Date of Graduation
Statler College of Engineering and Mineral Resources
Civil and Environmental Engineering
Leslie C Hopkinson
John D Quaranta
Surface mining and the associated reclamation cause changes in land use and land cover. This change can affect the hydrologic balance. In some cases, an increase in number and magnitude of flood events is observed both on site and in surrounding areas. This research analyzed the hydrologic effects downstream of a reclaimed surface mine, considering the impact of an alternative reclamation technique. Geomorphic landform design (GLD) is a reclamation method that considers the development mature landform shapes to help create a long-term hydrologic balance. Flood maps were created for the pre-mined condition and compared to maps created for three reclamation conditions: conventional reclamation, GLD (During mining) reclamation, and GLD (Post-mining) reclamation. The valleyfill and study site is located in southern West Virginia. Approximately 2.1 km of the adjacent downstream channel were evaluated. The study area receives 101.6-127 cm precipitation annually and has a basin slope range of 0.44-0.56 m/m. GIS data were used to develop a schematic of the downstream channel. Cross-sections were extracted from a triangulated irregular network (TIN) developed from 1/9-arc-second elevation data. These geometric data and projected stormflow hydrographs for seven storm events were used to develop both steady and unsteady flow 1-D hydraulic models (HEC-RAS). The resulting water surface elevations were used to display flooding extents over time resulting from each reclamation condition. For smaller storm events (e.g. 2-yr), conventional reclamation resulted in decreased flooding, and increased flooding was observed for large storm events (e.g. 100-yr, 500-yr). The GLD (During mining) reclamation condition resulted in increased flooding; this increase was mitigated with time. The GLD (Post-mining) results were comparable to those of the pre-mining condition. GLD has the potential to mitigate flooding impacts from surface mining in the long-term in southern West Virginia, but is dependent on properly sized channels and stability of landforms.
O'Leary, Erin E., "Floodplain Mapping in Response to Surface Mine Reclamation" (2014). Graduate Theses, Dissertations, and Problem Reports. 6345.