maximizing vegetation recovery and reducing hotspots of slope–area disequilibrium would reduce MTR’s influence on Appalachian watersheds both during and long after the vegetation recovery period. Insights from mining-influenced landscapes can inform mined land management as the renewable energy transition drives increased surface mining.
Biography
Charles Shobe, Research Geomorphologist
U.S. Forest Service Rocky Mountain Research Station
Charlie Shobe is a Research Geomorphologist at the U.S. Forest Service Rocky Mountain Research Station in Fort Collins, CO. His work focuses on river and watershed processes, with a major theme being how rivers respond to natural and anthropogenic changes. He has also worked on improving the computer models used to understand and predict landscape change over time. Prior to joining the USFS, Charlie was an assistant professor of geology at West Virginia University. He holds a BS from the College of William & Mary, a PhD from the University of Colorado, and did postdoctoral work at the Deutsche GeoForschungsZentrum (GFZ Potsdam).